Steve Brule for President ("Part Throttle" on Engine Masters!)
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Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Yes. This engine had been extensively dynoed, but only at WOT. Getting the part-throttle SA dialed in would be particularly problematic on an engine dyno, but a steady-state capable chassis dyno could get you very close re spark and fuel.
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
ptuomov wrote: ↑Mon Nov 20, 2017 9:40 am I was asking about part throttle dyno testing. What’s the point? Not to maximize torque at a given rpm, because if you want more torque you open the throttle, no?
I can see optimizing ignition, fuel, and cam timing for minimum BSFC. That would make sense on a dyno.
If dyno time is free, sure, every sort of tuning and sorting out is better done on a dyno. But for a hobbyist with limited dyno time, what’s the part throttle test that absolutely needs to be done on a dyno and can’t be done on the road driving the car with the sensors hooked up?
For a hobbyist road driving is just fine. For us emissions are uber important, and fuel economy second. A lot of thought has to go into balancing BSFC, emissions, temperatures, long term durability, etc. And often after lots of careful work and tweaks it all gets blown away by making it actually drive well on the road.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Interesting. I run closed loop, so adjusting AFR at light throttle (nominally 14.7 ) is difficult. There are tricks, also I might consider running open loop; it's possible the system is oscillating.MadBill wrote: ↑Mon Nov 20, 2017 2:20 pm The last such issue I tackled (reported in S/T some time back) was a 720 HP twin Edelbrock-carbed 572" Hemi. The owner had jetted up (well, 'needled down' to be precise..) and retarded timing trying to cure a bad 1500-2500 RPM, surge, just as described. With a combination of luck, a 60 year old King exhaust analyser and experience, I leaned out the 60 MPH cruise from 11:1 to 15.5 and added 14°of vacuum advance via a Crane adjustable unit.
Not only did this cure 90+% of the surge, he reported that on his next highway trip to a regular destination, he just made it there and back on one tank when previously he had to refuel at the other end.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
My .02 with the "race" engines I've assembled for street driving (with both carb and EFI) is that it is far easier to tune WOT than part throttle or "closed loop".
I spend hours and hours on the freeway at different throttle positions / rpm < WOT to get the tune right.
The difference is a far more crisp, responsive engine.
Doing anything less is a good way to get spanked by a vehicle with far less HP (off track).
I spend hours and hours on the freeway at different throttle positions / rpm < WOT to get the tune right.
The difference is a far more crisp, responsive engine.
Doing anything less is a good way to get spanked by a vehicle with far less HP (off track).
He who is in me is greater than he who is in the world.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
do you have a link?
Always enjoyed those shows, esp the one where dulchich ports those iron mopar heads
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
cuisinartvette,
Sorry, the thread went a different direction so i hadn't checked it in a while. You need to be a MTOD subscriber to see the show now, but it will show up on youtube eventually. Love the show too! There's some real eye-openers - the cooling fan shootout had surprising results. It's most interesting to me when 'small' parts do way better than they expect though - particularly heads. They do often comment on how a combo might feel in a car, but it's usually in reference to high rpm and high horsepower at wot, not part throttle responsiveness and feel.
bigjoe1,
Sir, hopefully you're still following this thread. I'm curious what surprising results you observed doing part throttle dyno testing. Care to share?
Sorry, the thread went a different direction so i hadn't checked it in a while. You need to be a MTOD subscriber to see the show now, but it will show up on youtube eventually. Love the show too! There's some real eye-openers - the cooling fan shootout had surprising results. It's most interesting to me when 'small' parts do way better than they expect though - particularly heads. They do often comment on how a combo might feel in a car, but it's usually in reference to high rpm and high horsepower at wot, not part throttle responsiveness and feel.
bigjoe1,
Sir, hopefully you're still following this thread. I'm curious what surprising results you observed doing part throttle dyno testing. Care to share?
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Cougar5.0 wrote: ↑Mon Nov 20, 2017 9:59 amIt's difficult to simply drive my 427W to the gas station without pulverizing the drivetrain due to incessant surging at part-throttle. The engine performs well at WOT, but I haven't yet figured out how to tune out the surging at part-throttle. Cutting timing at light-throttle keeps the engine from winding up so much (like a spring), but some of it is the simple fluid mechanics (reversion) of the system. Even if I don't want a higher velocity (lower HP) port, I am curious as to how much that is affecting my ability to tune it at part throttle.ptuomov wrote: ↑Mon Nov 20, 2017 9:40 am I was asking about part throttle dyno testing. What’s the point? Not to maximize torque at a given rpm, because if you want more torque you open the throttle, no?
