I'm just curious to know what kind of mileage you guys running the T56, and 2.73 rear gears? I'll be installing my LT1+T56 and I have the stock 2.73 non-posi, and i'm just wondering. I plan on upgrading the rear end later anyway, I'd just like to see what kind of insane mileage you guys are getting. I'm guessing 25+?

 

I don't have that gear combo but I would guess that sixth gear will be useless with 2.73's... I am revving about 1600 rpm@60mph with 3.27's and its barely useable as there is very little ability to pour on any hill climbing power at this low rpm. However... If I cruise at 85mph it revs 200 rpm it gets incredible mileage. I am in the process of a 3.73 swap now and I am sure you will find the 2.73 too steep for the six gear. First gear will likely take you to 90 mph! Anyway good luck with the swap.

 

you cant even shift into 6th until 70-80mph. even then you're overstressing the motor if its a L03.


you will have to slip the clutch to move from a stop.. first gear is kinda tall since you're suppost to have much better gears in the back.

in stop and creep traffic, its even more of a pain, since first you have to give it gas to get moving, then, because of the gearing, you have to hold the brake slightly to go slow.... the engine has to be below idle speed....or you can push the clutch in and out a billion times. i love manuals, and i dont mind them in traffic, but 2.73s are more of a bieach then you want.


i was a full second and a half slower with the manual in the EIGHTH! (1/8th)... it was really sad because it only ran low 10s/high 9s with the l03 to begin with. 11.5s means you're getting raped by stock honda civics.


not to mention, you WILL fry your new $300 clutch if you drive it that way for any extended peroid of time.




i dont regret the T56 swap at all, i LOVE it. but you NEED better gears ASAP, or wait.

 

oh, and gas miliage was about 5MPG WORSE since it was either too tall of a gear for that speed, or too low. so i could leave it in 4th with high RPMs, or stick it in 5th but have to push the gas down more.. (winALDL is useful to see what gear has better TPS readings)


then again, after being annoyed for awhile, i started going 70ish (in a 55-60) and i could use 5th.. on downhills i could use 6th, or if i started speeding more... but usually right after i go into 6th someone makes me slow and i have to go back into 5th.

 

I use 6th but, I have 3.45 gears and a pulling bottom end eng. (tpi sbc 400 small lobe sep.) and even with all the grunt I still only use 6th on flat 55 mph back roads or the hwy.

 

I've just recently switched to a T-56 from the 700R4 and I have 2.73 gears. I was averaging about 16 mpg (305 TPI). After changing to the 6-speed my mpg jumped to 23 mpg. So far the best tank I've gotten was slightly over 30mpg. I had to doublecheck the math on that one! For reference, I drive about 45 miles to work, then 45 miles back again on mostly the freeway.