I planning on installing a Vortech supercharger on my 89 305 TPI IROC with a T-5. Will my t-5 be able to take all the extra power? I will be running about 6lb boost. The only other engine mods are MSD ignition and TPIS intake runners.

 

Think of it this way. GM knows the limits of the T5 and never put one behind a 350.

 

Wlcome abaord. Check out the search function for additonal info on this topic. it is frequently asked and there are many threads out there that cover this topic in detail.

IIRC GM desinged the T5 to withstand 300lb ft. However, there is no real value. You can kill a T5 with a V6 or you can make it last with a 500hp small block. The T5 will not tollerate powershifts, clutch drops, and hard launches with slicks. Power alone won't kill it.

 

Oh mannnn. Kiss that tranny good buy with that kind of torque. Third gen trannys cant handle much. I think my 700RH is only rated up to 350 hp lol, and the T-5 is even worse.

 

you never know you might get lucky i know a guy the has like a 350hp 383 with the same or more torque and he beat the hell out of it and it lasted for like a year

 

exactly what happens when you give the t5 more than it can handle? mine has about a summers use on it since rebuild, and i need it to last me till next winter..

like does it just lose forward gears, blow up, or just not work at all?

 

Exactly what shifty said.

A T5 will live fine behind your engine you use it right.

I have a 150,000 mile used take out, non world class in my car that is going on two years in there now. Thats with 300 rwhp and 320 rwtq

 

Um GM didn't use a T5 behind a 350 because of the EPA, not cause of if strength.

The proof is in this forum, you will have to dig for it though.


I did a big thread about 2 years ago about it.
Factual info found that the 350 could not pass the downshift EPA rules in CA so they never built one.


in the thread there was a big 50/50 split of some guys who blew the guts out of a T5 with only a 305 every other day and some guys had built 383-400s with 3 years of racing.

One big factor I found was those with lost of power and a long lasting T5 changed the trans fluid with every oil change.


Then you had what kind of flid.

Some used ATF like the book says
Some use 80/90 [which may work but is to thick to get in the parts right.]
Some used a mix of ATF and 80/90
And then some like me use a straight weight 30w oil.


The 3rd big factor was traction. If your trying to run monster slicks with a T5, just forget it. And ya don't power shift it either.

But it really did come down to a 50/50 split of some guy blowing them with less then 200hp and other with 400+hp who had no trouble.

 

IMO, it doesn't have to do with traction. They usually pop third gear (mine did). I dont know about you guys but my car doesn't spin 3rd gear even with 600 plus hp. It is the torque that kills em, since 3rd gear doesn't spin and you are applying torque for much longer than first and second.

Ohhh, and and fluid changes won't extend the life of the gears. It may help the shifting mechanism (IE, synchros, blockers..) but the gears will break.

I broke mine 4 times. Pretty robust for what it is but I'd be looking to swap in a t56. FWIW, I went 12.3 @114.83 mph in the quarter with one.

Good luck with it, just remeber those WC t-5s fetch a pretty good dollar when not broken.....money that could make a good dent in a t56.

 

Though in 5th gear its weak at the case. Though ya shouldn't be racing hard in 5th to much. There is a new cover plate you can buy to make it stronger. But I have yet to hear of anyone busting the case when racin in 5th.

 

my motor is making over 450 ft pounds and i launch it off the 6,300 revlimiter with slicks..it lived through the launch but not during the 1-2 powershift....it pretty much exploded..

it ran 12.16@113 with a slick launch of 4,500 and no powershift..

on street tires id powershift all day...it would just lite the tires..

 

Why spend that kind of money and go with a T-5? If you went Tremec you'd be better in the long haul. There are some kits out there that will beef up a T-5 W/C but maybe not to what you're looking for. Try Richie at Streetwise performance in New Jersey. He sells some good rebuild parts that match or beat OEM.

 

yeah i got some parts for my t-10 at streetwise and i'm happy with them too. also, usally the weak part is the countershaft cuz it's all one piece and it's the most expensive. the guys that have t-5 in camaros and mustangs that i know a take out third gear and not the syncros but the teeth on the countershafts

 

I thought case flex from a weak case design was what caused them to nuke under heavy loads?

 

G-Force t-5 is the way to go. It's good for 500-600hp for half the price.

 

Half the price of what? Streetwise sent me an upgraded T-5 W/C shipped for $999. Landed on my doorstep in a woodbox, shipped 3000 miles. Granted, I'm only putting out about + or -220hp , but I couldn't be happier.

 

how much is the gforce tranny? can you buy it and not buy the parts for it?

 

http://www.g-forcetransmissions.com/tran_t-5_price.asp
this link will give you all the price info for G Force. I have never used the parts cause I still have not killed the t5 that I have now. I have a stock 305 and use DOT tires and 3500 rpm launch.

 

I think tremecs are cheaper then g force

 

how much is a decent tremec. i think id rather have 5 than 6.

 

I have a freind with a 91 rs that has a mean 350 with dual tunel rams on it. He has been running slicks and has been griping really hard. Let me just say his car dosent sit right(I told him to add sfc's, but know one ever listens to me. lol.). And he has been running the same t-5 that came in it stock when we were betting on it with the 305 tbi motor. So all I can say is he is a lucky sob. I guess results will vary. lol. Adam :-)

 

Another good mod to consider is a torque arm relocation bracket - some guys argue that the added flex at the rear of the trans (due to the arm) helps twist the guts of the T5. With the relocation bracket the force is transmitted into the body not the trans tail housing.
Upgraded gears (like g-force) will help, but one of the best upgrades (and not too expensive) is the rear contergrear reatainer. This keeps the bearing from walking around buy permitting both more bearing pre-load and also buy strengthening the case with a solid steel peice. An upgraded shifter will also help prevent internal damage due to the shifts stops incorperated into the design (ckeck out pro.5.0 etc.)
Most people will agree though, once you start to really stick the car to the road/track, well that's when the T-5 is really stressed..... Clutch drops and powershifts will take their toll very quickly. Even the last generation of stock factory Ford T-5's built for use in the cobra's (which were factory rated at over 300lb of torque) would not last long.
In daily use a T5 should last even with the power you are going to develop, however, any trans that is abused with heavy powershifting and clutch drops will eventually give up the ghost. Just a matter of time. Imagine the ticking of an old wind-up clock............ and then when you really need to count on the trans - boom And then your opponent pulls away Leaving you

 

Tremec TKO 500 & 600s run $1750 to $1950. They have bigger shafts, stronger gears & cases than a T5.

 

TKO 500 is that a direct bolt in - same spline count as the V8 GM T5?

 

I don't know about the TKO but think the T5 and T56 are more popular from being top loaders. Stick shift built right in.
Older stick trans have linkage that can bind and need a pricy shifter.

Though myself I aint into the T56 and the dual OD gears.

Anyone have a pic of that torque arm relocation bracket on a car?

Sounds intresting but odd. torque arm was made to transfer torque from engine n trans roll into the rear end. Hooking it to the body would make it just a rear end brace. Making the torque arm longer so it bolts tothe motor instead. That would take stress off the case.

 

Take a look at sphon's - this is just one example of a relocation bracket. The torque arm also needs to be changed to make up for the chage in distance/lenght - thus the adjustability factor is designed into the torque arm as well (this also aids in setting pinion angle....)

 

I built this using Spohn's basic idea. I beleive that getting the torque arm off the back of the tranny will help it live.