Automatics .....Gear Upgrade
Thread Starter
Safety Car
Joined: Jul 2002
Posts: 4,174
Likes: 15
From: Florida
Automatics .....Gear Upgrade
Wondering what the thoughts are on upgrading the gears in an auto. What is suggested and is there any obstacles such a whine associated with even the 3.42 Gm Unit ?? (Daily Driver)
Le Mans Master
Joined: Nov 2000
Posts: 7,294
Likes: 1
From: Coral Springs Florida
Re: Automatics .....Gear Upgrade (Killrwheels)
What are you uprading..2.73?..3.15? It makes a difference :rolleyes:
I went with the 3,42's from 2.73's and there is a significant performance gain ..from 3.15 it would be only moderate.. ;)
I went with the 3,42's from 2.73's and there is a significant performance gain ..from 3.15 it would be only moderate.. ;)
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 0
From: Winston Salem NC
Re: Automatics .....Gear Upgrade (Killrwheels)
I went from 3:15's to 3.42's and love them. No whine at all. The gears came from an M6 with 7000 miles. Go with a converter at the same time. It will be a really big difference that you will love. :steering:
Burning Brakes
Joined: Aug 2002
Posts: 949
Likes: 1
From: Cary Il
Re: Automatics .....Gear Upgrade (Killrwheels)
Stock was 3.15, upgraded to a 3.42, then went to an all-out highperformance 3.73. No problems with any of them. You must consider traction issues such as drag shocks and tires if you start to get serious with drag racing. All of them were totally streetable.
Good luck
JR :steering: :steering: :steering: :steering: :steering: :steering: :steering:
Good luck
JR :steering: :steering: :steering: :steering: :steering: :steering: :steering:
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Safety Car
Joined: Aug 2000
Posts: 4,154
Likes: 1
From: Murphy TX
Cruise-In II Veteran
Re: Automatics .....Gear Upgrade (Killrwheels)
Biggest issue (aside from cost of course) IMHO is probably proper programming. If you choose one of the reman 3.73/3.90/4.10 units, make sure it's from a source you trust to set up the gears in this unit correctly. That's where the whine factor comes in...
I went with a new Getrag 3.73 and am now thinking about a 4.10. After some initial concern about elevated RPM at highway speed I really warmed up to the 3.73s on the highway. Much more fun than the 3.15s.
I went with a new Getrag 3.73 and am now thinking about a 4.10. After some initial concern about elevated RPM at highway speed I really warmed up to the 3.73s on the highway. Much more fun than the 3.15s.
Instructor
Joined: Aug 2001
Posts: 192
Likes: 0
From: Virginia Chesapeak
Re: Automatics .....Gear Upgrade (dads01dream)
The ST3500 has a 2.5 STR that is better suited if you plan to run DRs or et streets. The SY3500 has low 1.65 STR that is better if you intend to run on street tires.
Team Owner
Joined: Apr 2001
Posts: 26,794
Likes: 614
From: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
St. Jude Donor '06
Re: Automatics .....Gear Upgrade (robsvette)
3:73's no more than that
Oh yeah, and make sure that you throw in a torque converter at the time you swap the gear as this is the best single mod for the $ that you can do for A4. The torque converter and gear will feel like you picked up 100 HP.
Best of luck,
MTI 427 Roadster
Safety Car
Joined: Aug 2000
Posts: 4,154
Likes: 1
From: Murphy TX
Cruise-In II Veteran
Re: Automatics .....Gear Upgrade (MC98)
The ST3500 has a 2.5 STR that is better suited if you plan to run DRs or et streets. The SY3500 has low 1.65 STR that is better if you intend to run on street tires.
Melting Slicks
Joined: Dec 2001
Posts: 2,877
Likes: 0
From: Texas
Re: Automatics .....Gear Upgrade (Killrwheels)
No more than 3.73. It really depends on what type of driving you will be doing. If you're seriously into the drag strip, 3.73, but for street and highway I think the 3.42 is best suited.
:cheers:
:cheers:
Melting Slicks
Joined: Apr 2002
Posts: 2,683
Likes: 0
Re: Automatics .....Gear Upgrade (ToplessTexan)
Hey Topless,
I get the benefits of a reduced weight t/c, but what's the story about the diameter?? I've read diameters ranging from 9-1/2" up to 12" - what's up with this? Is there a more beneficial diameter? What's the factory t/c's diameter?
Sorry for all the Q's, just trying to get an edumakayshum!!! :thumbs: :lurk:
I get the benefits of a reduced weight t/c, but what's the story about the diameter?? I've read diameters ranging from 9-1/2" up to 12" - what's up with this? Is there a more beneficial diameter? What's the factory t/c's diameter?
Sorry for all the Q's, just trying to get an edumakayshum!!! :thumbs: :lurk:
Racer
Joined: Dec 2001
Posts: 376
Likes: 0
From: BLMVOR R160 [] HOCVOR R305 Switzerland BL
Re: Automatics .....Gear Upgrade (CorvetteSS)
I have 3.15's and am going to 3.42's. I think more than that would not be great for highway driving.
Sorry that the General did not offer this nice intermediate gearset as an RPO for A4s !
Joe.
Instructor
Joined: Sep 2002
Posts: 133
Likes: 15
From: TX
Re: Automatics .....Gear Upgrade (Killrwheels)
It really depends on how you use your car. I do some highway driving but I also like to go to the dragstrip alot. I went with the 3.90's and have not been dissappointed. There is absolutley no whine. I would at least go 3.73. :cheers:
Melting Slicks
Joined: Apr 2002
Posts: 2,683
Likes: 0
Re: Automatics .....Gear Upgrade (1SlowC5)
I see by your sig you don't have too many hp mods on your car, just curious to know if you plan on anything like heads & cam, nitrous or s/c in the future? Do you think 3.90's may be too steep with further hp mods?
TIA! :lurk:
TIA! :lurk:
Instructor
Joined: Sep 2002
Posts: 133
Likes: 15
From: TX
Re: Automatics .....Gear Upgrade (dads01dream)
Not at all, I even contemplated going with a 4.10 gear but since I am spraying already (look In Sig) I went with the 3.90. I will in the future have to pick a cam that complements my gear, in other words allows me to continue to make horsepower at the certain rpm I am going through the traps at the dragstrip. I have a buddy that has a number of mods in an automatic in a 92 corvette that is running a 4.30 gear with a 3600 stall convertor. With no nitrous and stock heads he is running 11.50 at 119.66. He does drive this a good bit on the highway and it is really not bad at all. Feel free to look at his sig, his name on this board is DRAGRACR.
:cheers:
:cheers: