David Vizard said that the anti reversion mechanism is best done at as near to the exhaust valve as possible, that is by putting anti reversion flaps at the beginning of the exhaust header.
What he made there is called a merge collector. The cone shape is to allow scavenging (negative pressure waves) to occur over a longer duration per pulse, which adds power over a broader rpm range compared to a standard collector which causes a stronger but shorter duration negative.
6 years is a little late but he made whats called a reversion chamber that was placed past the merge collector. The design is to prevent reversion (exhaust resonance/reverse flow) which in turn assists in scavenging. another way that big racers do(F1, NASCAR, rally) is stepping up the header piping at increments to make it harder for those reversion pulses to travel back up to the exhaust valves hindering scavenging.
@@lilwewe1451 For whatever reason , the term "merge collector" seems to be used to describe a collector with an expanding exit, whereas a "collector" typically doesn't have that. I don't know if the anti-reversion chamber actually does what it's believed to do, because the incoming pressure wave encountering a constricting cone after an expanding cone would likely cancel some of the negative pressure that would otherwise have contributed to scavenging. Stepped headers assist scavenging by causing moments of negative pressure while the exhaust valve is still open (I'm assuming that's the goal), helping to evacuate the cylinder better. I would think a constricting cone would create some back pressure, but probably insignificant in this case because of how much larger in diameter the anti-reversion chamber is compared to the collector.
Turbo applications usually don't benefit from exhaust scavenging techniques, which try to create a vacuum effect in the exhaust manifold which the back pressure of a turbine negates.
Cool stuff but I thought anti reversion chambers were supposed to be as closed to the exhaust ports as possible, is that not the case? For those that don't know, anti reversion chambers also help with engines that have a lot of exhaust valve overlap, the chamber helps keep exhaust gases from being sucked back into the cylinder during the intake stroke.
yes, directly at the head would be the ideal location. packaging prevents that in this application. I've seen other fabricators have success gaining torque placing them post collector on n/a headers. there is a lot of math involved to maximize the potential of the chamber. the intent here is to encourage people to try new things and learn by doing.
*"Our Hearts bring back the Light."* Wishing you all a Wonderful Winter Solstice. A traditional celebration dating back well over 5000 years ago where the Sun is literally rebirthed in the passageway of an ancient tomb. "The Grand Passage Tomb." A World Heritage site. Witness the rebirth in person. A celebration of life and renewal, peace and camaraderie with food, song, dance, drink and goodwill. Happy Holidays. Let the Sunshine In... *Be Happy* "Solstice Night by S J Tucker"
Hey Vibrant, I need advice. What schooling (degrees or certs) would I need to have a job in a speed shop like this? What does the career path look like? Thanks in advance!
Hi William, that's a great question. The most important thing is you need is passion for the industry. I am one of the technical staff at vibrant along with Aaron and Jay. We all have completely different backgrounds, Jay is self taught, Aaron has a machining background and I am an engineer. We all bring different expertise to the table, but we all share a deep passion in racing, automotive design and fabrication.
The part that you slid inside the cone should've went outside of the cone because you're interfering with scavenging unless you butt connect the two together and weld it. Whenever you're connecting a piece to the exhaust going outward you always slide it over the previous piece.
so much about exhaust i didnt know, can u put these chambers on any natural aspirated car like an e46 straight 6 BMW or is it just for certin cars where this chamber will be beneficial?
That's a great question - There were a couple of reasons when considering adding the GESi Catalytic to this vehicle. Firstly, yes - the car is old enough to not have any emissions regulations by the government, however we have tested these catalytic converters in the past on naturally aspirated vehicles and have actually seen an increase in horsepower when adding them (refer to our video 'How can a Catalytic Add Horsepower?' ua-cam.com/video/56oLVgpwOAs/v-deo.html). Secondly, Art requested to add the cat because he wants to have an enjoyable experience when driving the car on the street - by having cleaner air coming out the pipe, eliminating the smell, etc. Lastly, the whole exhaust has V-Band connections will allow him to switch the catted section with a catless midpipe or even put on straight piping off the header all the way back if he decides to track the vehicle.
I was under the impression that carburated vehicles do not run efficiently enough to use a cat. I have thought about putting one on my car (Datsun 510 with side draft Mikuni's) but have heard that the cat would overheat and break down very quickly. Are the GESi Cats able to handle the variations in AFR that carbs present?
@@TheEldukerino I don't understand why either. But I know some cats have a metal core catalyst so they can handle extreme heat and richer running vehicles better. But the carb would still probably wash all the catalyst of the substrate then its not much of a convertor anymore just a muffler.
@@VibrantPerformanceTV This could only be because adding a slight restriction there benefits the pulse tuning. High performance honda guys have discovered that "high flowing" the cat reduces power, not realising honda know what they are doing when they release an emissions legal 100hp/litre engine. You'd almost certainly note the same gain in power with a piping size step-down then step-up in the same place.
