I've done exactly what you're talking about on my twin-screw 3800. I used a normal boost controller & mac valve on the bypass actuator to throttle boost production based on engine rpm for launching my fwd car at the track. It was programmed in 500rpm increments so that i could just matt the gas pedal and it puts in duty cycle via the program. worked really well
I think it would be interesting to have a pulley on it that actually spins the blower for only 5psi and see how the power/torque curves actually compare to the bypass valve open at the 'same boost' level
I use a CAN Bus enabled boost controller on my Cadillac CTSV to allow me to set up boost by gear on my LSA engine. It uses a boost solenoid and a 2 port bypass valve actuator. The stock CTSV already has this functionality in the factory ECU to allow for boost reductions in case of over temp, etc. But it doesn't allow boost by speed, gear, throttle position like the aftermarket controller. The aftermarket setup also has 8 maps and a scramble button, so I have maps for street tires ,track tires, rain, valet, etc. It definitely makes launching in first gear on the street much easier.
Is that something you built, or bought? I'm running a 370 inch LQ4 with an Eaton TVS2300 and even at 7 psi, launching in first gear on the street could be much, much easier...
@@plepgeat Cobbled together a bunch of existing componentry. Spent about $600 total, but the boost controller at $500 was the most expensive part. It's really nice though, and offered CAN bus inputs which was useful for semi-modern OBD2 car.
When dealing with drag, and compression resistance it is important to remember that it is not a 1:1 ratio, but drag increases exponentially with each psi of increase.
Regarding using a bypass valve to regulate boost, it's a bit of a mixed bag. Yes, you can do it with a Roots type supercharger, and it works reasonably well. The N.A.C.A. did it experimentally in aircraft, however they abandon it not because it didn't work but because they switched to centrifugals and used a different method of boost control. I have personally done this with a Roots supercharger on my cars, however rather than try to do it with the built in supercharger bypass I find it a lot easier to rig a manually controlled secondary valve, like a cable operated heater valve somewhere between the blower and the intake valves.
Amazing , my mind is blown (pun originally unintended) , I think 80-90 is a conservative estimate and I'll bet loss was higher with the small throttle body , poor blower trying to drag air through small opening .....but then there was less to compress so maybe not , love the boost control idea and you're just the guy to find the answer !
There’s a top fuel crew chief/shop foreman that runs a yt channel and he reconditions the race parts and sets the car up ect, a really fascinating channel, I can find it. I remember him saying that it takes 750 hp of the 10k hp to power the blower. Crazy.
Hotrod or CarCraft did an article back in the late 90’s, I believe it took 800 hp to run the roots blower at the 8,000 hp level (top fuel power at the time) one company used a massive electric motor to turn the blower, another company used a separate blown big block motor to spin the blower and both figured similar numbers.
The peak numbers aside on the Valet vs NA, it was really making worse power than NA. Under the curve power looked to be reduced noticeably, so I would say it was actually making less power in "valet" mode. Really interesting testing, it wouldn't be hard to make a simple valet mode bracket for these SC that have the same type of bypass valve. That seems to be a common type of bypass valve also, Magnuson uses a very similar/same one, and the LSA has a similar style as well.
I think the reason the boost/horsepower is the way it is is like wind resistance of the car. It's not linier. If it takes 100 hp to go 100 mph it takes 400 hp to go 200 mph. It's not doubled it's squared. I think they call that the inverse square rule or something like that. 1 to 7 psi is a lot easier than 7-14 psi. By the way I don't have a clue what I'm talking about. I like the boost controller idea. Might be a problem for us carb guys. Thank you for your time.
I suspect it takes 110-125 hp to drive the blower. I’m saying this cause the general rule of thumb is to make double the power on 14.5 psi vs the NA. The boosted version is about 150 hp below this. So based on this it will take about 110-125 hp. I say at 110-125 instead of 150 because the NA combo didn’t run a belt at al and blowers are not as efficient as turbos. Gm said it took 110 hp to drive the blower on the new zr1 which runs 14 psi which is close to this in boost level and hp. I can’t say for sure because no one knows what an lt5 does without a blower. I doubt this blower is more efficient by a margin of 35 hp over the blower on lt5. If anything I’d say it has a larger loss than an lt5.
I have an m122 on my l33 and I can agree with the 3 to 4 psi to overcome the addition of the blower, proved by time slips, when we first had the blower installed I used a used belt very crusty and cracked, blower only made 4 psi and the time slip was exact same as the n/a combo!!
I have run a boost controller from my turbo car to help with traction, you can take almost all of the low end hit out, it works very well you can ramp in boost just like with a turbo to adjusting for different track conditions we had to run c02 to make it work best but you can make the power curve what ever you want at that point
Not sure about the new stuff the BigThree are making but I know Mercedes M113K engines from E55/SL55 etc uses an electronic bypass valve that controls boost pressure at different load levels and you can actually control it with a tune
First comment! Lol Anyways, it’s be interesting to see the loss of running a turbo now for comparison sake. Or maybe also throw in different types of blowers at the same boost level to see what their losses are. Sounds like with this particular combination the drive losses are right around 10% which is huge imho. 👍
The pressure ratio is very important for determining pump efficiency. Your data isn’t meaningless but might be off by a pretty big margin, let’s say 30%. It’s the same thing as putting the same turbo on a big engine and a small engine, on the big engine it has lower boost (pressure ratio on compressor), does less work, and makes more power. Kenne bell probably has some curves for efficiency on similar blowers that could help make this estimate better
It’s a game of diminishing returns. The faster you spin the blower, the hotter the air gets and the harder it is to turn the blower at the higher boost levels.
Yep, but do you think people get that? Don't know how many times I have tried to explain that you can't just add more blower speed and expect X amount of increase. Not only is the blower being more inefficient, but the boost you are showing is not the real boost number either, they can't get there heads around that. The gauge says I am making X boost therefore I am making X boost... No you're not the gauge is only reading that, it's not what you're making.
