turbo 350 running in 2nd gear

**Dirtman29** · 07-10-2011, 09:15 PM

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.

**joeracer28** · 07-11-2011, 09:32 PM

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.

**adelvecchio3169n** · 07-12-2011, 01:26 AM

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.

**Dirtman29** · 07-12-2011, 11:18 PM

..........

**Dirtman29** · 07-12-2011, 11:20 PM

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...

**Moldymulldoon** · 07-13-2011, 01:29 PM

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

**3dinter** · 04-08-2012, 03:05 AM

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.

**3dinter** · 04-08-2012, 03:15 AM

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 ?

**dirtcarracer** · 04-22-2012, 05:25 PM

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

**sj valley dave** · 04-22-2012, 07:32 PM

@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...

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