Too much Torque?

[Excaliber]

I had a higher 1st gear ratio, much higher, than I have now. I was consistently FASTER with the higher gear ratio's because it was easier to control wheel spin and I could hook sooner.

Then, close ratio top loader driving a 3:31 Jag. Now, TKO600, same rear.

Some folks with a low 1st gear have found that starting in 2nd, at a drag race, gives them their best ET. But sadly, often at the expense of the clutch depending on how high 2nd is.

[YerDugliness]

QUOTE=Broadkill1;1106472]I was wondering if maybe a higher gear ratio would allow more stick or if a strong 9" rear would be necessary if I could acheive more stick to the road.[/quote]

As I read this thread, it appears to me that the issue is how to best use the available torque....which might be a huge challenge given the high torque figure and the low weight of the car.

A well set up 8.8" Ford will MOST LIKELY stand the torque b/c, as others have mentioned, the rear tires will most likely break loose before the breaking point of the 8.8 is reached. Sure, you could just leave the car as-is and "enjoy" the smell of burning rubber (smells a lot like burning money, to me, though).

IMHO, a change to a "higher" (almost an oxymoron, as the number will be "lower") rear gear ratio would yield benefit in at least two areas....first, IMHO the point at which the tires will break loose will be shifted to a higher ground speed, as the car will have gained more speed before the RPM's are reached at which the engine's torque will overpower the tires (this is assuming the clutch was used carefully so as not to break the tires loose as the car started from standing)....second, when the tires do break loose, the car will be easier to bring back under control than with the lower gear ratio.

An added benefit will be greater gas mileage....which with all the cubes, HP and torque this engine is producing might well be a great benefit.

I've said it before, will say it now, and will probably say it again in the future.....more torque=more tire smoke, not greater acceleration in one of these lightweight beasts . My small block is a great example....as long as the "challenge" isn't greater than 1/4 mile, I can leave a big-block car in their own tire smoke. Sure, they'll blow by me when they do finally get traction, but most of the time I'm already applying the brakes (don't really care for high speeds in these aerodynamically unstable cars ).

The Ford 9" would definitely be advisable if you plan on sidestepping the clutch at high RPM's.....even a well-built 8.8" can only withstand a certain amount of abuse.

Cheers from Dugly

[sspano01]

I have a 521 in my Cobra - its not "legal" to drive yet...but I have had it out up and down the block. I have a hydraulic flat tapped cam, the computer model says we should be around 550hp about 600 torque. It also has a T56 Magnum and 3.5:1 tru-trak. First gear was a little rough, on the edge of unusable. But 2nd gear was able to drive smoothly. And in 3rd as well. I was lightly pressing the accelerator, and it seemed to respond smoothly.

[mdross1]

When my car was first on the road with a 460 had a Top Loader and 3:55's.With BFG's it was too easy to kick the rear out in hairpins.Next installed a Tremec TKO as I remember a 3.24 first gear and a 3:73,it was much better in the turns.Ran some stickies for a while and could not live with all the sand they were pelting the car with all the time.As the car works so good in the turns cannot stay in the seat,with street rubber.Calling it just right.Love the big torque when play time strikes,otherwise the car is docile enough for every day running around.

[bigleo69]

i would try 3.27 gears and make the axles 31 spline
the weak link being the u-joint
3.73 are sweet but running highway with that much torque has to be very loud.
the 8.8 is strong but the 9" would fit you fine if you were racing on the strip.
strictlly street either leave it be or go to a 3.27 highway rpms will be just as sweet but tamer

[mdross1]

Having all that torque at hand is going to a challenge always.Sticky tires will help but there will always be that point when traction fails and at a higher speed.My compromise was running the best tires without sandblasting the car and learning that illusive point of broken traction which is not always the same.In the end making the driving experience that much more exciting.Yes the tail wags out once in a while,and knowing when your getting close is the fun part of driving the car.Good Luck

[Dwight]

I have a small block so my problem was small compared to yours,

I had to work with the alignment on the rear end to get the car to pull straight. When I got on it hard the tail would drift to the ride side, maybe a foot but in the car it felt like 4 feet.

I had to install double adjustable shocks. Increase the passengers side and soften the driver side. With the driver's weight on the drivers side you would think it would give more traction to that wheel. Not so, the torque of the motor plants the passenger side wheel and lifts on the drivers side. I adjusted my shocks to even this out and now I pull straight with the tires smoking.

Dwight

[392cobra]

Originally Posted by Dwight

I have a small block so my problem was small compared to yours,

I had to work with the alignment on the rear end to get the car to pull straight. When I got on it hard the tail would drift to the ride side, maybe a foot but in the car it felt like 4 feet.

I had to install double adjustable shocks. Increase the passengers side and soften the driver side. With the driver's weight on the drivers side you would think it would give more traction to that wheel. Not so, the torque of the motor plants the passenger side wheel and lifts on the drivers side. I adjusted my shocks to even this out and now I pull straight with the tires smoking.

Dwight

4 link rear ends do that until they are adjusted. It would have been a lot easier and faster to adjust the preload on the right upper link.

1 "flat" of less preload might have been enough preload if the rear was going right. 1 flat more if going left.
1/2 to 1 flat at a time is all the adjustment you should do.

I've done this adjustment to several Lone Stars in the DFW area.Works every time no matter the shocks,drivers weight,etc..

Your right tire was biting more than your left causing it to go right.

The right rear tries to lift and the left rear tries to dive due to the rotational torque thru the driveshaft.

What you did with your shocks was lessen the load on the right,deceasing it's bite. The same as less preload on the upper right bar. It then evened out the bite and went straight.

[Bruce M]

My Contemporary has a 502 Chev 675HP w/2.52 first gear and 3.70 rear on Hoosier Quick Time tires which really hook up. From a roll, marks on pavement but doesn't break loose. Was difficult to keep together but got it done added watts linkage, stronger rear suspension bolts etc. Built in 1982 with 454 Chev LS6 525HP and needed more power. Awesome !!

[vector1]

when i was researching alignment specs it has been a while and i'll try to remember correctly, a drag racer set the thrust line to the right around 5-7 degrees to compensate for the torque steer.