Hello All

During the last 2 years I have been destroying rear end and manual gearboxes on command - now I guess that problem is history :eusa_ange

A very good friend of mine made a TH400 conversion kit with all the goodies inside including Trans brake, manual shift kit, upgraded internals, 3600 stall converter etc. Well, he even managed to adapt the stock A340 speedo drive. This auto will hold more power than a 7M is able to produce..... I hope!
He decided to go another route than the typical adapter plate and take a look at the results below, a migrated A340 bell housing into the good old TH400 :snork_lac

He has tested it on his own 7M during all the national racing events and it have functioned perfectly so now it is time for it to settle down at its final destination. Only weak point at this moment is the converter as it is not bubble proof and "only" rated for max 650 RWHP - I guess it will do for now!

With his car and a GTR35 he managed to do some very good 1/4 mile times with 500 RWHP - best time so far 11.14 sec. I will cry if I can't get it down in the high 10's with my T-66 @ 35 Psi - that will be with the spare wheel still in the back as a daily driver :eusa_ange

My next challenge will be to find a way to adapt a 3.2 gearing into the rear end so I can have the possibility to cruise around at reasonable rpm's.

The pictures:


http://www.supra4ever.dk/upload/th400_1.jpg

http://www.supra4ever.dk/upload/th400_2.jpg

http://www.supra4ever.dk/upload/th400_3.jpg

http://www.supra4ever.dk/upload/th400_4.jpg

http://www.supra4ever.dk/upload/th400_5.jpg

http://www.supra4ever.dk/upload/th400_6.jpg

Greetings from Denmark

Karsten

nice setup. if i was about strictly drag racing, id probably research it a bit more:)

Hello

As a matter of fact this gearbox will give you the best of both worlds; you can use it for drag racing BUT also as a "normal" gearbox.

The way this auto is upgraded, you have to shift the gears manually as a true sequential dog box, it will not make kick down and one has to manually place it in the next gear - both up and down. The benefit is that you will not loose boost while shifting gear (you keep it at WOT while shifting gear manually) and you will always be in the middle of your power band with the correct stall. I have been racing my Supra on the local race tracks a lot and it is very hard to control the transition from no boost to full boost when accelerating out of a corner. By this you will always have boost and therefore no transition.

On top of it you have the possibility to do some spectacular starts from the lights with the Trans brake - You simply lock up the auto in 1. and reverse at the same time, giving you the possibility to build boost without having to apply the brakes. :eusa_ange

Regards

Karsten

Thats pretty damn sweet. Props to your buddy.

nice setup....too bad it's still only a 3 sp. how do you plan on going faster than 12X?

both trackability and streetability....seems like it is best of both worlds...but what is this thing about getting good starts...auto in 1st gear and reverse at the same time? is that like powerbraking...witout the brakes? how many gears are there in this setup and can the amount of gears be adjusted by changing the size? very interesting... i want to learn more...probably wont get one...id rather stick to the 5spd manny tranny that i got..but def wanna learn more cause i hear about the x-trac...like the 4 spd auto tranny that are kind of like this...not sure if theyre are similar or not...but it seems like it :eusa_shif

a transbrake puts the auto trans into 1st and rev- locking you place and providing load for the engine.....when you release the transbrake it releases rev- leaving you to GO GO GO in 1st....

nice setup....too bad it's still only a 3 sp. how do you plan on going faster than 12X?

I know 3 speed is the only downfall of this setup but the torque from the 7M kind of get it going rather good after all :snork_lac

I will try to find a new gearing for the rear end with around 3.2 - that will provide me with more than enough top speed - if I want to go faster I simply take the bike.
TRD used to make a a 3.2 for the rear end of the the so famous Group A factory car, will try to source one of those. If not, I will migrate a complete rear end from a Mk IV.

Regards
Karsten

i'd try out a ring/pinion for the 8" toyo truck diff....cheaper/easier.

i'd try out a ring/pinion for the 8" toyo truck diff....cheaper/easier.

Concur, that is a plan as well - just a little unsure if they will fit inside the housing and mate up to the LSD.

Already looking for one of those to try some test fitting but they are hard to find in Denmark - I know the TRD group A won't come cheap.

