2011 Camaro L99 timing cut and 1-2 shift issue

[Dewayne Smith]

Hello all. I'm trying to work out a couple bugs for a friend of mine but unfortunately with my lack of experience I can't seem to find whats causing the issue.

First of all from a dig with the shifter in drive the 1-2 shift is way late. Its hitting 6760rpms which I think is the REV limit. I have never tuned a transmission but looking at the tune it should be shifting at 6k like the other gears or 21 MPH (which is low for 6k) instead of 32mph.

Next,(I'm researching this now so I may get it worked out myself) it needs a lot more fuel at the hit. I was successful tuning the "pump shot" on a 2002 Corvette a few years ago but can't seem to find the correct parameters for this PCM. I see under Fuel-Power Enrichment-Throttle there is a HOT button but no Cold. The description under HOT stated there are 2 tables (HOT and COLD) but I only see HOT.
This is the description under the HOT button.
"ECM] 12420 - Hot Power Enrich Enable TPS Threshold vs. RPM: These tables define the minimum TPS vs. RPM that the VCM requires to enter WOT and is required to enable PE mode. There are two tables labeled Hot and Cold that allows different thresholds depending on whether the coolant temperature has exceeded the Hot Select temperature (see below). If the coolant temperature exceeds the Hot Select temperature then the Hot table is used, otherwise the Cold table is used."

Another issue is a brief timing cut around 4000rpms at WOT in 1st gear. Its possible that since I was rolling about 10mph at the hit that the trans had shifted to 2nd and that timing drop was on the downshift. I'll post 2 logs, its not there in the first which was from a dead stop so this may be a driver issue After a ton of reading last night I think I found why it cuts throttle and timing between shifts but have yet to work on that this morning.

A little about the car. 2011 SS 6.2 L99 BTR stage2 (still has VVT) long tubes and 4.10 gears. I have no idea who tuned it, it was this was when James got the car. I currently have a WB in the left header.

About my tuning skills, 89 Camaro Ive had for years and tuned with TunerPro. A year ago went twin turbo but right now in the middle of swapping to 0411PCM on the TT SBC.
Also tunes 4 other vehicles with TunerPro.
With HPTuners I have only tuned a 2002 Vette and a 1999 Firebird that were performance builds. Also currently trying to get a 2009 GMC tuned after installing a single turbo. Otherwise I have only used HPT for DOD delete and speedometer calibrations so this car is making me go to school so to speak.

Attached is the tune and 2 logs... I hope. I know I'm over my head so please don't beat me up too bad.

Thanks, Dewayne

[R3m0v3r]

If the car has the stock converter then I would suggest loading the stock trans tune back in it and seeing if that corrects the issue.. who knows what's been messed with and by whom..

I have a 13 ss l99.
4000 rpm I'm 1st is around 21 is mph.. Is could be pulling timing to make the shift (but then failing to shift)?

I've personally had an issue where burst knock retard appears to be causing wierd timing pulls... it's worth logging..

Also anything over 6200 is really bad for afm lifters (or so the internet tells me)

Can't rule out a mechanical issue either.. good luck

[rptuning1]

I would put the trans side back to stock and finish tuning the engine side correctly. Update the file for the gear change if you haven’t already. After the engine side is done correctly. Start tuning the trans. You may have to play with mph a bit to get it to shift at the rpm you are commanding. You should be able to log all the torque management types/advance and burst knock ect to see where the timing pull is coming from.

[Dewayne Smith]

AFM lifters are gone and from what I'm told the converter was loosened up some so I guess its not stock. I haven't noticed any knock retard at all
I was able to figure out how to stop from cutting timing and throttle between shifts and ended up lowering the 1-2 shift to 5800 which now hits 6500ish.

Before I could grab the brakes and do a burnout with no problem, now I can't even stall up while holding the brakes unless i turn off traction control. I get no throttle response at all if I have my foot on the brake. I don't understand what I could have changed to make that happen but I'll figure it out.

Overall this car is a lot better than it was.

[kevin87turbot]

I see several things that should be changed.
As far as the stall issue that you have...it's Stall Torque Management. Just disable it.

The biggest problem that I see is that you're running way too much timing for pump gas. It's even a little higher than I run on race gas.
If you have stock compression ratio and pump gas, you'll want to be from 22-24 max at peak torque and 25-27 at max hp. I saw a max of 35 deg in your datalog...way too much for an L99 or LS3.

You've also got 8 degrees of cam retard in it. If you haven't tried it already, you might consider trying 3-6 degrees max.

You'll also want to reduce or disable burst knock.

On the 6L80E...you have to add a minimum of 1 qt over full once you install a converter and are able to launch hard. The easiest way to do this is to buy a dipstick from Lokar or B&M. That will allow it to hit the commanded shift points.

[Dewayne Smith]

I see several things that should be changed.
As far as the stall issue that you have...it's Stall Torque Management. Just disable it.

The biggest problem that I see is that you're running way too much timing for pump gas. It's even a little higher than I run on race gas.
If you have stock compression ratio and pump gas, you'll want to be from 22-24 max at peak torque and 25-27 at max hp. I saw a max of 35 deg in your datalog...way too much for an L99 or LS3.

You've also got 8 degrees of cam retard in it. If you haven't tried it already, you might consider trying 3-6 degrees max.

You'll also want to reduce or disable burst knock.

On the 6L80E...you have to add a minimum of 1 qt over full once you install a converter and are able to launch hard. The easiest way to do this is to buy a dipstick from Lokar or B&M. That will allow it to hit the commanded shift points.

I found the Stall torque you spoke of and have disabled it but the car would stall up fine before but now does nothing at all if my foot is on the brake. It has to be something I changed, I'll figure it out tomorrow I hope.

Cam timing is something I know nothing about so I haven't touched it at all. Its on the "to do" list to research.

Burst Knock has been disabled after it was mentioned yesterday.

1 qt over full..... I'll give it a try, sure didn't find any other reason for the late shift. Lowering the shift point made a big difference but I knew that wasn't the cause.

Thanks for the help guys. Tuning this car is a long way from the 89 IROC I have or even the 2001 Vette I tuned for a buddy.

[kevin87turbot]

You'll need to go to Engine Torque Management and max out Brake Torque Limit to fix the foot brake issue.
Be sure to address the timing problem. I'm not sure why the knock sensors aren't going crazy with that much timing in it.
If you haven't already started tuning the VVE tables, I'd just disable them for now. That's likely causing the issue that you see at 4K rpm.
Just reduce the Dyn High and Low rpm to 400 and 390 respectively.

[Dewayne Smith]

Thanks to the help here I have this car performing much better. Hopefully after the first of the year I can get it on a dyno and fine tune it a little more.

Thanks guys!!

[AWEBB]

Mike Camaro 2010 stock tune.hpt

Donating a stock L99 just-in-case you need to know what stock would have looked like.

Also, back in 2014 when I tuned this L99, I changed the 1-2 shift to 5900 so it wouldn't hit the 6200 limit. Things have changed since then... adding an extra quart of fluid to the transmission? Who figured that one out? LOL