Ok you guys can see my current mods. The car just got fixed and they replaced the old pcm with a stock one. So my car doesn't realize I have 3.73's, a shift kit, and a stall. Easy driving is fine but everything screws up at WOT. It missfires, backfires, and bounces off the rev limiter. Now obviously I need a tune, but I'm REALLY dissapointed with the performance with the new addition of the stall and shift kit anyways. My question is this: Will the tune really help the car out that much? It seemed faster before when it was tuned with the 3.73's, now it has the shift kit and stall as well and seems to be running crappy AND slower. Will the tune help out a lot??

 

does it do it all the way through the RPM range or just when it should shift?

 

If its just when you shift then yes a tune would really help. Also are you experiencing a loss of traction with the new stall and gears? I know my z28 felt pretty quick with the 2.73's just beacues they hooked and went, after the gear change and countless other mods I spin .

 

The car cannot grip for anything..LOL it's that bad (255's- BFG KDWS) Sometimes it backfires and missires right when I punch it, it does something funny and I'm not EXACTLY sure, but it prolly sticks around 6400 and bounces then shifts. I am just hoping my car is fucked up right now because I was hoping it would be stronger from a roll.

 

Well there is no reason your car should be seeing 6,400 rpm. That is a problem in its own. You need to go get your car programed for those gears.

 

Yeah needs the tune.

EDIT: I am going to be shocked if you don't reach 1000 posts by next Friday.

LOL jk

 

If you have a stock PCM (why did you go back to stock?) your rev limiter should be right about 6k.

Tune will help you a lot with a stall that large.

 

^I had to get my tranny fixed, no 1st and 4th gear, we traced it back to basically a bad PCM(which was already tuned) and we threw my buddies stock pcm in there and the car shifted fine so I stuck with it. Cant afford the tune yet.

 

I know, I have been bored lately haha.

 

The PCM contains the shift tables (the shift tables control the shift points on a 4l60E and they're are calculated in MPH so having the wrong tables for your gear ratio will result in high engine speeds) a proper tune will definately help with your WOT shifting problem. I had the same problem when I went from 2.59 to 3.45. I hit the gas and was instantly on the rev limiter. It took me about 30 seconds to realize that I had to change my shift tables since a 65 MPH 1st to 2nd shift would no longer work due to the rear end swap.

Mike

 

If you have a lap top you can fix the issues yourself free if someone is willing to tune your shift points, and enter your gears.

 

Yea, you definately need a tune. These things are real touchy. I got mine done, and it still needs to be tweaked with. It bounces off the rev limiter when it shifts. The shift point needs to be lowered.

 

Or the rev limiter needs to be raised. Real simple.

 

Thanks for your replies. My car also wants to die at stop lights with the stall..It just starts shakin so I've been givin it some gas. My friend had a similar prob before his tune.

 

My Rev Limiter is set at 6200, it is high for Stock Timing set. I am just going to lower the Shift Point by 150RPM. I am converting it to M6 soon, so I am not really worried about how it drives in Auto.

 

If the tranny is sound then it should shift at whatever set and not bounce off the rev unless its spinning alot. Remember the tach on our cars arent accurate either.

 

You need a GOOD tune.
And you should not be revving your car to 6400 RPMs.
Ive taken down a couple LS1's, and my I left my redline stock ( 5700 )

 

With a stock motor you would be actually slowing down your car if you shifted at 6,400. That is way past your ideal shiftpoint and your powerband.

 

yeah when i had my car dynoed peak power is at 5000-5100 rpm but it only lost like 4 hp all the way up to 5700 rpm thats where i always shift and it seems to do real well take a look at the link in my sig if you wanna take a look at the power band

 

You nailed that one!