In a message dated 1/24/00 3:31:08 PM Pacific Standard Time, Gt6steve@aol.com
writes:
<<
Does anyone know and care to share experience on what to do to the D or J
type laycock overdrives to beef them for racing. I'm sure higher hydraulic
pressures are in order but I don't know much beyond that. Any help would be
appreciated.
Thanx, Steve
>>
Steve,
I'm curious. I can't guess why you would want to race vintage with an
overdrive gearbox. First, they are about 25 lbs heaver than a standard
gearbox (at least in the MGB). Do you seriously run out of gears on the race
tracks that you race? Do you get up into the dangerously high RPMs like
6,500 or 7,000 or more on the straights of the tracks that you frequently
race?
I have an MGB with and early standard gearbox converted to close ratio with
an MGA twin cam gearset. I run a 3.9 rearend on long tracks like Thunderhill
and either the 3.9 or the 4.3 on tracks like Sears Point with the 4.3 on
tracks like Laguna Seca.
I know that the MG car company ran very tall gears and perhaps an overdrive
in the early '60s at places like LeMans with the long 2 mile plus straights.
But vintage, where do you need it?
It seems to me if you have your car camed correctly you should make most of
your power at the top of the RPM band (say 6,000 to 7,000) and thats where I
would want to be at the end of my longest straight in top gear. Simply
adjust the final drive to do it.
I'd like to hear your thoughts and those of anyone on the list on this
subject.
Awaiting my flames,
Rod Schweiger
"64 MGB Sebring Coupe
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