LoveSCs

iTrader: (2)

I am curious to see what fellow SC'ers would prefer. I am thinking of either going with an ATF Speed built auto transmission, or else doing an R154 swap in my 1JZ SC400.

The built auto can handle in excess of 800HP according to ATF Speed, whereas the R154 can apparently handle around 600HP with stock internals. I would probably not see myself going beyond 600HP on a 1JZ, but would be nice to have the breathing room. Also, this is a daily driver, not a track car.

I have the SupraStick auto transmission controller with manual mode, so that makes the car unique in itself. That said, I don't "need" the manual aspect of a 5 spd, even though the clutch would be more enticing.

So, anyways, on to the poll, which do you prefer?

gerrb

iTrader: (34)

ATF Speed for me. Being rated at over 800rwhp, it would last longer for a daily driver car cause you will seldom use that power on the streets. Not unless you really abuse it, you have a lot of breathing room.

R154 with stock internals , beyond 500rwhp, you MAY start to have problems like tranny fluid leak on the tail or shifter area. If you don't have the right clutch setup , that maybe a constant maintenance.

Now a days, it seems that the cost of setup between the two is not far from each other. But again, the USE of the car and Personal preference will also influence one's choice of tranny. Some people just want to be able to manually change gear while pushing that clutch which I wouldn't on a busy city where I live.

LEXXIUM

iTrader: (1)

The fun factor driving sc is a manual transmission, built auto is great for cruising and a drag stop launches, but if you're a gear banger go for r154.
I'm In the process of building my w58 swap, because the only r154 I wanted was a jdm which costs a left nut, so I settled for a mint w58 for lightness and smooth shifting and availability of this trany.
I can't wait to find my drive shaft

SCereal

iTrader: (4)

I voted built auto although I plan to go 4L80e rather than try to build the toyota trans.

LoveSCs

iTrader: (2)

Thanks for the input guys. Let's get some more opinions here please!

Nova

iTrader: (21)

I dont know what u use your car for but my sc300 is more off a weekend car that I cant see myself selling. I currently have a 2jzge on the engine stand and plan on putting a th400 or powerglide behind it.

Th400s are a dime a dozen and parts are easy to find to build to any hp/tq rating. Manual valve body give you the feel of shifting without the delay or boost dropping between shifts. While the adapter plate and concertos can get pricey the fact that it is a hydraulically controlled transmission saves on having to get an auto to work with stand alone ems.

A reason Im thinking of a powerhouse is that it is only a 2 speed forward transmission which is nice on the track in my eyes.
on another note if you plan on getting your car to 600hp range you will be playing Russian roulette every time you get on it. Its nice to have a cushion to know you're safe

Ali SC3

iTrader: (10)

The day My sports car gets an automatic is the day I stop using my left foot for anything. I'll also have to find something for my right hand to do... sudoku maybe?
A drag car I would have to say a big maybe just cause that is the only way it makes sense to me that it would be better although there are v160's putting down pretty nice times.

grumpi300

iTrader: (1)

only reason I say r154 is because what you said on your very first post. r154 can handle your power goals stock, no money invested and your all ready. you would have to invest some serious money to rebuild and upgrade the auto trans for it to be able to handle your power goals. also, if your auto does happen to go out at any time, that's more money that you would have to invest in rebuilding it and upgrading it again, (assuming its broken beyond repair and you have to buy a new one.)
whereas a r154 breaks, you can get a new one, swap it In and call it a day.

KahnBB6

iTrader: (5)

Yes... but not quite, Grumpi. Some people have blown older R154's on less than 600whp. Depends on how those *stock* R154's are shifted. The OP's goals are easily *below* the maximum power holding capability of a built R154 and it's a perfect transmission choice for what he wants to accomplish.

However even at that power level I'd recommend getting it built with the MC 1st gear thrust washer and MC front bearing retainer plate. Also the MC/DM 1-2, 3-4 and 5th-Reverse billet shift forks as they are similarly night and day superior in strength to the original cast shift forks which will have some wear after as many as 25 years depending on which R154 you buy.

Keep in mind that the early MKIII and 91-93 Soarer (extension housing) R154's especially are known to have a single weak point: the OEM Toyota 1st gear thrust washer. The OEM front bearing retainer plate has also been called "swiss cheese" by some when it comes to getting into 500whp and beyond. The later tripod versions were improved but the MC parts are still the best ways to take any and all weaknesses out of the equation for high horsepower.

