Thread: How "built" is my transmission?

2002 40th GTP that I bought has had a lot of work down to it. A couple owners back and they had all of it done by shops. Have a lot of the receipts still. one is for transmission work done 10,000 miles ago. The car had 293 horsepower and 355 ft lbs torque last time it was tuned which actually seems low for all the performance parts it has but I'm gonna make another thread for that. My concern is is the transmission built to handle the power the car is putting out. Upgrades and repairs listed when the transmission was serviced are

EPC Solenoid, Shift Solenoid, Various?? Solenoid, Filter, Sprockets, Master Overhaul Kit, 4th Gear Hub and Shaft, Shift Kit (Must be light cuz I dont feel it much), Drive Chain Set, Channel Plate Sleeve, Reman COnverter, Input Sencor, Billet 3rd GEar Piston, 300M Input shaft.

Obviously other stuff could have been installed prior or after this but this is all I know for sure. Thanks for your thoughts guys

Originally Posted by Scottydoggs

they say stock tranny is good for 350 hp. the stock input shafts like to snap tho, so that 300 mm input shaft is a win.

what mods the engine got? if its got a cam it should be around 330 or so. trans tune makes the tranny feel a lot better too. no idea on its tuning work if any.

It's got a ton of mods. Well a ton in my opinion
-3.3" Pulley
-Headers
-3" Downpipe
-3" ZZP Exhaust and Mufflers
-Fenderwell Cold air Intake
-Northstar TB
-GenV SC (Possibly Ported)
-Ported Stage 2/3 Heads
-Roller Rockers & Lifters
-125# Lifters
-XPZ Cam
-L32 Bottom End (Balanced)
-XPZ Matched Rods (Staggered?)
-.020 Coated Pistons
-180* T-Stat

I feel like the car should be pushing closer to 400 whp with all these mods but maybe the tuner didn't know what they where doing exactly or maybe I just need to put a smaller pulley on it? I'm only building 12-14 lbs of boost. Its a fun car to drive and handles great between the coil overs and the drilled and slotted F-Body brakes I think it would make a really fun track day car.


Thanks for the input about the trans too. Didn't know the input shafts liked to break I always thought the drive chain was the "big upgrade" that needs to be done to hold power.

your map sensor maxes out at like 15 lbs of boost, so keep that in mind when you are dropping pulleys. I would drop a pulley and scan for kr and see what happens.

Originally Posted by Iceman6669

Biggest things I from your mod list that I would inquire about are, what injectors are you running? On pump gas I assume? What valve springs are you running?

Ive known a few guys with similar builds that get good power out of them, and your power #s do strike me as being on the low side. BUT that could be because of the pulley choice. And that could be do to fueling, or some other reason.

I never looked before but looking now the part number on them 0280155811 makes them the factory injectors. The AFR gauge reads about 12.5:1 while in boost so I suppose the tuner probably just maxed them out and called it a day. And yes it is just running on pump gas right now 89 or 91 depending on whats available. I don't get into it much when its on 89 tho.

Originally Posted by Scottydoggs

oh the chains stretch.

you got a few mods alright. that xpz cam likes to eat up timing chains. ive heard it should be changed every 10,000 miles.


hows the tranny fluid looking? smelling? maybe it needs to be tuned, or its knocking on heavens door? that's a fair amount of power going through it.

Sucks about the timing chain. I'll have to change that out asap since I don;t know how many miles are on it. Maybe I'll see if there's a performance one available. I'm sure with the extra lift from the cam it'll eat the valves if the chain fails!

The tranny fluid looks good and smells good. I haven't actually had any issues I was just curious as to how much abuse the transmission would take. I don't hot rod the car when driving for the most part so if I'm just taking it to the track every now and then I guess it'll probably last a while.