I did the same math on a roots blower several videos ago and you replied to my comment that it's all speculation and that's why you need to do dyno testing.
Supercharger efficiency has a lot to do with it too. I had a less efficient two lobe blower on my sbc that took around 50-80hp just to make around 520-600hp on a 383.
You take fuel flow (in lb/hr) and divide it by BSFC and you roughly get what the engine would make if it didn't have the parasitic loss. A better way is to calculate IMEP in both engines, which is roughly proportional to bhp. You could even get Bank's power idash and measure the air density in the manifold on the NA engine, and after the blower on the SC engine...again roughly proportional power.
I really dig the videos. And I'm mechanically inclined. But for whatever reason I am nervous tearing into my daily driver. Guess I'm stuck with my exhaust and cold air kit.
Would be very interesting to spin that blower to the same rpm for max boost(14.9) using a external source(ie..electricmotor) and see what the engine makes.
It would be cool to see someone integrate a cvt system on a Supercharger , like that will probably allow for variable pulley size on the run itself , ie the size of the pulley will be different on different rpm
@@richardholdener1727 Man, thank you for replying , I always thought why a procharger torque curve looked different from a roots blower or something similar
I'm looking at this a bit differently, at least for the math. Let's say you're running those 80# injectors at 25% duty cycle NA at peak torque, which you know to be 400 (Forgive me, I don't remember the actual peak). Then you run the test under boost, and you get, for example, 800 tq (Picking this number since it's double the number I used for NA). Theoretically, if the supercharger used no power at all, then you'd need 50% duty cycle. But if you check your logs, and it's 70%, then you know you needed 20% "more" DC than the ideal, and going back to your NA numbers of 25% DC = 400 TQ, you could say 20/25*400 = 320 TQ to run the blower. Obviously, I pulled these numbers from thin air since I don't know the DC numbers at your TQ peaks. (Or perhaps since blower consumption is RPM related, use the DC at the same max RPM). I would be interested in seeing the numbers if you used a 700HP turbo with that combo. I know the turbo is more efficient, but I've never seen any numbers apples to apples comparing the two.
Another way to look at this is to compare to a turbo charged engine with the same boost.. Of course there is lost from the turbine restriction, but negligible compared to driving a blower...
I’m a big fan of PD blowers and thank you for doing all these test but it does make me see how crappy they are pound for pound of boost compared to a well setup turbo application. Also did all this math compare the NA run of pump gas to E85 on the blower cause I’m sure that hurts the numbers slightly more. PS I’d love to see a test with some Meth injection testing pre PD blower and fuel distribution if possible as no one seems to really have a answer to that and rarely see it done
Hi, Take same engine, ( no internal changes ) Put a Turbo charger on it ??? Same boost pressure . ( maybe in all your other test dyno runs, You may have run this Combination??????????? ) Thanks.
Richard I had heard you say in a few different videos that at 14.7psi of boost which is double the atmospheric pressure, an engine HP output should be doubled. My thoughts are since you know what the engine makes na, then what it makes at 14.7psi with the PD blower, what ever the difference of that and double the na power should give you a rough estimate of what the blower takes to spin it? I'm sure there are some variables to consider, and I may be missing something. Just wonder what your thoughts are on that. Thanks
You could do a repeat of what you on the 3.8L by removing the rotors from the blower housing and belt, then dyno it, then compare the two results N/A and blown.....if you did “the formula” every 500-RPM for a range of speeds that the boost hovers around the same pressure ratio (that would show the audience how speed influences parasitic HP)......then subtract “the formula” calculated HP from The HP at each corresponding RPM point on the boosted dyno data you already have.
@@boosted0079 Thanks; yeah, I feel it would be about the most straightforward....It's not perfect, due to restrictions within the blower setup (like the intercooler)......which ideally could be removed / make a hollow plate to take place of the intercooler....but, even so it would still be more accurate than correlating numbers with the blower recirculating through the bypass, since its still having to pump the air / creating unmeasurable parasitic losses....
A test with definite results would be to run a centrifugal supercharger. Do 3 pulls, one baseline, one with the blower, and last with the blower and the charge pipe pulled off. (Been meaning to ask about this for a while) Problem on this test is the massive amount of power lost from switching intakes. You could run a hat with a throttle body and get a better baseline. Keep testing and we'll keep watching!!
To generate meaningful blower drive hp loss numbers, the centrifugal blower outlet would need to be restricted until it produced the same pressure it made while connected to the engine. Otherwise it would freewheel with little parasitic loss.
@@richardholdener1727 Brilliant!!!!!! Mr Holdener!!!! I totally missed that variable. Thank You so much for all of your hard work, and information you pass on to us. Been reading your articles and books since the mm&ff days. Still have the first mm&ff issue
This is cool and all but once you assemble all the parts to get the thing installed are you really saving any money over buying a set up from a dedicated manufacturer?
I think controlling boost via bypass valve on a supercharger is long ago been also done in some AUDIs (3.0tfsi). I installed such a blower on a different, opel motor and the stock pulley was so small that it gave some crazy amounts of boost (25-30psi), had to dramaticly enlarge the pulley. The SC i got had already bypass valve removed, but it was some kind of bolt on throttle body like valve, I think could have been a drive by wire kind. I did not dig for it, but I think it was electronicly controlling boost in stock form. As for the SC drive loss, I would calculate it in a different way, using Richard's NA vs boosted formula. We know that with a correct turbo system, power can be directly proportional to the boost applied, IF you do everything correctly (Richard's law :P ). So asumming you DO everything right on a turbo setup, on 14.2 psi of boost it should make (14.7+14.2)*427/14.7 = 839.5 hp. But we only make 704, so the power to drive the SC is more in the neighbourhood of 135 hp, assuming that driving the turbos also takes some power, but dramaticly less, we can assume it may be somewhere around 120 hp (SC drive loss). I'm very curious how much hp it would really take away, on a SC dyno... I wonder if my logic is correct :)
I look at crankshaft power required by the supercharger a bit differently. Assume 428 hp at 100kpa and factor that to 197, you get 843 hp. Actual power observed is 704, thus loss to the blower is around 139. It’s more if you consider that the blower gets a “boost” from running E85. This ignores the effect of a long runner manifold, which shouldn’t be much at the power peak. Another way to look at parasitic loss would be fuel flow or difference in BSFC. The engine is going to use fuel for the horsepower produced AND the parasitic loss. IMHO, the losses are bigger than you suggest. In reading comments, looks like others have a similar view…
@@bill2178 I didn’t see relative IATs, but that would affect power. With an intercooler it should be a small number, but you’re correct that it would be part of the difference.
