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Carolina91GT-S
04-14-2011, 02:25 AM
I was thinking about using a twin turbo setup on my 3SGTE. help me to think it through. I have a spare JDM twin turbo setup from a 2JZ complete for our mkiv. These are super cheap since the big money tuners just yank em out of the car and sell em off for next to nothing. I picked it up in case ours crapped out and as I said they sell em cheap on the supra forums. So I am looking at this setup thinking I could put it on my 3SGTE and get the same benefits from it's sequential operation. At low RPM the system routes all exhaust through turbo #1 and as the RPMs increase the gate opens and runs both turbos. Each of these turbos is smaller than the stock CT26 so I feel like running through #1 would give me faster spool on the low end. The two together are larger than the stock CT26 so I would benefit from a greater output on the whole...get the best of both worlds so to speak. I can control this switching easily enough with a simple controller, not an issue. If I treat it in all other ways as just a larger turbo i.e. bigger injectors, etc ... do you think it would work out? I have a plan for fitment so don't tell me it won't fit.

Comments? input? ridicule?

~Chris

vip09
04-14-2011, 02:48 AM
Would probably cost too much to have a manifold made that would work for it to be worth it. The CT26 already spools pretty much instantly, so I don't see a point.

T-spoon
04-14-2011, 03:23 AM
Could you make that work? Maybe, probably. But that setup is already cramped with the length of a straight 6 to work with. Really impractical, and not worth it, IMO. It would be cool to say you'd done it, but that's about it.

The Captain
04-14-2011, 03:23 AM
The 3S being 33% smaller poses spool issues. I'd be curious what RPM the 2JZ achieves full boost. Whatever it is you can expect it to be a third of the RPM's higher in a 3S, which may be beyond it's rev limit. It may be counterproductive. If it was a viable solution to have two smaller turbos on a 2 litre motor I think WRC would have implemented it long ago. Complexity is always worth it if it makes it more, ah, complicated.

I'd be more interested in how one of these would perform on a 3S.

T-spoon
04-14-2011, 03:36 AM
^ Nah, they're tiny turbos, one of the CT20A by itself would be pretty lame. 3S could probably even handle spooling both (slowly) I just don't think it would be worth doing over even just an upgraded CT26.

IIRC stock 2jzgte has the primary turbo spooled up almost instantly, and thinking the second kicks in around 3-3500, but not absolutely certain on that one. Haven't driven one in years.

Carolina91GT-S
04-14-2011, 05:20 AM
Thanks for the input guys. I was looking at this as a quick spool thing and to have a slightly higher top end than the CT26. And it would be cool, there is that I guess. The manifold doesn't have to be pretty, it just has to work. As far as the crossover RPM goes....that is user configurable with a simple controller. Regarding the decrease in output when used on a 4 cyl vs a 6cyl....I have considered this as well. I know plenty of guys are getting 17-18 psi easy out of this setup on the 6cyl, some even more. I have read about guys getting it 22. At those #'s minus the 33% it might end up just being a wash. I'll continue thinking on it.

T-spoon
04-14-2011, 05:24 AM
True, at those numbers those twins don't last long though, especially not the rear.. I suppose the good thing about that is they are plentiful as you've mentioned. I myself have a pair of them to get rid of ;)

joe's gt
04-14-2011, 06:50 AM
What is the flow rate out of this turbo? Are you going to get compressor surge as a result of the smaller displacement on the 3s?

Carolina91GT-S
04-14-2011, 10:09 PM
Is there any consideration for the reduced volume being compressed as well? What I mean here is that yes, with 33% less exhaust gas driving the turbine it will generate less boost. But, it will be boosting 33% less engine volume for the same reason (less cylinders). Don't you get back the loss effectively? at least in part?

What would this system produce on a 3SGTE with the wastegate closed? Good question.

~Chris

Mafix
04-15-2011, 03:34 PM
honestly if you want instant boost buy a supercharger.

MrWOT
04-15-2011, 08:36 PM
:stupid:

I don't think you appreciate how complex a sequential system is. Putting it together isn't the bad part, getting it tied together properly and mapped correctly is ludicrously difficult (getting a smooth torque curve). Much cheaper, less complex, more reliable, more powerful to add a positive displacement supercharger with a bypass.

Tuning around the crossover point is a NIGHTMARE. The turbos have to be sized just so for the displacement, cams, eachother, to make it work right.

