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I have an 87' Firebird and I just have the stock rear end and I would like to up grade to somithing I could use Mainly for Drag Racing And a couple trips to town every now and then with out having to get one of those comp. engineering frame kits. What could I replace with some performance part and maybe add like some kind of 4-link or somithin. Also I bought some new wheels 14-6 for the front and 15-10 for the back Im gettin some 295-50-15's for the back what should I get for the front?
do you know what rear end its got now? 10 bolt, single trac, posi? and what motor do you have, and with any add ons?
I myself would put a Ford 9" rear end in it, it is very dependable and there is a wide selection of gears for it. You can also find all kinds of 3 or 4 link brackets designed for it that will just have to be welded in place. You can get one from the junk yard or Currie offers all kinds and shapes of the 9".
Jimi G.
go with a ford kit and use the factory style torque arm suspension as it is basically a long ladderbar and can plant the tires really good , but don't use the stock one as you will bend it get the aftermarket ones . , if it wasn't for the torque arm I would say use a 8.5 ten bolt with a girdle as they are durable enough to hold up , we have been racing a 3300 bound camaro ( sec gen ) with a BBC running 10:35 @132 for the last 4 years without a problem the only thing we had to do to it was weld the tubes to the pig .
You cant go wrong with a 9" rear.You can get a extra pumpkin with street gears ,and easily change them for the street.Since everyone uses 9" rear ends there are plenty of parts.
Both Moser and Currie make a 9" with brackets that is a bolt in for your car... Not cheap but as close to bulletproof in street use or at the track (with good axles) as you can get. But, if the car is an automatic, not tranny brake, the stock rear with a good posi unit will hold up remarkably well....
Have to agree with Dave, if you have a Ford 9" you cannot go wrong, street use, go for a good 4 spider possi. If you have 31 spline axels all the better, because with those big tyres on one end a big HP motor on the other end sometning has to give. So your 31 spline axel will give you more insurance over a 28 spline. On the strip or burnouts, have another center section with a mini spool, so yo dont have to much money tied up in a detroit locker. And you wont have to rebuild the clutch pacs to often in the posi.
I have a way of calculating the correct rear gear for your application given the tire size and maximum engine rpm. BUT take into consideration THIS.....the formula I use only takes into consideration maximum engine rpm with a one to one transmission output and tire size. That considered, you need to look at it this way, with a one horse power engine capable of 4,000 rpm and the tire size of 30" and a gear ratio of 4-50, you will eventually reach a maximum speed of 100 mph. It may take all day, but you will get there, relatively with a 1,000 horse power engine capable of the same maximum rpm of 4,000 you'll reach the same 100 mph with the same gear ratio of 4-50 but you'll get there before you hit the end of the driveway :eek:
So all these things being understood it is up to you to consider you're power to weight ratio, maximum horsepower and torque and how far into the upper rpm ranges you want to push your engine.
All that being said, I need your tire size and maximum engine rpm and I will assume that you are running an engine with 375 to 400 horsepower, the higher horsepower and torque, the higher you can run your gear. I will also assume at this point you are running a 26" X 9" tire and if it is a small block you're probably capable of running 7,000 rpm. Which would give you an appropiate ratio of 4-30 which should run you through the quarter at approx. 125 mph and also give you a halfway decent streetable.
Shaggy
after all this I am on the wrong thread $#^^%*&^%$#
^^^^^^^^ big ooopps there shag !!!
Rutt Roow!!:eek: :LOL:Quote:
Originally Posted by SHAGGY