first of all i'm new to the site and have to say I love it. I have a 89 iroc-z that came with the 305 tbi. well It didn't take me long to realize that this motor would have to go, so I found me a 91 350 tpi out of a vette. The motor instantly felt stronger only problem being my tranny started to slip more day by day. the car only has 31,000 original miles on it so the tranny is fresh plus it ran flawlesly with the 305 tbi. I installed a shift kit and a corvette servo and this helped a little but it still slips. My question is, what is the differance between a tbi and a tpi tranny? They have to contain differant governer springs and so on. Also if I buy an aftermarket 700r4 is it going to have the same shift points as a factory tpi camaro 700r4? Most aftermarket transmissions probably shift pretty hard and thats fine at wide open throtle but do they shift hard at normal speeds because thats what I have now and It was cool at first, but now it's anoying to drive?

 

guess nobody is educated in this area?? thanks anyhow guys

 

they didnt make a 305tbi 89 iroc z, maybe you mean 305tpi.
the tranny is the same.

 

no, they did in fact make a 89 iroc with the base motor being a 305 tbi. It is engine code "e". and can be ordered with t-tops. what i'm saying about the tranny is if you floor it in drive it shifts at like 3500 rpm max, also if you floor it from a dead stop it starts spinning both tires furiously and then at like 3500 rpm's it just hits 2nd gear and drops way out of the power, which is not right. also if they are the same why would a perfectly good tranny start to slip badly after switching from 305tbi to 350tpi? they have to have different valve body calibrations and various other changes. unless the torque converters are different and that is the prob. but I seriously think its the tranny. any help guys

 

Adjust Your TV cable.

 

also have tried that in every possible possition

 

Replace the TV cable.

 

[QUOTE]if you floor it in drive it shifts at like 3500 rpm max, also if you floor it from a dead stop it starts spinning both tires furiously and then at like 3500 rpm's it just hits 2nd gear and drops way out of the power, which is not right.[QUOTE]

Seems to me its shifting to early,not getting high enough into the power band.
3500rpm isn't that high. Also,you may wanna check the O-rings on the servo, may have got pinched or is leaking.

Again,double check the TV adjustment, make sure you slide it all the way back toward the firewall, then slowly rotate the throttle, you'll hear the TV clickas it moves out.Once you get to WOT your done.
An improperly adjusted TV will lower and soften your shift point.

Sorry I can't be more help.

 

BANDIT5 has a point, it could be stretched.

 

thanks guys maybe i'll replace it and see what happens. See I thought that since different motors made power in different areas the tranny would have different internals depending on what motor your car had, but I guess if you had like say a tbi setup it would all be adjusted by the tv cable.

 

sounds like your tv cable, or you missed something while puting in the kit

 

when does the trans slip, what gears?

 

it used to slip going into 2nd and 3rd. instaling the shift kit didn't help, but the corvette servo helped as a temporary fix. now its starting to slip again. I think there might have been a time my tv cable was improperly adjusted and the 305 tbi didn't have the bal_'s to mess it up, but when I put the 350 tpi in, the torque shortened the life double fast. So you guy's are telling me I can get a 700r4 out of any third gen camaro/firebird with a v8 reguardless if it was tpi or tbi and their all the same?

 

time for a rebuild your 3rd gear clutches are going, pretty common problem with these trannys, but a misadjusted cable doesnt help the clutches either ...good luck!

 

well I've never rebuilt a tranny before. I do have the mechanical skills for it but I really dont have the time. Would it benifit me to find a used one for a couple hundred and just put a vette servo in before I install it? I don't want it to shift to hard just a little more than stock.

 

ok I ran my car yesterday (finally dug her out of the snow, don't worry roads are bare) and I verified the tv was adjusted right. well at full throtle it shifts at 4000 rpm and in drive when I floor it from a dead stop it burns the tires off in first and then as soon as it hits 2nd it catches traction and goes into slow acceleration mode until it gets into the power range. I think I figured it out. it is shifting to early due to the governer being wrong for this motor. if it was out of a tpi car i'm sure it would shift at a higher rpm like 4500 or 5000 rpms. this would put it in a higher rpm ( in the powerband) when it shifts from1st to 2nd at wot and solve my problem.