As a control systems engineer this shows an important point most people miss - Don't try and control a physical system faster than it can respond! It usually doesn't end well. I would be interested to know what would happen if the traction control input could be rate limited - ie. instead of oscillating wildly between 27 and 9, do it "slowly" over 0.3 seconds or something.
Hello Steve I'm not a racer. I'm not a huge car guy. Heck I haven't even owned a car the past 5 years. But your content still speaks to me and I enjoy it so much! Keep doing what you're doing with youtube, your personality, knowledge and passion to teach attracts people from all sorts of fields. much love from switzerland
Great stuff...not to mention the torsional vibrations through the drivetrain as the engine is speeding up and slowing down on a super fine level from moment to moment...
Your description makes a ton of sense. Getting fuel pushed into the rings when it pulls it back and then giving it full load is a great way to detonate in your ring lands.
I started out tuning on MegaSquirt and Hondata and UTEC and several others, back in the day...bloody hell but was a long ride learning how to street tune, a ride through a good few motors...... and not having to pull EPROM's and build a flashing jig was an EPIC advancement(for MOST tuning, anyway)...anyway.....I have known some pretty great tuners over the years, and I can tell you this from my experience over the last 30ish years. I have seen some maps and driven some cars that were supposed to be 'tuned' by 'somebody who is supposed to know what they were doing' who OBVIOUSLY didnt....seeing Steve pull apart this tune to SHOW why it could have been done better is a joy to watch!!!! I used to call these wonky timing issues created by guys who really didnt KNOW... 'timing cliffs'....and then 'lets watch this tune fall off the cliff!!!' and then the magic smoke ensues and.....yeah.... When Steve speaks, LISTEN TO EVERY WORD. You WILL profit. Steve, you get me wanting to dust off the old TOUGHBOOK laptop and cables and start data logging again....lol i wonder if it would all still work... 0_o
That’s one Smart Mofo right there. Luv the intricate detail on the amount of times the engine actually does cycles. Thanks mate. Keep this coming. I’m running a FT system and can learn so much from it. 🇦🇺🇦🇺
If its the one on the opening pic, its fucked up. I just noticed it when I was going to click on the video. Steve would have to confirm that its the same one. Joe
Thanks for putting this information out! I'm just getting back into the serious racing scene after being gone for about 20 years. As it said "back in the day" we ran carbs and didn't have these fancy electronics and traction control back then was the heaviness of your right foot which the engine could keep up with. These fast electronics are capable of switching 200 times per second and making those massive swings is going to lead to carnage. I'm betting it's more than just a couple of pistons. I wouldn't be surprised if the bearings didn't suffer due to harmonics as well. My theory is to leave the traction control loose to prevent MAJOR wheel slippage in the first 3 seconds of the run (on a mid 5 second car 1/8 mile) but allow a little wheel speed. Engines are expensive, WAY more than any 10 purses you could potentially win!
I have a 2009 Pontiac G8 GT 6.0 Liter V8 with a Magnuson Supercharger, Headers, Cam and other performance options. It was Dyno Tuned and it is a Beast! I was told by the shop that did the mods to absolutely Never Run Traction Control if I tracked the car or planned to run the car hard. They told me, simply put, the opposing forces could destroy the engine. If you run a high performance car please take this wise advice. 👍
Makes sense. You use the same timing fluctuations to create heat at low rpm to help build boost quicker (hotter exhaust). If the timing is doing this same type of fluctuation at high rpm. It's going to keep building excess heat, as your egt's show. Man, that's cool to see you break down and then extrapolate the root cause/s of the failure/s using blended data streams. You can literally see it without having to model it. IE: You know your cr@p. Always entertaining! Thank You
Steve I am so fascinated with your knowledge, keep it up I am turning 65 in November and being a retired mechanic after 48 years I totally understand your thought process in figuring out these issues, and yes I forget a lot of stuff keep your brain alive as I am relaxing a lot more now and enjoying life here in Arizona..
it's the changes to timing causing flux on valve return time which is causing induction pressure flux which then resonates into rich/lean per length of intake. the turbulence evens itself out by way of the amount of surface area available. imagine a garden hose with low water pressure, if you hold it vertically over a container with water in it, at the correct distance for the pressure and flow rate it will run silently with almost no surface ripples. too far away and the resistance of the turbulent air disrupts the density of the water coming out of the hose which then equalizes against the surface tension of the water, making noise and turbulence.. same kind of thing but in this example its making most cylinders far too rich and the other 2 far too lean. (path of least resistance gets the induction.) tell him to take longer to build the boost or adjust his boost controller to be more agressive with less timing pull?
also, the thermal conduction to the temperature sensors at fluxing density and pressure (due to rich / lean / vapour, low pressure / no vapour, high pressure) that last part where the temperatures spike is more likely just the temperature sensor being able to function properly when the flux stops. the cylinders were accumulating temperature the whole time. short time high energy proportions are quadratic afaik.. the likelyhood of the temperature reading measuring accurately such a peak is low because the amount of extra energy at the already leaned out cylinders required would be huge. like, a stick or three of dynamite extra energy spread over that last 0.2 seconds.
