V/e Changes After H/c Install
How many people have had to change the V/E tables after a h/c install ? I am having a problem with hot starts. The v/e tables have been changed to 85% on 400, 800, and 1200 rpms. should it be set back to stock settings ? Any help in this matter will help me sleep better.
Thanks, C5JIM
Send me an email and I'll respond and attach a spreadsheet with copies of my Primary and Secondary VE Tables and High Octane Timing Table for you to compare against what you have.
The tune I copied it from is running an X1 cam with (.592/571 - 230/227 - 114lsa). Don't know your cam specs but give this a try as a start.
V/e Changes After H/c Install
How many people have had to change the V/E tables after a h/c install ? I am having a problem with hot starts. The v/e tables have been changed to 85% on 400, 800, and 1200 rpms. should it be set back to stock settings ? Any help in this matter will help me sleep better.
Thanks, C5JIM
Yes you will need to change your Volumetric Efficiency tables after a major set of modifications such as this. Jim what you have done has increased the efficiency of your motor. This is its ability to fill the cylinders and exhale spent gasses more efficiently per engine cycle. Jim this would necessitate the need for complete remapping of your VE (base fuel table). The only correct proper way to accomplish this would be to have the car placed on a load baring chassis dyno and put the ECU into each of the load ranges (cells) and tune them accordingly.
Chris Macellaro
__________________
Macellaro's Performance Tuning
Instructor for EFI University
This is the only way I know of under a completely controlled safe environment to put the car in all attainable load cells long enough to make the correct changes to the desired tables.
In order to safely fill the entire ve table a load bearing dyno is definitely a good way to go. I would rather do that than attempting to watch each cell fill in while maintaining a set rpm and staying on the road at the same time (high rpm / high MAP cells).
I would argue however, that you can easily fill in the ve cells that you will fall into under normal driving by logging fuel trims via a laptop on a short drive and updating ve from there.
In order to safely fill the entire ve table a load bearing dyno is definitely a good way to go. I would rather do that than attempting to watch each cell fill in while maintaining a set rpm and staying on the road at the same time (high rpm / high MAP cells).
I would argue however, that you can easily fill in the ve cells that you will fall into under normal driving by logging fuel trims via a laptop on a short drive and updating ve from there.
Nah.
Buy EFILive/Flashscan and a wideband O2 setup. Then via it's "autotune" feature you can dial in your new VE table.
An aftermarket cam will generally reduce your sub-2000 RPM Volumetric Efficiency in relation to your stock VE. How big is your cam...specs???
Hot starts - will it start if you open the throttle some? If it does then probably too rich. You might try scaling your Cranking VE by same percentages as the Main VE table. Scan your Injector Pulsewidths at idle and initial start up. They should not be off by orders of magnitude - say 4msec vs 20msec. They should be closer in value. You can watch the enrichment decay out at startup - as the startup injector pw reduces to the Idle pulsewidth.
FWIW - Topless Texan has an abundance of knowledge on this subject.......................he's also polite and humble.
__________________ There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games. - E. Hemingway
In order to safely fill the entire ve table a load bearing dyno is definitely a good way to go. I would rather do that than attempting to watch each cell fill in while maintaining a set rpm and staying on the road at the same time (high rpm / high MAP cells).
I would argue however, that you can easily fill in the ve cells that you will fall into under normal driving by logging fuel trims via a laptop on a short drive and updating ve from there.
Yes I agree with you on the VE table cell tuning it would take more time but you could accomplish (most) of this on the street. But my point of view on this matter is the whole tune in general. How would you do spark timing without actually quantifying the results with real time feedback from a dyno. Seat of the pants just will not cut it for that one.
Yes I agree with you on the VE table cell tuning it would take more time but you could accomplish (most) of this on the street. But my point of view on this matter is the whole tune in general. How would you do spark timing without actually quantifying the results with real time feedback from a dyno. Seat of the pants just will not cut it for that one.
Chris Macellaro
Banzai runs - scanning for timing/spark and knock. Multiple PIDS available with EFILive.
Copy High Octane table to Low Octane table. Increase the recovery rate of knock - above stock, for faster recovery after an event.
IF Knock active - back spark down. Another run and scan..............
Idle - add spark and monitor AFR and MAP. It's amazing what 28* - 30* of advance will do for a cammed idle (cylinder pressures). Lower MAP values are a great way to monitor (greater efficiency- lower MAP).
FWIW.
__________________ There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games. - E. Hemingway
Banzai runs - scanning for timing/spark and knock. Multiple PIDS available with EFILive.
Copy High Octane table to Low Octane table. Increase the recovery rate of knock - above stock, for faster recovery after an event.
IF Knock active - back spark down. Another run and scan..............
Idle - add spark and monitor AFR and MAP. It's amazing what 28* - 30* of advance will do for a cammed idle (cylinder pressures). Lower MAP values are a great way to monitor (greater efficiency- lower MAP).
FWIW.
yes but how would you see if you have obtained maximum torque in all available load cells?
Hitting a knock value and backing the timing off has nothing to do with proper tuning techniques.
FWIW - Topless Texan has an abundance of knowledge on this subject.......................he's also polite and humble.
