Chuck/Rod/Listers,
I don't have an overdrive in my MGA (it's not legal in A's anyway), but the
hot set-up for MGB's is close-ratio gearbox, OD, and a very short rear like
4.88. Going from memory, the OD gives a 1:0.8 ratio, which makes a 4.88
rear equivalent to the standard MGB 3.9 rear in a non-OD car.
The OD gives essentially a 6-speed transmission, with very close ratios, and
overdrive 4th with the short rear gives appropriate gearing for typical
circuits. Depending on the circuit, the B's w/OD will run a 4.55, 4.88, or
5.12. The hot B's typically turn 7500 - 8000 RPM I believe (5-main, steel
crank & Carillos).
Regards,
Mark Palmer
envious in my MGA
>From: RodsINTOMG@aol.com
>Reply-To: RodsINTOMG@aol.com
>To: Ccanepa50@aol.com
>CC: vintage-race@autox.team.net
>Subject: Re: Racing with overdrives
>Date: Tue, 25 Jan 2000 10:02:21 EST
>
>In a message dated 1/24/00 9:15:22 PM Pacific Standard Time, Ccanepa50
>writes:
>
><< on Mike Kramers race healey 100-4 his overdrive was best used in third
>gear as a 1/2 step up instead of 4th, there is no clutching or shifting so
>it has a very constant pull thru the transition........I had that same
>overdrive on my BJ8 healey 3000, got to just love that 3rd gear overdrive,
>it
>just pulled and pulled forever .....especially useful on climbs in the
>mountains but just grand in any pedal down stuation >>
>
>
>Chuck,
>
>Road going overdrives are very good. I have a late gearbox/overdrive on my
>'67 MGBGT road car and the od on 3rd is as you say. I just can't see an od
>for racing and would be interested to know who get good use of one on the
>track and where
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