fot
[Top] [All Lists]

RE: changing spitfire gear sets

To: fot@autox.team.net
Subject: RE: changing spitfire gear sets
From: "Aaron Johnson" <fpspitfire37@msn.com>
Date: Wed, 03 Sep 2003 13:46:46 -0700
Bill,

You are correct 8K is tops for a car with stock rods, I shift around 7700, 
some of the big dogs are spinning close to 9500 with forged rods, pistons 
and weekly rebuilds (I won't be in that range but 8500 is safe working 
area).  For me the lower ratio is nice because I have no gaps between gears, 
1st is 1.6, 2nd 1.3, 3rd 1.1 and 4th is 1:1.  This uses a 1.04:1 input 
ratio.  I see about 700-800 rpm drop between gears and shift about 20 times 
around Portland. It is a little tough to get rolling and slow starts KILL 
me.  These ratios appear to be pretty close to perfect for PIR but next year 
is for fine tuning.

What is scary are the guys with 1147's that run 3.89's, I didn't think that 
small of a motor could put out that much power.

Aaron

<Prev in Thread] Current Thread [Next in Thread>