Transient Fuel Stops Working above 3999rpm

[10_SS]

Well I finally figured out my Transient Fuel problem. I've read allot and asked allot of people on here, and debated (argued) with some pro tuners about how these settings work, and I came to the conclusion that they must not be workign right on a Manual Trans, Whipple type 2010 E38 LS3 Camaro, and I was right since the settings never worked for me, it usually made it run pig rich and chug down low, and still was lean where I needed it (up high).. and finally have proof why I say these settings don't work right! Years of wonderment finally figured out.

This is a bench setup, I simulate RPM and MAP and other sensors and have to ability to ramp boost up similar to the scenerio's I have this problem in the car.

From Idle through 3999rpm, they do in fact work and I increased transient fueling (by quite a bit to see how it works) simply adding fuel to the Warmup Transient Base Gain which I knew... but at 3999rpm the transients quit completely! I found Evap Factor and had some RPM scale so I maxed all of those out also, and still I get no transient fuel above 3999rpm...

Pic and tune attached. tune is my bench tune so there is allot of stuff that isnt right...

Around 12:04:24 in the log notice the ton of transient added below 3999rpm and how much injector pulse gets added when I transition from low MAP to high MAP... above 3999rpm this goes away completely (this pic is included below).

Can anyone shed some light on why, or how I get Transients working above 4000rpm? This would be HUGE. TO compensate for this I slowed down my THROTTLE OPENING RATE a ton but it still is a bit lean shifting between gears (or going WOT) around 4500-5500rpm due to this major issue...

Transient 4000rpm Cutoff.PNG

Transient below 4000rpm.hpl
2016 2-14 Read for MAP Enrich Play Testing 3.hpt



Adding things I found since this original post... will post anything significant here:

EDIT 1: Had more time and found Transient Stops working at precisely 4000-4010rpm, and begins working again right around 3900rpm. So far the Manifold Volume has no impact on this.

EDIT 2: The stock file doesn't have any added transient fuel at all, as stock. With only the Warmup Transient Gain added (no Impact Factor Gains) then the Transients return to working, but still below 4000rpm.

EDIT 3: And of course, the same exact RPM's I see the transients quit working and re-working are the same as the stock Dynamic Airflow Enable/Disable.. as Mowton mentioned below...
Transient 4000rpm Cutoff 3.PNG

Edit 4: Transient FUel "ENABLE Delay" ECM 2287: Looks like it's a delay from Engine start... so ~50, Transients start working pretty quick after engine start. 5000, they pretty much start working ~20 seconds after startup. 10,000 transients start working after about 40 seconds both tested running at 3400rpm. Was really hoping 0 would fix the problem... dang

Edit 5: I played with the Transient Fuel Mass Gain/Gas and Gain settings, all I got was severely increased constant Injector Pulse... no change to the Transient at all.. just more fuel everywhere... and I saw this before... so near stock may be best for these.


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EDIT 8-22-2017:
Still trying to figure this out.. .now I see it show up as cut injector pulse when playing with the bench setup and most or all fueling tables set to either 1 or 1000 everywhere (so no change in fuel).

Injector PW gets cut from 8.5ms to 2.9ms, only thing changing is the rpm from 3999 to 4000 (or 4001rpm). It starts to climb back slow (relitively slow) to 8.5ms when RPM crosses 3900rpm.

Wish someone could figure this out! Tune and log attached. Tune is a bench tune, most fueling and spark tables set to constant values to narrow things down.

this is for my transients that just stop working above 4000rpm.. I'm convinced it's a problem at least with my tune or OS. I have looked at other peoples logs and they don't seem to have a problem.

Attachment 72795
Attachment 72796
Attachment 72798

[mowton]

Is it possible, based on the stock setting for Hi RPM Disable (4000 rpm in stock version I believe) that even though the cells have been reduced to 300 in your file under test, that there is some "Hardcoded" disable of transient fueling as they enter what we call "MAF only" (believe we know that some filtering still occurs above that setting)?

