[71rat]

I have a 468 595 lift th350 and 4:88s on a 28 inch tire the motor should be fine at 6200. I was wondering if i will run out of motor please tell me how i could keep the rear end

 

[Steve R]

You will run out of motor at approximately 110 mph. This does not factor in converter slippage. I wouldn't change anything until you get it down the track.

Steve R

 

[71rat]

steve what exactly does that mean 110? will that match the rpm limit of 6200?

 

[c4boom]

yup

 

[Steve R]

At 110 mph you will be taching 6200. You car may very well be able to run a faster mile per hour in the quarter mile, however, if it does you will rev past your self imposed redline.

Steve R.

 

[Bomber '67]

71rat, here is some useful 1/4 mile math for you:
(rpm x tire diameter x 2.98 constant)/(gear ratio x 1,000) = mph
Take the calculated mph and reduce by torque converter inefficiency, given mph x (1.00 - inefficiency)
All the preceding is based on a 1 to 1 top gear (auto or manual).

So: (6,200 x 28 x 2.98)/(4.88 x 1,000) = 106 mph
Then take off 5% or so for slippage, and 106 reduces down to ~ 100 mph.

The easiest solution to your gearing situation is to install some 32" diameter tires. This will produce a 120 mph theoretical trap speed, and ~ a 114 mph actual trap speed provided your combo pulls 6,200 rpm through top gear in the 1/4 mile.

114 mph is a whole lot more fun than 100 mph

If you cannot get suitable taller tires then a differential gear change is in order.

Best of luck, Thomas



------------------
"Bomber" '67 El Camino, Beater comes back to life.
Was 350/TH350 14.90 @ 93mph, 360,000+ miles on car
Now 406 roller, 340rwhp, more hp coming, 3.08 gears
Street radials, left in drive, 13.20 [email protected] mph
8/1/01 added Plum Mist '67 to collection
*New* 468 on its way - going Big Block!