Chris, my exception is to "the only way." I'm sure you'd agree that there are a lot street tunes running around now that are better than some dyno tunes. It's all about how one goes about measuring and interpreting the effect of their tuning modifications. I suspect we agree on that point too.
My thoughts on spark... I suspect you'll see people stop talking about maximizing timing (rather than maximizing power, oops) when EGA's get cheaper. E.g., consider how common cheap on-board WBO2s are now. But no, we're not quite there yet. In the mean time other observables like the PCM's torque PIDs are useful, at least within it's limits. Finding useful, alternative observables is often innovative, not wrong.
My chief concern relative to collecting tuning data while driving is actually safety. My preference is to have a buddy run the data collection gear and keep the high speed blasts to a minimum. Well, sorta.
Murphy is NE of Dallas, sandwiched between Plano and Wylie just south of Southfork Ranch.
Last edited by ToplessTexan; 11-30-2005 at 09:41 AM.
Chris, my exception is to "the only way." I'm sure you'd agree that there are a lot street tunes running around now that are better than some dyno tunes. It's all about how one goes about measuring and interpreting the effect of their tuning modifications. I suspect we agree on that point too.
My thoughts on spark... I suspect you'll see people stop talking about maximizing timing (rather than maximizing power, oops) when EGA's get cheaper. E.g., consider how common cheap on-board WBO2s are now. But no, we're not quite there yet. In the mean time other observables like the PCM's torque PIDs are useful, at least within it's limits. Finding useful, alternative observables is often innovative, not wrong.
My chief concern relative to collecting tuning data while driving is actually safety. My preference is to have a buddy run the data collection gear and keep the high speed blasts to a minimum. Well, sorta.
Murphy is NE of Dallas, sandwiched between Plano and Wylie just south of Southfork Ranch.
Absolutely 100%
As I get older the WOT stuff out on the street gets less and less fun for me. I have children and a lovely lady to think about now. You never know when something will run out in front of you.
I visited LG Motorsports a couple of years back. That must have been when I saw a Murphy sign. It rang a bell for me I just could not place my finger on it. We used to be next door neighbors and never knew it, It is a small world isn’t it brother.
yes but how would you see if you have obtained maximum torque in all available load cells?
Hitting a knock value and backing the timing off has nothing to do with proper tuning techniques.
Chris Macellaro
Excellent points!
I had my timing setup on a dyno.
I just wanted to get your thoughts and direction.
I did many Banzai runs to develope my VE table a couple years ago. Way back when it was done with the MAF and double checked with the wideband. My kids are grown (32 and 21) and I'm divorced. Most of my runs were on long freeway ramps, freeways and rural roads.
FWIW.
__________________ There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games. - E. Hemingway
V/e Changes After H/c Install
How many people have had to change the V/E tables after a h/c install ? I am having a problem with hot starts. The v/e tables have been changed to 85% on 400, 800, and 1200 rpms. should it be set back to stock settings ? Any help in this matter will help me sleep better.
Thanks, C5JIM
Looking at your mods., I'm sure someone here could send you a tuning file they have saved from someone with similar mods. That would give you a good starting point to tweak. Oops, good man 78Vette-SA already done.
__________________
2003 EB ZO6: Vararam Widemouth, Carbon Fiber Powerduct, FAST LSX 90mm Intake, Ported and polished 90mm LS2 throttlebody, 36# Fuel Injectors, Ported and polished 59cc LS6 Stage II heads, Crane 1.8 Gold Race rockers. Comp XR281HR (228/230 Dura.) (.606/.608 I/E lift) 112 degree lsa. Kooks 1-7/8" LT's 3" X pipe, Borla Stingers Tuning by "Slowhawk" DEZ Racing Seekonk Ma. New SPEC Stage 3+ Nitto 555RII - Rear 305/35/18's Front 275/40/17's
1999 Stock Magnetic Red Coupe 30K miles
Last edited by zo6vetteman2003; 12-01-2005 at 01:01 AM.
I did many Banzai runs to develope my VE table a couple years ago. Way back when it was done with the MAF and double checked with the wideband. My kids are grown (32 and 21) and I'm divorced. Most of my runs were on long freeway ramps, freeways and rural roads.
I get a chuckle every time I hear the term "Banzai run." I have this mental image of men gathering in their women, children, and small animals when that crazy guy blasts by shouting "banzai!" Tip: watch for stray cows on the rural roads. They take up a lot more road than you would think. Don't ask me how I know.
Ramps are great for those "hard to visit" cells. We don't have many natural hills where I am.
Last edited by ToplessTexan; 12-01-2005 at 08:53 AM.
V/e Changes After H/c Install
How many people have had to change the V/E tables after a h/c install ? I am having a problem with hot starts. The v/e tables have been changed to 85% on 400, 800, and 1200 rpms. should it be set back to stock settings ? Any help in this matter will help me sleep better.
Thanks, C5JIM
15% is not much of a change, depending on the cam. Try dropping the same values by 5% at a time. You will feel the starts getting better as you get closer to enough. Let us know how you do.
Corvette Store
V/E Changes After H/C Install ?
I have this mental image of men gathering in their women, children, and small animals when that crazy guy blasts by shouting "banzai!" Tip: watch for stray cows on the rural roads. They take up a lot more road than you would think. Don't ask me how I know.