Carolina91GT-S
04-15-2011, 09:37 PM
I understand it pretty well. I think that if I use the entire sequential system, that is everything from the intake to the exhaust including the the wastegate, valves and VSVs, it would function. The crossover point would be the only real issue getting it tied together. And you could just do a few runs with it at different points and set the crossover point where it makes the most sense(oversimplification yes). The idea of a supercharger being cheaper isn't true for me. I bought a JDM sequential twin turbo system complete (from air filter to exhaust) for $150 and this is pretty normal on the supraforums. I would need to fit it all in the engine bay of course, and I would need a custom exhaust manifold/adapter. The crossover point could be easily controlled with a diy controller, several of the mkiv guys sell them for less than $100. less complex, sure but I don't have to design it, it is already a working system. More reliable....maybe...hard to say...seeing as I know of no one with either a supercharged or Twin turbo 3SGTE to use for comparison here I'll reserve judgement on that. More powerful, maybe...hell even probably but...at the moment I am only looking to make it better than the stock CT26, for the cost it might be worth it. Is it the best way to go, most probably not. Would it work? is what I want to know. then the next question is to ask if it is worth doing.

I don't want a completely different alternative. otherwise, I very much like the input. I just want to know if this idea will function and how well it will work or how bad it will not work.

~Chris

Mafix
04-20-2011, 05:24 PM
there are a couple tt mr2ts but none of them knock my socks off that's for sure. honestly it's not worth the extensive effort. but if you insist them please just do it. it'll be a nice change of pace in the scheme of things 3sgte based. tt is easy, doing it sequential is the whore

Louie C
04-20-2011, 07:32 PM
twin scroll all the way

Mafix
04-20-2011, 11:34 PM
twin scroll /= twin turbo
twin turbo /= sequential turbo
sequential turbo /= HP monster
HP monster /= reasonable spool time

firgured i'd add to the irrevelance of the above post

vip09
04-20-2011, 11:37 PM
LOL thanks Mafix! :)

Luni
04-21-2011, 03:46 AM
Youre not going to experience compressor surge by putting the turbo on a smaller engine than its designed to go on. If the twins dont surge on a supra, they wont surge on a 3S.

Feasibility? Not sure. Worth it? Dunno. Cool factor? Absolutely if you can do it.

Carolina91GT-S
04-22-2011, 05:24 AM
Looks like each of these turbos (CT20A) is basically a CT20B but with a ceramic wheel...same dimensions

pintoBC_3sgte
04-22-2011, 03:34 PM
do it!! do it!! i think it would be cool to see done :)

rizin
04-25-2011, 05:59 AM
Compound turbo or a supercharger with a turbo over it sounds like fun. But that is me.

ChrisD
04-25-2011, 03:13 PM
I'd never do it personally, but always interesting when people try out something different. If you want to do it, then go for it!

Luni
04-25-2011, 07:07 PM
Supra twins are CT12a not CT20a.

Carolina91GT-S
04-25-2011, 08:45 PM
Supra twins are CT12a not CT20a.

USDM supra twins are CT12s

JDM Supra and Aristo 2JZGTE twins are CT20As

I have a set of the JDM ones which are much easier to come by, they are ceramic, and produce less HP when coupled with the 440cc injectors/cams on those engines (USDM use 550)

My concern for trying this is that the 3SGTE wouldn't have enough exhaust flow to generate much boost. I feel like if this SQTT setup can produce more boost on a 3SGTE than a CT26 can, then why not try it. Otherwise as others have said it wouldn't be worth doing.

I would be using these on a 2nd gen

T-spoon
04-26-2011, 01:03 AM
^ Yep, the twins I pulled off the Aristo 2j are stamped CT20A also.

MrWOT
04-26-2011, 09:04 AM
A sequential setup could be awesome on a 3S. Assuming you have the money (and other things...) to make power over 9k. (cue obligatory dbz reference)

Just not THAT sequential setup. You can't adapt them.

Carolina91GT-S
04-26-2011, 12:19 PM
What do you mean by "you can't adapt them" ?

~Chris

Smaay
04-26-2011, 03:18 PM
http://www.celicatech.com/gallery/files/6/1/6/picard.jpg

OMG this thread just makes my brain hurt. first off, where do you think you are going to put these turbos? its entirely possible to have 2 runners feed a turbo and have them both feed into one side of an intercooler. then have a single output to the TB. but why? the amount of time and money that you will put into this, you can get a good turbo kit that will perform much better.

