Results 1 to 12 of 12

3.90 good ?

This is a discussion on 3.90 good ? within the Drivetrain forums, part of the LSx Technical Help Section category; I have an automatic 2000 trans am and was wondering if 3.90 would be a good selection of gears. I ...

  1. #1
    Senior Member clg82's Avatar
    Join Date
    Feb 2007
    Location
    California
    Age
    35
    Posts
    2,453
    2000 Trans Am

    3.90 good ?

    I have an automatic 2000 trans am and was wondering if 3.90 would be a good selection of gears. I currently have the stock 3.23 performance axle. It's my daily driver and i want a little more ummff. and would the 3.90 gears even work in my stock 10 bolt rear end? thanks for the help.
    Last edited by clg82; 09-13-2007 at 08:27 PM.
    2000 Arctic White trans am, ws6 hood, ws6 air box, slp lid, slp smooth bellows, slp loudmouth exhaust,shift kit, rebuilt trans, LS6 intake, 3.73 gears, Shaner S3 p/p throttle body, and a tune . SFC. C6 ZO6 rims 18" in back 17" in front. Drilled and slotted rotors.

  2. #2
    Impounded
    Join Date
    Nov 2005
    Location
    Dallas, TX
    Age
    39
    Posts
    129

    Pewter
    2000 Firehawk #506 A4

    Usually, A4's don't go bigger than 3.73's, but you could do 3.90. If you do a lot of highway driving, you'll be filling up twice a week with them though. I had 3.73's on my 96 Z28 and they were awesome from a dig, but I probably won't get them again on my Hawk just because of the highway driving I do. Your RPM's would be around 500-700 higher with 3.73's, so I imagine close to 1000 with 3.90's. I have heard of 4.10's on an A4 daily driver, but he never got on highways and he loved them on the streets. It just depends on your driving habits and how much you're willing to pay in gas to launch like a bat out of hell. Just my opinion, though...

  3. #3
    Senior Member clg82's Avatar
    Join Date
    Feb 2007
    Location
    California
    Age
    35
    Posts
    2,453
    2000 Trans Am

    Thanks for the reply, i think i am going to go with the 3.90 i don't do much highway driving i just want it for that extra ummph anyone else have an opinion?

  4. #4
    Senior Member slims00ls1z28's Avatar
    Join Date
    Apr 2007
    Location
    TN
    Posts
    1,212

    2005 GTO M6 Black
    2000 Z28 A4 Red

    I put 4.11's in mine and drove it on the weekends to work (50 miles one way). Even got a 3600 Vigilante stall. Love it!! After it was tuned I was surprised that the gasmileage didn't go down that bad as long as I kept my foot out of it. One weekend I managed about 21 MPG average. I would do it all again x2 if I had to.cruising rpms are much higher than my 2.73's but cruising rpms usually stayed between 26-2800 from 65-70ish.
    My Toy 00 Z28 1SC A4 - MS3 cam with supporting valvetrain, Milled LS6 heads, LS7 lifters, , ARP rod and mains, All free mods, pacesetters, True duals, moser 9 with 4.11's and Detroit Locker, Vig 3600 tuned, tubular SFC,adj PHR, LCA, adj TA, PHR reloc, LCA reloc. all with poly bushings, ZR1's and Nitto DR's (315).

    My other toy 05 GTO LS2 M6- Comp XR269HR cam, 918's, hardened pushrods, Dart Pro 1's, pacesetters, X-pipe, flowmaster 1 chambers, TSP oil pump, Tick master cylinder. Pedders RR bushings, end links, SB bushings, tie rods and strut mounts, total performance poly F&R bushings. Polk DVC 12", Infinity Kappa 6.5 component and 6x9's with corresponding amps.

