Was there a bi turbo STI?

[Kelly]

A freind of mine has a Bi Turbo setup layin around. The guy he got it from, said it was off an STI motor. Is this so?

[BAC5.2]

Legacy Twin Turbo.

Never an STi Twin Turbo that I know of. Maybe he was thinking TwinScroll?

[-K-]

Was there never a STi Legacy during the twin turbo model?

There is the twin scroll turbo on newer JDM STi's but that's just one turbo with two inlets.

[Kelly]

not a twin scroll.

http://www.wintersthorn.com/albums/album95/IMG_0922.jpg

Two turbos and a manifold, said to be off an STI. Probably off a legacy, but I was just wonderin.

Any idea of what this setup would run for?

[THAWA]

s401. Good ass find! Now tell him to get the rest of the car

[91White-T]

Or something RHD that it will fit into.

[Kelly]

http://www.wintersthorn.com/albums/album95/IMG_0925.jpg

Looks like it says RHF 4. They dont look new enough to be s401

But what little info I can find points to them possably being ball bearing? Maybe I should be bugging the Aussies about this.

[simonasaur]

I always knew you were a twin scroller

[THAWA]

Well I dont know what turbo's the s401's came with but if it's not from an s401 then it's not an sti setup. Could just be a regular RS, GT, or one of their variant's setup.

[azn2nr]

hrmmm. i see 2 turbos and 3 wastegate actuators. one of which is huge.

definatly bug the aussies about it. they would know.

[Kelly]

Well, Ive had a hard time getting info on this setup, but I have found some info on the turbos. They are ball bearing, and they seem to be about the same size, or a bit smaller than ours. They both have the same housings, but different turbine sizes, and all those wastegates leads me to beleive that this is a sequential setup.

Im thinking this might be my spring project, but theres a lot of questions on how to set something like this up. Like air metering, and intercooling. Ive seen the intercooler for these, and it had a valve too. As for the fabrication, getting a turbo placed where the brake booster is, I think can be solved.

But ya, I need to find some info, and any help would be greatly appreceated.

[J-MoNeY]

Wait, you want to do a TT set up?

You might as well screw the crappy TT engine from down under and go with a custom twin 16/18G setup.

[-K-]

Go for it!
But I would start with a front cut to get everything you need to do it right. Just putting the turbos on won't do a lot of good because you will need the ECU and a lot of other small parts to get it to run right.
I'm pretty sure there is enough room to make it fit with some work.

I don't know anyone on here who has driven a TT so I'd be a little more reserved with complaints of it. I have seen dyno sheets and it doesn't look like it's for me. I don't drive auto's but I have heard the powerband is liveable with an auto. I would not put it in a 5 speed but that could just be me.

That said, other than the cool factor I don't believe it's worth the hassle to fab up for me. There are more powerful single turbo engines for less money out there. You are very limited in Mods for a TT, from what I've heard they don't run right if you mess with them too much.

So a custom install without all the OEM parts would require a lot of tuning to run good. How many good tuners with experance with sequential twin turbos do you know?

It's going to be a lot more than just slapping on two turbos but if you want a project I'll still say go for it.

[91White-T]

TT wont fit into a LHD car though, the steering shaft is in the way of the driver side turbo. That looks to be a regular EJ20TT setup, those engines come up on ebay all the time complete.

[Kelly]

How many good tuners with experance with sequential twin turbos do you know?

Thats probably the best arguement for not doing it, or maybe the best arguement to do it

And a TT will fit into a LHD car with a little work, cause its been done. Shit, Im sure I could squeeze a V8 in there if I really wanted.

Ive heard the power band of this setup is quite boring, with a flat spot around 4 grand.(but we know with some tuning and/or a turbo swap that flat spot could be changed)
But I really like a flat power band, especially when it comes on real early. (This car will eventually be my Club Rally car) Shit, maybe what I need is a supercharger, or to just sell this car and get a 2.5 RS. But the coolness factor I admit is a factor in this for me. Plus it seems that at first getting it all figured out would be a bit tricky, but the tuneability of two turbos might be a bit more fun. I really need to get a hold of some aussies.

