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.

Hi Joeblow19,

I have a gt4 engine but has a ct26 as well. I usume they are the same excect yours should be twin entry unlike the gt4's have single entry. I would suggest to turn the boost down asap! The stock turbo has crematic interals, which brand new is only good for 14psi-16psi. U maybe able to run 20psi on a standard turbo but u find it wont last very long. 1 Bar is = to 14.6 psi im sure, to be safe i would turn down to 10psi atleast until u get it comfirm that it is crematic interals.

If the turbo is going u can do quick check your self, if u pull off the intake side of the turbo and have a look and see if the compressor wheel is cutting into the houseing. Also check to see if there is any shaft play, hold the centre of the turbo and see if it moves up and down or side to side. It should only move slightly up and down, and while moveing it spin it slowly, listen for it touching the houseing. If u find there is exsesive movment or it is touching the house or maybe there are metal savings, dont drive it full stop! Arrange to get it fixed, driveing with a stuff turbo can lead to engine damage. Fixing a ct26 will mean highflowing = bigger, but can cost $2000.

As to your question about ct20b turbo i have no idea. Maybe check out www.mr2.com.au i think the web site is they have forums there that might help u out. Failing that there is www.toymods.com.au.

May guess is a ct20b turbo has a small exhuast houseing to the ct26. Keep in mind a ct26 is the same turbos that supras use. They just weigh alot more.

A high flow ct26 on a stock 3s running 14psi gives a punch i can vouche for that.

Hope that helps.
Nathan

Thanks for your inputs, I will try that out and take a look at those sites. Thanks again!

Checked the turbo today and there was oil on the intake side of the turbo. Which prolly means that I will soon be upgrading it to the 1994 turbo(ct20b) maybe with a bigger compressor wheel. I am not sure if that can be done without porting the housing. Oh well, if any suggestions please let me know. Thanks!

A friend of mine had a turbo fitted on a series 3 mr. Around T67 size. Big. This thing kicked arse. Response was awesome. Maybe u should check second hand large turbo with external waste. Cost is high but will give u great midrange and up.
Go large dude.

rather than upgrade to a only-slightly-different CT20B - look at hi-flowing it or replacing with a CT26.

'cause if you want to increase the size of the turbine wheel - you would have to modify the housing.

Also, i don't think a T4 compressor wheel would fit on/in that turbo without some modifications?

but there's probably much better non-toyota turbos out there - tho you'll have to modify your exhaust manifold to suit a different flange pattern.

other mr2 sites
<www.mr2mk1club.com> (UK)
<www.mr2club.com.au>

I think I am just going to save my money and get a T03/4 turbo. But for now I will put on the ct20b. Unless you guys have some suggestions for me towards the ct26 that has oil on the intake side by the compressor wheel. Thanks