Few Mr2 questions??

Hello, I have a JDM Mr2 turbo, I was just wondering if anyone could help out on a few things. First off I was curious as to what the specs are for the ct20b turbo in comparison to the earlier ct26. I have a 1994 ct20b and I am dbating whether or not I should put it on. If I do put it on I will put a T-4 compressor wheel in it, would this be a good move to put a 1994 turbo in a 1992 Mr2? Also, I have a boost controller, and it is set to 1 bar on the stock ct26, but I cannot seem to hold 1 bar of boost. I feel that the turbo is going, but could it also be a vaccum leak somewhere? I am kinda new to the turbo world, so I don't really know all of the minor things of such nature. Lastly, does anyone know the pin settings for the Greddy Profec B boost controller? I can only find one online. Thanks for your inputs! :smokin:

umm one thing u prolly shouldnt run a bar of boost all the time on the stock turbo b/c well its stock and its not made to withstand that much boost all the time.

yep he is right

Well gee thanks for the insight. I never said I am running it at 1 bar all the time. Thanks a bunch though!!

1 bar is 14.5 psi of boost.
Any generation of hte 3SGTE can handle that much boost all day, everyday without worries.

As for andyeagle19's question, the CT26 can not hold boost till redline and depending on your mods, you most likely will not be able to make full boost in 1st gear. You should not run over 15-16 psi with the CT26 turbo.

It is the nature of the turbo. It is a fast revving, low RPM turbo.
If you want big boost in higher rpms, you will need a bigger turbo.

Ok, one more question. If the turbo is alright/not damaged, then what could cause the variance in boost pressure? If I have it set to 1 bar, and I am going balls out, the boost will never read a steady 1 bar noteven for 5sec. Is this normal with the ct26 turbo or is something else wrong?? Thanks for all the inputs!
Also, anyone know the specs for the ct20b and if it would bolt onto a 1992 3sgte? And if the 1994 head is interchangeable with the 1992 head? Thanks.

The CT20B is a direct bolt up turbo for our cars.
The 94 and 92 heads should be interchangeable as long as they are both USDM (not sure about the JDM stuff).

As for your boost variance ... when you installed your boost controller, did you cap off the T-VSV?
That will greatly affect boost.

Explain to me briefly what theT-VSV is. I read about it but not sure if it was capped off.

When you look at the compressor of the turbo (from the driver side), there is a wategate actuator hanging below it.

There are 2 hoses that go to the WG actuator.
The hose on the left goes to the turbo's compressor and that is the line your boost controller should be interrupting.

The 2nd hose (on the right) goes under the engine to the T-VSV (vacuum switching valve). This valve is what allows you to run high or low boost form the factory depending on conditions.
It is basically the OEM boost controller. If it is not capped off, it will battle your BC for control.

Simply cap of the vac line that runs to it.

Thanks I will do that in the morning! Apparently I forgot to do that! Hopefully that will fix the probs!!

Ok, actually I did cap the T-VSV off. But when I pulled of the intake piping, I found oil all up in the turbo. So I will be putting on the ct20b in a little while! Any suggestions or thoughts feel free to mention them. I am more than open to them right now!! Thanks

Some amount of oil is "normal".
It comes from the PCV.
If it was an excessive amount of oil, that would be cause for concern.

The turbo had a little bit of oil in the opening from the intake piping side and the intake pipes had oil in them also. But it wasn't a lot of oil, just a little. So this is normal?? If so, what else would explain the inability to maintain boost? I am at a loss with options and ideas here. Thanks

That amount of oil sounds normal.

Is it sputtering under boost at all?
If so I would check out your ignition. How new is it?
I get new TOYOTA cap/rotor/wires every year and I sap in ngk copper plugs every 3000 miles.
Bad ignitions can cause mr2s to run poorly.

What octane of gas are you using?

It doesn't really sputter under boost, actually it is smooth until redline. But the turbo cannot hold boost, I can hear the turbo spooling faster and then slower constantly. But there is no known sputtering of the car. The car is a 1992 with only 80,000km on it right now. I have always changed the oil and such things like that, but never really thought to check the ignition system. I am using about 98 RON fuel right now. Thanks for the help. :smokin:

Nevermind all! I seemed to have fixed the prob. I did not have the boost controller fully hooked up, there was still some factory boost controller functions being used. This would explain the variance in boost pressure! Thanks for all the suggestions though! :grinno: :smokin: