Drive By Wire is a painful upgrade. But SO worth it
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- Опубліковано 8 лют 2025
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If you need anything brother don’t hesitate. I so love this system
Hell yeah
Thats why we all love Brent and everyone at PFI Speed, they want everyone to succeed
Yo this man is always down to help everyone. Everyone needs a Brent in their life.
@@DJDMHaze everyone should be a Brent for other people as well! You're the f'ing man Brent!!
Brent is the Man #PFI
“Something is loose” *everything rattling while the car shakes*
The difference is, it’s rattling more
😂
I thought about that the whole rest of the video lol
hahahaha
Rattle mobile
I speak for everyone when I say - we want more street driving footy. Get follow cams. Get drone shots. Interior shots. Even for a test drive like this, would be epic Rob. I already feel like I'm watching Fast and Furious 1 irl.
@@greatestevar one,$1000 drone a few go pros and a friend later.
@@greatestevar did you just wake up from a twenty year nap? 😂😂
@@ellisberry8747 Ha! Yeah, like *that's* a possibility...
Talk about *totally unreasonable* requests.
"A friend..."
Come on man, don't be an ass! Why don't you just ask him to wave a pepperoni stick and say "Alakazam" to summon himself, like, flippin Shaquille O'Neal right quick, to hold the camera?
... A friend... Pffft. Right. Get real dude.
Excellent idea !
At the very least, another camera watching the front would be a nice extra pov
ECU based pedal tuning is a BIG step but you might want to take a look at the spring load and/or friction of the pedal itself.
You can tune the pedal response up to a point but if your foot is blipping a lightweight, low friction throttle and setting up a kangaroo effect it'll be nearly impossible to tune out fully in a car with such a responsive engine without creating an overly dull throttle response.
I drove a supercharged Arial Atom and was amazed how heavy it the throttle pedal seemed but it makes sense in such a light responsive car for exactly the same reasons.
A bit like the brake issue, you can have great pads, rotors, brake lines calipers and brake balance, but if the master cylinder is loose... its gonna feel weird!
100% you need a higher load pedal
The video gave me kenworth t800 vibes
Yeah, right on. I have an ariel atom 3. Even with the pedal set as is, you can still get a rubberband effect if you're not careful at low speeds. Difficult car to drive slowly.
It also had me thinking there needs to be some way to incorporate an accelerometer (aka. g-sensor) into the feedback loop. It'd let the ecu filter some of those "oh, the throttle has dropped off" responses due to the acceleration raising your foot. But It'd probably also be a lot of work if the ecu doesn't already have provisions for such a thing.
@@AnonyDave That'd be a pretty cool feature!
at this point, you should just integrate that laptop into the dash
Maybe a surface tablet with a wireless keyboard and touch pad.
Hatervision
@@tich18 AdamLZ's gf Collete got sponsored by microsoft for doing just that in her RX8 build I think?
Rob should go big dick into a meeting w/ microsoft & have them set him up with the most dialed in-car tuning solution like that
@@tich18 Or get a GPD Pocket 3 when it comes out. It would be so perfect for this use case.
That's so funny. Real talk
the amount of attention to detail to everything is amazing, anytime there's a dahm video, it's going to be a good day.
Check out Kevin’s channel if you wanna see attention to detail.
ua-cam.com/users/TheCutlassRacer
Dahm good day
I still think he needs to name the garage he's working in "The Dahm Garage." So when the car gets messed up he can say "I have to take the Dahm car to the Dahm garage to fix the Dahm thing."
Yea a lot of detail and nothing ever works 😂😂
dahm good videos
I am one of those calibrators at a big oem Rob. So many people have no idea how much time we spend on the smallest calibration. I also do the throttle to position curve, so I know the frustration. Keep it up
Wow
Transmission sounds so good man. That "clunk" is so satisfying
True
yeah, super brutal sound, i love it
I thought something broke...❤️
The amount of learning you've done to get you to this point makes me glad that I didn't abandon you way back when the 4 rotor was a shell at SEMA
Rob: **Puts kill switch in literally the most inconvenient (or should I say, convenient for thieves) location on the car.**
Also Rob: "If you see this car, do not take this."