The short runner blower intake un-boosted is going to lose 30-50hp due to the short runners compared to a good NA intake. That messes with those calculations a LOT.
As good as the numbers are, something seems off. Where was the boost taken from? Above or below the intercooler. Either way I would like to know what the boost is both above and below the intercooler. It might be a significant restriction. Maybe 2-3 pounds boost loss due to the IC. Then the numbers would make more sense. 14.2 psi boost should be making about 800hp not 704hp when n/a is 427hp.
I'm going to guess the power draw is more than 100hp @ 15psi with that blower, Even the little M90 Sucks 44hp @ 10psi maxed out at 12000rpm, The M112 is 60hp @ 10psi 12000rpm. Eatons numbers from some data sheets I printed out in my super coupe days.
Going simply by hp/psi leaves the variable of drive efficiency. Wouldn't it be more accurate to use the Ritchie boost formula and the difference is roughly the drive loss? With a higher pressure ratio, there is a higher loss...
The blower is still physically moving/working the same about of air if not more air than with bypass valve closed and instead of the work done resulting in dense air doing into the engine and burning fuel resulting in power it is just pumping air around for no benifit
I'm curious when you were comparing HP / psi, N/A 427HP and the PDB is 704HP and with the bypass valve wired open 450 HP and the bypass valve to the PDB had more HP/psi than from na to pdb , what's really sad is from the na to the bypass valve horsepower! From 427 HP to 450 HP 23 horsepower for 5psi of boost! I think we found some parasitic loss!
So if you were gonna try to run this setup on say a rock bouncer, how could you manage the bypass valve? Would a boost controller work? You could use XX lbs of boost, then if you needed more you could turn it up to XX lbs of boost? Because in my mind (and driving situations) you don’t always need 700 hp, cause 450 will do fine.... but there are times when you need ALL THE PONIES to get the buggy to jump Also considering a remote mounting scenario, for simplicity (and honestly cheaper) installation, and using meth injection vs intercooler (due to packaging issues in the buggy) Thanx
so the pumping losses in this example makes me wonder if there is a way to test vacuum pump theory i dont believe that power gained is all ring seal part of it is less pumping losses from air pumped in the crankcase and less aeration in the oil due to less air to mix and less hydraulic lifter squish
Question... would this combo be a good streetable engine on pump gas i know have to dial it back some. But I'm thinking about a daily driver in a pickup that would be used as a truck occasionally and a little bit old school hotrod street truck as well? I want something fast but still able to pull a trailer or make a home Depot run once in a while I have access to a 6.0 thinking same basic combo using it. I have always messed with hotrods and a few drag racing bracket car but have no experience with boosted engines
@@richardholdener1727 That's true. We can either look up the efficiency for the blower (not always an option), or use a pessimistic standardized value.
You have to use ratios of absolute pressure instead of quoting HP/psi of boost. Think of it in this way: If you don't add atmospheric pressure, you're ignoring the first 14.7 psi of air pressure that produced the 427 HP in the NA engine. Extending this thinking, if the engine made 427 HP on 14.7 psi of absolute pressure, it should make 854 HP on 29.4 psia. The actual boosted test data had 28.9 psia (14.7+14.2) of manifold pressure. That should have yielded 1.966 times the power: 427x1.966=839 HP. This is if the power for making the extra manifold pressure came for free, and the intercooler was 100% effective. The difference between the theoretical power and actual supercharged power gives an approximation of the supercharger drive power: 839-704=135 HP. As far as using the bypass valve to regulate boost is concerned: we tested this at Eaton when I worked there (censored) years ago. We seized two blowers in a row when the discharge temperature went to 350F. The blowers that were tested had the discharge air recirculating from the discharge, instead of after the intercooler. If the bypass valve is being cracked open to bleed off boost when running high (>10 psi) boost, the discharge temperature is already at ~260F, and that is the air temperature that is being recirculated to the intake, so it doesn't take much recirculated air to put the blower in a thermal runaway situation. Your system has the bypass from after the intercooler, so the recirculated air temperature will be much closer to the virgin induction air, and thermal runaway should not be a problem.
Whipple claims less then 3/4 of a horse power to run it during regular running durum normal driving which is less than a mechanical fan . Not sure where I read it but makes for a good balance.
What if you put a turbo on the engine and set it up to make the same amount of boost, would the HP you get from the turbo be close to the HP it take to drive the blower?
That's kinda what my thoughts are. The boost pressure is what it is in the intake and it shouldnt matter of it's turbo or SC boost. Getting the same boost pressure from either should be the same on rush of air into the cylinders when the intake valve opens. I'm sure we'd see the turbo produce a lot more power, abs give us a better idea of how much parasitic loss the pd blower takes. Intercooling is slightly different and turbo intercoolers are more efficient at cooling the charged air. But still be a closer number to give us I'd think. From what I understand, at 14.7psi(double they open atmosphere) it's supposed to double the na HP.
@@richardholdener1727 That's kinda what I am talking about, shouldn't the HP difference between the turbo HP and the the SC HP pretty much be about the same as what the SC is using up to drive it?
Hey Richard, how do you think it would go compounding the blower with a turbo and opening the bypass valve when the blower starts to become a restriction and then let the turbo direct feed the engine. Get the low down torque of the blower and the top end power of the turbo?? You must have some stuff laying around there to be able to test it while you've got it on the Dyno 😁
Definitely not easy to measure tension in the belt. But the blower pulley could be strain-gauged to measure drive torque, and blower speed could be measured with an optical tach. Then blower drive power could be calculated.
