What ratio gears are other people using in their rear ends and transmissions for V8 conversions?
I have 2.78s out of a fairmont at the rear axel and a 4 speed srod trans and 5.0ho from an 82 mustang gt. My final ratio in 4th is .7. My only fear is that it may be too low of a gear to use. Any comments?
I had a 4:11 in the 9" behind a 289 with a C-4. It was nuts on the freeway. I am in the process of changing it to a lower gear. Im thinking some where in the 3.08 range.
i have a 3.50 gear and a C5 (same as a C4) tranny without the lockup convertor. Very happy with it on the street, just wish it was a 4.10 when i'm at the track, then i'd have an 11 second timeslip for sure!
3:50 / 4:11 ???? That is the question. If you never see the freeway or go cross country, then go with the 4:11 AND a posi-track. It is much easyer to drive a hi-po car when the tires have broke loose, with a 4:11 than with a 3:50, because of the rpm that the tires are makeing when broke loose. And beleave me, you will break the tires loose with a nose heavy V-8 Pinto.
The question was " Any comments" preceded by the fear that his car my be to low geared with a 2.78.
What ratio did the Mustang have in it? The lower the gear ratio the higher the number. With that being said, 2.78 are pretty high IMO. Those are highway gears. My 96 Mustang GT had 2.73's from the factory and it was a slug off the line and fifth gear was totally useless. At 55 mph my RPM would be under 1500 rpm, way out of the powerband of the motor. It would bog the motor if I tried to to pass someone quickly. I am not 100% sure but I think the 5th gear in my T45 is .68. I had 3.73's installed and it is much better now ;D My girlfriends 00 GT has 3.27's in it from the factory. It has a little more torque off the line and more importantly, you can use 5th gear. I would hunt for some 3.08's or maybe 3.25's at the minimum. Maybe look for some 3.45's or 3.55's if you want to get a little more radical.
I think he is calling 2:78 low and 4:11 high. Should be the other way around. 4:11 with overdrive is the best of both worlds. After all, you do build a V-8 Pinto to go don't you?
Quote from: turbopinto72 on September 16, 2004, 12:26:57 PM
The question was " Any comments" preceded by the fear that his car my be to low geared with a 2.78.
OK, I need to clear somthing up. The ratio of the gears is 2.78 to 1. It has 39 teeth on the ring and 14 on the pinion. If you divide 39 by 14, you get 2.785...
Also, my fear is that it is geared too High, I was incorrect stating to low. I had been working on the car all day when I wrote it...
Thanks
We probably ought to mention the car will see both highway and track use.
Highway and track. That's a fun combination! I'm running 63mph @ 4000. I have a 1:1 direct drive high gear, not an overdrive though. I'm screaming along in the far right lane while fully loaded log trucks pass me. 8)
Ouch.............. :o
Go to www.project33.com and use the calculation tools on the left side of the page.
The Srod is not a listed transmission ::)