swapping to 2.73 gears......
swapping to 2.73 gears...... Will I get into boost alot sooner? Setup is a 5.3, TH400, mid mounted on3 76/65, 3200 stall, 3. 73s, E85 with a 27inch tire. I daily drive it so its a bit of a pain on the highway. I really hope this gear swap tames it on the freeway because it is just a complete animal cant hook at all and it just easily roasts the tires. Spool is pretty much instant. I can blip the throttle and as soon as it hit boost the truck just fish tails in other lanes lol. I plan to do alot of highway driving this year with LS fest/ect and all..
yes it will tame it down but im not sure it will slow it down much. I ran a 4.00 gear (9" axle) with a 28" tire on my gn and the car ran 11.70s and sucked on the highway so just to drive the car I went to a 3.00 gear to cruise it felt so good I took it to the track and it ran 11.09 all on the same tune and boost. the car loved to be loaded.
not only was the 3.00 faster it was also the best 60' wich I still don't understand.
not only was the 3.00 faster it was also the best 60' wich I still don't understand.
Joined: Mar 2007
Posts: 1,145
Likes: 50
From: Saskatchewan, Canada - where arguing "DA" is for the slow and weak...
I also swapped to 3.08s in my Turbo Buick (w/TH400) about 10 years ago. Runs 11s on a 315/35R17 drag radial on a 1.7 60'. The theory is that you accelerate faster by staying in the torque band longer; it is the strength of a well tuned turbo motor (unlike a 8000rpm turbo Supra/Honda which makes power far too late).
I've never experienced it on an auto car, but in a 6 speed C5 going from 3.42 to 2.73 at ~780 rwhp, made the car incredibly driveable, would hook from slow rolls where it would just destroy the tires previously, and was simply faster in every respect.
Go for it and let us know how you like it!
Go for it and let us know how you like it!
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Verdad Gallardo It just freaking screams on the highway. The only reason I want 2.73
is because I want the best bang for the buck as Im having a very reputable shop rebuild the rearend.
more than likely will I go through the traps in 2nd gear?
is because I want the best bang for the buck as Im having a very reputable shop rebuild the rearend.
more than likely will I go through the traps in 2nd gear?
Maybe... depending on power and converter slip. Is it a 9" rear?
TH400 2nd ratio is 1.48... with a 2.73. (Not accounting for slip.)
129 at 6500.
134 with a 28" tire.
Would be like a glide and using 3rd for OD.
TH400 2nd ratio is 1.48... with a 2.73. (Not accounting for slip.)
129 at 6500.
134 with a 28" tire.
Would be like a glide and using 3rd for OD.
Its an 8.8 explorer rear, Ill be making around 600-650rwhp.. I found a set of used 2.73s For $60 shipped? Think I should grab em? Heres a couple of pics. Im having a shop install them.
Last edited by Ron_Stoppable; Feb 1, 2015 at 01:30 AM.
If you don't mind if they might be noisy. It's harder to get a pattern on used gears. New gears are cheap. If your paying to have them installed no question buy new.
On The Tree
Joined: May 2012
Posts: 175
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I rolled the teeth on a new set of 3.08's in an 8.5. Don't know if it was the pinion bearing deflecting that helped it or what. My rear end guy got a set of used gears when he built the 9in, when they get enough use/break in they get hardfaced (the shiny spots you see). If you set the gear to run in the same pattern its not a problem, my rear end is dead quiet.
I think alot has to do with the installer as far as noise and used gears go. We have a local that specializes in gear changes here. I've probably had him do 10 gear changes in the last 8 years or so. All used gears. The only noisy gear I had was an EX-nascar gear that was polished and lightened. Every other gear set was perfect noise wise. He uses a formula to calculate the shims needed and checks the tooth engagement pattern.