Gears & Axles - what gears are you th400 guys runing?




wichoms4
02-19-2008, 08:11 PM
what gears are you guys runing with a th400? what rpm are you guys toping out at the 1/4? 9' or 12 bolt?


Websy21
02-19-2008, 09:44 PM
This wouldn't pertain to all but just finished reading a thread in the FI section you should check out and it seems most are running a average of a 3.42 but anything from a 2.73 to 3.73 I am debating 3.25 or 3.50 in my 4l80e, same shit, different pile as a th400 but with an o/d.

wichoms4
02-19-2008, 10:21 PM
thanks. ill take a look. sorry im new to this site. please delette


Jays00ss
02-20-2008, 08:09 AM
I have 3.73's in my 71 SS elcamino with a Built 402 Big block, th-400 and 12 bolt. They work really well for the track on 26" tires.

Websy21
02-20-2008, 10:31 AM
No need to delete I don't think, just was pointing out a thread to you as FI is a different story as n/a for gears. I want higher gears to load my turbo so it will spool quicker and when it does it doesn't blaze my tires................. well as much anyways :secret2: for N/A I'd go with 3.73 is a great all round comprimise for street and track but depends entirely on the whole setup though.

wichoms4
02-20-2008, 09:18 PM
im consurn a bout my rpm. dont want to be hitting the rev limiter before the end of the 1/4. wantting to forge the 346. if so want to do a 250 d.p set up. also im doing the rear, but still not sure of a 12bolt or a 9'? & what gears to get?

BigJls1
02-20-2008, 09:54 PM
zombie has a turbo mounted in the rear, hes got a th400 with 2.75 gears. I think hes running tens if not low 11 for sure. who says 2.75 gears cant be fun or fast.

RAGENZ28
02-21-2008, 03:29 PM
In my old car I had a TH400 RMVB Transbrake with 4,500 stall, 4.86 gears and revved to around 7800. I had a 33 spline strange axles, pro gear, 1350 strange c-moly yoke in a 12 bolt.

I'd just go with a 9" and run a modest gear, unless it's a straight race car I would guess you'd maybe run a 3.73? You didn't list much about your car.

Best way is to run your car as is and you'll have an idea around how much mph your car will run, then from there gear it to work with a 26" tire and when you add power and go faster you can step up to a 27,28,29" tire at the track to allow you to run more mph down the road.

RAGENZ28
02-21-2008, 03:31 PM
zombie has a turbo mounted in the rear, hes got a th400 with 2.75 gears. I think hes running tens if not low 11 for sure. who says 2.75 gears cant be fun or fast.

That's true you don't need a lot of gear with a good power turbo car, one of our buddies runs a 3.08 gear and runs 7's on a drag radial.

wichoms4
02-21-2008, 09:16 PM
my car is pertty much stock.
list: tsp ms4 camshaft, rosslers stg 2 th400 w/brake, ls6 intake, LT, ORY w/cut out, stock 10bolt with stock 3.42. hotches LCA & panhard, stock sway bar. full wieght. tuned at synergy motorsports by Rick. every thing else is bone stock.

ncnumber8
02-25-2008, 10:29 AM
I'm running 3.73's w/ my tH400, but I'm crossing the line at 6400 rpm, mainly due to I am having some converter slippage issues. I think 3.73 is the way to go for the TH400.

Black8Banger
02-25-2008, 04:39 PM
4.11s right now. They work well on 28" tires but 26" kinda sucks.
Im about to step back down to some 3.70s for nitrous

Steve Burger
02-25-2008, 08:41 PM
What is your max RPM, what size tire, and what do you estimate trap speed at. I had 4.33s with an NA 347. 7200 at 128 on a 28" tire.

RAGENZ28
02-25-2008, 08:50 PM
Put some 5.29's and throw some D's on it :jest:

code4
02-25-2008, 08:55 PM
zombie has a turbo mounted in the rear, hes got a th400 with 2.75 gears. I think hes running tens if not low 11 for sure. who says 2.75 gears cant be fun or fast.

Zombie is running 10.0xx. I run a 2.75 gear in mine as well but a turbo car is a different animal.

02SS:ZEUS
02-25-2008, 10:58 PM
I've got 4.11's in mine now with a 28" tire. I need to go to a 3.73. I run out of gear 50 feet from the 1/4, and the car tops out at about 128 mph. It runs 10.40's now, and won't go any faster until I get the 3.73's in it.

wichoms4
02-25-2008, 11:06 PM
hey guys sorry been away for a min. well the motor is stock 346 my rev limiter is set at 6800 rpm's dont want to run out of rpm's by the end of 1/4. 3.73 it is.