gear slipping?
 

hey guys i have a highly modified 03 ss supercharged, my question to you guys is this. when I'm accelerating past second gear around 50-60mph i feel hesitation as my speed is increasing. first could this be a failing fuel pump? i am running an arm high flow fuel pump from zzp. fuel pump failure? belt slip? Second issue is that besides this happening 7/10 times, when i hit the gas the car revs up and jerks into gear. I'm running a stock converter with an xp cam and i am aware that the stock converter is not sufficient whereas i should run a 2750-3000 stall converter. does this sound like it is the converter or is my tranny starting to give out? also, my driver side axel is on its way out and one of the axel mounts snapped. i not sure if his has any effect on the revving issue, but when i go go around turns usually making lefts, my car hesitates usually chugging back and forth but shifts normal when straightened out. its hard to explain in words I'm sure some of you guys will read this and be like wtf? lol thanks

Going to be tough to diagnose since the 03 didn't come with the L67 stock.

What have you done for tuning? Did you do this swap yourself? Do you know if it has a PCM from an 04/05 that goes with the engine and trans?

Could really just be trans tuning issues.

i did not tdothe swap myself, the first time it was done by my local mechanic who has a lot of experience with these cars and was tuned the first time by a domestic tuner. the second time it was built, cam heads and injectors was by the new performance shop i go to and tunes by the guy as well. the pcm is actually the one that came with the car but was dyno tuned for 6 hours. i had one from zzp that was tuned but that was way back when i bought the supercharger and had to swap back to my stock cpm because the tune was terrible.

i agree with you that its either the tune or the trans is going I'm going to try and have my mechanic drive the car on the highway when he has time.

Do you know what transmission is in the car? Is it the same trans that came with the L67, or is it the stock transmission with the 03?

I just really feel like it could be part of the tune in the trans. You can tune when it shifts depending on speed or rpm or throttle percentage, perhaps they aren't all trying at the same point and the computer is messing up.

Definitely try to have the person who last did the work, or the tuner take a look at some data. Might not be a hard part failing.

Stock trans

In 2004 they changed some electronics in the transmission, your PCM is either a hybrid 2003, using L67 settings, or a 2004 L67 trying to talk to that stock trans.

I would recommend picking up a trans that would match the PCM and gear ratio and such better. There is probably some conflicting tune info going on.

Damn I was afraid of the transmission that's 3600$ from zzp stage 3 but I will price around to see if I can find cheaper it sucks I have a few grand in the bank to continue building my monte in spring or to go towards a daily driver. Now the 3rd option is a trans

Talk to Dave at triple edge performance, he can probably build you a really strong trans for like half the cost.

Ok thanks dude