I can see optimizing ignition, fuel, and cam timing for minimum BSFC. That would make sense on a dyno.
If dyno time is free, sure, every sort of tuning and sorting out is better done on a dyno. But for a hobbyist with limited dyno time, what’s the part throttle test that absolutely needs to be done on a dyno and can’t be done on the road driving the car with the sensors hooked up?
427W, AFR220, 2924 supervic, EFI, 247/250 110LS hyd roller
I don't understand the phenomenon you are describing with, "winding up so much (like a spring)... etc.. What do you mean? It seems odd retarding is desirable, ordinarily an engine wants more timing and a leaner A/F for light-throttle. Retarding timing will make it run hotter, higher exhaust and water temps.Cougar5.0 wrote: wrote:Cutting timing at light-throttle keeps the engine from winding up so much (like a spring),
Good job on the Hemi MadBill..Cougar5.0 wrote: ↑Mon Nov 20, 2017 9:52 pmInteresting. I run closed loop, so adjusting AFR at light throttle (nominally 14.7 ) is difficult. There are tricks, also I might consider running open loop; it's possible the system is oscillating.MadBill wrote: ↑Mon Nov 20, 2017 2:20 pm The last such issue I tackled (reported in S/T some time back) was a 720 HP twin Edelbrock-carbed 572" Hemi. The owner had jetted up (well, 'needled down' to be precise..) and retarded timing trying to cure a bad 1500-2500 RPM, surge, just as described. With a combination of luck, a 60 year old King exhaust analyser and experience, I leaned out the 60 MPH cruise from 11:1 to 15.5 and added 14°of vacuum advance via a Crane adjustable unit.
Not only did this cure 90+% of the surge, he reported that on his next highway trip to a regular destination, he just made it there and back on one tank when previously he had to refuel at the other end.
Cogar5.0, what kind of EFI is this? I though these things were supposed to learn the ideal tuneup all by themselves. Do you have a way to monitor the system to see what it is doing in real time while you are driving? Can you tune it with a laptop or ?? How are you controlling the timing? What type of O2 sensor is it, wide-band or narrow-band?
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
The windup is the engine revs up and then bogs. The AFR isn't lean when this happens. Timing is pulled so the engine is less efficient, thus it doesn't pull hard when you're barely touching throttle and it "catches" where is manages to capture enough fuel to have a decent burn for a number of cycles in a row. The issue is due to the cam is large and dynamic compression is very low, I have no idea if fuel is reverting to intake or escaping through exhaust or both (depending on location of cylinders.) Simulation program warns that controlling air charge at these low RPMs will be difficult.Tuner wrote: ↑Sun Dec 03, 2017 7:32 am
I don't understand the phenomenon you are describing with, "winding up so much (like a spring)... etc.. What do you mean? It seems odd retarding is desirable, ordinarily an engine wants more timing and a leaner A/F for light-throttle. Retarding timing will make it run hotter, higher exhaust and water temps.Cougar5.0 wrote: wrote:Cutting timing at light-throttle keeps the engine from winding up so much (like a spring),
Good job on the Hemi MadBill..Cougar5.0 wrote: ↑Mon Nov 20, 2017 9:52 pmInteresting. I run closed loop, so adjusting AFR at light throttle (nominally 14.7 ) is difficult. There are tricks, also I might consider running open loop; it's possible the system is oscillating.MadBill wrote: ↑Mon Nov 20, 2017 2:20 pm The last such issue I tackled (reported in S/T some time back) was a 720 HP twin Edelbrock-carbed 572" Hemi. The owner had jetted up (well, 'needled down' to be precise..) and retarded timing trying to cure a bad 1500-2500 RPM, surge, just as described. With a combination of luck, a 60 year old King exhaust analyser and experience, I leaned out the 60 MPH cruise from 11:1 to 15.5 and added 14°of vacuum advance via a Crane adjustable unit.
Not only did this cure 90+% of the surge, he reported that on his next highway trip to a regular destination, he just made it there and back on one tank when previously he had to refuel at the other end.
Cogar5.0, what kind of EFI is this? I though these things were supposed to learn the ideal tuneup all by themselves. Do you have a way to monitor the system to see what it is doing in real time while you are driving? Can you tune it with a laptop or ?? How are you controlling the timing? What type of O2 sensor is it, wide-band or narrow-band?