Prevents the exhaust pulses travelling back upwards. It happens because of valve overlap during high intake vacuum. When done right, the benefits includes improves torque at lower RPM, ability to use more aggressive cam timing, can go full throttle at much lower RPM, less Nox.
What schedule pipe do you use for the headers and the rest of the exhaust? I see SS turbo Headers used SCH 10. Do you use thinner tubes for N/A aplications?
The best exhaust after a turbo is a laminar bell which is super short and would change shape depending on the variations in flow. It's kind of like how rockets loose parts as they change altitude the thrust cone(bell) keeps the correct burn happening for max thrust but on a turbo it's going to be reversed where we will take the pressure coming out of the turbo and try to diffuse it with the greatest pressure transition possible without inducing more turbulence.
David Vizard said that the anti reversion mechanism is best done at as near to the exhaust valve as possible, that is by putting anti reversion flaps at the beginning of the exhaust header.
What he made there is called a merge collector. The cone shape is to allow scavenging (negative pressure waves) to occur over a longer duration per pulse, which adds power over a broader rpm range compared to a standard collector which causes a stronger but shorter duration negative.
6 years is a little late but he made whats called a reversion chamber that was placed past the merge collector. The design is to prevent reversion (exhaust resonance/reverse flow) which in turn assists in scavenging. another way that big racers do(F1, NASCAR, rally) is stepping up the header piping at increments to make it harder for those reversion pulses to travel back up to the exhaust valves hindering scavenging.
@@lilwewe1451 For whatever reason , the term "merge collector" seems to be used to describe a collector with an expanding exit, whereas a "collector" typically doesn't have that. I don't know if the anti-reversion chamber actually does what it's believed to do, because the incoming pressure wave encountering a constricting cone after an expanding cone would likely cancel some of the negative pressure that would otherwise have contributed to scavenging. Stepped headers assist scavenging by causing moments of negative pressure while the exhaust valve is still open (I'm assuming that's the goal), helping to evacuate the cylinder better. I would think a constricting cone would create some back pressure, but probably insignificant in this case because of how much larger in diameter the anti-reversion chamber is compared to the collector.
For a turbo application would be benefit or useless?
Turbo applications usually don't benefit from exhaust scavenging techniques, which try to create a vacuum effect in the exhaust manifold which the back pressure of a turbine negates.
I would love this guy to build a full exhaust for my 370Z
pretty please!!
Cool stuff but I thought anti reversion chambers were supposed to be as closed to the exhaust ports as possible, is that not the case? For those that don't know, anti reversion chambers also help with engines that have a lot of exhaust valve overlap, the chamber helps keep exhaust gases from being sucked back into the cylinder during the intake stroke.
yes, directly at the head would be the ideal location. packaging prevents that in this application. I've seen other fabricators have success gaining torque placing them post collector on n/a headers. there is a lot of math involved to maximize the potential of the chamber. the intent here is to encourage people to try new things and learn by doing.
FORCED-INDUCTN
A proper pulse tuned exhaust does not need them.
Aaron Weir Super cool, I didn't realize they would work that far down, awesome work! @ Phone User, interesting, makes sense too.
Is there a mathematical equation to figure out tube length and diameter for the anti reversion pipe?
Never heard of a chamber like that for 4 stroke engines. It seems to resemble a 2 stroke technology for controlling exhaust pulses.
*"Our Hearts bring back the Light."*
Wishing you all a Wonderful Winter Solstice.
A traditional celebration dating back well over 5000 years ago where the Sun is literally rebirthed in the passageway of an ancient tomb.
"The Grand Passage Tomb." A World Heritage site. Witness the rebirth in person.
A celebration of life and renewal, peace and camaraderie with food, song, dance, drink and goodwill.
Happy Holidays.
Let the Sunshine In...
*Be Happy*
"Solstice Night by S J Tucker"
Great welds! Heat sink idea is brilliant. The 1980’s porn music not so good.
Bad ass work, thumb 👍
Can you talk about what this does for turbo applications, the Pagani Huayra uses these in place of mufflers
The theory is The exhaust pressure wave can push The mixture back to admission loosing some VE
Nice! I see the Speed Academy boys have reverted to your method of fabrication. I guess their "digital wizardry' can't work any more...LOL
it looked like such a colossal and unnecessarily overcomplicated timewaste..
A set of webers would finish the look of an oldskool sportscar engine.
Hey Vibrant, I need advice. What schooling (degrees or certs) would I need to have a job in a speed shop like this? What does the career path look like? Thanks in advance!
Great question. Hoping they answer.
.
william ulibarri, start with vocational schools. Learn welding and automotive.
I work at a speed shop and I have had zero schooling.... teach yourself and get skilled trade jobs and look at college to expand your people base
Hi William, that's a great question. The most important thing is you need is passion for the industry. I am one of the technical staff at vibrant along with Aaron and Jay. We all have completely different backgrounds, Jay is self taught, Aaron has a machining background and I am an engineer. We all bring different expertise to the table, but we all share a deep passion in racing, automotive design and fabrication.