Carolina91GT-S
04-26-2011, 05:10 PM
OMG this thread just makes my brain hurt. first off, where do you think you are going to put these turbos? its entirely possible to have 2 runners feed a turbo and have them both feed into one side of an intercooler. then have a single output to the TB. but why? the amount of time and money that you will put into this, you can get a good turbo kit that will perform much better.


You obviously have not read anything that I wrote.

MrWOT
04-26-2011, 07:58 PM
What do you mean by "you can't adapt them" ?

~Chris

The entire purpose of a sequential system is to size the turbos to the engine so it has a broad torque band, and the exhaust and intakes are tied together in such a way as to allow a smooth handoff at a specific point that has been tuned for. You can't just bolt it to a different setup and expect it to function.

Carolina91GT-S
04-26-2011, 08:33 PM
Please don't take this as arguing. I view it as a discussion. I'm looking for someone to say it can't be done, why it can't be done, and give a reason that I cannot figure out a solution for.


The entire purpose of a sequential system is to size the turbos to the engine so it has a broad torque band

The factory sized turbos are not always the only way to go. Plenty of people put bigger turbos on all kind of engines. This is not enough to say it won't work.


the exhaust and intakes are tied together in such a way as to allow a smooth handoff at a specific point that has been tuned for.

For this particular sequential setup I have the specific intake and exhaust "ties" (i.e.all of the associated plumbing, wastegate valve, Intake air control valve and Exhaust gas control valve, Exhaust bypass valve, reed valve, pressure tank, the VSVs to actuate it all, and a controller for all of them to have a smooth handoff at a controllable point. I don't know what the handoff point(RPM) would be, it's something I would have to figure it out along the way. I feel like this directly addresses what you mentioned.


You can't just bolt it to a different setup and expect it to function.

I'm not sure this is entirely true. It may be true in this case, but I am not convinced yet. If someone could say that the 2.0l 3SGTE can't generate enough exhaust gas flow to spin the turbos and generate boost within the normal RPM range of the engine then that would mean it won't work. I haven't seen a compressor map for the CT20A and I don't truly know how to read that map when the turbo is used in sequence with another one.

My thinking is that plenty of guys put much bigger turbos on the 2JZGTE indicating that the engine can flow more than enough for the SEQ CT20As. in other words...the sequential CT20As could be considered undersized for the 3.0l engine. in that sense, perhaps they would match well for a 2.0l 3SGTE. I'm not saying this would all work out no problem. I'm just saying if there is a reason it won't work, I'm not seeing it yet. I hope to be able to try it by the end of the year.

Facime
04-26-2011, 09:39 PM
Questions like this really come down to the "Why?" factor. Can you pick up cheap sequential systems off the 2J folks? Yes. But I can pick up cheap diesel turbos as well, that doesnt mean I should spend a small fortune adapting them to something they werent specifically built for.

IF you could find a way to mount to everything intact enough that you arent defeating the purpose of using the stock setup in the first place, and IF you can manage to make or adapt the manifolds to work on the 3S, and IF you can manage to support those turbos in proper tuning and supporiting mods, and IF you could manage to do it all cheaper than starting from scratch with a pair of turbos and decent welding/fabricating skills, and IF you can manage to do all that and have it still not totally suck worse than just slapping on a properly picked out and supported single...then more power to ya. But I still have to ask the question WHY?


Quick story: There was this guy I know that was told that he could never get BIG horsepower out of an N/A 7M. He wanted to show all the naysayers that he could do it. He spent at least 3 years engineering and building that motor. Guess what, it failed. It didnt fail to run, it just failed to prove anything except that if you throw enough money and time at a problem you will probably succeed, but in the end you still end up with nothing more than a "Spruce Goose".

Carolina91GT-S
04-27-2011, 12:30 AM
The why part is mostly because the parts are available cheap. The entire set up was $150 plus I need the $75 or so controller. So $225. I need to make a manifold, here it is just the cost of metal, I can make it in the shop here and the time doesn't cost me anything. I will need to make some support braces also and connect this to my intercooler and air filter. I can do this for under $500 total easy is my guess. For me the time spent is enjoyment, it is a hobby.

The second part of the why is it is cool to me.

