how efficient is the th400 compared to the 4l60?
I went with a TH400 and don't regret it one bit. It feels so good knowing that I don't have to worry about my tranny breaking. Yeah, the dyno numbers aren't that impressive for what I have, but it'll run with any 500+ hp dyno queen all day. 
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Joined: Sep 2003
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From: bethel PA
I just ran out and checked mine my old 4l60 was 148 lbs that still has a little fluid in it tho, my th400 was 140 lbs, so there probably really close in weight sence my old trans still has some flid in there, but the parts inside are a lot heavier so it takes more to turn.
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Joined: Aug 2005
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Originally Posted by lethal93ta
I just ran out and checked mine my old 4l60 was 148 lbs that still has a little fluid in it tho, my th400 was 140 lbs, so there probably really close in weight sence my old trans still has some flid in there, but the parts inside are a lot heavier so it takes more to turn.
I dunno what I lost when swapping in the th400 in my car from what it would have made with the M6, because I did a whole motor swap at the same time.. but I can tell you one thing, when I had the M6 in my car, I coudl barely run what the et calcualtors would come up with for a car with my rwhp and weight, now I can beat every calculator I can find by at least a 1/4 second. 
It's more fun to tell people you have 445 rwhp, then tell them it runs high 10's. Then they look at the car, see it's not really lightened up much.. and then scratch their heads
Is the th400 a little obnoxious on the highway? Yes. Does it run at the track? Yes. Will it break? no. The last 2 mean way more to me then a little extra fuel used.. when I only put about 2000 miles or less on the car every year, I'm not overly concerned.
It's more fun to tell people you have 445 rwhp, then tell them it runs high 10's. Then they look at the car, see it's not really lightened up much.. and then scratch their heads Is the th400 a little obnoxious on the highway? Yes. Does it run at the track? Yes. Will it break? no. The last 2 mean way more to me then a little extra fuel used.. when I only put about 2000 miles or less on the car every year, I'm not overly concerned.
a local with a mustang had his motor on the engine dyno and did 550fwhp. When he put it in the car with a c4 he only made 350rwhp on the dyno. I need to get more details from him and report back. On hp calculators they say my car makes right at 700fwhp. Which calculators do you guys use?
Originally Posted by JL ws-6
Is the th400 a little obnoxious on the highway? Yes. Does it run at the track? Yes. Will it break? no. The last 2 mean way more to me then a little extra fuel used.. when I only put about 2000 miles or less on the car every year, I'm not overly concerned.
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Me and JL have another friend in CT who runs a 383/th400 setup and when he swapped from a t-56 6speed to a th400 he lost just around 70 rwhp. If I see him tonight i'll confirm it.
you're probably right. The kid I knwo that lost 70 hp, he was at 497 I think with the stock in the car, after swapping in the th400 it made 430. his converter is a little tighter then mine, and I made 445 on the same dyno.... tells me it's over 500, how much I have no idea, and really have no intrest in finding out.
th350 parts are a little lighter, but to build one to take the same power as a th400 will not be cheap. If you already have a th400, I wouldnt' bother unless you are tryignto get every last .1 out of the car.. because realisticially, that's about what you are talking about getting.
BY gettinga custom made converter to your car (not sure what you are running now) you'd stand to probably gain more then swapping to a th350
BY gettinga custom made converter to your car (not sure what you are running now) you'd stand to probably gain more then swapping to a th350