Th400 Gear Sets?
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Launching!
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Th400 Gear Sets? I know they have different gears for first and second gear, but what about third? Is it just not possible to make another ratio for 3rd gear (say making 3rd like an over drive? Also for FI (say 650 rwhp) wouldn't a gear set like 2.1 for first and 1.4 for second be better for traction with a rear end gear like 3.73s? Thanks
Not sure about the other gears but in the case of third because its direct drive and does not actually use a planet and rather just transfers power straight through I do not see how you could get a different ratio for it, because really its not a gear at all ,its very much like if you had a steel rod directly from your converter to your drive shaft
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Launching!
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That would make sense why there are no third gears to be changed.. I'm thinking about going with a th400 with the lower gears or higher what ever is the correct way to say it for the street, being able to due 60mph in first gear would be nice. I would think would have better traction on the street too, but i could be wrong.
Well going to a higher ratio to get better traction probably is not the best way to do it, I would keep the trans you have and spend the money on traction mods instead and keep the overdrive if you have it and have a much more streetable and quicker car
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On The Tree
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From: so cal
Originally Posted by performabuilt
Well going to a higher ratio to get better traction probably is not the best way to do it, I would keep the trans you have and spend the money on traction mods instead and keep the overdrive if you have it and have a much more streetable and quicker car
Originally Posted by performabuilt
Well going to a higher ratio to get better traction probably is not the best way to do it, I would keep the trans you have and spend the money on traction mods instead and keep the overdrive if you have it and have a much more streetable and quicker car
Different points of veiw I see lol. I know guess im old school but the way we did it back in the days of big blocks we would build till we couldn't possibly hook up then we would work on the tires and suspension until we could , the back to building lol. A never ending circle,
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Launching!
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Definetly a lot of good info you guys have.. Here is what i'm planning on doing... I want to procharge my car with a built ls2 with l92 heads and intake and of course the supporting mods for it. I'm shooting for about 650rwhp its mostly a street car (i might take it to the track once in a while once its done) and i know its more than over kill for the street 
.. I already have a strange 60 rear end with 3.73's. Thats why i was thinking about going with the th400 with the 2.10 first and 1.4 second (because the smallest gears i can get in the rear end are 3.54's). I wanted to stay with the 4l60e but i just dont want to spend the money on it and know there is a chance of it breaking especially being driven hard on the streets with that much power. And i don't want to go to the 4l80e just because its gonna cost anywhere from 3-4k. lol i know you have to pay to play but i dont need overdrive that much since the car is only driven in the city and only when its nice outside. Any recommendations would be appreciated.
.. I already have a strange 60 rear end with 3.73's. Thats why i was thinking about going with the th400 with the 2.10 first and 1.4 second (because the smallest gears i can get in the rear end are 3.54's). I wanted to stay with the 4l60e but i just dont want to spend the money on it and know there is a chance of it breaking especially being driven hard on the streets with that much power. And i don't want to go to the 4l80e just because its gonna cost anywhere from 3-4k. lol i know you have to pay to play but i dont need overdrive that much since the car is only driven in the city and only when its nice outside. Any recommendations would be appreciated. Thread Starter
Launching!
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Originally Posted by gator's 99TA
once you make bigger power, the best way to put the power to teh ground is to reduce the first gear (numerically). thus why so many love the powerglide or TH210
There are only 2 choices in gear ratios for the th400 that I am aware of;
2.48 1st 1.52 2nd 1.00 3rd (stock)
2.75 1st 1.57 2nd 1.00 3rd with an aftermarket planetary, this is what I went with for my build but don't have it on the road yet to see how I like it.
Edit; I just saw tci added a 2.10 gear set.
2.48 1st 1.52 2nd 1.00 3rd (stock)
2.75 1st 1.57 2nd 1.00 3rd with an aftermarket planetary, this is what I went with for my build but don't have it on the road yet to see how I like it.
Edit; I just saw tci added a 2.10 gear set.
Last edited by code4; Jan 31, 2007 at 10:52 PM.
Originally Posted by gator's 99TA
um i believe the stock first gear is 2.48 in a th400 right?
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Launching!
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Ohh i found them on the web but they are i'm not sure if expensive is the right word to describe them... they are close to $1400 just for the gear and on another site they had the 2.1 and 1.4 for like $1700 
Might as well buy the 4l80e instead of the gears lol.. Guess the standard TH400 gears are the only option.. I'm curious to know why it would cost $1400 for a gear... Ohh well was a nice thought to be able to do over 60 in first gear...
Might as well buy the 4l80e instead of the gears lol.. Guess the standard TH400 gears are the only option.. I'm curious to know why it would cost $1400 for a gear... Ohh well was a nice thought to be able to do over 60 in first gear... Thread Starter
Launching!
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Originally Posted by code4
Yea, 2.52 is th350 I believe plus I just noticed that tci added a new planetary with 2.10 1st gear.
On The Tree
Joined: Mar 2005
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From: so cal
Originally Posted by 98 Z28
Definetly a lot of good info you guys have.. Here is what i'm planning on doing... I want to procharge my car with a built ls2 with l92 heads and intake and of course the supporting mods for it. I'm shooting for about 650rwhp its mostly a street car (i might take it to the track once in a while once its done) and i know its more than over kill for the street .. I already have a strange 60 rear end with 3.73's. Thats why i was thinking about going with the th400 with the 2.10 first and 1.4 second (because the smallest gears i can get in the rear end are 3.54's). I wanted to stay with the 4l60e but i just dont want to spend the money on it and know there is a chance of it breaking especially being driven hard on the streets with that much power. And i don't want to go to the 4l80e just because its gonna cost anywhere from 3-4k. lol i know you have to pay to play but i dont need overdrive that much since the car is only driven in the city and only when its nice outside. Any recommendations would be appreciated.
.. I already have a strange 60 rear end with 3.73's. Thats why i was thinking about going with the th400 with the 2.10 first and 1.4 second (because the smallest gears i can get in the rear end are 3.54's). I wanted to stay with the 4l60e but i just dont want to spend the money on it and know there is a chance of it breaking especially being driven hard on the streets with that much power. And i don't want to go to the 4l80e just because its gonna cost anywhere from 3-4k. lol i know you have to pay to play but i dont need overdrive that much since the car is only driven in the city and only when its nice outside. Any recommendations would be appreciated. On The Tree
Joined: Mar 2005
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From: so cal
well those 210's not only have different gear ratios but he uses 4l85e five pinion planets he also puts the aluminum drums in all of which booko bucks. Well the th400 is a super strong unit stronger than a power glide and they go 6's.
Originally Posted by back4more
well now you just threw something else into the equation. the procharger is a centrifugal supercharger, which do not spool up to a higher rpm so when you do build the trans i would suggest a lower gear in order to spool the motor up. you could cover it up with a high stall converter true, but then you loose top end effeciency, so... in all honesty it is all combination.
You sound a lil mixed up there buddy
Peak boost on centri will coincide with peak RPM. There is no spooling up; it's physically tied to your engine. The higher the stall, the more boost you will have when you mash the happy pedal. On The Tree
Joined: Mar 2005
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From: so cal
no what i meant is you need rpm to make boost, so.... you through a 2.10 first gear and the rpm of the motor climbs slower because it has to struggle less boost, less power down the pavement. now through something with say a 2.75 first your in a rpm range your making lots of boost = more happiness. (i know a centri supercharger is just a belt driven turbo you can change pulleys on.)