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Author Topic:   Racing in 2nd gear??
UFnARacing
Dirt Full Roller

Total posts: 68
posted May 30, 2002 11:53 AM
I'm going to race on a big 3/8' mile clay oval soon. Right now I race in first gear on a 1/4' mile. I'll be running the 3/8' in second gear. It's a th350 auto. What do I need to do to the trans? There is no kick down cable, at least I haven't seen one. Don't know what the previous owner did to it. I'm not too worried about proper gearing just yet, I want to race the track a couple of times first. Just wanted to get a heads up on this before I went racing. Nothing worse that assuming everything will be OK, then burning up a tranny or something during the heat races.

Thanks for any help.

Randy

wam24u
Dirt Full Roller

Total posts: 66
posted May 30, 2002 08:31 PM
I ran the same size track a year or two ago, I ran a 3.73 for a while and then went to a 3.93 in 2nd gear . The best I can remeber with the 3.93's I turned 6200 rpm.
Hope this helps ya!

racer17j
Dirt Forum Champ
Total posts: 1565
posted May 31, 2002 02:24 AM UIN: 54865418
make sure you do not hook up the vacume line just put a plug on it and then drive it like a stick go out in first then shift her into 2nd shouldn't have any problems

smayo964
Dirt Forum Racer

Total posts: 90
posted May 31, 2002 07:19 AM
Hey Racer17J. Have you ever had one of those vacuum lines come off your regular car or truck while you are driving. Guess what, it kicks down and stays in first gear. At least this is what happened to me in my vehicle. I also ran my camaro street stock with a T350 and no matter what gear I shifted into to race, the car ran in 1st because of the lack of the vacuum line. The vacuum line actuates the modulator, or whatever it's called, to make the trans shift. I don't know if there is enough adjustment in the modulator to make the trans shift like a manual (adjustment inside modulator). Like I said, based on my experience, you probably need to run the line and just shift the trans to second and leave it there. Or, see if there is a way to adjust the modulator to allow manual shifting. Just my couple pennies.....

TCI
Dirt Full Roller

Total posts: 32
posted May 31, 2002 08:18 AM
To make sure you don't have any problems and do it right, the best way to go is with a full manual valve body that has a standard shift pattern. it will do away with the throttle cable and modulator and will stay in whatever gear you put it in.

------------------
Scott Miller
TCI Automotive, LLC
662-224-8972 ext 332
scott@tciauto.com
www.tciauto.com

BayouGent
Dirt Forum Racer

Total posts: 87
posted May 31, 2002 08:44 AM
UF, I know your post dealt more with the transmission, but a TH350 gear ratio drops significantly from 1st to 2nd gear. It's got a 2.52 first gear and drops to a 1.52 second gear. We raced a pure stock on a 1/4 mile and used a 2.56 in first gear which gave us a 6.45 final drive ratio which worked fine for us because we didn't want to turn the motor up to extreme RPM's. Some run a 2.73 rear in first and turn the motor up higher for 1/4 mile tracks. However, when you have those same gears and put that tranny in second gear, with a 2.73 rearend your final drive ratio will drop from a 6.88 in first gear to a 4.15 in second. In my opinion you may be disappointed in how your car will perform with that low of a final drive ratio on a 3/8 mile track. I have run a 2.41 rear in first gear on a 3/8 mile and did just fine with a 6.07 final drive ratio. We have raced TH350's in both first and second gear without problem, and the manual valve body that Scott previously mentioned would be a very good move no matter what gear you want to race your car in. I just thought I'd offer an opinion on your final gear ratios for the length tracks that you are planning on racing on. Hope this info helps you.

Bayou

racer17j
Dirt Forum Champ
Total posts: 1565
posted May 31, 2002 12:47 PM UIN: 54865418
smayo yes i have had my line come undone and it wouldn't shift from 1st to second that is why you have to manualy if you hook it up if it ever gets bogged down it will down shift on you we've been running our trannies this way for 7 years and it will go into 2nd and stay there if you shift it manual by just unhooking the line

smayo964
Dirt Forum Racer

Total posts: 90
posted May 31, 2002 03:44 PM
Hey Racer17J. I wasn't aware that you could run them that way. I'm going to do some testing over the weekend and see if I can get mine to shift manually. Like I said earlier, my line came off my truck and the thing would not leave 1st. Thanx for the update. Hope mine will shift.

hobby23
Dirt Full Roller

Total posts: 33
posted June 01, 2002 03:03 PM
i have never used a vac line just shift like a stick even at the slowest of paces it never has down shifted also i run a 1/4 with a th350 & run in 2nd with 456 rears =693 final put a set of 241s in run in 1st 607 not the greatest but it workes or put in a set of 410s =623

[This message has been edited by hobby23 (edited June 01, 2002).]

[This message has been edited by hobby23 (edited June 01, 2002).]

smayo964
Dirt Forum Racer

Total posts: 90
posted June 02, 2002 08:36 AM
Hey Racer17j (and others). Took the line off my truck to play around with the shifting. Worked great. Thanx for the education. Mine did not down shift either when slowing (2nd to 1st, etc.). I do think the modulator setting has a lot to do with that also. Mine is set kind of high for towing. I'm going to loosen the setting on the car so rmp won't become an issue. Thanx again.

rusty9cab
Dirt Roller

Total posts: 18
posted June 14, 2002 02:47 AM
If you have $50-60 to spend,you might try a b&m trans pak. you can install it with the trans still in the car. it turns your trans into basically a manuel tranny. it involves some throttle body work but it is very easy to install.

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