oSUPRAo

I just got back from the Toyota dealership and have fresh brake fluid. The mechanic complimented the car and said it needs nothing other than a throttle body cleaning at some point. The brakes definitely feel firmer and more confidence inspiring. On the way home I got to try them more than I planned on thanks to morons. Now I will buy some cheap 350z wheels, save more cash, and then get a set of PSS and the LS400 front upgrade.

KahnBB6

iTrader: (5)

I was agreeing with you on that point. However I was disagreeing with you on the implication that the metallurgy choice in the TT calipers counted for nothing at all compared to them. Toyota changed many other aspects of both the Soarer and Supra MKIV (Non-Turbo and Turbo 6-speed) in 1996 and 1997 for Japan... which trickled into changes for model year 1997 and 1998 for the USA and other export countries. They obviously had the budget to change whatever aspects of the mechanicals they wanted to but elected to leave the big brakes on TT Supra 6-speeds alone while spending money on other areas that arguably have less of a noticeable impact.

Bottom line in general and especially for the OP and most folks is that you don't need to seek out TT calipers because LS400 calipers will do almost exactly the same thing on the street. I have no racetrack experience myself so I cannot say in that environment.


Yes they did. For 1997-1998 model years the MKIV Supra (all model trims) got aluminum front lower control arms. I haven't looked into it but it could be that aluminum front uppers and aluminum upper rear and lower rears also switch to aluminum. For 1997-2000 SC300's and SC400's the same changes went into effect with exactly the same control arms in the front with the exception of the rubber formulation between the Supra and SC (meaning both cars should have different part numbers for those front arms)... and the higher cost for a Lexus part. The rears similarly could have gone to aluminum. In the cases of both cars for 1997+ the revised aluminum control arms cost more than the preceding cast-iron units. In the real world the only difference is a small amount of weight... which doesn't really justify the higher price of the late model OEM control arms unless your car came with them to begin with as a 1997+

I still disagree given the numerous other things that may or may not have made much of a noticeable difference (like those aluminum control arms) that Toyota went about changing during the middle 90's revisions to the Supra, SC and Soarer (which were all built on the same assembly line at the same time). Clearly they could have but didn't whereas other aspects of those cars got very substantial revisions. The V161's introduction for instance. I tack it up to the overbuilding they were known for at the time. The 6-speed transmission was overbuilt. The turbo engines were overbuilt. The Non-turbo engines were still overbuilt. The big brake design has undoubtedly been surpassed by today's technology from Brembo among others but it was good enough that for a system originally designed in 1991-92 it wasn't bested for braking distance performance until the release of the Porsche Carrera GT in 2005.

That doesn't mean you NEED an entire TT braking system to effectively get nearly everything it has to offer with a simple LS400 front caliper swap into your SC. I'm just saying that for whatever reason it was that effective for a very long time and Toyota had all the resources they needed to revise the braking system only a few years after the car's introduction but they chose not to while spending money to change other design areas of the car and its sister vehicles.

Without a pair of identical cars on a track with an LS400 and TT braking setup doing 100-0 testing and high speed laps we'll never really know how much difference there is. On the street it really won't matter in 99.9% of scenarios anyway The LS400 calipers are the cheapest and most effective reliable solution and really should have been standard on all of these cars to begin with.

Most of the famous turbocharged RWD and AWD Japanese performance cars from the early 90's had older 5-speed designs throughout their production runs ended until about 2002 (Japan): the MKIII Supra, Soarer, Chaser & Mark II, Skyline GT-S and GT-R (until 1998), RX-7 twin turbo, 3000GT VR-4 (until very late in the model run), etc.

I've shifted better modern manuals with 20+ years of R&D on the R154 but I can tell you it's a very normal transmission to use day to day down to the shifting characteristics. Below 500whp they are utterly durable and normal and will handle 700whp at the top. Pretty good if you ask me. If I had another type of car I'd use an appropriate transmission for that model. A Tremec TKO 5-speed or Tremec 6-speed in a Mustang or Camaro for instance. No need for an R154 there. Same with Nissan/Infiniti or Mitsubishi.

Generally the most swapped manual transmissions I hear about going into other cars in the last twenty years are primarily those originally designed by Tremec, BMW and ZF. It's still easier to use the hardware specifically designed for the manufacturer's model platform or at least the manufacturer's drivetrain. Hence the popularity for quite some time of the Toyota/Aisin R154 in the 1JZ/2JZ engine world.