Ed M

[10_SS]

I'll have to play around with that... Wonder if that is something HPTuners can fix? I wonder how many other ECU's or OS's have this problem... I feel like there should be more tables avail for the Transients... more related to RPM, there really arent any.

I'll have to compare my stock file vs the 2bar OS upgrade see if there's any difference... this is a big problem. Auto's and Turbo's probably don't notice it though.

[GHuggins]

The biggest factor into transient fueling is "manifold volume". I and some others I'm sure have all ready requested it be added to all of the OS platforms. Not sure on the current "apply rate" of this into the tunes?

Something else I typically do while focusing more on transient fueling via the impact table I will also modify the evap table ever so slightly in the same regards to the impact table. It was the only way I could fix some lean issues early on when facing this "like" problem? No guarantees though....

- Checked yours has the manifold volume - Have you tested with this any yet?

[10_SS]

The biggest factor into transient fueling is "manifold volume". I and some others I'm sure have all ready requested it be added to all of the OS platforms. Not sure on the current "apply rate" of this into the tunes?

Something else I typically do while focusing more on transient fueling via the impact table I will also modify the evap table ever so slightly in the same regards to the impact table. It was the only way I could fix some lean issues early on when facing this "like" problem? No guarantees though....

- Checked yours has the manifold volume - Have you tested with this any yet?

no I have not adjusted Manifold Volume on the bench setup yet... I really hope there's something here that will make it work... it's been years trying to figure this out, now I feel like Im so close, but there's no setting to fix it. lol

Thanks for the tips, I'll play around later, prob going to try every setting I can think of, and go back to stock non-2bar OS as well confirm it happens stock. To get this level of consistency I may have to use a mircocontroller to ramp the MAP consistent each time. I I can only control the POT that I'm using so much

[mourat]

I don't work much with transients in fact I have disabled them and went with vacuum/boost referenced fuel pressure regulator which did away with a lot of the issues. That being said, if you're having issues past 4k rpm why not set your PE enable delay to 0 and low TPS after 4k RPM? Also set your enrichment ramp in to 2.0 instead of 1 to help?

In what exact scenario are you experiencing the lean stumble?

You might be able to adjust "intake volume" I have never adjusted intake volume but I assume it would affect fueling lol.

[10_SS]

I don't work much with transients in fact I have disabled them and went with vacuum/boost referenced fuel pressure regulator which did away with a lot of the issues. That being said, if you're having issues past 4k rpm why not set your PE enable delay to 0 and low TPS after 4k RPM? Also set your enrichment ramp in to 2.0 instead of 1 to help?

In what exact scenario are you experiencing the lean stumble?

You might be able to adjust "intake volume" I have never adjusted intake volume but I assume it would affect fueling lol.

My real tune has the proper PE setup you describe, with 2 for ramp in rate... attached, but that's not the problem.

With a Whipple and 6 speed manual, I was getting very high MAP boost spikes when I would go WOT, especially between gears, creating lean and slow AFR recovery between shifts, never good with high compression and pump gas for Knock. I've done all of the things people do to try to fix it... Reducing the TPS opening rate took care of 90% of the problem but these are all band aid fixes.

I know why some people don't use Transients now.. they dont work above 3999rpm... lol I too went round and round with them, now I know why.

My over 4000rpm transients are still slow to richen up, and a bit lean turning transition, with occasional knock. Need this fixed to make it all perfect.


Current Tune.PNG

[mourat]

Yup plus once you start modding everything, heads / cam, boost, different fuel pressures all that goes out the window unless you're an engineer. I will look into this for you but for now why not try scaling your injectors, go "half" size so if you're at 60 LB set to 30 and scale the heck out of the whole tune well by 50% and see if that works.

