legacycentral bbs

Gday,

I've just scored a toyota CT12A turbo.

I'm under the impression that the wastegate controls maximum boost..... is that right?

These turbos come fitted in pairs to toyota 1J-GTE engines. they all run at 12 psi standard. The toyota 1J is a 2.5 litre straight six, the red line is approx 7.5k rpm and they tend to be very very peaky (do not make boost untill well after 3k rpm)

I was hoping that running a single turbo on the EJ22 I would end up with nearly no turbo lag. Would this turbo be to small? (if there is a tiny amount of boost at 6k rpm i will be very happy)

Is 12 PSI insane on a bog stock EJ22 with 290k km's on it. (Will it just blow the head gasket straight away?)

Thanks in advance, any advice would be greatly appreciated.

Your head gasket will not blow.

Your ringlands will.

Over 5 psi you need to do alot, ie more fuel, piggback computerl, clutch.

do you rekon i could get away with 5 psi without an intercooler?

how would i go about getting less boost out of this turbo...... i'm not exactly sure how boost controllers work but from what i understand they can only be used to make the wastegate actuator open at a higher boost pressure than it usually would.

You can only raise the boost pressure with controllers, the minimum is determined by the strength of the spring in the wastegate actuator. You can change the spring, change the wastegate actuator, or just put a helper spring on the outside that reduces the amount of force necessary to open the wastegate.

Our stock VF11 turbos come with a ~6PSI wastegate actuator...

That turbo is going to be too small. You will have to make everything custom in order to put it on. If you're going to go through the effort, fit a larger turbo. You'll get boost and make power with that turbo, probably make more power than a stock EJ22T, but not a whole lot more. Remember, two of them feed a 2.5 liter engine, you want one to fill a 2.2 liter engine. It will work, but I'd be quite surprised if you were able to make more than 200bhp with that turbo, an IC and even some head work.

Don't be discouraged by that though, fabbing up a custom setup is an awesome way to go and there are lots of turbos off other cars you can use. I originally put a Toyota CT-26 on mine (7MGTE). It's designed to feed a 3.0 liter engine and can make over 300rwhp on the 7M. I put down 155whp with it on my scoob (EJ22 N/A) before the turbo started leaking so much oil I could no longer see the cars behind me though the smoke screen. I've since swapped to a T3/T4 and still have to finish up that work before I can post about results.

Whatever you do, run an intercooler and you may want to run a pretty big one. Detonation is going to be your biggest problem. The EJ22 seems like it can take quite a beating though, so it's a good platform to experiment on. The combination on high compression and boost made my wagon a nasty little street machine. Being nearly 1000lbs lighter than similarly powered sports cars it can hold its own with the best of them. Pretty impressive when you can run door to door with a bi-turbo S4 in your 15 year old rusty old wagon.

Yah right now I am running 6psi with a vf11 ported on stock 94 NA internals, with a side mount intercooler of a 95 eagle talon. Dont forget you will custom oil lines , coolant lines, and intercooler pipes. Boosting an NA is awesome but two much boost on NON forged internal like the NA's have is just asking for problems. Make sure you send douglas vincent a pm he has blown his share of pistons boosting an NA and has a pretty good idea for what the EJ22 can take. Best of luck with build up.

Thanks again guys, heaps of usefull info

I thought an intercooler would probably be essential.....

sammy..... you say that the 12A should be good for about 200hp.... won't that be alot more than i will ever use.

Idealy i would like full boost to be in by 3000 rpm and it would be even better if boost started to drop after 5500 rpm.

I realised that there will be alot of plumbing involved (exhaust, ic, oil & water) Though i thought i might be able to modifly some wrx headers, up-pipe and downpipe if i can get my hands on some

with that CT-26, which is significatly larger than a CT-12a, I got 10psi of boost in the 2.5 -3k range no problem.

That turbo can maybe support 200hp. That's based on halfing the amount of horsepower 1JZ guys seem to be able to push the stock turbo (and that's the high side of estimates). Remember, that's also on a 1JZ which has an incredibly good flowing head, so that 200 number might be a little overzelous. Even at 200chp, that's only 70 more than stock, pretty good, but if you're going to go through all the effort of fabbing up a custom turbo setup, you'll probably want more than that. Plus, since you're running a non-standard turbo, simply upgrading isn't as easy as you'll need to build new stuff (unless you have the turbo modified). If you want to run a turbo off another car, find something that will flow enough to give you the power you want or go with a standard aftermarket platform.


BTW, if you want to use WRX exhaust parts you'll need a turbo crossmember. I just built around the stock N/A stuff.

Thanks again sammy.

Though i still think i'll give it a try.......

Considering the age of my engine i would be happy with 140 hp

I'm only looking at running 5-6 psi at the most.

By my calculations this turbo should easily be able to hold 5-6 psi to the red line..... and the whole point of adding the turbo was to make some power without having to drive it to the limiter

you'll get bored quick with only 5-6psi... things don't get fun until 10 or so.

once i have stuffed this engine i'll rebuild with lower compression ration, stronger pistons and then........... 15 PSI?????

sammy, what have you done as far as fueling your beast? rrfpr? pump?
I wonder how far the NA ecu can go.

two very good questions jeremy.

maybe douglas can help us out.

How much boost before pump, fpr, computer or injectors can't keep up and the mixture leans out? (i'll definitly be installing a wideband AFM when the turbo goes in)

And when will the ECU trip out and hit fuel cut on an NA.

I just put an adjustable FPR and raised pressure to about 45psi base, I also ran my AFM post IC in blow through mode. I was able to run up to 10psi without fuel issues. Knock was a problem at that level unless it was nice and cold out or raining. I never got a chance to get a good tune on it as things broke for reasons that had little to do with boost.

The NA ECU seems to not have a fuel cut. You'll reach the limit the stock MAF can read though, running a Jecs MAF can get you a little more, I'm not sure where the limit on this setup is though.