The part that you slid inside the cone should've went outside of the cone because you're interfering with scavenging unless you butt connect the two together and weld it. Whenever you're connecting a piece to the exhaust going outward you always slide it over the previous piece.
They're also called reverse cone
Nice
So you build a nice free flow exhaust and then go stick a massive restricter ( CAT ) in the middle. DOH!
Refer to our video regarding out GESi Catalytics: ua-cam.com/video/56oLVgpwOAs/v-deo.html
work on dino at low rpm ?
Who sells these exhaust sections again????? Don't forget a silencer or two....maybe a resonator??
@2:44 Wish I could say the same of my welding lol.
Anti reversion chamber. Is this like dv’s chamber?
so much about exhaust i didnt know, can u put these chambers on any natural aspirated car like an e46 straight 6 BMW or is it just for certin cars where this chamber will be beneficial?
Why does a 2002 need a cat? They never came with one so why add the exhaust restriction?
That's a great question - There were a couple of reasons when considering adding the GESi Catalytic to this vehicle. Firstly, yes - the car is old enough to not have any emissions regulations by the government, however we have tested these catalytic converters in the past on naturally aspirated vehicles and have actually seen an increase in horsepower when adding them (refer to our video 'How can a Catalytic Add Horsepower?' ua-cam.com/video/56oLVgpwOAs/v-deo.html). Secondly, Art requested to add the cat because he wants to have an enjoyable experience when driving the car on the street - by having cleaner air coming out the pipe, eliminating the smell, etc. Lastly, the whole exhaust has V-Band connections will allow him to switch the catted section with a catless midpipe or even put on straight piping off the header all the way back if he decides to track the vehicle.
I was under the impression that carburated vehicles do not run efficiently enough to use a cat. I have thought about putting one on my car (Datsun 510 with side draft Mikuni's) but have heard that the cat would overheat and break down very quickly. Are the GESi Cats able to handle the variations in AFR that carbs present?
@@TheEldukerino I don't understand why either. But I know some cats have a metal core catalyst so they can handle extreme heat and richer running vehicles better. But the carb would still probably wash all the catalyst of the substrate then its not much of a convertor anymore just a muffler.
@@VibrantPerformanceTV This could only be because adding a slight restriction there benefits the pulse tuning. High performance honda guys have discovered that "high flowing" the cat reduces power, not realising honda know what they are doing when they release an emissions legal 100hp/litre engine. You'd almost certainly note the same gain in power with a piping size step-down then step-up in the same place.
@@skippy2987 Got a 100 cpi metallic core cat on A k24 still today. Thank you
Why not use a rotary fixture? It makes the process so much easier and consistent.
Doesn't that bother you that the vibrant merge bottle necks the flow so much??
whats the use of the Anti-Reversion Chamber? can some shed some light over here please...
Prevents the exhaust pulses travelling back upwards. It happens because of valve overlap during high intake vacuum. When done right, the benefits includes improves torque at lower RPM, ability to use more aggressive cam timing, can go full throttle at much lower RPM, less Nox.
What schedule pipe do you use for the headers and the rest of the exhaust? I see SS turbo Headers used SCH 10. Do you use thinner tubes for N/A aplications?
Yeah, if you're running an NA build then there's no point in having thick piping such as (Sch 10, 40) it'd be best to use thin wall tubing
have you dyno tested any of this .... thinkn not ..
Would an anti-reversion have benefits on a turbo set-up (assuming it's after the turbo outlet or down pipe)?
Rigo Hernandez don't think so. The exhaust would have to come back through the turbo, which I don't think is possible.
no, there is not a significant benefit in a turbo application as all the pulse waves are disrupted by the turbine wheel.
The best exhaust after a turbo is a laminar bell which is super short and would change shape depending on the variations in flow. It's kind of like how rockets loose parts as they change altitude the thrust cone(bell) keeps the correct burn happening for max thrust but on a turbo it's going to be reversed where we will take the pressure coming out of the turbo and try to diffuse it with the greatest pressure transition possible without inducing more turbulence.
Where did you get the background music, because it sounds like my classic disco set 1 that I posted on my soundcloud my name is J.Golden Productions
Porn Pop .....
Sigma kids - bella mi amoir
Man this guy can weld
where is the background music from?
D Rell bella mi amoir -sigma kids
Trust me, I’m a tube engineer..... 🤦🏻
This is not a working mans exhaust. I would probably have to take a second job. STEP back son, I got this....
looks nice, but do you have any math to back it up?
Black bars = cinematic.
Like it!
Iirc. Your anti reversion part is at the wrong end.
No math just looks
Omgherd itr a 2002trrrree
You could cut out half the work by doing a side exit!!! Mwahahahaha!!!
Lol anti reversion chamber and a CAT.........wtf dudes.