Had to draw out all those numbers on a piece of paper to see why it didn't make sense. You should be an accountant for the mob with that creative math. You are measuring the delta after you have nobbled the first 5.1 pounds of boost, giving you a higher hp / psi delta number. Was wondering how you managed to get more hp / psi the higher the boost went up (making it look like it is getting more efficient), but that isn't really the case, it only looks that way. By reducing the first 5.1 lbs to 4.5 hp / psi that pushed up the delta to keep an average of 19.5 hp / psi. It does however give you some kind of indication of the power loss between it being bypassed and not being bypassed for the same RPM. Which gives you an indication of the parasitic loss for a given blower speed.
Well, I guess it doesn't mean if you don't have race gas or E85 easily available you should give up on your cam Springs turbo wishes completely, just got to turn it down, glass half full, less parasitic loss, then you got to decide is it worth all the plumbing for a 100-150 horsepower , not plus not equals not, 🤔? Guy could almost just go nitrous at that rate. Okay they don't have E85 but they got nitrous🤦♂️ well, sounded good there for a minute
A turbo on this engine doing 15psi would probably have made around 850ish hp whereas this blower only made 700hp so I reckon it took about 150hp to turn the supercharger at this level...
if true..150 more hp to turn compared to turbo. but not 150 more then NA. a turbo is not free to run, it generates a lot of heat which mean friction and pressure
Could you test, or explain the reasons why someone would run a wastegate on a centrifugal blower setup? I can't wrap my head around placement and function of such a thing lol. Also on the topic of centrifugal setups, is this test a good illustration of how much more efficient they are than the positive displacement stuff? 25hp gain at 5psi is nothing. A V1-S at 5psi would add like 75hp or more.
@@aaronliddell4280 negative. Look it up. It's a thing lol. I'm quite familiar with all of the terminology. I own a twin turbocharged car with internal wastegates and bypass valves, and a Vortech equipped small block with a bypass valve.
Couldn't you multiply the NA hp by 2, and that is what the engine should make at 14.5 psi of boost, then subtract the actual HP number under boost (14.7 is really close) and the difference would be the parasitic loss(roughly)????? If the boost was truly free. So my guess is 120-140 at the high end. The Richy formula!
@@richardholdener1727 well there you go. Why wouldn't that be very close? Learned something new. I knew one Bar was 14.5 so I thought 1 atmosphere was the same. Apparently not.
It’s not as simple with blowers that replace the intake. Because of the intake change that alone will change the power, and as the blower works harder it gets less efficient so you’re using more power to spin it and heating the air more. The doubling of power per atm works somewhat well with turbos though.
I've done exactly what you're talking about on my twin-screw 3800. I used a normal boost controller & mac valve on the bypass actuator to throttle boost production based on engine rpm for launching my fwd car at the track. It was programmed in 500rpm increments so that i could just matt the gas pedal and it puts in duty cycle via the program. worked really well
I think it would be interesting to have a pulley on it that actually spins the blower for only 5psi and see how the power/torque curves actually compare to the bypass valve open at the 'same boost' level
I use a CAN Bus enabled boost controller on my Cadillac CTSV to allow me to set up boost by gear on my LSA engine. It uses a boost solenoid and a 2 port bypass valve actuator. The stock CTSV already has this functionality in the factory ECU to allow for boost reductions in case of over temp, etc. But it doesn't allow boost by speed, gear, throttle position like the aftermarket controller. The aftermarket setup also has 8 maps and a scramble button, so I have maps for street tires ,track tires, rain, valet, etc. It definitely makes launching in first gear on the street much easier.
nice
Is that something you built, or bought? I'm running a 370 inch LQ4 with an Eaton TVS2300 and even at 7 psi, launching in first gear on the street could be much, much easier...
@@plepgeat Cobbled together a bunch of existing componentry. Spent about $600 total, but the boost controller at $500 was the most expensive part. It's really nice though, and offered CAN bus inputs which was useful for semi-modern OBD2 car.
When dealing with drag, and compression resistance it is important to remember that it is not a 1:1 ratio, but drag increases exponentially with each psi of increase.
Regarding using a bypass valve to regulate boost, it's a bit of a mixed bag. Yes, you can do it with a Roots type supercharger, and it works reasonably well. The N.A.C.A. did it experimentally in aircraft, however they abandon it not because it didn't work but because they switched to centrifugals and used a different method of boost control. I have personally done this with a Roots supercharger on my cars, however rather than try to do it with the built in supercharger bypass I find it a lot easier to rig a manually controlled secondary valve, like a cable operated heater valve somewhere between the blower and the intake valves.
Amazing , my mind is blown (pun originally unintended) , I think 80-90 is a conservative estimate and I'll bet loss was higher with the small throttle body , poor blower trying to drag air through small opening .....but then there was less to compress so maybe not , love the boost control idea and you're just the guy to find the answer !
There’s a top fuel crew chief/shop foreman that runs a yt channel and he reconditions the race parts and sets the car up ect, a really fascinating channel, I can find it. I remember him saying that it takes 750 hp of the 10k hp to power the blower. Crazy.
a top fuel blower takes more than 750 hp
@@richardholdener1727 how much does it take then? (Approximately)
@@richardholdener1727 awesome!
Hotrod or CarCraft did an article back in the late 90’s, I believe it took 800 hp to run the roots blower at the 8,000 hp level (top fuel power at the time) one company used a massive electric motor to turn the blower, another company used a separate blown big block motor to spin the blower and both figured similar numbers.
@@Mattvardaman If this needs 13% (80HP in addition to 707HP) That top fuel blower needs more like 1,300HP for 10,000HP output. Absolutely insane.
I like that you always run a baseline
I run a bypass valve controller on my TVS 1900 from the company “Smooth Boost” and it most definitely controls the boost.