They really can’t take any longer to build boost. 6 seconds is already really pushing it. Remember he has about 7 seconds to get into the beams once his opponent lights his bulbs (assuming they aren’t using “courtesy”staging). And smart opponents will take note of a very slow spooling turbo car and can take advantage of it when staging. Retarding the timing like what Steve showed (and was not concerned about) to build boost prior to staging is not the problem. The engine is at much lower rpm’s and not under any load. It’s the almost on/off timing during the run that is creating the problem.
While the TC is pulling 1/2 the power out, it's putting 2X normal heat into the pistons and combustion chambers for a total of what, ~8 seconds (staging+run) before letting the engine put out max HP the last 1/2 second. It's too hot and late at that point to expect max power output, detonation/meltdown is inevitable. Look up 2618 aluminum properties at 500-600 degrees F. It'll need unobtanium internals to withstand that torture test.
I've always said this with electronic controls and nannies on cars. You can make a car fast with electronic wizardry, but it's a lot better to design it to be "mechanically" fast to start with. Traction and stability control are amazing things, but they are no replacement for a car designed to go fast without them.
I’m all for electronic controls, I’ve ran electronic controls for years and it just has to be tuned properly like everything else. However, it’s going to amplify characteristics of whatever your base mechanical traits are to begin with. I hate electronic aids as a band-aid, they work wonderfully to put a razor edge on an already fine sword though.
@@captainobvious9188 Yeah, I would agree with that. Fuel injection is a wonderful thing and lets you turn a lot of dials and play with a lot of things that are difficult or impossible to do with a typical carb for insurance. But agreed you need to tune them right to start with. It would be like throwing a generic tune in a car and letting O2 feedback do all the work. Yes, it might function, but it's always going to be reactive and trying to "fix" things, not run directly to begin with.
This is just a flawed control system. A lot of tuners / mechanics / software devs etc. never had a control systems engineering course and this is what you get. If you want a system where you can let it do the work for you and ride it right on the edge perfectly you need far higher sampling rate and effective system bandwidth than most ICE automotive traction control systems can offer. Tesla is a good example, you can stand on the pedal and they just give you everything the surface and tires can give. The wonders of a stable control system with high enough bandwidth.
Watching this helped me understand my engine failure more in depth. I do appreciate that! It also will help me set up a better tune, and understand the mechanical limitations of my setup. Great info!
All i can say, is FREAKIN AWESOME, great job explaining the exact happenings inside the cylinder walls. Another fantastic informational video. Thanks Steve
Steve I could work for you and have a ton of fun learning and wrenching on these super nice rides. 25 yr auto tech shop owner here! I absolutely envy your ability to teach! Your explanations make total sense and the way you convey them is fantastic! I also admire that what appears to be your desk is still in the shop and not a closed off from the world office space. Keep ‘em coming. Maybe we will meet some day
AWESOME VIDEO Steve! I've never heard this concept (which has been touched on by others) explained so perfectly before. EVERYone tuning an engine for quartermile should understand this.
Hey Steve, While I generally agree with the premise of delayed ignition causing higher cylinder temps, it should drop combustion temps because your pressures are lower. Another note is that the waviness you are seeing in the manifold pressure is likely the swings in the efficiency of the engine changing the rate at which the engine can pull in air, which sends pulses through the intake because the impeller has enough inertia that it wants to stay at a constant speed. Otherwise, it's nice to see an explanation in laymans terms on this kind of stuff!
I have a Gen3 Hemi with an EFI Source Goldbox and use Tuner Studio to program everything. I'm a dummy when it comes to the technical stuff and have had help from someone who's learning me on how to use it. I find all this technical stuff that you show very informing. I'll never use traction control but when you explain things like you do I can understand them and it makes sense enough I can apply some of it to what I'm doing.
He’s not saying don’t use traction control, he’s saying don’t use it incorrectly! This car was using the traction control to make the entire pass! Even Steve uses traction control!
make MANY fine adjustments, KNOW which map is which!!!.....keep all your datalogs!!! KNOCK is BAD....dont let it do that.... and if you cant afford to toast the motor.....STOP....until you can afford to toast the motor. Especially if its FI
Steve I’m learning so much from your channel. Even though lm 68 years old and drive a 60s muscle car I’m learning something new on every episode. BTW I only live 15 minutes from Rosslers shop and it’s great to hear a local guy being mentioned on your channel. Keep teaching!