I assume the smaller injector size will command any pump shot to increase by 50% as well. Furthermore try lowering your IVR terms / AFR^2 by 50%. Just shoot in the dark with extremes for now instead of wasting your time finessing the unknown. Furthermore you can also play with the following (band aid below)

- Increase your ETC Area scalar
- zero out your Throttle follower
- pull 50% from your Base running airflow after 4k RPM

Try those as a side file to see what happens.

[10_SS]

Yup plus once you start modding everything, heads / cam, boost, different fuel pressures all that goes out the window unless you're an engineer. I will look into this for you but for now why not try scaling your injectors, go "half" size so if you're at 60 LB set to 30 and scale the heck out of the whole tune well by 50% and see if that works.

I assume the smaller injector size will command any pump shot to increase by 50% as well. Furthermore try lowering your IVR terms / AFR^2 by 50%. Just shoot in the dark with extremes for now instead of wasting your time finessing the unknown. Furthermore you can also play with the following (band aid below)

- Increase your ETC Area scalar
- zero out your Throttle follower
- pull 50% from your Base running airflow after 4k RPM

Try those as a side file to see what happens.

i did the Injector scaling thing to my LT1 2Bar, I had the first working 2bar on a stock LT1 ecu... then discovered the Baro Reset problem the same time as this, and Tunercat found a table to fix it... was hoping HPT would find something similar for this transient thing.. it worked incredibly good, not sure I'm going to try that here since I have it running ok enough, would prefer HPT to either say nothing exists if it really doesn't, then move on.

I will have to wait a month or two for the ETC Area Scalar and base running airflow stuff though... thanks for the tips, hadn't thought of that.

I was able to narrow down the RPM it's occuring... looks like it has a 100rpm hystresis.. so Transient Stops working at precicely 4000-4010rpm, and begins working again right around 3900rpm. So far Manifold Volume has no impact on this.

I mean, look how crazy the non-transient thing is when I use a switch to increase the MAP from ~50kpa to ~113kpa... it's a nice square wave beyond 4000rpm. Transient totally disabled.

And of course, the same exact RPM's I see the transients quit working and re-working are the same as the stock Dynamic Airflow Enable/Disable.. as Mowton mentioned earlier...
Transient 4000rpm Cutoff 3.PNG


Its funny because before this I was under the impression i had a low fuel pressure problem causing the transients up high to not show rich on my wideband like they do down low... so I was richening up the lower end on tip in thinking it was helping high end... nope, not one bit!
Transient 4000rpm Cutoff 2.PNG

[mourat]

Interesting well here is what you might ask HPT to look for, I don't know if BARO update does anything on these ECU's but I edited mine asked TC to add it a few years back on e38s.

I can send you the file for my buddie's 2013 ZL1 I tuned a few month back, it ran really well but I'll also look through your file tonight see if I can figure anything out. It's one thing to be there and it's another to do it remote. We added a small pulley on his and zero issues with stumbles. Maybe add a meth kit and have it activate in that MAF range using the MAF converter lol. Sorry had to throw that band aid in there

[10_SS]

Interesting well here is what you might ask HPT to look for, I don't know if BARO update does anything on these ECU's but I edited mine asked TC to add it a few years back on e38s.

I can send you the file for my buddie's 2013 ZL1 I tuned a few month back, it ran really well but I'll also look through your file tonight see if I can figure anything out. It's one thing to be there and it's another to do it remote. We added a small pulley on his and zero issues with stumbles. Maybe add a meth kit and have it activate in that MAF range using the MAF converter lol. Sorry had to throw that band aid in there

I don't have stumbles. It runs great. Just want to fix the lean tip in with transient like it should be. I have my Boost a Pump powering my stock pump and I drop down to about 38psi at WOT... that's like a crutch right there. Tried to adjust the injector flow way down right at that spot to fake more flow like a wheelchair, but messed other things up. What were the stock Baro Update settings on yours? I don't think it's a problem stock but I'm sure there's room for improvement. I do have an open support case right now for this Transient thing it wouldn't hurt to ask if they could find the Baro Update table.

