2.77's to 3.73's
02-26-2007, 02:21 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
2.77's to 3.73's
What ET gain can i expect from swapping the Salt Flat-friendly 2.77's to 3.73's in the IROC? (see profile)????
Also, where online can i buy the appropriate speedo gear for the auto?
Thanks!!!
Also, where online can i buy the appropriate speedo gear for the auto?
Thanks!!!
Last edited by AUSSIROC; 02-26-2007 at 02:50 AM.
02-27-2007, 02:43 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Have you tried those slightly taller gears in your iroc??
02-28-2007, 04:15 PM
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When my car was near stock I switched from 2.77's to 3.73's, I agree that a stock car with no intake mods will be better with 3.42's.. I knew I was modding my car so I went 3.73's.. Car responded well to them regardless!
If you are planning to mod go woth 3.73's
My car gained about 1.5-2 tenths but street tire limited.. it was a 14.1 car prior then 13.9 car aft. Feels alot better though.. They will really shine after tires are on and you can use the gear advantage.
If you are planning to mod go woth 3.73's
My car gained about 1.5-2 tenths but street tire limited.. it was a 14.1 car prior then 13.9 car aft. Feels alot better though.. They will really shine after tires are on and you can use the gear advantage.
03-02-2007, 01:23 AM
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Car: 1989 iroc Z Hardtop
Engine: 350 tpi
Transmission: 700r4
If you plan on upgrading that tpi then 3.73's are doable but on a stock top end your L98 will be out of breath @ the end of the 1/4 with those gears.
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How do you like yours?
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How do you like yours?
Last edited by rocluvr0013; 03-02-2007 at 01:24 AM. Reason: Automerged Doublepost
03-04-2007, 11:56 PM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Cheers guys,
I will probably go with the 3.73's since i will likely junk the tpi in the future.
Or port the crap out of the plenum and runners as a low-buck option until cash is available
I will probably go with the 3.73's since i will likely junk the tpi in the future.
Or port the crap out of the plenum and runners as a low-buck option until cash is available
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03-05-2007, 12:41 PM
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Car: 92rs
Engine: 350
Transmission: 350
Axle/Gears: 3.73/Moser 12bolt
I am hoping to have my 3.73 's in by this weekend . My motor is stock but I got the whole rear w/ the 3.73 in it .12 bolt moser 33 spline . Will post improvements if I get to the track this weekend.
03-05-2007, 01:59 PM
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Car: 1989 iroc Z Hardtop
Engine: 350 tpi
Transmission: 700r4
You might even be slower in the 1/4 since you added weight and your a little overgeared for that tpi setup.
03-12-2007, 05:22 PM
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Car: 92rs
Engine: 350
Transmission: 350
Axle/Gears: 3.73/Moser 12bolt
3:73 swap
well went to the track Sat. & everything improved except the e.t. , even lost 1 mph .
car leaves great ( from a 1.89 - 90 60' b4 swap to a best of 1.81 after ) , hits second great , then 3rd , then done about 1000' mark .
best b4 of 13.65 @ 99
saturday i went 13.71
13.51
13.64
13.62 all at 98 mph
I do need to play with it some more to get consistent times .
I do plan on going carb so i'm only a little disappointed .Sooner than not if i cant find the problem w/ my Maf .
good luck Mike
car leaves great ( from a 1.89 - 90 60' b4 swap to a best of 1.81 after ) , hits second great , then 3rd , then done about 1000' mark .
best b4 of 13.65 @ 99
saturday i went 13.71
13.51
13.64
13.62 all at 98 mph
I do need to play with it some more to get consistent times .
I do plan on going carb so i'm only a little disappointed .Sooner than not if i cant find the problem w/ my Maf .
good luck Mike
03-13-2007, 05:05 AM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Raptor,
Good stuff, great to know! Shame bout the et but huh. Thanks for the post tho.
The IROC's in surgery at the moment, getting the new gears, and the motor and trans are getting a freshen up so hopefully i'll be at the track soon.
Cheers!
Good stuff, great to know! Shame bout the et but huh. Thanks for the post tho.
The IROC's in surgery at the moment, getting the new gears, and the motor and trans are getting a freshen up so hopefully i'll be at the track soon.
Cheers!
03-13-2007, 04:59 PM
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Car: 1989 RS convertible
Engine: 305 TBI LO3
Transmission: TH-700-R4
Axle/Gears: stock axles 3.73 LSD
i would go 3.42 since you have the 700 r4. imo its too much gear for the auto and i would trade mine for 3.42's any day
03-13-2007, 06:04 PM
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Car: 1999 subaru forester GT (urgh)
Engine: ej20 turbo
Transmission: 5speed
Axle/Gears: 4.11:1 awd
Gray, I'm hoping to dump (or port in the short term) the tpi so that is swaying me. However, one of the guys here said i would top out in 3rd a fair way before the traps on the strip. Not good. Wish they had 'try before you buy' rearends.
03-14-2007, 10:35 AM
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Car: 92rs
Engine: 350
Transmission: 350
Axle/Gears: 3.73/Moser 12bolt
Yeah it was maxed out at about the 1000' . I am running 26" DRs though .
A buddy of mine has some 29" slicks i may try out to cut the gear back some .
Wont be this week though unfortunately . And yeah I am going carb as soon as funds allow , so I'm just getting what I can out of what I got .
Good Luck , Mike
A buddy of mine has some 29" slicks i may try out to cut the gear back some .
Wont be this week though unfortunately . And yeah I am going carb as soon as funds allow , so I'm just getting what I can out of what I got .
Good Luck , Mike
03-14-2007, 04:23 PM
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Car: 1989 RS convertible
Engine: 305 TBI LO3
Transmission: TH-700-R4
Axle/Gears: stock axles 3.73 LSD
yeah im pretty sure my car would top out in 3rd in the 1/4 mile but thats impressive to say haha...
04-10-2007, 12:38 PM
#17
Re: 2.77's to 3.73's
Raptor… is this in the Iroc? 3.73’s should put you right in your powerband with a 350TPI if all is right with it… It should go a little faster with a 27-28” tall tire (I’ve run my fastest times shifting at 4600, a 28” tall tire would put you through the traps right around 4600. I suspect the car would run fastest going through the traps at 4700, and with 26” tall tires now you’re going through at just over 4800…
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