well first, I am going to try to build an 11sec FB, with a 85 gs rx7, not sure if I should weld the diff instead but I dont know what I am doing when it comes to diffs lol.

what gearing can I use and where do I purchase the gearings, this is all new to me.

thanks guys, I appreciate everything, and I apologise if this is a stupid question.

 

anybody?

 

Do you have a target HP that you know is attainable? In order to select the best 1/4 mile gearing you need to work backwards.

Figure out what type of power you can make, then work the numbers backwards to figure out how to build a a setup that only requires the 1-2-3 shift instead of the dreaded 1-2-3-4 shift. That would be the start.

You might consider buying the parts from Mazda Competition Parts aka Mazdaspeed Motorsports Development or consult with a shop with a well known/successful RX-7 drag racing history such as Mazdatrix, Rotary Performance etc.

 

thank you so much keith, I appreciate the info.

 

Are you building the 7 for a specific class or series or is this just something to have some fun in on the weekends and score some "1/4 mile cash"?

 

optimal gearing depends on the hp/torque curve of the engine, and the track you're racing on.

if you wanna use a STOCK trans, they have a wide spread between gears, so the engine needs a wide power band.

www.yawpower.com has a nice calculator

 

www.grannysspeedshop.com

ford 8.8 with many gear choices. and lighter than a 9 inch. and plenty strong enough.

gears are the least of your worries right now...12a, 13b? full bridge, half bridge, P-Port, NA, turbo, nitrous??? full interior, gutted, street legal, carb, fuel injection???

get your motor ideas in order first... gears will not push you down the track...