Regards
Karsten

wow, thats so simple yet so difficult. easier said than done, thats for sure.

so you basically have a built TH400 setup for bracket racing or moderate street performance.

sounds like its a race build w/ manual valve body... possibly reverse pattern. integrated a trans brake to stall up the converter. the only thing left to add is a deep sump pan and delay box for bracket racing.

quite beefy, but a "Basic performance upgrades" for any domestic car planning to be decently fast.

the TH400 only has 3 gears, ever. driving w/ a TH400 is like not having 5th gear in your stock Supra. it is possible to keep this setup and get an overdrive unit to bolt onto the tailshaft housing. the only downside is the added weight of the over/underdrive unit. i suppose its possible to set this up w/ the overdrive unit and a shorter driveshaft, then have a spare tailshaft housing and longer driveshaft to swap out on trackdays. so the car would be as driveable as before, with Overdrive, when weight doesnt matter. but it could be removed for competition.

Thanks Chris

With 800+ Nm of torque 3 gears is ok, I'm presently looking into different options to lower the final gearing. Arnout has a way to get a 3.07 into the rear end as well as I have found a local shop that is able to custom build any ring/pinion setup I want.

The overdrive option have been tried on the Mk IV with no joy as it could not hold high hp and created lots of vibration. I will go for the new final gear ratio and possibly a new lock-up converter controlled by the AEM.

There will be a new and bigger oilpan for sure and yes, the box has all the goodies inside :snork_lac

Regards
Karsten

also, if you havent already purchased a trans fluid cooler, look into a Setrab unit. they are supposed to be far more efficient than just about anything else on the market.

3 gears are typically just fine, but its the final drive or redline that has to keep getting higher and higher for fast cars. even tire height will help out too. a Lockup converter would be the Best choice for keeping streetablity. a high-stall converter will burn up fluid FAST during cruises or long drives. MKIV's with high stall converters burn up fluid quickly and typically need flushed as frequently as engine oil changes.

if you do happen to have a custom gear set made for your rear end, i would be VERY interested if you could take some pics of the machining process and the equipment they use. im trying to learn more about gear cutting and whats involved. ive got some ideas that im toying with and trying to find out how viable they are in relation to potential cost.

if you do happen to have a custom gear set made for your rear end, i would be VERY interested if you could take some pics of the machining process and the equipment they use. im trying to learn more about gear cutting and whats involved. ive got some ideas that im toying with and trying to find out how viable they are in relation to potential cost.

I sure will, I'm not the type of person that keeps the "secrets" for myself - If I will follow the Local solution I will have the Mk 3 community in my mind.
This could be of benefit for all of those that want to go the V160 route as well.

BTW my car will not see much drag race, as I'm kind of the anonymous type of guy, I simply want something that will last and in a "factory" manner. If I see a 10.xx on my G-Tech Pro next year and the car is street able, I'm more than happy.

Regards
Karsten

Nice set-up. I was gonna stay with an auto but decided to stick with the manual. "pun intended"
Flat shift mode in a stand alone will allow you to keep boost while shifting. How many manuals you go through? Just a thrush washer or?

Duane

Again nice set-up and give us some videos when you hit the track ;)

Edit: just re-read your post and relized you don't track race? If you G tech it is fine but you need that time slip dude and get that :respekt:

Thanks Duane, There are only 2 or 3 racing events in Denmark a year and I don't like the way they run them. Apart from those events, typically old airfields, we have no Drag racing track in this country :cry:

Therefore I have to rely on the G-Tech and that is good enough for me, simply said I just want a fast street car to have fun with in the weekends.

BTW Ron has just completed my new FFIM, a copy of yours :eusa_ange

How many manuals you go through? Just a thrush washer or?

I'm on the second box this year in only 2500 miles, typically I loose 2. gear when shifting from 1. to 2. - I guess a thrush washer. Another issue, I find it hard to put it into next gear when shifting at 7k - too much rotating mass I guess.

Thanks Duane,
BTW Ron has just completed my new FFIM, a copy of yours :eusa_ange

LOL really! Joke. LOL You will be very happy with the spool time and power it will give you

I don't shift mine that high so I can't say it would be a problem for me. I did notice however when shifting higher once it was hard to get it in to second. :confused: Maybe that would be the same problem...

Duane

Duane, when you say flat shift on a standalone... do you mean not pulling timing when upshifting? ive noticed on some Autos that boost spikes when upshifting.

anyways, karsten, you said you have trouble shifting at 7000? thats kind of unusual. unless you are powershifting (not releasing the throttle). the R154 behind the 1jz can shift fine at 7500... i hope i dont have shifting trouble when i rev my 7m to 7500. :(