[GHuggins]

They aren't going to fix the baro. All ready tried several times DStek tried several times before that, so don't think they'll do anything... You can still ask. We do need more to ask after all If your running a 2 bar enhanced OS, it should all ready kill the automatic baro update anyway. Was one of the benefits of the OS upgrades..... I have seen fuel pressure wreak havoc on pd blower setups going lean right into boost. Damn near impossible to tune out in fact and doesn't matter how big of an injector you throw at it.... You might want to start with that and install a pressure reference regulator at the same time. Would benefit you the most. I think your fighting the "delay" of fuel pressure combined with supply to overcome manifold pressure anyway from the sound of things - especially dropping to 38psi fuel pressure..... If the MAF and PE settings are correct, MAF calculated fuel corrections should be instantaneous anyway, right?

[GHuggins]

Interesting well here is what you might ask HPT to look for, I don't know if BARO update does anything on these ECU's but I edited mine asked TC to add it a few years back on e38s.

I can send you the file for my buddie's 2013 ZL1 I tuned a few month back, it ran really well but I'll also look through your file tonight see if I can figure anything out. It's one thing to be there and it's another to do it remote. We added a small pulley on his and zero issues with stumbles. Maybe add a meth kit and have it activate in that MAF range using the MAF converter lol. Sorry had to throw that band aid in there

What tuner are you using to be able to do this. Appears to be EFI? Do the max map parameters also work to limit baro updates?

[10_SS]

What tuner are you using to be able to do this. Appears to be EFI? Do the max map parameters also work to limit baro updates?

C.A.T.S.?
C.A.T.S is pleased to announce that Jet Performance Products has licensed our OBDII Tuner program and as of April 25th 2006 will the exclusive distributor for the software under the product name JET Dynamic Spectrum Tuner.

[10_SS]

I should send you my actual file if you want to play with it... thanks for looking at it!

For anyone with a 2010ish Camaro LS3 stock other than a complete Whipple kit... you may like this file

119d less PE TPS to enable PE.hpt

[10_SS]

They aren't going to fix the baro. All ready tried several times DStek tried several times before that, so don't think they'll do anything... You can still ask. We do need more to ask after all If your running a 2 bar enhanced OS, it should all ready kill the automatic baro update anyway. Was one of the benefits of the OS upgrades..... I have seen fuel pressure wreak havoc on pd blower setups going lean right into boost. Damn near impossible to tune out in fact and doesn't matter how big of an injector you throw at it.... You might want to start with that and install a pressure reference regulator at the same time. Would benefit you the most. I think your fighting the "delay" of fuel pressure combined with supply to overcome manifold pressure anyway from the sound of things - especially dropping to 38psi fuel pressure..... If the MAF and PE settings are correct, MAF calculated fuel corrections should be instantaneous anyway, right?

I agree about the regulator and fuel pressure, just so expensive to do everything at once (good pump, regulator, etc) then if Im in there Im going to want to add a return. What's a good regulator to use anyway? However, there really should be some spike in Injector Pulse due to transient no matter how you look at it, and there is none ever above 4000rpm. Not sure if you've looked at the MAP and MAF spike you get with stock Throttle Rate Opening on the Whipples when shifting at high rpm? It's crazy high, all that pressure in the manifold gets blasted when you re-open the TPS fast at high RPM. My Procharger never did this. I could also switch to a Turbo or Automatic, either should take care of this.

[mourat]

Yeah it's C.A.T.S has Baro update set to the following stock (in pic)

I run Vacuum referenced regulator on the vette and did the same on my buddie's CTS-V with a PD blower and there is zero spikes. There is a lot of benefits going vacuum referenced and hence all the systems I put together I strongly recommend switching.

