Hi guys,
I write from Italy (where, unfortunately, it is not easy to find info on this kind of car) I joined this forum some time ago, in truth, because I am looking for information on a job to do on my Supra, and I did not know if it was it is advisable to create a new topic not having a Lexus ... unfortunately I could not find the necessary information (I have read dozens of topics here, on the Supra forum and elsewhere), but I could not find the necessary information. I am rebuilding the diff. of my Supra (2000 RZ-S 2000m.y., 2JZGTE VVTi, V161 / A03B Torsed LSD 8" and 10 bolts) with stock gear ratio of 3.26 . I would like to put a shorter ratio than the standard, and, in my opinion, the ideal would be a 3.615 (which I have seen available for some Lexus models), because I think the 3.76 is too short (I have on a simple full BPU and wheels from 18 ").
I would like to know if you have any idea which Toyota / Lexus model or part number I can use for a ring and pinion gear. I have read that some crowns are thinner than Supra ones and I don't know if they can be used. on toyota epc i found these codes for 3.615 final gears:
41201-59055
41201-49135
41201-49125
and these were often compatible with more than one model (such as gs300 / 400, sc430, ls400 ...)
hope someone can give me some help
Thanks in advance
Greetings
Marco
There hasn't been people swapping those ones but we have discussed the ls400 one on here before somewhere for more gear ratios.
I think the consensus was that the ls400 or sc430 ones you are looking at could fit, but I haven't seen it done to say if there is a difference in crown size or not.
My guess is that they might just swap over since it was used on the 430, but no guarantees when doing new combinations.
I think members have swapped internals from GS diffs before, but I would be hesitant about the 350 as it is much newer than this generation of parts.
You have a pretty rare and nice diff already, most people want the 3.1-3.2 with a v160/161.
I wouldn't run a 3.6 personally unless I was running a wide ratio 6 speed transmission like a T56 or a 5 speed R series, especially not with a single turbo.
If you are planning to stay on twins or have a really fast spooling setup maybe, but close ratio transmission and more rear gear on a turbo car just makes for a lot of constant shifting.
I am in agreement with Ali SC3. You have a very desirable combination already in a JDM A80 Supra with the factory 2JZ-GTE VVT-i, factory V161 6-speed and, I assume, a factory 200mm 3.266:1 ratio "small diff". If you happen to have the 220mm "big diff" on the other hand then your alternative ratio options would be fewer.
I know that a couple of the European A80 Supra TT 6-speed models came with or had the option of a 3.5xx or 3.6xx rear diff. This may have only been available on A80 TT's originally sold in Germany, Austria and Switzerland. I *think* that would have been a 220mm big diff ratio but I believe it may have been available on the 200mm small diff as well.... or else it would have been (for 200mm) the same 3.615:1 ring and pinion that Ali SC3 mentioned.
The 3.615:1 200mm compatible ratio, to our knowledge, or at least just within the United States, can only be found on 1990-1997 or so model years of the Lexus LS400's before those cars went to 5-speed automatics and before the VVT-i 4.0L V8's were introduced.
To get those parts to Italy it would make the most sense to find the diff and confirm the ratio is what it is supposed to be and then have someone dismantle it and remove the ring gear and pinion gear/shaft to ship those to you separately. The rest of an old 1990-1995(or so) LS400 diff pumpkin will be useless to you anyway.
For rebuilding the 200mm A80 Supra diff size, unless you go through the Toyota EPC and order each part yourself I only know to recommend Driftmotion's 200mm diff rebuild kit (they are located in Montclair, California). But it may make the most sense to just look at the exploded diagram on Partsouq and write done each rebuild part that you will need to order from within Italy. The correct thickness OEM side carrier shims should be ordered by your diff rebuilder in Italy since only the measurements at the time of rebuilding will tell what specific sizes to order.
Ali SC3 is right however. I think with a V160 or V161 a 3.133 or 3.266 are still the ideal ratios. However Toyota *did* manufacture the A80 TT 6-speed with the ratio you want in just a couple of Euro markets for a few model years. And Toyota did manufacture the JDM only A80 SZ-R with a V161, non-turbo 2JZ-GE and a 3.769 ratio.
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Really it comes down to which ratio is best suited for how you will be using the car. I also agree with Ali that the oddball LS400 3.615 (3.62) or more common 3.769 (3.77) will be more suited if you will be keeping your stock twins (in factory CT20 spec or aftermarket GT28 Hybrid spec) installed in your 6-speed car but with any big single conversion using that V161 you may want the 3.266 ratio back again.
As Ali said, with a V160/161 going from 3.266 up to 3.615 or 3.769 will very likely depend entirely on what state of tune you will keep the engine. There will be more shifting with either ratio but a faster pull through each gear but also less time for boost in each gear. This can be okay... up to a point. Also slightly less ultimate top speed and slightly higher cruising RPMs in 6th.
