3.73 gears in an automatic?
Thread Starter
Drifting
Joined: Feb 2006
Posts: 1,600
Likes: 2
From: Outer banks North Carolina
3.73 gears in an automatic?
O.K. My "99" coupe has the 3.15 gears, Blackwing, Catbacks and a tune. I feel that going to 3.42s would not be worth the money as it wouldn't be that much of a change ratio wise. Have any of you guys went with the3.70s from the 3.15s and actually checked the 1/4 mile E.T. gain from this change? I want my car to be a bit quicker but don,t really want to do any real big mods to the engine as It is just a reliable street car. i would like to have a mid 12 car that is very streetable.
old school Dave
old school Dave
CHICAGO CREW !
Joined: Nov 2001
Posts: 17,591
Likes: 93
From: We are living in a Bazzaro World everything is upside down half ass backwards !
CI 4-5-6-7-8-9 Veteran
St. Jude Donor '06-'07-'08 & '12
I have 3:90s in my A4 car very streetable .my car has a cam headers 2800 stalll converter and the gears . it went from about 28 mpg to about 24 25 on the highway . it's about 3000 rpm at 70 mph . my best time on street tires at beach bend track 12.3 at 114 mph. it had 3:15s from the factory it ran in the mid 13s
Last edited by johnnyvettes; Mar 23, 2011 at 09:40 PM.
Safety Car
Joined: Jun 2004
Posts: 4,986
Likes: 393
From: Stoney Creek Ontario
if your car runs good, a set of headers/cold air intake/tune/3,73/torque converter will get you into the 12's pretty easily.... my bro went from 3.15 to 3.42 to 3.73 and gained a few tenths each time.....was running under 12.5 steadily, he's waaaaaaaaaay faster lately though, after heads/cam/fast 102 etc etc...
Racer
Joined: Oct 2010
Posts: 419
Likes: 3
From: Lexington VA
St. Jude Donor '11
I have 3:90s in my A4 car very streetable .my car has a cam headers 2800 stalll converter and the gears . it went from about 28 mpg to about 24 25 on the highway . it's about 3000 rpm at 70 mph . my best time on street tires at beach bend track 12.3 at 114 mph. it had 3:15s from the factory it ran in the mid 13s
In the automatic, put the car in 3rd, not OD and run it up to exactly 75 MPH. The 3.15 tach will read 3150 rpm's. The 3.73 @ 75 MPH will read 3730 RPM's etc.
Like I said, you probably already have this info. Nice info for someone looking at a used C5 though.
Drifting
Joined: Dec 2004
Posts: 1,706
Likes: 5
From: Toronto Ontario
You might knock off a tenth or two by swapping to a 3.73 gear but is the cost worth it? It is a lot cheaper to find a used 3.42 set from a 6 speed Vette. I was able to get a 3.42 gear from a Z06 with only 3,000 miles on them from a forum member and for only $400.
I also have a Yank SS3200 stall and I feel that it is a very good combo for the street. The Yank converter drives very close to stock. This combo feels better and faster than the combo I had previously in my old 98 Z28 which was a 3.73 with a 3400 stall.
It all comes down to how much extra a 3.73 would cost you vs a 3.42 gear. The gains you would see between a 3.42 and a 3.73 would be rather minimal in my mind. Gears to me have been more about SOTP than numbers at the track.
Good luck.
I also have a Yank SS3200 stall and I feel that it is a very good combo for the street. The Yank converter drives very close to stock. This combo feels better and faster than the combo I had previously in my old 98 Z28 which was a 3.73 with a 3400 stall.
It all comes down to how much extra a 3.73 would cost you vs a 3.42 gear. The gains you would see between a 3.42 and a 3.73 would be rather minimal in my mind. Gears to me have been more about SOTP than numbers at the track.
Good luck.