Somebody is definately going to seal that the next event he goes to 😂
A lot of drag strips require it be there for access outside of the car in case of serious injury.
in case of an accident and an ensuing fire and the driver is knocked out or cant shut the car off for whatever reason track/strip officials can do it from the outside
@@tomk169 lol I know what it's for, I'm just saying he could've put it in a different spot. I've mostly seen them in the cowl area between the windshield and the hood.
@@kasper_429 most require the trunk area
I am so glad you were able to capture the pure emotions of yourself being frustrated by the initial drive by wire! (The flash forward definitely got me to chuckle) If only all of us could just have a glimmer into the future for just a second to know it'll all work out!
I was a little embarrassed to include it but I wanted the honest first take. Since that’s real life
Admittedly, throwing wrenches is my favorite pastime when working on a project til something clicks. I have a piece of drywall hung on my shop's wall just for this.
@@RobDahm Dude, it was so worth seeing you get pissed, because I was pissed too. That had to have been the most frustrating drive to have to suffer through, and thinking to yourself "I've ruined this" or "how am I gonna fix this crap". Troubleshooting is always a bitch.
@@RobDahm that's why we love you rob, thanks for being real
Without the lows the highs are not the highs. I admire your work sir and your fortitude. Keep up the quality content
Geez, the tuneablity of that fly-by-wire is magnificent.
My manual drive by wire Corvette does the same sometimes in parking lots. As Rob touched on, I think it's kind of a feedback loop between my foot and the car chugging a bit when I'm lugging it more than I should at low speed.
Happens to my Genesis as well. Wish I could turn down the sensitivity a bit
@@MEatRHIT2009 Just rip out your factory ECU and replace it with a FuelTech! haha
Can use the clutch to smooth it out when this happens
@@literallyanythingelseother yeah, I just depress the clutch, and it settles down. I think it only does it because it's cammed and tuned. It doesn't like to go slow.
@@jasepoag8930 cammed rotary
Now that you have drive by wire with a sequential dog-box you can potentially do auto-blip clutchless down shifts.
This car has a 6 speed if I recall, the 4 rotor is what has a sequential
@@TheSaif78 He mentions the strain gage shifter being "unhooked" on yhe car.
@@KrKrypton the strain gauge is on the shifter, but it's still an H pattern. He says that he needs to put it into 5th gear to line up the dogs to put it into first at the start of the video
@@flakey7832 ah. Then there's no real way to do it effectively. Nissan had an auto blip on their 370 when it saw no input from the gas pedal and input from the clutch pedal, but that defeats the purpose of a clutchless downshift.
Wait... No, it can still be done, but reliability of the system will be up to the absolute skill of the driver. If the ecu detects no input from the throttle with input from the strain gauge, then the ECM can determine that a downshift is being demanded and can blip the throttle permitting a clutchless downshift.
Rob, you should see how much test and analysis goes into just getting a modern window switch assembly into a vehicle.
Have to proof the everything AND the manufacturing line. If you move the assy' line to make room for more stuff in the building, you have to re-validate with testing again.
Many teams. But for all the frustrations and hell we put ourselves through, we do it for the end result you showcase here. Having hair left is just a bonus
"the new supra is just a bmw!" -Some guy who won't buy a $150,000 in house supra.
When I race RC cars we have a setting on our radios called "exponential throttle".. Its basically a setting that can adjust the sensitivity. The speed controller is very similar to your electronic throttle body. Picture a graph of your throttle output where the X axis is the ECU throttle output and the Y axis is the throttle input. If you apply zero adjustment you would see a perfect straight line at a 45 degree angle on the graph. If you apply a positive number it would in effect make initial throttle input more sensitive (very little input to more output). A negative number would do just the opposite. Racers use this feature for better low to mid throttle. I think that "graph" you were adjusting for throttle output is similar to what I am talking about. The curves I see that work well in your case is a parabolic curve starting from 0,0 (x,y) its very low slope that gradually curves upward almost like a logarithmic curve. This will automatically cure your throttle bouncy feeling. Some racers sometimes have an "S" curve where the very bottom and top of the curve is horizontal in nature. A curve like that will do both better control at very high and low throttle settings so you can have better driveability and better control at the limit to control tire slippage at full boost.
Hope all of this rambling helps. Good luck.