The 1st gear thrust washer and the tendency of the OEM front bearing retainer plate to allow the shafts to have minute axis shifts with extreme horsepower and hard shifting are the reasons people build the R-Series gearboxes. YES, they are a hell of a lot stronger STOCK than a W58 ever will be but at 600whp it's well into the territory of "replace those items while you have a good chance to".

A rebuild is about $550. The MC/DM upgraded billet parts aren't cheap but they aren't expensive. It's worth the investment to do once and forget about it.

750whp is the proven safe maximum ceiling. Even if people have attained higher horsepower on built R154's the longevity AT those constant power levels all depends on how the transmission is shifted... similar to how some people blow W58's with a turbo very quickly at barely more than 300hp and others seem to do well with them for several years at 300-350whp or so.

Yes, you can just get another R154 if the first one breaks but these days they are beginning to get harder to find in good shape. And you'd still be faced with the same limitations if it's another bone stock R154 which has never seen a good rebuild.

Some people have better luck than others but getting a 25 year old transmission with some mileage (beefy as it may be from the factory) rebuilt while replacing a couple of critical parts in the process is the best way to make sure you invest once and probably won't have to again.

...unless you go up to and/or beyond 750whp or start missing gears at speed. Or start slamming into 3rd gear rather than treat it with care.

I love the R154 personally and if I wanted 600whp as well I wouldn't be concerned at all about pushing it that far. But I wouldn't try that with a stock gearbox. Make no mistake... it's not "glass" like the W58 by any means. It's very tough. But Toyota/Aisin didn't make it 100% perfect from the factory even with 300-350hp stock applications and extremely high and generous duty cycles in mind that allow it to be taken to such extreme power levels.

grumpi300

iTrader: (1)

damn kahn. you just learned me today. haha. thats a lot of information i did not know about the r154. i just swapped in my r154 and now i feel like buying one just to be safe. haha. i know its not necessary considering im stock right now but its better to be safe than sorry.
but yeah, most of it does depend on the driver and how hard/smooth he/she shifts the trans. i really only thought the weakest point was the 1 gear thrust washer. not the retainer plate as well.
edit: i'm guessing that this is the reason people say ****** it and spend the extra money on a v160/161. theres almost nothing to worry about on this trans. the only things to break are behind the trans.

99SC42

iTrader: (44)

Lol my stock R154 holds 700whp 680tq On Ethanol, I have never broken an R154 in the 9years that I have been using them.

1A1

Depends on how you plan to use the car. They both have their positives and downsides. What are your plans?

Steve

KahnBB6

iTrader: (5)

Even some very used and abused V160/161's get rebuilt/refreshed and they are tough as nails with no weak design points. The difference is that V160's don't need any upgrade parts when they are rebuilt. Though I'm sure there *are* some stronger gear sets (dog gears?) available somewhere if someone wants to spend a fortune on even more internal strength.

The R154 is really a tough transmission and more affordable and adequate for most applications. I want to reiterate again that it's magnitudes more likely that someone will blow a W58 with a turbo than an R154.

^^ And after all I've posted, I can't argue with an example like this, 99SC42 But part of this has to be how you treat your R154. That's fantastic though!

grumpi300

iTrader: (1)

99sc4 is obviously one of the lucky few to have gotten the strongest batch of r154's. lol. i'm hoping my doesn't go out anytime soon cause it does scare me. the trans I got was sitting in a mk3 supra in the middle of las vegas sun beating on the car all day for 4 years. first thing I did when I took it out was drain the fluid. I opened it up for the shifter extension and looked inside and everything "looked" good but i'm no trans expert. that's mny dads forte. haha. but yeah he said it looked good and just put it in my car. when I put it in my car I put motul 90. shifts and feels like butter.

KahnBB6

iTrader: (5)

Grumpi, unless you're pushing a LOT of horsepower and slamming those gears instead of shifting very precisely before letting out the clutch you will probably be fine. I got mine out of a 111k mile MKIII Supra and I probably could have not bothered rebuilding it for turbo use. Since I bolted it to my NA engine I definitely went overkill. I think you'll be okay unless you really up the ante or start doing a lot of drifting at the track (which is where a lot of R154 abuse comes from. That and drag racing).

For transmission fluid, run ONLY Redline MT-90. Specifically that brand and type of oil. It's universally recommended for the R154 and will help with longevity and shift quality.