The peak numbers aside on the Valet vs NA, it was really making worse power than NA. Under the curve power looked to be reduced noticeably, so I would say it was actually making less power in "valet" mode. Really interesting testing, it wouldn't be hard to make a simple valet mode bracket for these SC that have the same type of bypass valve. That seems to be a common type of bypass valve also, Magnuson uses a very similar/same one, and the LSA has a similar style as well.
What your seeing is the loss from the short intake runners the truck intake has long runners and better low end power
Great question on the boost control
I think the reason the boost/horsepower is the way it is is like wind resistance of the car. It's not linier. If it takes 100 hp to go 100 mph it takes 400 hp to go 200 mph. It's not doubled it's squared. I think they call that the inverse square rule or something like that. 1 to 7 psi is a lot easier than 7-14 psi. By the way I don't have a clue what I'm talking about. I like the boost controller idea. Might be a problem for us carb guys. Thank you for your time.
I suspect it takes 110-125 hp to drive the blower. I’m saying this cause the general rule of thumb is to make double the power on 14.5 psi vs the NA. The boosted version is about 150 hp below this. So based on this it will take about 110-125 hp. I say at 110-125 instead of 150 because the NA combo didn’t run a belt at al and blowers are not as efficient as turbos. Gm said it took 110 hp to drive the blower on the new zr1 which runs 14 psi which is close to this in boost level and hp. I can’t say for sure because no one knows what an lt5 does without a blower. I doubt this blower is more efficient by a margin of 35 hp over the blower on lt5. If anything I’d say it has a larger loss than an lt5.
I have an m122 on my l33 and I can agree with the 3 to 4 psi to overcome the addition of the blower, proved by time slips, when we first had the blower installed I used a used belt very crusty and cracked, blower only made 4 psi and the time slip was exact same as the n/a combo!!
I have run a boost controller from my turbo car to help with traction, you can take almost all of the low end hit out, it works very well you can ramp in boost just like with a turbo to adjusting for different track conditions we had to run c02 to make it work best but you can make the power curve what ever you want at that point
Not sure about the new stuff the BigThree are making but I know Mercedes M113K engines from E55/SL55 etc uses an electronic bypass valve that controls boost pressure at different load levels and you can actually control it with a tune
First comment! Lol
Anyways, it’s be interesting to see the loss of running a turbo now for comparison sake. Or maybe also throw in different types of blowers at the same boost level to see what their losses are. Sounds like with this particular combination the drive losses are right around 10% which is huge imho. 👍
Very cool to see that it takes 4 psi just to break even
THAT BOOST LEAK MAKES ME FEEL VERY VERY GOOOD👍🏿👍🏿👍🏿👌🏿👌🏿👌🏿💯💯... NICE, RICH😁😁😁😁😁
Boost control???... 😁👂🏿👂🏿👂🏿👂🏿👂🏿👂🏿👂🏿👂🏿👂🏿👂🏿
The pressure ratio is very important for determining pump efficiency. Your data isn’t meaningless but might be off by a pretty big margin, let’s say 30%. It’s the same thing as putting the same turbo on a big engine and a small engine, on the big engine it has lower boost (pressure ratio on compressor), does less work, and makes more power. Kenne bell probably has some curves for efficiency on similar blowers that could help make this estimate better
A TWIN SCREW IS A DIFFERENT BLOWER WITH DIFFERENT PARASITIC LOSS-BEST TO RUN IT ON THE BLOWER DYNO-EATON HAS FIGURES
It’s a game of diminishing returns. The faster you spin the blower, the hotter the air gets and the harder it is to turn the blower at the higher boost levels.
Yep, but do you think people get that? Don't know how many times I have tried to explain that you can't just add more blower speed and expect X amount of increase. Not only is the blower being more inefficient, but the boost you are showing is not the real boost number either, they can't get there heads around that. The gauge says I am making X boost therefore I am making X boost... No you're not the gauge is only reading that, it's not what you're making.
Good stuff here nice video Richard
I did the same math on a roots blower several videos ago and you replied to my comment that it's all speculation and that's why you need to do dyno testing.
as indicated in the video-the correct way to measure is on a blower dyno
Supercharger efficiency has a lot to do with it too. I had a less efficient two lobe blower on my sbc that took around 50-80hp just to make around 520-600hp on a 383.
You take fuel flow (in lb/hr) and divide it by BSFC and you roughly get what the engine would make if it didn't have the parasitic loss. A better way is to calculate IMEP in both engines, which is roughly proportional to bhp. You could even get Bank's power idash and measure the air density in the manifold on the NA engine, and after the blower on the SC engine...again roughly proportional power.
NO ON BSFC-JUST MEASURE ON A BLOWER DYNO FOR THE REAL NUMBER
There are two kinds of people in the world, @@richardholdener1727 - people who use BSFC, and people who just measure on a blower dyno.
I really dig the videos. And I'm mechanically inclined. But for whatever reason I am nervous tearing into my daily driver. Guess I'm stuck with my exhaust and cold air kit.
Would be very interesting to spin that blower to the same rpm for max boost(14.9) using a external source(ie..electricmotor) and see what the engine makes.
You'd have to sync it to engine RPM somehow if you wanted to test power losses.
@@Prestiged_peck , agree, rpm is rpm, I wouldn't think it would be that hard to duplicate in that controlled environment.
@@kdeupser wouldn't but it's not gonna be plug and play either.
It would be cool to see someone integrate a cvt system on a Supercharger , like that will probably allow for variable pulley size on the run itself , ie the size of the pulley will be different on different rpm
procharger has that
@@richardholdener1727 Man, thank you for replying , I always thought why a procharger torque curve looked different from a roots blower or something similar
I'm looking at this a bit differently, at least for the math. Let's say you're running those 80# injectors at 25% duty cycle NA at peak torque, which you know to be 400 (Forgive me, I don't remember the actual peak). Then you run the test under boost, and you get, for example, 800 tq (Picking this number since it's double the number I used for NA). Theoretically, if the supercharger used no power at all, then you'd need 50% duty cycle. But if you check your logs, and it's 70%, then you know you needed 20% "more" DC than the ideal, and going back to your NA numbers of 25% DC = 400 TQ, you could say 20/25*400 = 320 TQ to run the blower. Obviously, I pulled these numbers from thin air since I don't know the DC numbers at your TQ peaks. (Or perhaps since blower consumption is RPM related, use the DC at the same max RPM).