Engine control is stock Ford EEC IV. It is self learning to a degree (fuel) using feedback from the narrowband switching O2 sensors. I also have a wideband on the drivers side that I use to dial in WOT and other open loop situations (startup, lugging.) I monitor many parameters on a laptop mounted to my dash, also record for later analysis. No matter how hard I look, I can't see the chicken for the egg - I have no idea what's triggering the spin up, then bog though I know this is a common issue with EFI and medium to large cams.
When I say low timing, it's around 20 degrees at light throttle versus 30-40 for maximum light-load efficiency typical with a stock or mild cam.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
burbfixer havnet been on a dyno in a long time, seen Steve mention on one of his shows that PT results were much different sounds like he knows
Think it was on the testing of the 410 ci ford with the tiny cam/afr head test
Have to ck into signing up I like the little details they go over even behind the scenes stuff. They have been around a long time
Think it was on the testing of the 410 ci ford with the tiny cam/afr head test
Have to ck into signing up I like the little details they go over even behind the scenes stuff. They have been around a long time
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Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
"I have no idea what's triggering the spin up, then bog though I know this is a common issue with EFI and medium to large cams".
Simply not true. A good system will allow you to tune virtually all of that out. The EEC-IV was decent for it's time but has limited capability once you start running bigger cams etc.
Simply not true. A good system will allow you to tune virtually all of that out. The EEC-IV was decent for it's time but has limited capability once you start running bigger cams etc.
Engine Builder, Accel, AEM, Comp, Erson, Holley, and Lunati Dealer
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
How does it do it? Recommended system? I'm looking at getting something like the Holley HP, which is self-learning but I'm not sure how it deals with the mechanical issue of flow reversion. A little meat on the bones would be useful since I can do most anything with the stock ECU - the only limitation it has that I know of is spinning it above 7k RPM or so. What am I missing?Cutlassefi wrote: ↑Wed Dec 20, 2017 7:45 am "I have no idea what's triggering the spin up, then bog though I know this is a common issue with EFI and medium to large cams".
Simply not true. A good system will allow you to tune virtually all of that out. The EEC-IV was decent for it's time but has limited capability once you start running bigger cams etc.
Goal: Idle about 900 RPM, be able to cruise in 4th gear @ 1500 RPM, deal with load going to zero (crest of a hill) and then deal with tip in once load starts increasing again to say 10-30%.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
I enjoyed watching test between the three different heads but the question I had was about cam selection.
Surely each head could have used a cam to optimise the different style of head used.
Even though the duration was fairly short I'm wondering what the larger head would have done with more lift and keeping the duration short.
It may have had an entirely different outcome.
Surely each head could have used a cam to optimise the different style of head used.
Even though the duration was fairly short I'm wondering what the larger head would have done with more lift and keeping the duration short.
It may have had an entirely different outcome.
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Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Totally agree mate, and even if they wanted to keep just 1 cam for the tests , personally I would have liked to at least use something with upper 220's@.050 on the intake and touching the .600" lift area simply to push the smallest head a little harder and to allow the biggest head at least enough lift to begin to show some potential. That said, always interesting anyhow!russxr67 wrote: ↑Wed Dec 20, 2017 7:15 pm I enjoyed watching test between the three different heads but the question I had was about cam selection.
Surely each head could have used a cam to optimise the different style of head used.
Even though the duration was fairly short I'm wondering what the larger head would have done with more lift and keeping the duration short.
It may have had an entirely different outcome.
Craig.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Cougar 5.0 are you sure that your tips is working right? Kinda sounds like it's output might be erratic.
Re: Steve Brule for President ("Part Throttle" on Engine Masters!)
Exactly mate, I thought it had way less lift than what it needed.cjperformance wrote: ↑Wed Dec 20, 2017 7:49 pmTotally agree mate, and even if they wanted to keep just 1 cam for the tests , personally I would have liked to at least use something with upper 220's@.050 on the intake and touching the .600" lift area simply to push the smallest head a little harder and to allow the biggest head at least enough lift to begin to show some potential. That said, always interesting anyhow!russxr67 wrote: ↑Wed Dec 20, 2017 7:15 pm I enjoyed watching test between the three different heads but the question I had was about cam selection.
Surely each head could have used a cam to optimise the different style of head used.
Even though the duration was fairly short I'm wondering what the larger head would have done with more lift and keeping the duration short.
It may have had an entirely different outcome.