[azn2nr]

i think it would take too much effort to be worth it. most guys down under dich the tt setup in favor of single turbo

[boostjunkie]

There was only ONE successful LHD twin turbo project that I know of. It was done by some guy in the Philippines, or something like that. My thoughts are that it's just too much time/effort for the net gains.

And afterwards you'll have to deal with the "valley of death", especially when you decide you want more power and swap out the larger turbo.

[THAWA]

I say do it.

[-K-]

So what are you thinking?
Stock setup just changed to fit in the LHD.
Or a custom setup with a lot of tuning, standalone ECU?
If you want a flat power band the TT setup is not for you.
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Most people recomend switching to single turbo to make much more than stock power. I have seen a few with pretty good numbers but the dyno chart still looks like above.

Again if it was me I'd get a good complete front cut and run it off the stock ECU and as stock as I could to fit it in a LHD.
The cool factor is high enough that you sell it for more than you put into it (exept time) if you end up not liking it.

[Kelly]

Ive got an SDS setup layin around. And Id probably do some sort of electronic boost control along with it. Im assuming that the flat spot is due to the second turbo not coming on early enough.

I havnt quite looked at the physical placement of things yet, as my car is in storage for the time being. But I know theres a bit of room on the drivers side. Even if I had to swap in a smaller brake booster/larger master cylinder combo. Ofcorse a custom up pipe/down pipe, intake.

Im just throwin this idea around for the time being. Im still having a hard time sourcing any factory diagrams of how the system works.

[-K-]

The thing about the TT setup is I don't know if the transfer from one turbo to the other is controled by the ECU. If it is SDS won't help you.

[Kelly]

I know the SDS wont control boost. Im assuming the valve on the intercooler plays a part, and the 3 dumps are all vacum/pressure activated, which would be a lot of stuff to control electroniclly. But say you use MBC's for the turbo dumps, and something electronic for the third dump, and the intake flap. Would certianlly be a LOT, of tuning time. Getting the boost to come on evenly, then adding fuel, and timing accordingly, then more boost, and so on. Even IF I got everything fabbed up, Id still need to use a dyno for a day, and have it towed there, assuming nothing went wrong.

When I start thinking about how much projects cost, I usually double that number. A $500 dyno day, can easilly turn into a $1000 need new pistons day. Ive tuned SDS, Haltek, and UTeks before, and sometimes you get it all dialed in, and that motor with 150K on the clock decides to shit on you anyway. But I dont have to explain that to you Kelly do I?

So for now, Im not being too serious about it, just toying with the possability. I really should spend the money on all the rally gear, and have a competetive Club car with one turbo. Two turbos would put me in Open class, where Id have a lot tougher competition anyway.

[THAWA]

The hole might not only be attributed to the larger turbo coming on too late. It could aslo be the smaller turbo dieing too soon.

[Kelly]

Well, there really the same size, only difference is the turbine size so there effency is at different RPMs. But ya. Only twin turbo setups Ive worked with are Porsche. They use the same type of sequential setup, only with drasticlly different sized turbos, and when they switch, its instant with no overlap.

The more and more I think about this, the more I think its a lost cause. These turbos are for smaller displacement engines to begin with, kinda the opposite of what I want right? I mean the difference between 2 litres, and 2.2 can be a lot. Im thinking sure, the twin setup might make a lot of power down low, but even if I did get it all setup correctly, it would still probably die out at 5 grand, and then Id just want bigger turbos anyway. I foresee dumping 10 grand into this before Im happy.

I suppose this thread was just me thinking out loud.
Move along, nothing to see here.

[THAWA]

After some googling it seems to be the turbos from an EJ20H rated for 260 PS. Came in GT's (auto or man) and GT-B's, RS's (auto only)