Posted by Frank Haas on June 22, 1999 at 11:18:56:
In Reply to: 3HP22 swap to 4HP22, is it possible? posted by Carlie Bentley on June 22, 1999 at 10:08:47:
: I have been looking for a way to drop my RPM's on the highway. My car is a '78 530ia. It has a 3HP22 trans now. I know they built a 4HP22 trans later. I currently average 3000 RPM at 60 MPH 4000RPM = 80MPH or there about.
: Would the 4hp22 give me another gear to lower RPMS or just another gear? Is there an auto I should look for?
: I have heard that some of the later trans were electronically controlled. I know this will be a problem. but I drive highway so much I need to shed some RPMs. I drive in town so much I don't want a stick.
: THanks Folks.
Hi Carlie,
An easier solution to decreased rpm's at high speed would be to install a 3.07 geared rear end, instead of the 3.45
that you have in the car now. It takes about 2-3 hours and is pretty easy to do. Call some local wrecking yards to
get one --shouldn't be much over $200-$350. The one you need to look for is out of a 79-81 635csi, as a benefit
it might be a LSD to boot.
Regards,
Frank