How much HP/TRQ can a Factory T5 take...

Morales

New Member
Apr 29, 2005
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Miami, FL
...before it explodes? Im wondering if it's worth dumping my stock tranny and upgrading before i even go to H/C/I . Im not planning on a wild combo, probably the Trickflow kit and maybe later a S/C
 
it all depends on how its driven. some people drive 600 hp cars on them without a problem, and some people blow them with a stock engine just beating the piss out of it.

with a mild h/c/i i dont see it causing a problem. maybe with the blower i would look into another transmission.
 
personally i know of a guy with a built 408 thatwent 11.00 super granny shifting and lasted the whole week he raced ...... then broke all the teeth of most the gears and what not ....
thats a car that will trap high 120's
 
About 800 HP if you never dump the clutch and drive like a little old lady... :D

If smokin' tires and full power upshifts are your thing, about 250 HP for 90 days or less :(
 
As the others have stated.... The stock T-5 will last forever if you don't like to drive fast. After a few passes down the strip or making the 1 - 2 shift at 6,500 (stock tach) you'll soon learn that the T-5's real weakness is in the strength of the case holding all the parts together.
 
You guy say it will last with 600+hp, but who the hell has 600hp and NEVER uses it?! LOL

My point, if you plan on upgrading the engine too seriously, do the tranny as well.
 
I broke a stock t-5 but here's the catch: It hade a smaller than spec. -> GM??!! <- imput shaft, that ultimately caused the failure. Someone must have done a half ass rebuild in the past. I now have a real WC-T5 out of a 91GT, and it's standing up to all the abuse I chuck at it. I drive normally with moderately quick shifts, and when street racing shifting at 6000, sometimes more. When I race extra fast cars, I power-shift. My transmission tunnel is starting to split, and I've busted some welds in the back-seat area of the "frame".
 
I have an 88GT with 448rwhp and 485rwtq. I roll out of the gate and granny shift to mid - high 11's. Over thirty passes with BFG Drag Radials. I'll say this much...It is starting to give me "shreeeaaak" going into third. Any day now. I seriously reccomend an upgrade with mods and sticky tires. I shift a t 5,800 and am surprised at how long it has lasted. Any day now...trust me. The stock T-5 is a grenade once power and abuse are mixed into its make-up.
 
The key here is traction -- how much of the motor's torque you can actually make the tranny transmit. Those of you with rear suspension mods and sticky tires - you can break a T5 with brutal 5500 rpm first gear launches or power shifts into 2nd. On the other hand you've got chvyeetr who's been careful on the launch pad, but has enough traction (and certainly torque) in the upper gears to put all the torque through the tranny -- and sure enough, it's starting to protest.

I have the other problem - with a 225 section tire being the biggest tire I can run in the back, my 'fuse' is my tires. You won't hurt the tranny in the lower gears if you spin the tires - they're the fuse that protects tranny/rear end/clutches from abuse. And as a confirmed European car nut -- I've been waiting for 50 years to smoke the tires at will - I don't want to go screwing that up with traction. :)
 
Thats why you have to take internet advice as just that advice. My car doesnt represent the norm, and neither does anyone elses. Read what everyone has to say and in the end its your decision what you choose to do. I can only share what me and my friends have done, but dont assume it will hold true across the board. I assume most people will understand this, but then again, you never know!
 
I was talking with a G-force rep and he told me that rear end gears play a huge part in it. The best thing anyone can he told me is have a rear end ratio larger than the first gear in the tranny. Since the stock t5 is a 3.35 first gear that would mean at least a 3.73. (3.55 is too close to beeing even).

I had a 347 with 4.10s and never had any problems with the stock T5. I did go to a Z spec for piece of mind and its a cheaper upgrade when you can still sell your old tranny. :)