    Her toy 77 F100-6.6/c6. All original (for now)

  5. #5
    Senior Member clg82's Avatar
    Join Date
    Feb 2007
    Location
    California
    Age
    35
    Posts
    2,453
    2000 Trans Am

    Quote Originally Posted by slims00ls1z28 View Post
    I put 4.11's in mine and drove it on the weekends to work (50 miles one way). Even got a 3600 Vigilante stall. Love it!! After it was tuned I was surprised that the gasmileage didn't go down that bad as long as I kept my foot out of it. One weekend I managed about 21 MPG average. I would do it all again x2 if I had to.cruising rpms are much higher than my 2.73's but cruising rpms usually stayed between 26-2800 from 65-70ish.
    so what do you suggest if you were me.....i have 3.23 should i go 3.73 or 3.90?

  6. #6
    Member {FzS}BlacKMagicK's Avatar
    Join Date
    Jan 2007
    Location
    Florida
    Posts
    917

    BlacK
    2001 WS6

    Just remember, if your doing this on a stock 10 bolt, you have a thinner gear, you could end up breaking it, especially since your doing it for increased acceleration purposes (launching) a lot of people say they just end up broken.

    You'd prolly have to baby it, so then what would be the point?

    Look at Slims sig, he has a 9" Moser with 4.11's and a detroit locker, big difference, he can stand on it all day.

  7. #7
    Senior Member slims00ls1z28's Avatar
    Join Date
    Apr 2007
    Location
    TN
    Posts
    1,212

    2005 GTO M6 Black
    2000 Z28 A4 Red

    True 3.73's in your case might be safer. 3.90's would DEFINATELY be more fun but your stocker might not hold. Can't say for sure I went from stock 2.73/10 bolt to my 9"/4.11, I just wanted to be positive I wouldn't have any problems from the rear when I started my "real" mods. Like Magik said I broke my motor before my rear.

  8. #8
    Senior Member Bottesini's Avatar
    Join Date
    Sep 2007
    Location
    Denton, Texas soon Lafayette, Louisiana
    Posts
    2,955

    Blue
    2002 Z28 Camaro M6

    The difference in strength should almost be negligible. In fact I would wager the lower gears (higher number) would hold up better since they take less torque to move. However, for a street car I think you might prefer the 3.73s unless you really don't care about higher speeds like on the highway. I would also check to make sure that you don't go into overdrive if you want a car to run on a 1/4 mile track.

  9. #9
    Senior Member clg82's Avatar
    Join Date
    Feb 2007
    Location
    California
    Age
    35
    Posts
    2,453
    2000 Trans Am

    Bottesini, what would you do 3.73 or 3.90.....keep in mind i have 3.23

  10. #10
    Senior Member Bottesini's Avatar
    Join Date
    Sep 2007
    Location
    Denton, Texas soon Lafayette, Louisiana
    Posts
    2,955

    Blue
    2002 Z28 Camaro M6

    Well for me I would have 3.73s but I drive alot on the highways (one reason why I have a six speed), and I would have to do some research to make sure I could make it at least 1/4 mile in third. The later part is the tricky one since different setups will run differently. I think if my car was a A4 with the quick and dirty research I have just done 3.73s which should let you get around 112 MPH in 3rd gear @5500 RPM compared to 108. (these numbers are done with a few assumptions and quick and dirty internet calculators)

  11. #11
    Senior Member clg82's Avatar
    Join Date
    Feb 2007
    Location
    California
    Age
    35
    Posts
    2,453
    2000 Trans Am

    so 3.73 it is!

  12. #12
    Senior Member Bottesini's Avatar
    Join Date
    Sep 2007
    Location
    Denton, Texas soon Lafayette, Louisiana
    Posts
    2,955

    Blue
    2002 Z28 Camaro M6

    With either choice you should notice a considerable umph in your cars get up.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Need a Good Mechanic or a Good Garage
    By FastTA in forum General Help
    Replies: 0
    Last Post: 12-08-2010, 02:34 PM
  2. Good to be here
    By Chucky in forum New Member Introductions
    Replies: 1
    Last Post: 08-29-2009, 12:12 PM
  3. Red light cameras too good for their own good?
    By Speedy_Gonzales in forum Almost Anything Goes
    Replies: 23
    Last Post: 03-24-2008, 11:48 AM
  4. good day good kill.
    By 95Fyrebyrd in forum Kill Stories
    Replies: 19
    Last Post: 03-22-2008, 09:33 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •