Rear-end question

[Gary Perkinson]

Hey, everyone:
 
 I'm building an '80 Pinto wagon for the salt. What kind of center section do most racers use at Bonneville--open? posi? locker? spool? Does it matter? And I assume the gearing should be as tall as possible, right?
 
 Thanks--
 
 Gary  

[jimmy six]

Yes too all of the above. You gear to the RPM, tire size you have, and the speed you think your HP will reach. I would blow up with 4.11's, go fast with 3.08's, and go slow with 2.29's

[Dave Cox]

If you're on a budget, go with a 9" Ford with a mini-spool, look for Lincoln Versaille with the disc brakes, it's the narrowest available and runs about $350 from a wrecking yard, but you're likely to have to narrow it for a pinto.. As for gear selection, make your decision on tire diameter (what will fit the body) and determine the top speed you'll want to shoot for (and what your top engine RPM is). That will determine what ratio you'll need to run. This assumes you'll have the HP to pull the gear.... You'll be changing rear end gears as you increase the powetr and the 9" has alot of choices available.
 
 Dave

[fwilly]

-what engine and class will this car be in?
 -How fast is that class?
 -What gears to you have for it now?
 -I don't know if that 80 pinto has the same gear choices as a 74 pinto but if it is the same then you are limited to something like 4.62, then the next step up is a 4.10 and then the next one is a 3.80.
 -Several sets of different diameter tires all mounted and balanced sure helps.

[Gary Perkinson]

Thanks, everyone.
 
 I'm shooting for D/CGALT. The engine will be a naturally aspirated 302, with a stock crank, home-ported E7TE Ford heads (1.94/1.60 valves), a solid-roller cam in the .550 to .600 lift range, a single-plane intake, and a 750 cfm carb with mechanical secondaries. I'll be replacing the stock C4 automatic with a T-5.
 
 The class record, I believe, is 224+, and I have no illusions about coming close to that. I just want to go out there and see what she'll do....
 
 Thanks again!
 
 Gary

[fwilly]

-Is that T5 an overdrive in 5th?
 -What are the gear ratio's of the T5 and what tire diameter do you plan to run?

[Rick Byrnes]

Gary, beware of using 5th gear in the T5.
 The gear is overhung, in the tail housing, and if you make enough torque as I did the gear and snap ring are pushed rearword till the gear fails due to limited engagement.  This happened a number of times in drag race testing and I made some modifications, but it happened in the 3 mile and overreved the engine.  It ruined my week....from that point on we used 4 speeds only and geared for 1:1.  A much better choice would be the TREMAC, but when I switched, I still used only 4 speeds.

[Gary Perkinson]

Guys:
 
 Don't have the new tranny yet--I just assumed that having a 5th gear (overdrive or otherwise) would be beneficial in a top-end-heavy style of racing like LSR. If four gears works just as well, maybe I'll just look for a Toploader....
 
 Gary

[jimmy six]

If you feel you still need an overdrive, look to Tex-Racing or Jerico for a Nascar overdive type trans.  Infinate ratios are available. Transmissions are for the most part bullet proof. Tex-Racing is good to work with I was able to purchase a 4 speed overdrive with perfect used gears all of my choice. Keith Turk has been using one for years and was instrumental in helping me with it. Good Luck

[dwarner]

Holy cow JD! What are you doing up at 1AM on a Monday morning. Do you have old man's sleeping sickness?

[bfolkestad]

Gary,
 
 I have ran a locker and open dif.. It really made no difference.. We used a Jerico the first time (From Tex) and a ZF 6 speed the second time.. (the open diff would be less radical if you buzz the tires @ 150 mph)
 
 If your engine has some RPM use a T-10 or Jerico. Depending on your tires size (example and 30" Tire and 3.50 gear will go aprox 205 mph @ 8500 rpm
 
 The lowest new gear I have found for the 9" is a 2.48 (Tex Racing)
 
 I would use a floater 9" Like the stock car guys, they are fairly cheap and you do not have to take the wheels off to pull axels for a gear change.

[jimmy six]

Dan are you nuts?  Must be eastern time.  I was on just before going to bed at 10:15