Deceptik1

iTrader: (6)

I hate my 4.27 auto diff also. It was fun at first but I commute a lot and the drone of my exhaust and high rpm's in 5th on the freeway got old. I could only imagine what my mpg would be with a 3.92.

KahnBB6

iTrader: (5)

Is your car just 5-speed swapped or have you also gone NA-T or GTE swap?

KahnBB6

iTrader: (5)

I find these two threads on Supraforums rather interesting:

http://www.supraforums.com/forum/sho...ht=axle+ratios

http://www.supraforums.com/forum/sho...ht=axle+ratios

Apparently USA model 93.5-96 Supra Automatic AND 5-speed manual cars all came with 4.27:1 axle ratios. Only in 1997-98 did USA market Supra NA's switch to 4.08's, again for both automatic and manual transmission cars.

stockhatch

iTrader: (12)

Just for the record, the 4.27 auto rear DOES get old fast whether you are NA or boosted. I have run my car both ways, and the gears are just too short. I plan to go 3.92 with TRD LSD eventually behind an R154 which should make a huge difference in driveability.

lev00221

iTrader: (28)

KahnBB6,
In my SC300, the W58 and the 4.27 rear end it always felt like I needed another gear on the top.

With the v161/3.26 I could immediately tell that the drivetrain was designed for the engine and for boost. It feels great off the line and it is always easy to keep the car in boost when running the higher gears. I don't ever boost 6th gear but 3rd, 4th and 5th are great fun! Cruising in sixth gear is nice because of 2200 rpm at 65-70mph and you still have plenty of reserve if you want to go faster. Again, the best way of explaining it is that it feels properly designed for the engine and the car. It probably feels even better in the Supra.

Stockhatch,
I also own a 1998 SC400 that I am currently having swapped to a W58 (the one I took out of my SC300) and I will be using the Auto TT 3.77 LSD. I did the RPM calculations using W58 mated to the 4.08 and 3.92 and opted for the 3.77. I PM'd RedPhoenix and he is using the 3.92 rear end in his SC400. He recommended the 3.77. I will let you guys know how it feels.

KahnBB6

iTrader: (5)

Especially since your car is running a 2JZGTE (looking at your sig) I agree with you. Turbocharged cars will not benefit from this *at all* and *should* have less aggressive gearing. They can, however, make up for it with boost.

My last car was geared more aggressively than my SC from the factory and it was just as underpowered (read: anemic). Adding turbo of any kind would change this but I am not entertaining that option anytime soon.

Respectfully, I hear what you are saying but I haven't made a decision yet on changing the axle ratios.

lev00221, I hear you as well. Believe me, I understand what you and many others have been saying about the SC/Supra and any factory 2JZ car having been designed primarily as turbocharged vehicles with necessarily less aggressive final drive ratios. I do not doubt this or question it.

All I can say is that I'd love to play the turbo game but I have no immediate plans to. I've read a LOT of information about swaps and NA-T setups and personally feel that the collective tradeoffs of doing anything less than a full USDM 2JZGTE engine swap (not to get it BAR approved but just to have a USA VIN on the block and functioning EGR) are just not worth it to me at this point in time. When I swap a car's drivetrain I want to be entirely done with it from that point forward other than maintenance or very discreet BPU mods. Paying a smog guy a few hundred to pass my vehicle every two years is no big deal but other than that I don't want to have to remove anything from the car should there any police/BAR related issue. That only leaves the expense of going full USDM 2JZGTE without cutting corners (other than that I'd prefer an R154 over a pricey V160/161).

Dropping $10k into my car for a swap is not that important to me at this time and USDM is the only way I will boost my SC. I've done a LOT of reading educating myself on NA-T and all types of swaps and I know many other Cali owners find a way into NA-T or a JDM swap for far less than going USDM despite the legal realities involved. That's fine. I just don't care to do it that way. I'm too busy with other more important things in life to have any lingering concerns about my car once I've modified it. For me, when it's swapped, it's swapped and that's going to be it. I would not plan to get it BAR inspected unless I absolutely have to but if I did have to I'd rather have a very stock looking BPU'd USDM in my SC.

