Wedge diff

[MARSHO]

Hi, can someone please advise me as to which diff would be most suitable for drag racing?.I am running a 350 chassis with a standard diff(dont know what ratio),I am in fourth gear at 98 mph just before I cross the line .WhatI would like to know is would it be better to change the diff for one which is faster on acceleration or one that gives me slightly less acceleration but better top end speed?any advise greatfully recieved of course. The wheels are 17" and I was thinking of dropping down to 16 " next year just to see if I got some improvement ,thanks David.

[Number 7]

Well the standard 4HU diff should be a PowerLok, with a 3.54:1 ratio. Should be on a tag bolted to the diff. With a standard'ish 3.5L engine, peak power is going to be a little over 5K rpm, so little point in taking it above 5500rpm. What revs are you changing up from 3 to 4 at?

7.

[MARSHO]

Hi, thanks for the reply,the engine is a 4.6,ported heads and lightened flywheel the cam is a Kent 214,I am changing gear at about 5000/5500 revs but cannot guarantee that because everything is happening so bloody fast(this is my first year at this kind of stuff)thanks David.

[JR]

MARSHO said:

The wheels are 17" and I was thinking of dropping down to 16 " next year just to see if I got some improvement ,thanks David.

Better still to drop back to the original 15" for drag racing - lighter, less inertia and the taller side walls transmit the power better. Have a look at other drag racings cars and you'll see what I mean. J