This is because only now are R154's beginning to become harder to find and get some major service parts for. They were and still are one of the easiest bolt-in manual transmission solutions for these cars that is reliable in turbocharged applications. This is even more so the case when you look at the V160 and V161 which there were even less of in circulation to begin with before they were discontinued. Less good bolt-in transmissions stay in circulation which raises the price and concern if something breaks so people look for alternatives that can be adapted that are both more affordable and perhaps use newer and better technology.

This always happens no matter what the model and make are given enough time. Personally I think the new transmission options are great. The V160 is beyond the point of it making sense any longer due to the rarity. The R154 isn't quite there but it probably won't become any more ubiquitous. It's good but also not in the league of the V160. I say use whatever works for the goals and intentions with your car.

The Grannas Tremec Magnum kits so far look like the best new option around. The total cost is more than an R154 swap but far less than a V160/161. Then there's the Aisin AR5 conversion to R154 spec as an alternative when not building for massive horsepower. I'm not as well versed on the Nissan CD009 swaps but they are worth mentioning.

Having more proven transmission options is always great!

Heck... we even have much more improved brake caliper options with six pistons up front that are available for the MKIV and SC in official aftermarket kit and adapted alternative OEM form. But most of the time those aren't anywhere needed ;D

t2d2

iTrader: (8)

Well then, what does it count for? We've got no measurable data presently that can't be easily explained by the however slight rotor size increase. However, there are Supra owners who have switched to the LS calipers for comparable performance and weight savings.

And they could have adapted the Supra's aluminum hood for us, addressing one of the SC's biggest shortcomings. There's no rhyme or reason to much of what they did.

That got me curious, so I went out and checked my '98 control arms. They're clearly magnetic (front and back lowers), so not aluminum. I suppose it's possible that a P.O. replaced them and not with the '97+ parts, but I'm skeptical. Can anyone else confirm that their LCAs are aluminum?

To be fair, though, you seem to be in the minority in R154 threads I've read when it comes to your liking of it. Lots of people complain about its crude behavior.

Okay, I may not have framed that well. Putting it in broader terms, how many people are adapting any generation Toyota transmission to their vehicles? If Toyota trannys are viewed as being as smooth shifting as they are durable, they should be a very popular swap option, right?

KahnBB6

iTrader: (5)

Awesome, oSUPRAo!!! A new fluid flush can do wonders sometimes. Glad to hear they liked the condition

You're on the right track. One step at a time and you will slowly begin to see your car change in front of you

KahnBB6

iTrader: (5)

Whoops! t2d2 I will correct my earlier post: I had a mental slip. MKIV rear upper and lower control arms have always been different than Z30 SC/Soarer rear upper and lower control arms. I did not mean to confuse anyone with my mistake in wording. They will not interchange of course. What I meant was that I haven't checked into it but I think the Z30 SC/Soarer and JZA80 Supra both switched to their own versions of aluminum rear upper and lower control arms for vehicle respectively.

Neither of us knows the real answer to that, unfortunately Yes, there is no measurable data to compare between the LS400 calipers and Supra TT calipers on identical cars (or the same test car) with measured 100-0 stopping and repeated track lap data. Without that it is purely up to speculation and the what one feels from the driver's seat.

I'd like to see the thread(s) that discuss Supra MKIV owners switching to LS400 calipers over TT calipers or a six-piston braking system. I'm not disbelieving you, I just haven't read them myself.

I haven't been arguing that LS400 front calipers are somehow ineffective in comparison or even that effectively different in terms of braking performance 99% of the time under most road and track conditions. All I've been saying is that I'm not of the opinion that the choice of metal on the part of Toyota designing their TT calipers was a matter of their being lazy or incomprehensible.

The only way to know more beyond someone volunteering controlled track data sets is to find one of the original JZA80-TT or TRD engineers and ask them directly what they were thinking at the beginning and middle of the model run.


Yes but I assume this had more to do with cost at the time. Extensive use of aluminum in bodywork in the early and even middle 1990's was often an exceptional thing. It made sense to do it for their flagship sportscar. It wasn't needed as much with a (in Toyota's eyes) moderate luxury performance car where weight wasn't so much the enemy given the car's intended purpose. Not the same thing but I have seen a 100% carbon fiber hood with pins fly off an SC300 running 25-30psi of boost and a V160 and low ratio rear end traveling at 160mph. Not sure if it was an isolated case but the problem was solved by switching back to the factory steel hood. Aluminum might have not presented the same issue at such a high speed but I still think it was a matter of aluminum body panels being more of an exotic thing for the 1990's.

