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  1. #1
    Join Date
    Jul 2011
    Posts
    2

    Default turbo 350 running in 2nd gear

    I'm looking for info on what needs to be done to a turbo 350 in order to run in 2nd gear.

    I've been told that if I put the car into 2nd it will shift into third once the rpms reach a certain point.

    I've also been told that I need to start in 1st gear, then it will shift into 2nd.

    Any help is appreciated
    thank you

  2. #2
    Join Date
    May 2007
    Location
    Illinois
    Posts
    1,690

    Default

    If you put a TH350 in 1st, it will stay there. If you put it in 2nd, it will go thru 1st, then shift to 2nd. Thats what my old SS had in it, I ran in 1st gear all the time. You have to get your final drive ratio thru the rear end. (TH350's are 2.52 in 1st gear). I used to use a 2.56 or 2.73 ratio in the rear end on the 1/4 & 1/3 mi. tracks, turned about 6500 RPMs.

  3. #3
    Join Date
    Jul 2011
    Posts
    2

    Default

    I want to run 2.56 gears but can't find any for a metric rearend.
    Know of anyone that makes them?

    So I'm thinking of running in 2nd with 4.10's. Is there anyway to bypass the shift from first to second. Like run is 2nd only. At what RPM would it shift into 2nd?

    thanks for the help.

  4. #4

    Default

    Had some linkage problems with my turbo 350 last year that caused it to shift into 2nd. Once it was in second it stayed their even when the rpms were down and I stood on it. I did not have the kick down cable hooked up. Don't know if the kick down cable needs to be hooked up or not but I ran all last season and part of this season without it. Hope this helps. Good luck.

  5. #5
    Join Date
    May 2007
    Location
    Illinois
    Posts
    1,690

    Default

    ..........
    Last edited by Dirtman29; 07-12-2011 at 11:21 PM.

  6. #6
    Join Date
    May 2007
    Location
    Illinois
    Posts
    1,690

    Default

    I think there is a way to have them stay in a certain gear without shifting, possibly a manual valve body? I never used the kickdown cable in mine.

    A 2.56 for a GM 7.5" shouldnt be hard to find, look in the older 2WD S-10s & astro vans as well as metric cars, may check 82-92 camaros too. Something with the larger engine for the model would be my guess...
    Last edited by Dirtman29; 07-12-2011 at 11:24 PM.

  7. #7

    Default

    Drill and safety wire the govenor weights closed. Use a zip tie to keep them closed. Weld them in place... anything to keep them from opening up. If they do open up the trans will think it is in a higher RPM shift mode.
    Leave the TV cable alone. Dont hook it up.
    Don't run the vacuum line to the modulator.

    With the govenor weights tired down you can shift back to 1st, care should be taken as it will do it at almost every RPM.

    Why not run 2nd... there are a mess of gear ratios out there. 3.42's 3.73's 4.11's 4.30 and 4.56's... use your math and multiply 2nd gear ratio by the gear wanted.
    With 2nd gear part of the trans isn't spinning in reverse of the crank. There would be less heat also.
    Higher gear rations doesn't always mean higher engine RPMS. Traction VS buzzing the tires to the moon. More gear more control of tire spin.
    This an opinion, it has worked for me and other cars I have worked on. You do as you please. Hope you find a combination that works for you and your car.
    152x342=5.19's
    152x373=5.66's
    152x411=6.24's
    152x430=6.53's
    152x456=6.93's
    This is some of the ratios you could run in 2nd gear.
    Good luck

    Moldy
    Last edited by Moldymulldoon; 07-13-2011 at 01:40 PM.

  8. #8
    Join Date
    Jun 2011
    Location
    Ft Worth, Texas
    Posts
    235

    Default

    Quote Originally Posted by joeracer28 View Post
    I'm looking for info on what needs to be done to a turbo 350 in order to run in 2nd gear.

    I've been told that if I put the car into 2nd it will shift into third once the rpms reach a certain point.

    I've also been told that I need to start in 1st gear, then it will shift into 2nd.

    Any help is appreciated
    thank you
    so what did you do ?.....I'm kinda curios also running second gear in the 350. We couldn't get any traction tonight in first gear.

  9. #9
    Join Date
    Jun 2011
    Location
    Ft Worth, Texas
    Posts
    235

    Default

    Quote Originally Posted by Dirtman29 View Post
    If you put a TH350 in 1st, it will stay there. If you put it in 2nd, it will go thru 1st, then shift to 2nd. Thats what my old SS had in it, I ran in 1st gear all the time. You have to get your final drive ratio thru the rear end. (TH350's are 2.52 in 1st gear). I used to use a 2.56 or 2.73 ratio in the rear end on the 1/4 & 1/3 mi. tracks, turned about 6500 RPMs.
    What kinda rpm do you think you would turn if you ran a 2.73 in a 350 first gear on a 3/8 & 1/4 mile dirt track ?
    And
    Would a pure / factory stock motor hold up to the rpm's ?

  10. #10
    Join Date
    Aug 2010
    Posts
    122

    Default

    just run it in drive and put a 6.66 gear in the rear. saves you all the trouble of first and second

  11. #11
    Join Date
    May 2007
    Posts
    1,016

    Default

    @dirtcarracer...It sounds like this guy is in some kind of real factory stock deal if he is talking about 7.5 inch rear ends...You know they do not make a 6.66 ring and pinion unless you have a 9" in..Comment didn't help at all...

  12. #12
    Join Date
    Sep 2012
    Location
    canada
    Posts
    9

    Default

    Hi every one am beginner here and i study this community message board it's really awesome and most useful i like it and thanks for giving such a useful details i get from here many useful details for which can confirm valuable for me keep it up and i appreciate you on this operating.

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