Guest Paul Felker Posted August 6, 2002 Share Posted August 6, 2002 hello everyone its been a little while since my last post. i finally got myself a nice 78 with an automatic that is blown. now i have a T-5 turbo trans that i want to put in now (turbo conversion coming soon) so i can drive the car soon. I like the T-5 i like theway it shifts(notchy) i have a steedia triaxx shifter so that meke shifting slmost idiot proof, anyways i plan to use the turbo flywheel and new clutch and all that fun stuff, but heres my problem, what about the driveshaft? do i use the turbo one or do i have a custom one made or what?? what are the deminsions of the drive shaft that i have to make or modify? what are you turbo guys doing about this? also i plan to change the diff also for better gear ratio, wich ratio would be the best, 3:54 3:70 3:90 or what? Im more intrested in low to mid range power than top end performance than any thing, and keep the revs in a resonable range on the freeway. thank you in advance for your time and info Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 6, 2002 Share Posted August 6, 2002 I've heard some people are able to use the turbo driveshaft - you have to swap the differential flange, as it is different on the turbo 3.54. I just had a custom shaft made - it's stronger and has replaceable u-joints. You will hear differing opinions about rear-end ratios. I am running the T5 and a 3.90 - it is very streetable with a stiff clutch, but not the best for building boost. I am planning to go to a 3.70, and lots of folks even prefer the 3.54. Prevailing thought dictates the widest spread in the gearing is best to match the broad torque band the turbo gives you... Quote Link to comment Share on other sites More sharing options...
Guest Paul Felker Posted August 6, 2002 Share Posted August 6, 2002 thanks sleeperz, what are the dimensisions of the custom drive shaft, length, and all that? Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted August 6, 2002 Share Posted August 6, 2002 I just put a T5 in my 72' 240 (about 2 weeks ago) and what I found is that no two cars are quite the same dimensionaly. What that means to you is that you are going to be without your car an extra day because you need to install the tranny put the drive shaft in then measure the distance from the u-joint to the face of the "turbo flange" on the diff. if the driveshaft is pushed all the way into the tranny subtract 3/4" from your measurement and make sure the driveshaft shop knows what referance points you used for measuring. With mine I only needed it shortened by 1" so I was able to have the turbo drivshaft shortened and re-balanced. I also run the 3.9 rear diff. and although I have not run the car in the quarter I have pulled a 9.4 second 1/8 mile run with tires smoking through first. Dragonfly Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 6, 2002 Share Posted August 6, 2002 Originally posted by hotshift13:thanks sleeperz, what are the dimensisions of the custom drive shaft, length, and all that? It's been a while, and I don't remember. Your best bet is to bolt the whole mess in, and measure several times. Quote Link to comment Share on other sites More sharing options...
speeder Posted August 6, 2002 Share Posted August 6, 2002 I used the turbo driveshaft in my '77 t5'ed car- shortened the driveshaft 1" and used the turbo diff input flange. Also I needed to use the ZX turbo trans crossmember because the t5 rubber mount needs to be offset. I've just changed to a 3:36 gear from a 3:90 - I'll let you know how that works out. It seems a little slower off the line but pulls way harder on the top end. Quote Link to comment Share on other sites More sharing options...
Guest Paul Felker Posted August 6, 2002 Share Posted August 6, 2002 anybody else with any info or comments? Quote Link to comment Share on other sites More sharing options...
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