Gear Ratio question
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Joined: Mar 2011
Posts: 72
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From: hialeah FL
Gear Ratio question
Hey Guys,
I'm rebuilding my L-48 and I'm looking to get around 350 fwhp. However, I'm alittle worried about whether I should change my Gear ratio.
I have the original 4-speed, and my gear ratio is 3.08.
What's a good ratio to have for a daily driver and highway cruiser. I want to be able to drive this car normally and yet perform when i want it to.
Thanks
I'm rebuilding my L-48 and I'm looking to get around 350 fwhp. However, I'm alittle worried about whether I should change my Gear ratio.
I have the original 4-speed, and my gear ratio is 3.08.
What's a good ratio to have for a daily driver and highway cruiser. I want to be able to drive this car normally and yet perform when i want it to.
Thanks
Race Director
Joined: Mar 2008
Posts: 15,161
Likes: 17
From: coffee
http://www.700r4.com/speedoCalc/rpmcalc.shtml
It's all a matter of what RPM you want. A 5 or 6 speed overdrive is ideal, but presuming you're sticking with the 4 speed, just plug in 27 inches for your tire diameter and see what rpm a given gear gets you. If you don't mind revving, a lot of folks seem to like stuff in the 3.50 range, but that's totally a subjective thing.
It's all a matter of what RPM you want. A 5 or 6 speed overdrive is ideal, but presuming you're sticking with the 4 speed, just plug in 27 inches for your tire diameter and see what rpm a given gear gets you. If you don't mind revving, a lot of folks seem to like stuff in the 3.50 range, but that's totally a subjective thing.
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
I would not change ratio until you have driven the new motor, you may find you like the way it drives as is. I was going to suggest something in the 3.5 range as well. From what I've read, many find this to be a good compromise. I'm planning to move to a 3.70 but plan to install an overdrive tranny to bring the hwy RPM back down.
Drifting
Joined: Oct 2010
Posts: 1,972
Likes: 6
From: Chester Virginia
I've got a 4 speed L48 like you have and a 3:36-1 rear end. It seems to be a good compromise and with double the horsepower you'll have you will be able to do just about anything with the rear end. The 3:50+ will give you more wheel spin at first in low gears but your engine will be running a whole lot more rpms at 70 on the highway than you are used to with a 3:08. Mine at 70 in fourth gear (bw S10 manual 4 speed) is around 2950 rpms or so for info.
p.s. If it weren't so expensive I'd like a five speed for better highway mileage and the power you are going to have but in the meantime, I kinda like what I have for road driving. It's not going to be a drag car without more power anyway.
Lance
p.s. If it weren't so expensive I'd like a five speed for better highway mileage and the power you are going to have but in the meantime, I kinda like what I have for road driving. It's not going to be a drag car without more power anyway.
Lance
Last edited by LancePearson; Jul 6, 2011 at 05:25 PM. Reason: added
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If you want decent highway speed comfort and reasonable economy, keep the 3.08. If you have the money to do it, a 3.55 or 3.70 gear combined with an overdrive 5-speed transmission will give you everything you want....but the price and effort is increased a bunch.
