BBC, which Transmission is the best?

[betzjr66]

Hello all,
I have a BBC that I plan on running in a Cobray. I decided to go with a Richmond 5-speed partly because I got a great deal, but also because I was able to keep the stock 3.08 gears in the rear (saves $$$ on a gear swap)with this trans and have it act like a 3.73 geared car with a .8 overdrive. What is everyones transmission preference? Anyone else using a Richmond?

[Lightingrod]

How much torque?

Al

[vettestr]

Hey betzjr66,
Are you running the Street Richmond tranny? Here is a good info site with RPM's listed at different gear selected (1 to 5th) and tire size listed. I think the Street version is rated at 600 for torque so you should be fine, especially with a light car.
http://www.5speedtransmissions.com/5sp_comparison.html

[RICK LAKE]

betzjr66 I have a couple of questions. What is the power output on your BBC? What tires are you running, Street autocross, slicks? This question is most important, what are you going to do with the car? Street driving and Shows? autocross and roadracing, Drag racing, alittle of all this? Here is the issues. You have not said which trans you have. The one that has been out for the last 15+years has a tork and HP rating of 450HP and 450ft pounds of torque. For normal street driving with street tires this trans SHOULD be no problem and holdup. The gears inside are cut a 22 degrees to keep the trans quiet and keep noise down. The new Super street trans has straight cut gears and a 600 HP and torque rating. I'm sure that you BBC is maken 500+ ft of tork. I run 2 different transmissions. I have a 6spd Richmond for street with the overdrive. The first gear is 3.25, what a waste with 3.31 rearend gears I never use it. It's 1" longer for the trans mount location. It only has a 450/450 rating. I don't beat on this trans and ONLY run BFG street tires because they have poor traction on the street over other tires. I race with a G-Force 5 spd. The externals are the same as a richmond 5 spd but this trans is good for 1000 HP and torque. It's a semiclutchless 5 spd. It is also about twice the price as the cheaper Richmond 5 spd. I am looking at the superstreet 5 spd with the 2.87 first gear and overdrive 5th gear. This is the one that would BEST fit you over all needs. IMO You will not hear the straight gears when driving if you have side pipes. I like and run both transmissions in my car, I also KNOW there limitations. Rick L.

[betzjr66]

The trans that I got is the 4+1. I believe that it is rated at 450 lbs. I only plan on using street tires on this car and driving it for fun and to local shows. There is a possibility that I take this car to the local drag strip, if so, I would probably run a drag radial instead of a full slick and keep my fingers crossed. I believe that the wheels will break loose before the trans. breaks. the car will weigh under 2500 lbs. with the big block when it is completed. I am thinking of a 10 in. wide rim on the back with a 285/40 tire.

[RICK LAKE]

betzjr66 The problem is wheel hop that does most the damage to the trans, clutch and rearend IMO. You you have to do is come out of the hole easy and then you can get into it. The gain and lose of traction is what breaks more parts than anything else. Leave the starting line at 1,200 rpms, If the car squats and leaves, raise the rpm's another 100 rpm, When you start to spin you tires off the starting line back down 100 and stay there. Make sure that both rear tires have the same pressure in them. If the rear shocks are adjustable, turn down the dampeners to softer so the car will that weight transfers, the rear of the car will go down and leave. This puts more weight on the rear tires to hold the track surface. If you get wheel hop off the line, and the whole car shakes, GET THE HELL OUT OF THE GAS. Don't try to quick shift the trans too fast. I have seen some guys go from 2nd to 5th more times than I can count ( 7 ) . I race with 2nd gear and stay out of first, the shift is to quick, and in 2nd it slows down some of the power shock to the rear tires. Don't worry about the other car, If you are ahead great, if not keep 1/2 an eye on him for keeping control of his car. If that little voice starts talking in your ear, listen and get out of the gas. Save the car for next run. That's the best info I have to give you. Don't run fastern than 12.00 They will throw you off the track for safety issues. Been there had this happen. OPPPSSS. Have fun and be careful Rick L.

[vettestr]

Rick's description of the launch as a squat and squirt motion was very accurate. With the torque of a big block and the low car weight many people would be happily surprised with the launch. Because the Cobray is over 1000 pounds lighter than a stock 68 to 82 Corvette the handling is greatly improved.

In most cases if wheel hop is encountered on our car the shocks need to be firmer and /or the RPM lowered. The driver can feel the car squat and begin it's launch but you can throw that run away if you roll power on so fast it blows the tires off the car. Aftermarket companies like VBP now have a Dual Mount Rear Suspension set up that helps to tame the torque. With big HP/torque numbers you can boil the tires at will but it will tell you it is coming if you listen. If not hang on.