Which is why sportscars like the Supra, RX-7 and NSX all variously used aluminum to reduce weight but even luxury GT's largely did not at the time. Today we've got aluminum frame pickup trucks with aluminum hoods and the cost to use durable aluminum body panels and even structures in production vehicles has come down significantly.

Interesting. I just know the that front lower control arms should be aluminum alloy from 1997-2000 in the SC's and MKIV's. If you go through the EPC you'll find that control arm prices for the late model cars suddenly get more expensive. Now it could be that only the fronts went to aluminum or that the Supra MKIV got those control arms a year early. It's possible since the mid-cycle revisions came in two model years for the SC300/400: partly in 1997 and again with the drivetrain in 1998.

It certainly is cheaper to bolt in the less expensive earlier iron control arms. It's possible someone did that depending on your mileage. The answers are probably in forum threads here somewhere to confirm one way or the other... however I assure you that aluminum front lower control arms do exist in the front for both the Z30/SC and MKIV even if we can't be sure of the year in this one thread.

All I can say is that I am being honest and not candy coating anything. I've talked about how reverse lacks a synchro (like the V160) and that in my case I have a very recently rebuilt and upgraded MKIII R154 with an aftermarket short shifter. Maybe that makes a difference and maybe not. I've compared it to late 80's and early 90's Mustang 5-speed transmissions which I feel is fairly accurate. Those are not refined either but they aren't in any way terrible. It's a transmission feel from a near but definitely earlier era that modern manuals or state of the art manuals for 90's cars moved forward from. No more and no less.

Also, I don't think everyone is comparing apples to apples when you have some rebuilt or upgraded and rebuilt early R154's compared to non-rebuilt tripod R154's and early R154's with really high mileage and a lot of abuse.


The Getrag 233/V160/V161 should be given how strong it is but it's always been very expensive even before its 2016 discontinuation and its value went up as soon as MKIV Supra values went up years ago. This wouldn't have made it a reasonable choice for hot rodders outside of the 2JZ engine world. I've heard of them being bolted to a couple of twin turbo 1UZ engines but little else. The only other OEM application of the Getrag 233 was in the 1998-2002 Skyline R34 GT-R series which uses the same internals in a unique casing which supports an AWD setup.

R154's are, again, specific to JZ engine applications. Until recently they were the easiest solution. For other vehicles like the 5.0/302/351 Ford and GM's 90's LT1 and subsequent LSx engines there were initially Borg-Warner and later almost exclusively Tremec manual transmissions that were the go-to OEM and aftermarket gearbox. Same for BMW's having their own partnerships with Getrag and ZF.

This is why I have said that over years of observation well before I knew what an SC or MKIV was and before I even toyed with a Honda for a few years I usually see domestic V8 transmissions being swapped into things when any of the gearboxes from a particular OEM's parts bin will not do. Where we are today it's really mostly Tremec in the aftermarket. And with automatics for drag racing there are the utterly ubiquitous GM TH400 and Powerglide 2-speed.

There are so many good and great transmissions for particular makes and models that do not find their way in the hot rodding scene into other vehicles because they work best to a cost and reliability point with the chassis platforms and engine types they were originally designed for.

Tremec stands out from this because they sell aftermarket gearboxes for many V8 applications. Even Aisin, Getrag and ZF don't do that.

...

Anyway, I want to get things back on topic for oSUPRAo.

We can continue the transmission topic in a new thread if you wish, t2d2

t2d2

iTrader: (8)

I didn't bookmark any of them. Probably found them on SF, but it's been ~2 years, so who knows. The discussions were along the lines of, it would be an easy choice if the LS calipers had better pad selection.

A) The Miata got an aluminum hood several years earlier, and it sold for a third as much, B) the SC was Lexus' flagship just like the Supra was Toyota's, C) both cars had an alleged gram shaving directive, and B) the chassis are so similar, it shouldn't have taken much more work than reshaping of the headlight cutouts to adapt the Supra hood to the SC. That should have been a very easy decision. The fact they didn't tells me they were inconsistent with execution of their stated goals.

I've seen that aspect mentioned before, but wasn't aware the difference is attributed to going aluminum. You mentioned a slight weight savings. If the newer front LCAs truly are aluminum, shouldn't the savings be quite massive? I would think on the order of 5+ lbs.

No one's going to question that! I'm just saying, you're usually the one defending the R-series while other people tend toward indifference.