Hey Steve, this is the first video of yours I've seen but I have to say I really do enjoy this style of video, would love to see more maybe a series where you look at peoples datalogs from tuned cars that gone boom. Really interesting having the final moments of the engines life explained and how it maybe could have been avoided
Makes you wonder (without knowing the valve event timing and fuel type) if its pulled enough timing to afterburn the cyls, goes whoosh instead of bang. Cool follow up video would be of the piston and ring lands. Drill the top of the pistons to see if there was enough heat/cold cycling to cause annealing. --very instructional video (grabs laptop to change tune ;))
That is exactly why tuners retard timing to get the turbo(s) to spool. Retarding the timing results in the bang happening so late that a lot of the bang goes out the exhaust ports which both heats up and accelerates the exhaust pulses being fed to the turbine side of the turbo. Manual trans turbo cars have historically gotten the most extreme with this on the starting line given they have nothing to push against like a converter to build boost. Hence why those suckers typically really bang and pop on the starting line.
@@danmyers9372exactly as I (longtime racing fan/viewer) envisioned was happening. I’ve also wondered how much leftover fuel detention in the pipes was happening in some of these tunes.
Saving my engine parts 1 day at a time, with Dr. Steve!! Dang I have learned a lot from you brother! I know you have learned a lot in your walk as well. I truly enjoyed this video, thank you Sir. Now if I only had a hot rod with enough power for traction control… wha wha wha.
Definitely explains why that piston was probably about ripped in half you showed us either way you Definitely gained me more knowledge and understanding of what timing does to the engine or lack of timing
Oh this is a good one. Think you mentioned this when the spark plug blew out. Ive been learning about traction control strategies and was wondering if running excessive timing retard and dropping cylinders could cause engine issues. Everyone raves about the Davies technology setup. Thanks fir sharing.
I come from a Nitrous background starting in the mid-90's till even now, I still do Nitrous stuff here and there. I remember when the 7531/7531T came out. We never used the T. We always made the car work by chassis adjustment, taking a little more timing out, disabling a stage or two, timing them out further, running the progressive out more, depending on the track or when in mexico. It seems a lost art anymore! Make the car work it's best without relying on a crutch such as traction control, when it's best at a bad track then click on the traction control to where it barely needs to compensate to get a good pass. On a good track it will do well and won't even come close to getting on TC. My two cents!
the traction control science was what racers need to here. I my self thought that has to be extra hard on all the drive parts. I do know what that engine go threw.
I’m no professional engine builder like Steve but my guess is it most likely I would think it got too hot from the excessive timing retard (the excessive exhaust temps) but detonation is also possible due to excess fuel in the chambers that suddenly fires earlier when the timing goes back up. So probably both like you said! 😉
Love your knowledge and the will to share it. Ive always wondered how these big hp "no prep" cars get down the track and the only solution i can come to is tc. Like if your gonna not prep the track then dont run tc!
Excellent video... And the realities of racing! Always learning something new at the cost of the pocket book. I like doing things right the first time... But that is not reality in the performance arena. Time and budget always being the limiting factors, and time the most valuable.
I wish I knew about your channel when I was a mechanic and racing. It was stuff I knew, some from trial and error, others from learning off the old timers. But I could never put it into words for customers, I remember once we kept having the same issue, burning out 1 piston, damaging a couple others every few runs. Seriously some major damage sometimes. I kept saying we need to just drop the traction control (if it existed I never found it, but pretty sure our tuning software couldn't control the TC), was always told we would loose too much time especially by the new driver. That said he didn't last long as a driver, he wasn't bad, but his way if driving was 100% throttle, ALL the time in all our vehicles, be it auto or manual. It of course did drop below it sometimes, but from what I could see on the logs it looked more like the gs were moving his foot off ever so slightly, the two lowest numbers recorded by him was 92% throttle and around 80% throttle....the second was when we had a tire failure and he kept that foot on the accelerator and brake whilst the chute was out until the engine suddenly hit 0rpm, that was the day he stopped being a driver, lots of things built up to that point, but that crash likely didn't need to happen and completely wrote off the vehicle
Just imagine the vibrations/harmonics induced by this strategy... might really hurt parts in a short period of time. But that final stretch with advanced timing and scorching valves/plugs maybe detonated it all.
Thanx Steve. I think I know how engines work until I hear you explain something. Thank you for not only sharing your knowledge with us but also for the way you do it. I wish I could get your voice on my GPS maps app, I would never have to reroute.
