SC400TT

iTrader: (4)

I stated earlier that 3 speeds are not great for driveability....nor for fuel economy...

Ryan

morris

iTrader: (2)

I know a guy that has consistently run 10 second passes in a NDRA supra with the 5 speed auto. The tranny will hold up.

As someone that has gone through a couple tranny's I agree that it is best to pay a little more the first time and do it right. But with that said some people forget that the average guy is not building a 9 second Drag car. While it may make sense for them to spend 10K on a tranny that will handle 8 or 9 second passes, it doesnt make sense for the average guy that has to balance his "hobby" with things like bills, Mortgage, wife wantign a new car braces for the kid etc. A built A340 will handle 90% of the guys on this board with FI, without any problem

racing fan

While the Toyota transmission is not the BEST base for a performance transmission, we have modified it to work well under certain conditions. We have hundreds of units in the market working with 100% success and consistency. There have been issues but they have been a small minority of the many we have sold. Feel free to call us and I will discuss in full detail our transmission.

Im2gq4u

in my personal experiance with a TH350 on a 550 RWTQ Firebird, 3.23 rear gear, 3500 stall...driveability was not bad. I would hit about 90-95 at 4k rpm ish. I had no problem cruising around town and driving on the highway(3k-3500 rpm) but ran out of trans around 125-130ish. You will lose all top end, but be very consistant in the dig. If you are into track drag racing, the TH400 is for you...if you are into Street/roll racing the 5 speed seems to do fine at those power levels from what I have read...but id roll out on a 6 speed.

My TH350 was only 200 bucks and getting it built cost another 200.00. So you are looking at 400 for trans, 800 ish for DaveH trans adapter, Decent stall for 300ish and you are only 1500 into it for basic parts. Throw on a junkyard starter, cooler of your choice and shifter from the local redneck hot rod parts store or used on a local forum and you are sub 2k for your tranny swap. You wont have cool things like speedo, ect...but...neither did I on the formy. I paced a friend at 40 60 and 80 mph, got the RPM readings and worked from there.

rdm20fan

I'm assuming your talking about me Chris, and I disagree with you. If you have a goal of 500-550 and "DAILY DRIVER" which is what the tread stated I would use a built toyota trans.
TH400 is for someone who wants to "drag race only".
If you want a daily driver the TH400 is a bad choice.
and the 4L80E was built for mobile homes. it's huge, and weighs a ton. I bet the 4L80E trans weighs more then the 1UZ v8, and the A340 put together.
The only reason you should be using a trans that big, and HEAVY is if your again ONLY drag racing, and you have broke a TH400 cause of the power your making.

If you want a "Daily Driver" stick with the toyota A340

rdm20fan

BINGO!!! Hit the Nail on the head!
especially with the SC's 3.96-4.10:1 rear end gear.
Not a good choice for a Daily driver.
Great trans for Drag Racing

DIrEctQL

That's funny Bob. We had similar conversation along with Chris who mentioned that A340 will not last and TH400 is the way to go for reliability. Didn't you go through one of those transmissions? You changed your opinion that fast?

durtysc300

honestly i'd go with the BL build auto 500-600 isn't a huge amount of power and 3 speeds is terrible for daily driving. My dads buddy has an 84 blown 383 s10 with a th400 3 spd ran 9.8s to 10.3s and was driven on weekends. not a good daily tranny

rdm20fan

Chris you hear what you wanna hear.
My trans lasted 505 ftlbs to the rear wheels. I changed it to a getrag, cause 1) I got a great deal on one, & 2)the stock auto isn't a great choice for a good off the line time, not because it was bad for drivabilty, or that it failed.

My rebuilt A340 trans is now going into another TT SC400 who has a goal of under 500HP, and daily drivability. They last, and are the right choice if you want your car to be a daily driver, which is what "YouLose" had stated in his question.
If you want to drag race, then no it's not the right choice.
But if you want a daily driver then it is your best choice.

SC400TT

iTrader: (4)

Agreed!!!!!!!!!!!!

Ryan

Gunnar

I don't see where the gigantic costs for the GM transmission swaps come in. Maybe it's just here in the midwest but I see TH350's and TH400's go for $50-$100 left and right. My friend got his for free even.

Does the adapter, converter, and a driveshaft really cost another $4500-7000 or so that people claim they spend to get that into their car?

Lextreme

There are few ways to make the TH400 both strong and daily.

* You can change your SC rear differential to the Supra or Post 98 (SC/GS) different. From the spread prepared for me by a friend in Europe is almost same as LS400 stock RPM and MPH

* You can also get split gear for the TH400 and convert the 3 speed to 6 speed. This move is about $3000.

I am doing the first route for my SC470TT. Actually, I will be swapping the LS400 gears into the SC400 punkin. The LS400 is alot gas friendly then the SC400 or the last gears.

Here is a good article on this https://www.clublexus.com/forums/sho...d.php?t=350692

rdm20fan

Hey Gunnar you are right the cost of a used th400 is not expensive, but stock they won't hold much more torque then the stock toyota trans.
the aftermarket support to rebuild the trans is where you can make them very strong, and where the price difference is.

Gunnar

I guess with a shop, yeah. My friend has built them for his own car and my roommate's car and the parts themselves weren't really that expensive. But after seeing everything he was doing, I can see why paying labor costs for it would add up.

aka paco

iTrader: (15)

guy down here had a na-t supra making around 400 to 450hp

went through 3 boost logic transmissions


i personally feel like the only transmissions to have with 400+hp and the reliablity to beat on them are a R154, V160, or something like a TH400.



why are toyota tranny's so weak anyways? people run 500+hp on honda manual transmissons all day.