I dont know if this mentioned in the video just yet, but idle control with ignition is very good to get things smoothly idling, you basically put a "hole" in the ignition timing table where you want it to idle, and put more timing below that rpm. That way the extra timing will push the revs up when idling too low and the ignition cut will stop the idle from running away.
Ignition timing can adjust idle speed part way through an engine rotation (basically between every ignition event) but idle air control can't really do that because air has momentum/inertia, even if the throttle blade closes theres all the air in the intake.
Something that can help a lot also is acceleration ignition advance, if you put negative advance at small throttle changes it will pull a bit of timing on gentle acceleration which will make it less jerky, but this won't hurt steady state throttle (if your not moving your foot its not pulling timing) and it won't hurt high performance driving (larger throttle changes or steady stare high end).
I usually put a few degrees of advance for tiny throttle changes (delta of 0.5-2.5%) so that way you can "creep" and "bump" the car a lot easier, then for small throttle changes (delta of 2.5-7%) i pull a bunch of timing, maybe -15degrees, this settles down a huge amount of the jerky area, and then for higher throttle changes i leave it alone or give it a degree or two even. This gives it a bit more response on throttle stabs (since it can add timing a lot faster than you could possibly add fuel or air).
None of this effects steady state timing or throttle, so you still get your cruising efficiency and WOT timing etc, and the retard or advance fades out very quickly because you have stopped moving the pedal.
i threw up another comment with a google drive spreadsheet but it may have been flagged as spam, i'd really appreciate it if you took a look
Wow, drives like OEM by the end of the video. Went from undriveable to perfection.
This just goes to show you how complicated and intricate cars have become. Just the throttle response alone could take months to tune to be just right. Imagine the number of other electronics involved in modern cars and you realize the difficulty that comes with all of it. Great work Dahm
I love the science you put into speed. Man, honestly you're doing the work of an entire race team by yourself essentially.. that's crazy cool. Just the fact that you compare the acceleration to G's pulled and determine you can add more snail power blows my mind. Great job, love your content!
It's mixing computers/technology and internal combustion I love it. I like watching you mess with everything learning.
17:30 i see the tears in your eyes man emotional when everything goes as should! Im happy for you man cant wait for this thing to be properly raced
Rob, what kind of throttle curve did you have at the beginning? I’ve found that a linear curve with no tip in will cause bucking really bad. Tip in with a progressive throttle is massively more street drivable.
dumb question but what is bucking?
@@its__abraham when it kicks you back and forth as your foot is bouncing around pushing the pedal
Isnt it more the PID loop that needs tuning ?
@@ggallen3156 which causes a feedback loop, making your foot bounce on the pedal more, making the bucking worse. New operators on skid steers are really bad about it, and the only way to fix it is to completely let go of the controls.
@@MrJermbob Problem with this PID loop (speaking in general terms and ideas) is that one of the response inputs is human and the human is causing the oscillation. As Rob finds that as he increases his 'gain' the oscillation goes away - however his natural tendency is to reduce his 'gain' which causes increased oscillation. This is also why truck and trailers often crash when they get the death wobble; driver input is reduced instead of increased. Mash the gas is not a long term solution, but a factor that needs to be considered in resolving PID loop oscillations involving human inputs. This may or may not have contributed to a few fly by wire aircraft accidents and has been studied extensively in both the aviation and automotive industries.
In many cases the solution is to limit the output gain from the controller so that it doesn't induce magnified gain change from the human. Rob smoothed the throttle response to make the controller gain less. There are other settings in most all ECUs for drive by wire TBs that help address this like tip-in that can be fine tuned to help control this issue, but ultimately this engine configuration could be the biggest factor in the throttle control. Don't take my comments as knowing the actual issue or solution, just my observations from my experience in similar matters that involve human feedback in a PID loop.
Man that must be such a sick ass feeling crusing around in such a raw ass car, amazing
0:37 😄 *Rob's opponents noted*
If I was him, I'd keep at least 3 of those keys in different locations throughout the car and on my person.
at least add a cable tying it to the car so no one can simply take it off and go away
@@enso3140 That sounds like a solution to keep honest people honest, only problem is that people aren't.