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Within Europe it seems that this Euro GS300 has the same 3.615 (3.62) ratio that you are looking for which should be the same as in the USDM 90-97 LS400's:
"98-00 Lexus GS300 (auto)---- 3.615:1, open, small diff, small flange (UK/Europe Market)"
As a bonus, you can probably test fit that UK/Euro GS300's diff pumpkin into your Supra without opening it up just to try the ratio out. That is of course so long as your A80 Supra has the "small diff" rear subframe and not the "big diff" rear subframe.
In the U.S. we have to dismantle the entire externally incompatible donor 90-97 LS400 pumpkin to harvest the 3.615 ring and pinion just to be able to install it into one of our SC/Supra/GS/Aristo/Soarer 200mm diffs. The effort involved just to try out that ratio in the U.S. is why it has seldom been used here by enthusiasts despite being available.
Thanks a lot guys for your suggestions .... Actually my choice to try a shorter ratio is because my current configuration includes a FULL BPU (fmic, full 3 "exhaust, cats delete, free flow intake filter, no fuel / boost limiter), upgrade twin CT20a turbos (inconel shaft, titanium exhaust wheels, new size and diagram for intake wheels, upgraded double wastegate), beyond that I have 18 "wheels (originally comes with 16") and gears seem really too long from third gear onwards .... in the end I will only have 400/420 hp (and I have no plans for a single turbo) The idea of switching to a Big diff. 220mm I don't consider it as too expensive since I would also have to buy the driveshaft and modify or replace the propeller shaft (and since I have no plans to get a lot of horsepower it would also be wasted). I have already purchased all the internal parts for my differential to perform the rebuild, I would only have to decide which R&P to try / find. My doubts arise from the fact that all 3 codes that I have listed for the 3,615 R&P can be found in GS300/430 LS400 and Toyota Century:
41201-59055
41201-49135
41201-49125
and I do not understand, therefore, which one could fit, since, at least hypothetically, all would be installable .... and if this were also true, it is not clear why equal and compatible parts, have different prices ranging from 500usd to 720usd ....
I point out these cross-checks on some spare parts (this is also where my doubt about the question of this post was born). if I look at the spare parts of the Toyota Century GZG50 (che hanno parti compatibili anche con Lexus GS300/430) I see that all 3 of the ring and pinion codes in 3,615 that I have posted here are referred to it; in addition to this Toyota model and to all 3 3.615 ring and pinion codes, is associated the differential part n ° 41301-50030 or also the part n ° 41301-24031 (the latter used on the Supra JZA80 "small diffs. "). At this point I noticed that always for the Toyota Century GZG50 (Lexus GS300/430) on the diff part n° 41301-50031 it is possible to fit the ring and pinion 41201-49155 whit a 3,416 ratio. At this point it would appear that for Toyota and Lexus users with small 8 "diffs there is another alternative of ring and pinion, in 3,416. Obviously I have no confirmation of this, but it would seem a fair assumption since the differentials are identical.
Marco, I completely understand your wish to keep your MKIV TT on the stock twin turbos. Even at BPU spec with the 18" wheels, depending on your tire sizes I can see how the 3.266:1 ratio might feel a bit too long. You probably won't be attempting Autobahn speeds with the car anyway. Further, I know that Italy can be quite restrictive in terms of modifications (not to mention engine displacement size per tax bracket).
I have to admit that I am just as perplexed as you are with the same 3.615 ratios showing up with three different part numbers. I wonder if it could be three whole differentials that they are referring to rather than just the ring and pinion sets themselves. Further, the Toyota Century sure does get around. I thought it was a Japan-only model until I recently discovered that the SC300/400 and Z30 Soarer share its gas door actuator part. Now according to your EPC dive the Century was also sold in China, Singapore, Hong Kong, Thailand and Brunei.
This is also the first time that I've been made aware that the older Century differentials or at least the internal gear sets are compatible with the SC/Soarer/MKIV/GS/Aristo small diffs.
I am not sure how to tell you to proceed. There needs to be some further investigation to be sure that you would be ordering the correct parts. I am not sure that the Toyota Century connection has even come up on the Supraforums differential thread.
Without being much more than a guess (and I don't like ordering expensive parts based on a guess) I would say to look more closely at the gear ratios listed around the 1998-2006 timeframe. That suggests to me that it would be much closer in lineage with the older 200mm GS300 diff design.
As to why these ratio sets all cost very different prices? My guesses are:
1) That we are looking at fully assembled differential pumpkins rather than just gears.
2) These listings really do represent different designs that happen to be of the same mathematical ratios (for instance, Toyota made a 3.266 ratio for the 200mm diff Supra and a 3.266 ratio for the 220mm diff Supra... and the USA did NOT get that 3.266 220mm ratio option, just 3.133 in 220mm).