I would be interested in seeing the numbers if you used a 700HP turbo with that combo. I know the turbo is more efficient, but I've never seen any numbers apples to apples comparing the two.
I think valet mode is really cool though it reminds me of mad Max when he used to flick his shifter n The Roots blower would come on
Another way to look at this is to compare to a turbo charged engine with the same boost.. Of course there is lost from the turbine restriction, but negligible compared to driving a blower...
I’m a big fan of PD blowers and thank you for doing all these test but it does make me see how crappy they are pound for pound of boost compared to a well setup turbo application. Also did all this math compare the NA run of pump gas to E85 on the blower cause I’m sure that hurts the numbers slightly more. PS I’d love to see a test with some Meth injection testing pre PD blower and fuel distribution if possible as no one seems to really have a answer to that and rarely see it done
Hi, Take same engine, ( no internal changes ) Put a Turbo charger on it ???
Same boost pressure . ( maybe in all your other test dyno runs, You may have run this
Combination??????????? ) Thanks.
Richard I had heard you say in a few different videos that at 14.7psi of boost which is double the atmospheric pressure, an engine HP output should be doubled. My thoughts are since you know what the engine makes na, then what it makes at 14.7psi with the PD blower, what ever the difference of that and double the na power should give you a rough estimate of what the blower takes to spin it? I'm sure there are some variables to consider, and I may be missing something. Just wonder what your thoughts are on that. Thanks
different intake design and likely inlet restrictions
Also need to measure how well the intercooler is working
You could do a repeat of what you on the 3.8L by removing the rotors from the blower housing and belt, then dyno it, then compare the two results N/A and blown.....if you did “the formula” every 500-RPM for a range of speeds that the boost hovers around the same pressure ratio (that would show the audience how speed influences parasitic HP)......then subtract “the formula” calculated HP from The HP at each corresponding RPM point on the boosted dyno data you already have.
@@ericschumacher5189 that actually sounds like a good idea. Then at least the intake setups kinda stay the same to have a more controlled test
@@boosted0079 Thanks; yeah, I feel it would be about the most straightforward....It's not perfect, due to restrictions within the blower setup (like the intercooler)......which ideally could be removed / make a hollow plate to take place of the intercooler....but, even so it would still be more accurate than correlating numbers with the blower recirculating through the bypass, since its still having to pump the air / creating unmeasurable parasitic losses....
Based on the Eaton blower map for the TVS 2.3L it should be between 75-80 hp to drive this flow and pressure.
A test with definite results would be to run a centrifugal supercharger. Do 3 pulls, one baseline, one with the blower, and last with the blower and the charge pipe pulled off. (Been meaning to ask about this for a while)
Problem on this test is the massive amount of power lost from switching intakes. You could run a hat with a throttle body and get a better baseline.
Keep testing and we'll keep watching!!
To generate meaningful blower drive hp loss numbers, the centrifugal blower outlet would need to be restricted until it produced the same pressure it made while connected to the engine. Otherwise it would freewheel with little parasitic loss.
IT ALSO DOES NOT HAVE THE EXHAUST FLOW OF THE ADDED POWER OUTPUT TO CONTEND WITH
@@richardholdener1727 Brilliant!!!!!! Mr Holdener!!!! I totally missed that variable. Thank You so much for all of your hard work, and information you pass on to us. Been reading your articles and books since the mm&ff days. Still have the first mm&ff issue
This is cool and all but once you assemble all the parts to get the thing installed are you really saving any money over buying a set up from a dedicated manufacturer?
Mr Holdener, running the engine na with the super short runner blower intake would be a meaningful data point
I think controlling boost via bypass valve on a supercharger is long ago been also done in some AUDIs (3.0tfsi). I installed such a blower on a different, opel motor and the stock pulley was so small that it gave some crazy amounts of boost (25-30psi), had to dramaticly enlarge the pulley. The SC i got had already bypass valve removed, but it was some kind of bolt on throttle body like valve, I think could have been a drive by wire kind. I did not dig for it, but I think it was electronicly controlling boost in stock form.
As for the SC drive loss, I would calculate it in a different way, using Richard's NA vs boosted formula. We know that with a correct turbo system, power can be directly proportional to the boost applied, IF you do everything correctly (Richard's law :P ). So asumming you DO everything right on a turbo setup, on 14.2 psi of boost it should make (14.7+14.2)*427/14.7 = 839.5 hp. But we only make 704, so the power to drive the SC is more in the neighbourhood of 135 hp, assuming that driving the turbos also takes some power, but dramaticly less, we can assume it may be somewhere around 120 hp (SC drive loss).
I'm very curious how much hp it would really take away, on a SC dyno... I wonder if my logic is correct :)
Ok, I've just read some other comments, I see I'm not the only one with this drive loss calculation idea... :)
I look at crankshaft power required by the supercharger a bit differently. Assume 428 hp at 100kpa and factor that to 197, you get 843 hp. Actual power observed is 704, thus loss to the blower is around 139. It’s more if you consider that the blower gets a “boost” from running E85. This ignores the effect of a long runner manifold, which shouldn’t be much at the power peak. Another way to look at parasitic loss would be fuel flow or difference in BSFC. The engine is going to use fuel for the horsepower produced AND the parasitic loss. IMHO, the losses are bigger than you suggest.
In reading comments, looks like others have a similar view…
what about the density loss from heating the air vs na
@@bill2178 I didn’t see relative IATs, but that would affect power. With an intercooler it should be a small number, but you’re correct that it would be part of the difference.
The difference in intake runner length between the NA and Blower intake is worth at least 30hp over the entire curve.
The short runner blower intake un-boosted is going to lose 30-50hp due to the short runners compared to a good NA intake.