And if I ever do get a USDM in my car, it will not be running anywhere near a 4.272 or even 4.083 final drive.

Back to the thread topic, I hear the unanimous feeling that a 4.272 gearset is too short for a W58 NA car. The ONLY thing that has kept me interested are the two links I have posted above from Supraforums which seem to indicate that 93.5-96 USA Supra NA 5-speed and Automatics DID come with factory 4.272 ratios. That is interesting. Supposedly only in 97-98 did they go to 4.083.

account2x

iTrader: (5)

Boost does not change where an engine revs. The lag with NA-T or single turbo conversion on a GTE would keep you out of boost makeing it no different from NA at 2-3k rpm.

Does not that confirm what everyone has been saying if even Toyota changed the Supra to match SC300 rear end.

KahnBB6

iTrader: (5)

I did not suggest that boost changes where an engine revs for a given RPM. Where did you read that in my comments? Perhaps I wasn't specific enough when I said that boost can make up for less aggressive gearing: because the hypothetical turbo car is geared less aggressively it may have slower off-the-line acceleration but the simple fact that a turbocharger will have spooled enough at a certain rpm means that where the NA engine would not have a significant jump in power at 3k rpm, the turbocharged engine will. But we all know this.

Personally, I've never been interested in anything but the US 2JZGTE's twin turbo setup anyway, so lag from an NA-T or doing a single conversion on a GTE is out of the question in my case.

Not really. It just confirms to me that especially in the USA Toyota initially marketed the NA Supra in a sportier configuration than it did the watered-down-for-USA SC300.

It tells me that at least for some years they went with a 4.272 in the Supra NA for a sportier feel and then later caved into whatever negative buyer feedback or other nonsense may have caused them to make a less aggressive base model of their sportscar. This is not an uncommon thing among car manufacturers with specialty cars getting odd changes year to year and it doesn't necessarily mean that all MKIV Supra 5-speed manual 4.272 diff cars are somehow impossible or poor to drive.

Apparently they did sell the cars that way with a drivetrain nearly identical to ours. One chassis was a cruiser for a luxury division while the other was a sportscar for the mother brand.

It tells me that Toyota offered one flavor of the base model and only some buyers liked it while others didn't. Being a corporation interested primarily in making money and not just satisfying a few niche owners who liked more aggressive gearing, they made the base NA less aggressive. And they dropped $10k from the sticker price of the Turbo.

Two years later they pulled them from the market.

It sounds more like Toyota was trying whatever they could to gain more buyers for a great sportscar for which they unfortunately didn't have many buyers.

So... if Toyota actually put a 4.272 in the MKIV Supra NA 5-speed for a few years and later changed it out of panic that tells me it may not be a popular configuration but it was a factory configuration I could use on my mechanically similar SC if I wanted to.

I'm not very into the luxury aspect of these cars, nor do I care to put a bodykit and fart can on mine. I like the chassis and how it drives with Supra running gear. If Toyota used a 4.272 against a 5-speed MKIV at one time then I see no reason not to try it since I'm not going to turbocharge my car. If they never used it on an MKIV 5-speed then I won't since it was never a factory configuration.

EDIT ADDENDUM: come to think of it, the real reason the NA Supra rear ratios were changed probably had a lot more to do with saving cost on a low-volume and slow-selling USA export model. JDM's always had 4.083's so it was probably just another way to reduce the number of variants and thus the cost to manufacture MKIV's. That, or Toyota changed the ratio to help meet their required CAFE fleet average for the time. I seriously doubt that Toyota would have changed it if it weren't for abysmal sales in the USA and CAFE, both things that weren't the fault of the car.

account2x

iTrader: (5)

What happens more often? (1)Driving to redline and shifting at redline in 1st, 2nd and maybe even 3rd gear. (2)Driving conservatively and shifting at 2-3k rpm until reaching 5th gear to cruise. Scenario 1 weak engine is weak. 3500 pound 180 horsepower car is not sporty. Scenario 2 you get worse mileage. The performance gain is almost nothing and the mileage lose is definitely something. Makes sense why Toyota reduced the Supra's ratio.