3) Toyota has attributed a different part number to essentially the same physical gear sets and/or whole assembled differentials solely based on the fact that a Century is a more exclusive model than a GS300... or... the price differences actually do reflect differences in outer pumpkin design despite all of the internals of each listed differential being exactly the same parts.
It's hard to say without having better firsthand knowledge of Toyota Century rear diff pumpkin designs over the few model refresh cycles. I believe the old 1967 era design was finally refreshed in 1993 and that design lasted until 1997 which in turn lasted with minor updates until the new and current model Century was released in 2017 or so.
Marco, I completely understand your wish to keep your MKIV TT on the stock twin turbos. Even at BPU spec with the 18" wheels, depending on your tire sizes I can see how the 3.266:1 ratio might feel a bit too long. You probably won't be attempting Autobahn speeds with the car anyway. Further, I know that Italy can be quite restrictive in terms of modifications (not to mention engine displacement size per tax bracket).
I have to admit that I am just as perplexed as you are with the same 3.615 ratios showing up with three different part numbers. I wonder if it could be three whole differentials that they are referring to rather than just the ring and pinion sets themselves. Further, the Toyota Century sure does get around. I thought it was a Japan-only model until I recently discovered that the SC300/400 and Z30 Soarer share its gas door actuator part. Now according to your EPC dive the Century was also sold in China, Singapore, Hong Kong, Thailand and Brunei.
This is also the first time that I've been made aware that the older Century differentials or at least the internal gear sets are compatible with the SC/Soarer/MKIV/GS/Aristo small diffs.
I am not sure how to tell you to proceed. There needs to be some further investigation to be sure that you would be ordering the correct parts. I am not sure that the Toyota Century connection has even come up on the Supraforums differential thread.
Without being much more than a guess (and I don't like ordering expensive parts based on a guess) I would say to look more closely at the gear ratios listed around the 1998-2006 timeframe. That suggests to me that it would be much closer in lineage with the older 200mm GS300 diff design.
As to why these ratio sets all cost very different prices? My guesses are:
1) That we are looking at fully assembled differential pumpkins rather than just gears.
2) These listings really do represent different designs that happen to be of the same mathematical ratios (for instance, Toyota made a 3.266 ratio for the 200mm diff Supra and a 3.266 ratio for the 220mm diff Supra... and the USA did NOT get that 3.266 220mm ratio option, just 3.133 in 220mm).
3) Toyota has attributed a different part number to essentially the same physical gear sets and/or whole assembled differentials solely based on the fact that a Century is a more exclusive model than a GS300... or... the price differences actually do reflect differences in outer pumpkin design despite all of the internals of each listed differential being exactly the same parts.
It's hard to say without having better firsthand knowledge of Toyota Century rear diff pumpkin designs over the few model refresh cycles. I believe the old 1967 era design was finally refreshed in 1993 and that design lasted until 1997 which in turn lasted with minor updates until the new and current model Century was released in 2017 or so.
yes friend, in fact here in Italy everything is damn difficult and meaningless (from taxes, to bans on tuning and so on ..). As you said, the Toyota and Lexus spare parts catalog is not easy to understand and the various cross-checks do not define the parts well .... Obviously, before spending 500 or 600 usd for a new set of ring and pinion I will also look for a pumpkin complete with older 200mm GS300 / 430 (which costs less and in case it does not go well at least I can resell it as used), since the spare parts for the rebuild they have no deadline heheeh. It would also be nice to know if the 3.416 ratio is actually possible to use in small diffs, but I think this is much more complicated to verify due to its rarity. on ebay I found many complete diffs, but no one reports the gear ratio, and often from the simple code or description it is difficult to trace the relationship that I would find inside. I'm going crazy between which model to see ... LS ... GS ... SC ... 300/430 5 or 6 ATM: /
this could be a lot of help (from the cousins on the American Toyota forum that I asked for suggestions) and the person who answered is very reliable being an experienced user on various Supra modifications. this could help in the various cross-checks of the various catalogs and therefore also be able to use the ratios 3.615 and 3.4 (in addition to the more classic ones 3.2 and 3.7)
Wreckless knows his stuff, if he says he has done it that is the one I would try. It is along what we were thinking of sticking to the 400/430 generations and not the newer 350 stuff
Wreckless knows his stuff, if he says he has done it that is the one I would try. It is along what we were thinking of sticking to the 400/430 generations and not the newer 350 stuff
Marco, once again I agree with Ali SC3 here. Once into hardware for the post-2005 models it is less likely that you'll be working with compatible internal parts unless something has been specifically verified as compatible already Wreckless has been working with these vehicles and compatible parts and sharing his findings with the community for a very long time. I also highly trust his recommendation.