I run 35 psi at idle and get about 55 psi at WOT and full boost. My 60 lb injectors are pulsing at 1.8 ms which really is nice compared to sub 1ms at 60 psi. I also turned CPP (charcoal canister purge) OFF at idle to help (another TC feature we need in HPT)

The car drives just so much better IMHO with a vacuum referenced regulator / return.

[cc-rider]

I should send you my actual file if you want to play with it... thanks for looking at it!

For anyone with a 2010ish Camaro LS3 stock other than a complete Whipple kit... you may like this file

119d less PE TPS to enable PE.hpt

Thanks for sharing that file 10_ss. I have a Kenne Bell on my 2010 Camaro LS3 M6. While not a Whipple...I'm sure these two blowers behave extremely similar. I'm following this thread closely. My car currently has the stock KB tune in it and is otherwise completely stock car other than the KB. But I am in the process right now adding some ID1000 injectors, ZL1 pump with ADM FPCM, and long tube headers, wideband, and ZR1 map sensor.

I have been working on building my base tune....and I am building it using an upgraded 2 bar OS. I'm a rookie tuner as well so lots for me to learn. I'd love to chat with you sometime if you're willing to get some more knowledge of how your tuning journey has been. Sounds like you've been working on this tune for a while and have a lot dialed in.

Wish I could help on transients but I'm a rookie and learning. Good luck. Only thing I can add is that 38 psi is really low for fuel pressure. I've got a BAP on my stock pump and I've seen down as low as 45 and people have gotten on me saying that's too low. The BAP's just don't do much on these cars because of the FPCM. It controls the voltage to the pump and just doesn't let all the voltage boost work its way through. It does work some...but minimally. The ZL1 pump combined with the ADM FPCM and tune settings comes highly recommended. You can find these used on camaro5 forums all the time and pick up both for $300-$400. Or just buy them new and its $525.

[10_SS]

Thanks for sharing that file 10_ss. I have a Kenne Bell on my 2010 Camaro LS3 M6. While not a Whipple...I'm sure these two blowers behave extremely similar. I'm following this thread closely. My car currently has the stock KB tune in it and is otherwise completely stock car other than the KB. But I am in the process right now adding some ID1000 injectors, ZL1 pump with ADM FPCM, and long tube headers, wideband, and ZR1 map sensor.

I have been working on building my base tune....and I am building it using an upgraded 2 bar OS. I'm a rookie tuner as well so lots for me to learn. I'd love to chat with you sometime if you're willing to get some more knowledge of how your tuning journey has been. Sounds like you've been working on this tune for a while and have a lot dialed in.

Wish I could help on transients but I'm a rookie and learning. Good luck. Only thing I can add is that 38 psi is really low for fuel pressure. I've got a BAP on my stock pump and I've seen down as low as 45 and people have gotten on me saying that's too low. The BAP's just don't do much on these cars because of the FPCM. It controls the voltage to the pump and just doesn't let all the voltage boost work its way through. It does work some...but minimally. The ZL1 pump combined with the ADM FPCM and tune settings comes highly recommended. You can find these used on camaro5 forums all the time and pick up both for $300-$400. Or just buy them new and its $525.

I will do that one day, maybe. But here is what I'm dealing with with stock Throttle Opening Rate... this is only 2800-3000rpm, and I get big MAP and MAF spikes at tip in, and creates knock. And the MAF reacts fast but that doesnt make injector PW go up fast enough. This was before I increased the Transients in this area (stock didnt really have any and you can see that in the slow Injector Ramp up). So I easily fixed the below 4000rpm Transient problem... it's above 4000rpm I need working and now realize I cant actually get them working.. they dont work above 4000rpm. 4000rpm+ has much bigger MAF and MAP spikes at Tip In.


TIP_IN_SPIKE_LEAN.PNG

[10_SS]

Now Compare that Log with Full Speed THrottle Blade Opening to this one with reduced Opening Rate... (no spikes, even at higher RPM/Boost)

TIP_IN_SLOW THROTTLE.PNG