- US spec 2JZ-GTE overrated.

KahnBB6

iTrader: (5)

You are basically just trying to prove you're right at this point, and it's pointless to get into an internet pissing contest. I've been asking about what I can, legally, do in the state of California based on my desires for my car.

Of course scenario 2 will net slightly worse mileage. The SC300 was never designed as an economy car and nets about 15 mpg to begin with. If I wanted to maximize mileage, I would have bought a ______ (insert whatever four-cyl, soda-bottle displacement car you want).

I want to have fun tinkering with and noticing a bit more pep out of my car, within the realm of not getting pulled over and my car being impounded for the slight chance of failing a visual.

This thread was started to find information about running a more aggressive final drive on my car which happens to be exactly the final drive standard on non-turbo MKIV Supras until 1997.

Troll less,please.

BAD954BOI

iTrader: (5)

hey, i just stumbled upon this member: (buckwheat)

thats doing a new ls 430 3.266 ratio and getrag 6 speed for his sc300 2jz na-t setup...
Attachment 210909

has anyone heard of this?

KahnBB6

iTrader: (5)

I'm not familiar specifically with using an LS430 diff but that FD sounds to be in the right ballpark for a Getrag swap. I believe 3.133 was the stock FD for early MKIV Turbo 6-speeds.

account2x

iTrader: (5)

Hasn't everyone with the 4.27 on a W58 confirmed what I said so many posts ago?

This has happened to who? If so worried about staying legal trade for a 1998 SC400 with variable valve timing. More low end power, 60hp+ more top end with another 30hp from intake & exhaust. That is an extra third more power with up to a 15 percent increase in mileage.

KahnBB6

iTrader: (5)

Last word much?

Here, I'll make it very easy for you.

http://www.mkiv.com/specifications/9...ure/page24.jpg

Lexus used a 4.083 on 5-speed SC's to please 59 year old buyers who still wanted a stick. I don't hear MKIV owners complaining about their 5-speeds unless they're actually going turbo.

You're really serious? Search.

I own a manual SC300. Why would I want an automatic SC?

1998-00 SC400's have no factory manual transmission. W58 swap on them triggers a CEL light due to missing auto trans shift solenoids. Phoenix Tuning no longer offers transmission simulators to cure this problem. End of story in Cali. Again, search.

2017 Update: in the last few years a solution to the auto trans shift solenoid CEL in USDM VVT-i manual swaps has come to light. The alternative has to date been physically removing the shift solenoids from an A650E Auto, plugging them bak into the car's body harness and securing them somewhere on the undercarriage. Although this is still a legal gray area in California as far as regular smog inspections go. The link below references an import aftermarket shift solenoid simulator:
https://www.clublexus.com/forums/per...m-t-swaps.html


Trade my car? If I really wanted another faster car with a turbo I'd get a 2005-08 Legacy GT 5-speed, not another SC.

EDIT: At the time I originally wrote this post this was correct but since, forum member Cartmill cracked the 1998-00 SC300/400 CEL light problem when performing a manual transmission swap. Following his instructions and threads, it should no longer be an issue putting a W58 or R154 manual transmission into a 98-00 SC400 VVT-i. As Account2x points out, bumping the final drive ratio from 3.26 to something like 3.769 would probably be desired to make up for the longer transmission gearing in the W58/R154's. This would also make a TT Auto LSD pumpkin swap a no brainer).

KahnBB6

iTrader: (5)

Mods, feel free to lock up this thread.