I mean he’s created a head hunt to mess with him lol
@Rob Dahm, It almost may be worth for you to buy a dyno machine in the future to really help the fine tuning of your cars without having to road test, make guesses, tune, test, rinse, repeat. With the dyno you could save hours to days over time being able to focus on specific areas of the map. Awesome job Rob, keep up the great work!!!
This video makes me soo happy as a petrolhead. The ammount of tech related talk this video has, and yet it is soo intriguing, interesting for us to watch, and the ammount of details in which people are discussing in the commenents section, it is just awesome. The change in the car's characteristics really made me so happy at the end. Almost felt like we audience were sitting besides you. Keep going! All the best!
one thing i love about dahms videos is that you know the whole length of the video is gonna be content and no bullshit 15s intros/ outros. 100% content from start to finish.
I've seen you before on hoonigan but this is the first time I've watched one of your videos, super interesting and Informative! Amazing to see the difference you managed to achieve with little adjustments.
Sounds like it's jumping between timing cells. That can cause some severe low throttle jerk. Smooth out the low rpm timing.
Tons to be learned and can't think of a better way than videos like this to help people skip past the frustrating parts sooner- there isn't much more frustrating than bucking and clunking and swearing while working the bugs out BUT learning to overcome it is well worth it. You really captured it well
Regarding the dogs clunking on each other, I remember mazzei saying if you wait half a second before shifting after you let off the throttle it should avoid bouncing them. He had a sequential, but I guess the same principle could apply to manual dogboxes as well
I spy a 10th Anniversary Edition FC RX7. Excited to see some FC content.
Wait, where? I need FC content!
@@capnthepeafarmer 0:46
@@benpinet8488 WOW, that's a great catch!
12:42 at this moment rob activated 200% focus for a brief few seconds, his concentrated power was so great the rx7 couldn't handle it... Seriously though, love the progress you're making rob!
I know your videos do well with views and likes but it should be better. This is amazing content and you do it so flawlessly. Even while showing the flaws. Thank you and everyone who’s working behind the scenes to bring it to us. Oh and a special thank you to valvoline
I've experienced this jerking and could not tune my 12A like you so I tuned my foot by stabilizing it with pressure against the engine tunnel on the right. Luv your skills man keep it up.
Great work on the tuning, Rob! This came out fantastic.
Rob might have forgot to deactivate the "Rodeo Wild Horse" mode on the CPU settings.
Lol, looks that way 😂
😂 YEEEEE HAAAAAW
Suggestion: Use a stiffer pedal spring.
don’t really need to when you can tune them sensitivity
@@arnavdeol5951 will be much nicer with a stiff pedal with the power and response
That's what I was screaming🤣
I love your videos. At the beginning, this was hard to watch, but not in a bad way. It was so interesting watching how you took small steps to change how poorly the throttle was performing at first, and it was a great look at how difficult building high performance cars can be instead of the mentality of "bolt it on and it'll work right away!"
Ramp up the return spring on the pedal also helps a ton. Makes accelerator actions more deliberate.
These are the kind of videos that I really find fascinating! Just seeing how much you can fine tune a car and improve it that much. Keep up the great videos Rob
Rob next time try puting the side of your foot on the trans tunnel it will eliminate user error. I did it when my 70 k5 blazer had 15 year crusted carbs on it... And it helps when your on the highway trying to stay the same speed, glad you figured it out tho at the end
Thank you for showing what learning to tune is really like. I really feel the highs and lows of it.
That's awesome watching. I guess the way to think about it is how many horses do you want your engine to deliver with each change in pedal position: the output of that 4 rotor is BIG but for cruising you want to be able to make fine adjustments in HP output
I wonder how many people saw him driving early on and thought, “I thought Rob knew how to drive a stick! He must edit that part out.”.
This was like watching Tokyo Drift when Sean was learning to drift the Evo.
Glad you got that sorted!
The ad transition is so good. Scene of rob being stressed as hell just got to a ad about balding and being stressed I love it
I have noticed the same rubber banding effect when I’m training firefighters to drive fire trucks. It helps to plant your heel on the floor, especially at those low throttle openings. Having your foot floating really amplifies the rubber band effect. I’m curious if this would help for you. If it does, you could probably tune the throttle response to be a little more aggressive.
