Hey guys, just joined the forum to see if you guys have and pointers. I use HP Tuners for my tuning. I know my way around it pretty good. I have a Supercharged Cobalt that I learned on but tuned various others.

I'm tuning a friend of mines 2001 Firebird LS1 automatic, he's got a higher stall converter, bored out throttle body, and I think high flow cat converters, 373 or 410 gears. He runs it at the track here. So far he ran 13.2 - 13.3 I think. We are at a high altitude.

So do you guys have any kind of advice on where to start? I'm not playing with the fueling until he gets a widebad. Mostly want to tweak transmission and torque managment stuff. His car also stalls sometimes in parking lots since the higher stall torque converter.

 

As mentioned above, Dave is lending his tuning skills to help me with my car...

Upgrades include:

-Ported and Polished T/B
-SLP FlowPak
-Vig 3200 stall converter
-3" hi-flow cats (old ones were plugged)
-hi-flow exhaust

I know its not much, but I'm just getting started.

I've noticed a little while after having the convert installed, the car stalls sometimes when backing up. I rev the car a bit to back up and soon as I let go of the gas, the rpms dive down to 3-400 and the car will either stall, or shudder.
I've also noticed that when the car is warmed up and I'm sitting at a street light in gear, the rpms will sit at 500. When I hit neutral, the rpms go back upto 700... then drop to 500 again when I go back into gear.

Last month I had a pooched diff bearing that wailed like a banshee... I opted for 3.73 gears (3.23 stock) for slightly better 60' times and more acceleration down the track in general. However I went from a personal best of 13.19s @ 101.9mph and a 60' time of 1.79.... down to a VERY disappointing 13.8 and even a 14.1 @ 98mph. 60' time was 1.83-1.89s.

I use M/T ET Drag radials which give me a dead hook and I have no wheel hop.

So I'm at a loss as to why I was getting much worse times at the track and the only thing I could think of is trq management.
The initial launch seemed a bit off and when I got into second gear, the car wasn't pulling as hard as it normally did. 3rd gear seemed really nice and pulled pretty good, but didn't help my mph enough to make up for the flat spot in 2nd.

As far as I've read, these cars should be 12.5-12.8 with drag radials alone, but I'm just not seeing it.

So we're going to take the car out of a few runs tomorrow out of town and see what we can log, then try with trq management on/off and tweak a few things.

I'd really appreciate any tips!

 

No one has any advice? We are tuning tonight.

 

Deleting or adjusting TM & setting the shift points to where you want would be a good start, then work on a/f & timing from there. Being a bolt on car it should be pretty straightforward.

 

Thanks for your reply foff667! He doesn't have a wideband yet so I guess I'll just play with the timing, tq managment and shift point.

 

obviously the other little things such as speed limiters, fan temp turn on/off points as well will get you going pretty well.

 

Thanks for your help

 

Thanks for the tips!

Our quiet little test road was busier than we thought so we we unable to get any real dead stop to 180km/h runs.

1st run was bone stock tune from 80km/h to 160ish.

2nd run was after some tweeking and disabling trq management. Car felt MUCH better ad pulled nice and hard. I think this one was 40-160km/h.

3rd we tried some water to heat up the tires and tr a dead launh. i hastled some water down then tried to light them up but the car just pushed forward so I spun them a bit, then just went upto 180.

4th run was from 20km/h to180 again. I was going to stop completely and try a launch, but more vehicals were coming and we didn't watn any attention so we headed ome right afer.

We only tweaked after the first stock pass so we'll deffinatly need more work on it.
This saturday is our very last chanceto hit the treack before its done for the season. Hoping to make lots of time only passes!

*edit*

I have the data logs if anyone wants to peek at them.
Feedback and suggestions on where to tweak next would be great!

You can PM me, or email me at frisky13@hotmail.com