That messes with those calculations a LOT.
Maybe, 5.1# is 35.9% of 14.2#
254hp x 35.9%= 91.86hp
Does this look plausible? 🤷♂️
As good as the numbers are, something seems off. Where was the boost taken from? Above or below the intercooler. Either way I would like to know what the boost is both above and below the intercooler. It might be a significant restriction. Maybe 2-3 pounds boost loss due to the IC. Then the numbers would make more sense. 14.2 psi boost should be making about 800hp not 704hp when n/a is 427hp.
I'm going to guess the power draw is more than 100hp @ 15psi with that blower, Even the little M90 Sucks 44hp @ 10psi maxed out at 12000rpm, The M112 is 60hp @ 10psi 12000rpm. Eatons numbers from some data sheets I printed out in my super coupe days.
Going simply by hp/psi leaves the variable of drive efficiency.
Wouldn't it be more accurate to use the Ritchie boost formula and the difference is roughly the drive loss?
With a higher pressure ratio, there is a higher loss...
DIFFERENT INTAKE, NO ACCESSORIES AND POTENTIAL BELT SLIPPAGE AND INLET RESTRICTION
With the valve open it's not as efficient and if it's recirculating the air through the intercooler then the iat will be hotter too
My guess was 85hp and yes there is a company using the bypass valve as a waste gate a company called smooth boost
Doesn't a multi-speed supercharger, like WWII aircraft, work a little like a boost regulator?
The blower is still physically moving/working the same about of air if not more air than with bypass valve closed and instead of the work done resulting in dense air doing into the engine and burning fuel resulting in power it is just pumping air around for no benifit
about 10-15% loss to drive the blower sounds about right to me. For my money, Turbo FTW.
I'm curious when you were comparing HP / psi, N/A 427HP and the PDB is 704HP and with the bypass valve wired open 450 HP and the bypass valve to the PDB had more HP/psi than from na to pdb , what's really sad is from the na to the bypass valve horsepower! From 427 HP to 450 HP 23 horsepower for 5psi of boost! I think we found some parasitic loss!
YOU CAN'T CALCULATE PARASITIC LOSS LIKE THAT-BEST DONE ON A BLOWER DYNO
So if you were gonna try to run this setup on say a rock bouncer, how could you manage the bypass valve? Would a boost controller work? You could use XX lbs of boost, then if you needed more you could turn it up to XX lbs of boost? Because in my mind (and driving situations) you don’t always need 700 hp, cause 450 will do fine.... but there are times when you need ALL THE PONIES to get the buggy to jump
Also considering a remote mounting scenario, for simplicity (and honestly cheaper) installation, and using meth injection vs intercooler (due to packaging issues in the buggy)
Thanx
an electronic waste gate controller should do with a solenoid (like the factory M90 blower has on the 3800)
so the pumping losses in this example makes me wonder if there is a way to test vacuum pump theory i dont believe that power gained is all ring seal part of it is less pumping losses from air pumped in the crankcase and less aeration in the oil due to less air to mix and less hydraulic lifter squish
Question... would this combo be a good streetable engine on pump gas i know have to dial it back some. But I'm thinking about a daily driver in a pickup that would be used as a truck occasionally and a little bit old school hotrod street truck as well? I want something fast but still able to pull a trailer or make a home Depot run once in a while I have access to a 6.0 thinking same basic combo using it. I have always messed with hotrods and a few drag racing bracket car but have no experience with boosted engines
NOT AT THIS BOOST LEVEL
(Boost pressure * CFM)/229 = Nominal horsepower.
Nominal HP/blower efficiency = real hp.
420hp NA 700hp SC, 700/420 = 1.67
1.67*5.3 = 8.83 liters effective. 8.83/3.8=2.32 2.32*231 = 536 cubic inches effective.
536 cubic inches at 5500 RPM converts to 854 CFM.
(14*854)/229 = 52hp. 60% efficient blower
52/.6 = 87hp.
you don't actually know blower efficiency
@@richardholdener1727 That's true. We can either look up the efficiency for the blower (not always an option), or use a pessimistic standardized value.
You have to use ratios of absolute pressure instead of quoting HP/psi of boost. Think of it in this way: If you don't add atmospheric pressure, you're ignoring the first 14.7 psi of air pressure that produced the 427 HP in the NA engine. Extending this thinking, if the engine made 427 HP on 14.7 psi of absolute pressure, it should make 854 HP on 29.4 psia. The actual boosted test data had 28.9 psia (14.7+14.2) of manifold pressure. That should have yielded 1.966 times the power: 427x1.966=839 HP. This is if the power for making the extra manifold pressure came for free, and the intercooler was 100% effective. The difference between the theoretical power and actual supercharged power gives an approximation of the supercharger drive power: 839-704=135 HP.
As far as using the bypass valve to regulate boost is concerned: we tested this at Eaton when I worked there (censored) years ago. We seized two blowers in a row when the discharge temperature went to 350F. The blowers that were tested had the discharge air recirculating from the discharge, instead of after the intercooler. If the bypass valve is being cracked open to bleed off boost when running high (>10 psi) boost, the discharge temperature is already at ~260F, and that is the air temperature that is being recirculated to the intake, so it doesn't take much recirculated air to put the blower in a thermal runaway situation. Your system has the bypass from after the intercooler, so the recirculated air temperature will be much closer to the virgin induction air, and thermal runaway should not be a problem.
YOU ARE MISSING ITEMS IN YOUR EQUATION
@@richardholdener1727 Such as?
About 10hp on the supercharger run is a loss from the accessories too.
Whipple claims less then 3/4 of a horse power to run it during regular running durum normal driving which is less than a mechanical fan . Not sure where I read it but makes for a good balance.
ONLY WHEN THE BYPASS VALVE IS OPEN UNDER CRUISE CONDITIONS AT VERY LOW SPEEDS
But because the boost is vented around the blower the parasitic loss is lower than when the blower is just compressing the air to feed the engine.