These videos are my drugs I can never wait for the next one wish i could come down from canada to see you and isiah
jesus, the amount of comments and the video's been up literally 2 minutes! crazy, can't wait to watch! been hoping for the next instalment! need that Rob Dahm fix!
Never thought I'd see you get frustrated on something like that, but you always push through and fix the problem. nice job. I've learned a lot from watching you.
Rob Dahm , this LEGEND is modernizing the rotary while companies like Mazda do nothing. I wish they still made rotaries.
That super sensitive touch to the pedal is why i prefer cable to DBW on my truck my daily has DBW and it's jerky compared to my DBC car .. bit if I had the control of my settings like you do itd be different and I'd like it more I'm sure
Pedal commanders actually help with this. Not for power but for feel
I drove an old S10 for years and when I finally got a new DBW truck....god I hated it. The tuning and response is just terrible. I'm used to being able to floor it, feel the tires break loose, and quickly pedal it to maintain control and acceleration. My new truck can't do that. The response time from stop to go is measured in seconds. You can be sitting still and then floor it and it will just sit there for at least 1 second. There is another problem that if you coast up to a stop sign and don't fully stop, but roll through, the truck will either take off in 2nd gear or it will hesitate for 2-3 seconds. I'm not exaggerating the times either. It will literally lag for 2 seconds before it decides to go and when it does go you're in 2nd gear so you almost get run over.
I actually had to relearn how I actuate the accelerator and the timing of when I press it. DBW may be good for a lot of things, but it fucking sucks for throttle response when you can't actively tune it.
My car did this when I went from the stock throttle body to the RW 90mm item, made it undriveable on the street, great if you are full gas everywhere but anything less than 70% throttle the car was buckaroo.
Mazda knew what they were doing when they made it
I literally smiled when I saw this. Sometimes ur videos don’t come soon enough
I’ve been watching your channel for years and damn you’ve come a huge way! I love the progress and everything bro! Keep up the great work man!
Read somewhere that the reason there were multiple throttle bodies on the original intake system was to maintain intake plenum airspeed at the lower RPMS while the engine was transitioning from idle to part throttle...
New idea: The motto for his garage. "The Dahm Garage, where you fix the Dahm car."
Gotta say Rob, you're becoming my new favorite to watch!
Been here a long time, but the content didn't always vibe with what I wanted to watch (no offense, it was always *good* content).
Lately you've been killing it! So damn interesting. Keep it up man!
Hahah good start Rob on the new drive by wire throttle!
Hey Rob. In relation to your last video and Hylomar, if you buy it in a tin you can inject it into the coolant seal groove with a medicine syringe. Much cleaner and precise.👍
My old opel has a "sport" button that changes that throttle map on the fly. If not in sport, the curve is very mellow, giving you a lot of control around the cruising. If sport is on, the initla ramp up is fast, but high in the throttle pedal the curve is flat, so you have a ton of control at high throttle pedal positions. Perhaps you can try implement something like this? Otherwise try an S shaped curve, so you have control in the middle and top ends
Thank you for being our research and development team for 90s junk. It’s appreciated.
Love the technical side like this...tho can be very frustrating, it takes passion to learn all the ins and outs (unless you are a crazy freak genius lol) great work! Cant believe how smooth she ran after a little variable throttle expo 👍
Logarithmic input is the name of the game. Though I'm certain that an adjustable mechanical version could be made pretty easily. But of course that would include something like 3D printed or CNC -machined "curve plates" for getting the proper pull ratio curve. A simpler version could be made that can be adjusted, but not so precisely. Some old mountain bike cable brake levers have a variable cable pull, so that in the end of the travel you get more modulation. Gas pedal should work the other way around.