The third part is for an upgrade over the CT26

The questions....can it work? Will it be an upgrade over the CT26? if these 2 are a yes I'll do it, if they are no I won't

Hookecho
04-27-2011, 12:50 AM
I think you should at least try it. There's no reason why one should not experiment. Even if you don't like the outcome we will at least have the data. Then someone else may be able to expand on the setup and make it better. I believe in forward thinking. Do something that hasn't been done and have fun doing it. There will always be a million reasons why you shouldn't do something.


I was told that the automatic trans from a 5sfe would never work on a 3sgte. I did it anyway and found that it will work and holds up just fine. I didn't perfect the setup but the data is recorded and maybe the next person will do the extra mile.

Hookecho
04-27-2011, 12:55 AM
I didn't like it either.

rizin
04-27-2011, 03:24 AM
I had to pull out one of my old dsport mags that talked about a single turbo against a twin.

"single turbo compressor's inducer diameter/1.4141=twin turbo inducer diameter"

"Converting the required flow capabilities of a twin turbo system to a single turbo, twin turbo inducer diameter x 1.414= single turbo inducer diameter."

"as the maximum horsepower capability of a turbocharger is determined by the diameter of the compressor inducer, these are used to calculate what would be needed to make the same horse power when switching from one setup to the other."

I can't think of anything I have read about the exhaust side of the twin sequential setup.

joe's gt
04-27-2011, 07:19 AM
Is there any map data on the sequential turbos? That would help determine how well it could fit the 3sgte displacement. I am all about ingenuity and taking risks. If you got the funds and the time, I say do your research and and take a best guess at whether you think it will work or not. Its easy for everybody to tell you not to do it, or that it won't work. You don't really know though till you do extensive research which will allow you to determine whether you want to make the progression into fabrication to provide proof of concept. The main challenges I see is how well the turbine/compressor match up to the displacement of the 3sgte and the tuning and control it will take to yield a smooth transmission between the sequential turbos. I don't know much about the sequential turbos tho.

v8killer
04-30-2011, 11:33 PM
btw ct20, there is no a or b, its smaller and came off the 22rte truck, and they will work if you can fit them, there is really no point other than show-off-ability you would be far better off in just doing on really good expensive turbo that can do most of what you want, orr you can do 2 small really good turbos like 2 4648's from comp turbo or maybe ask them to make smaller ones. i would support you on this just because it would be something new and cool to see on a 3sgte yes its no needed and a headache to do but it would be good to be a part of it. if you do go for it just give me a call and i will help however i can 831 207 9851.

the 2jzgte turbos are not sequential and they have ct9's or the usdm ct12's

Carolina91GT-S
05-01-2011, 05:28 AM
... you would be far better off in just doing on really good expensive turbo that can do most of what you want, orr you can do 2 small really good turbos like 2 4648's from comp turbo or maybe ask them to make smaller ones.

Ha! I guess I could always be better off just getting something really good and expensive....but that's not the goal in my line of thinking. Still thinking that with a starting price point of $150 for the whole twins setup if you could make it work, it would be cool.


i would support you on this just because it would be something new and cool to see on a 3sgte yes its no needed and a headache to do but it would be good to be a part of it. if you do go for it just give me a call and i will help however i can 831 207 9851.

I will be giving you a call on this. More minds are better than one, especially when the one is mine.


the 2jzgte turbos are not sequential and they have ct9's or the usdm ct12's

This is from the 2JZGTE wiki....yes, I know it is just the wiki, but everything else I have read says the same thing.
The export version of the 2JZ-GTE achieved its higher power output with the use of newer stainless steel turbochargers (ceramic for Japanese models), revised camshafts, and larger injectors (550 cc/min for export, 440 cc/min for Japanese). The mechanical similarities between the Japanese-specification CT20 turbine and export-specification CT12B turbine allow interchangeability of the exhaust-side propeller shaft. Additionally, the export-exclusive CT12B turbine received more durable turbine housings and stainless steel turbine and impeller fins. Multiple variants of the Japanese CT20 turbine exist discretely, which are identified with the B, R, and A part number suffixes (eg.: CT20A).


I am thinking more and more about trying this....don't anybody expect any info anytime soon though. I am still prepping for paint when I have spare time so the car looks like an exploded view diagram right now. I might be able to start this sometime this summer. Once the car is back together and running, gotta start with a running car.

~Chris