What if you put a turbo on the engine and set it up to make the same amount of boost, would the HP you get from the turbo be close to the HP it take to drive the blower?
That's kinda what my thoughts are. The boost pressure is what it is in the intake and it shouldnt matter of it's turbo or SC boost. Getting the same boost pressure from either should be the same on rush of air into the cylinders when the intake valve opens.
I'm sure we'd see the turbo produce a lot more power, abs give us a better idea of how much parasitic loss the pd blower takes. Intercooling is slightly different and turbo intercoolers are more efficient at cooling the charged air. But still be a closer number to give us I'd think.
From what I understand, at 14.7psi(double they open atmosphere) it's supposed to double the na HP.
14.7 psi can double the power, but not on a blower application. You have to subtract the losses associated with driving the blower.
@@richardholdener1727
That's kinda what I am talking about, shouldn't the HP difference between the turbo HP and the the SC HP pretty much be about the same as what the SC is using up to drive it?
Makes sense to me.
Hey Richard, how do you think it would go compounding the blower with a turbo and opening the bypass valve when the blower starts to become a restriction and then let the turbo direct feed the engine.
Get the low down torque of the blower and the top end power of the turbo??
You must have some stuff laying around there to be able to test it while you've got it on the Dyno 😁
I have compound tests up already-the turbo won't feed enough just through the bypass valve
@@richardholdener1727 did you get back to completing them after the belt slip issues, or did I miss some of your vids 🤔
Does say... a Paxton, Vortech, or TQ Storm take similar power to turn?
Much less.
Could you measure the force on the belt turning the blower?
Asking for a friend…
Definitely not easy to measure tension in the belt. But the blower pulley could be strain-gauged to measure drive torque, and blower speed could be measured with an optical tach. Then blower drive power could be calculated.
What a nice setup. Are those intakes readily available?
Yes they are-check with demuse engineering
What the cost on them
Had to draw out all those numbers on a piece of paper to see why it didn't make sense. You should be an accountant for the mob with that creative math. You are measuring the delta after you have nobbled the first 5.1 pounds of boost, giving you a higher hp / psi delta number. Was wondering how you managed to get more hp / psi the higher the boost went up (making it look like it is getting more efficient), but that isn't really the case, it only looks that way. By reducing the first 5.1 lbs to 4.5 hp / psi that pushed up the delta to keep an average of 19.5 hp / psi. It does however give you some kind of indication of the power loss between it being bypassed and not being bypassed for the same RPM. Which gives you an indication of the parasitic loss for a given blower speed.
trust me-the math presented is accurate
@@richardholdener1727 yeah the math is accurate, I checked it.
👍
Hey rich question is how much does the tvs blower adapter cost?
contact demuse engineering
Well, I guess it doesn't mean if you don't have race gas or E85 easily available you should give up on your cam Springs turbo wishes completely, just got to turn it down, glass half full, less parasitic loss, then you got to decide is it worth all the plumbing for a 100-150 horsepower , not plus not equals not, 🤔? Guy could almost just go nitrous at that rate. Okay they don't have E85 but they got nitrous🤦♂️ well, sounded good there for a minute
Are you still pumping the same amount of air even
So I'm guessing a turbo on the same engine, at the same boost level, would make about 800 HP?
That's probably about right, depending on the difference between intake and exhaust pressures.
A turbo on this engine doing 15psi would probably have made around 850ish hp whereas this blower only made 700hp so I reckon it took about 150hp to turn the supercharger at this level...
if true..150 more hp to turn compared to turbo. but not 150 more then NA. a turbo is not free to run, it generates a lot of heat which mean friction and pressure
Could you test, or explain the reasons why someone would run a wastegate on a centrifugal blower setup? I can't wrap my head around placement and function of such a thing lol.
Also on the topic of centrifugal setups, is this test a good illustration of how much more efficient they are than the positive displacement stuff? 25hp gain at 5psi is nothing. A V1-S at 5psi would add like 75hp or more.
A WASTEGATE?
@@JohnnyAnderson1 people do it lol.
I think what you meant to say was a bypass valve, not a waste gate lol
@@aaronliddell4280 negative. Look it up. It's a thing lol. I'm quite familiar with all of the terminology. I own a twin turbocharged car with internal wastegates and bypass valves, and a Vortech equipped small block with a bypass valve.
To limit boost in certain situations. (creates a boost leak) The ones I've seen are electric WG s so they are "easy" to control
Yeah... but how much does that TVS Blower cost?
Add a turbo to help it.
Could do the same with a centrifugal and just disconnect the charge pipe, seal it, and let a boost controller bleed it off.
seal the charge pipe?
Couldn't you multiply the NA hp by 2, and that is what the engine should make at 14.5 psi of boost, then subtract the actual HP number under boost (14.7 is really close) and the difference would be the parasitic loss(roughly)????? If the boost was truly free. So my guess is 120-140 at the high end. The Richy formula!
1 atmosphere is 14.7 psi
@@richardholdener1727 well there you go. Why wouldn't that be very close? Learned something new. I knew one Bar was 14.5 so I thought 1 atmosphere was the same. Apparently not.
It’s not as simple with blowers that replace the intake. Because of the intake change that alone will change the power, and as the blower works harder it gets less efficient so you’re using more power to spin it and heating the air more.
The doubling of power per atm works somewhat well with turbos though.
well in bypass the blower takes less power to spin
In your own word at 14.7 psi you should double your HP. So 428 HP double is 856 HP. so you loss (856hp - 704 = 152 hp.
the intake design also changed and is the throttle opening a restriction?
It’s a parasitic power loss. You are requiring the blower process all of the air and then bleeding it off.
Could the supercharger fit the l83
the blower will-not the adapter or intake
if you want free power get a turbo ..
80-100hp just to spin it.
That's some pretty wonky math you're doing. If you could measure blower belt tension you could calculate HP.
There is no free lunch. Pick your poison. Thank you for your time.
Personally I blame squirrels
what a good one omg thats crazy talk.dam you are witty