Also would it be beneficial to have the gas pedal curves by gear?
i like the hefty clunk from the face plated gears and I personally think the hunting idle speed sounds cool
Gm does vehicle speed vs pedal position vs throttle pos (sort of) in my car. At lower speeds the throttle is less sensitive and higher speeds it gets more responsive. 60% throttle and up is where I have it set to start picking up proper power, makes cruising alot smoother than just having throttle vs pedal position. Not sure if FT has this available but if they do, definitely worth messing with
Thanks rob to shine some lights in those engineering work. Even when i press the gas pedal on my car.
on the pedal sensitivity. the way BMW do it (atleast on older cars) is when the clutch is up the pedal is smoothed out, enough that in first gear the car is smooth but not so much it limits acceleration(nice in traffic), if you rest your foot on the clutch it becomes the jerk master 5000 (like in your video) and th throttle response is just as snappy in the upper gears.. Im a drive by cable guy, but tbo I have no hate for a well setup modern Drive by wire system. EDIT TLDR if your ecu can detect what gear your in, is there a provision for just having it chill right out in 1st and 2nd.
Watching you show the learning process was very cool.
Wow that’s an amazing transformation from what it was like before 😮
Brother, the segway for keeps in this was nothing short of perfect. Because I was losing hair over how painful the way this video started.
Props on not completely losing it, on camera. 😅😂😭😭😭
*segue
You should also be able to alter the amount of throttle opening Vs pedal depression against the rpm. This can have two benefits - the throttle will be much less sensitive, and sometimes an engine will actually produce less torque at full throttle opening than a partial one - you can soometimes feel this as a 'flat spot' under full throttle vs partial throttle.
Part of it may also be down to the altered interaction within the intake-exhaust-turbo systems causing some turbo' surging.
If my prediction is correct, get some really thick walled boots that don't allow any ankle movement, so that you can have a controlled pivot point, and prevent the fluctuations
this reminds me of tuning the throttle curve on a mini quad copter. It helps to have the throttle really unresponsive at low stick inputs so when you’re cruising around and doing fine aerobatic stuff the throttle is super predictable and then at max deflection it exponentially adds throttle so you can do super quick punch outs and rapid maneuvers easily.
This sounds like a sick sportbike. But better. Awesome job tuning!
Manufacturers does a lot when offering different driving modes or sensibility controls over the car, and yet, we humans are not satisfied with what they offer. It’s nice to see how much goes into the fine tuning of an accelerator pedal to really appreciate all the features we already have
Just hearing this thing fire up is a thrill. Awesome car!
Dude in the background tuning his bicycle, getting ready for that 3 rotor smoke
Way to stick with it and get it sorted, sounds amazing
What a smooth transition right into a Hair loss add. 👍🏽nice
man im so happy for you that you can do this!!!
I was checking daily for rob Dahm video… finally my fix !!! I was even watching Vargas brothers
Cars can buck with and without pilot error. Load table manicuring and foot/throttle interface development can resolve most of it. Respek to OEM engineers. And Rob👏👏
Rob, it's like training a horse! Ride it until it stops bucking and your broke the horses fight and train it smoothly until it rides like the wind!
Rob telling you exactly at what point his tires will break loose with a laptop is all you really need to know about this guy 👏🏽🤯
Weird thing i do that might help, keep your heel and right side of the foot during pulls to keep the gas steady?
It sounds like a video game! just music to my ears! Great job, love it
Hell yeah rob!! All that hard work tune show it.
I guess this is why my GTI with drove by wire goes by the time the throttle is pressed along with the distance rather than just the distance. Smooths out those peaks passively
Just like tuning control loops for process instrumentation. Lots of time and effort. Definitely needed more filter value and a different ratio/slope for the throttle. The hunting at idle is just like a control loop out of tune. Pretty cool project
Rob: Man, this is so smooth!
4-Rotor: *BRAP BRAP BRAP*
About the kill switch on the back, you could tie it so that you can unplug it but never lose/steal it :)
I'm sure this opening would have Casey Putsch screaming "DEGRADING OSCILLATION!!! STAHP!"
Think of making the throttle input like the rotation of a cam lobe thats the way your numbers should look. Also if you add a throttle Damper you'll tune out throttle bounce
That's not the pedal trying to idle by itself, it's just your big cam bro :*)
Nah it's his blinker fluid leaking out of the flux capacitor causing quantum fluctuations.
our firetrucks do the same thing when drivers dont have their hear on the floor when pressing the throttle, one shop placed a shock dampener on the pedal action.
Damn. Need some Dramamine after watching the beginning of this haha. Regardless, glad to see the infamous 3-rotor coming back to god level.
2:25, I do this with my old pickup. Go into reverse and then first gear so it doesn’t grind