re-gear or not?
Thread Starter
Intermediate
Joined: Nov 2007
Posts: 27
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From: Wallburg North Carolina
re-gear or not?
first off, 89 l98 with zf6 and 3.33 rear axle. Performance mods: full 2.75 exhaust with high flow cats, cut air lid, remove waterpump frisbee, light weight single mass flywheel.
The posi is about done, and needs a rebuild. Also I can hear a gear whine from the diff when on the gas. SO, I plan on a full rebuild of the rear with all new bearings seals, ring/pinion, and rebuild the posi.
The question is, should I switch to a lower(numerically higher) gear ratio. With the 6 speed, and the 3.33, I'm under 1400 RPM @ 60mph in 6th, which means i use 5th until i hit 70. most back roads on't allow me to run 80 and use the gear advantage i have for high speeds.
I'm considering going to a 3.73, don't want to go as high as the 4.10 due to the l98, if it was a LT1, I'd consider it.
BTW 1/4 mile performance means almost nothing to me. I get my fun cruising back country roads, and in the twisting streets of the North Carolina mountains
ANy thoughts, opinions, etc on l98 with a 3.73 and zf6?????
The posi is about done, and needs a rebuild. Also I can hear a gear whine from the diff when on the gas. SO, I plan on a full rebuild of the rear with all new bearings seals, ring/pinion, and rebuild the posi.
The question is, should I switch to a lower(numerically higher) gear ratio. With the 6 speed, and the 3.33, I'm under 1400 RPM @ 60mph in 6th, which means i use 5th until i hit 70. most back roads on't allow me to run 80 and use the gear advantage i have for high speeds.
I'm considering going to a 3.73, don't want to go as high as the 4.10 due to the l98, if it was a LT1, I'd consider it.
BTW 1/4 mile performance means almost nothing to me. I get my fun cruising back country roads, and in the twisting streets of the North Carolina mountains
ANy thoughts, opinions, etc on l98 with a 3.73 and zf6?????
Last edited by Chris_M; Apr 8, 2010 at 09:05 AM.
Safety Car
Joined: Sep 2001
Posts: 4,157
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From: Glenbeulah Wi
My opinion is that 3.73 gears with a (relatively) stock L98 is too much gear, but that really depends on what you want to do with your car. The intake does not like to rev higher then 4500 RPM so in a 1/4 run you will be shifting into 5th gear to complete the run and that may hurt performance. If you don't care about 1/4 mile performance and want to cruise at a higher RPM in 6th then go ahead and make the change. It really depands on your goals. (To tell you the truth the change in gear ratio to 3.73 will probably have little effect on the 1/4 performance, it just won't make it faster but it will allow you to cruise at higher RPM)
Le Mans Master
Joined: Jun 2006
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From: One day you're a Comet...the next day you're dust... Arkansas
If you run at highway speeds a lot I wouldn't do it. If it's a town car 3.73 gear should be fine. If you plan future mods that will raise rpm range ie. intake with short runners, I would do it.
Le Mans Master
Joined: Nov 2009
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From: Bangkok, Thailand
Thread Starter
Intermediate
Joined: Nov 2007
Posts: 27
Likes: 0
From: Wallburg North Carolina
thanks mcm95403, I already saw your post with that calculator, and saved the xls file to my pc.
I'm still not sure what I'm gonna do, but at interstate speeds, the gear change to a 3.73 would ony move my rpm's up 200, don't think that would have any noticable effect on my MPG's, in fact, it may improve them instead of lugging the engine @ 65 mph in 6th
also, how would i go about correcting my speedo?
I'm still not sure what I'm gonna do, but at interstate speeds, the gear change to a 3.73 would ony move my rpm's up 200, don't think that would have any noticable effect on my MPG's, in fact, it may improve them instead of lugging the engine @ 65 mph in 6th
also, how would i go about correcting my speedo?
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
