<VV> 5-speed transmission

Joel McGregor joel at joelsplace.com
Tue Aug 18 16:33:32 EDT 2020


2200 at 75mph is totally different than 2200 at 45mph.  Much higher load with the same cooling and you aren't likely to run 45mph for hours like you might run 75mph.
That said I don't think it's an issue since FCs do fine with much higher loads than cars.  It might not be good to run an FC in 5th at high speed with a load.
Joel McGregor

-----Original Message-----
From: VirtualVairs On Behalf Of Cliff Tibbitts via VirtualVairs
Sent: Tuesday, August 18, 2020 11:44 AM
To: virtualvairs at corvair.org
Subject: <VV> 5-speed transmission

Wowzer, I never dreamed my simple answer to a question would arouse so much interest.

Kent, was there any empirical testing done prior to your installation?
Just curious because I was not around when these units came out.  The testing would be nice to have but expensive and who would want to do it?

On the other hand, seat of the pants experience counts for something as well.  Consider this.  These cars were built in the 60's before most of the present day Interstates were even built.  The national speed limit for most thoroughfares was 60 or 65 MPH.  Also consider that these cars were expected to spend most of their time running around town at speeds of 35-45 MPH.  At those speeds the engine would have been 2000 RPMs plus or minus
500 depending on gear ratios.  Therefore I think again, that the cooling should not be a problem unless the RPMS dropped below 2000 rpm.  In which case, I would downshift.  I do that now with my 4 speed.

Finally, and I don't have the information in front of me, but I read once that the cooling ability of the fan decreases above 4000 RPM so for people who like to drive at 75-80 on the interstate, I think a 5th gear would help quite a bit.
-- 

Cliff Tibbitts
cliff at tibweb.com



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