MR2 Owners Club

I think that my Turbo is worn out. Still makes full boost but I can hear it chattering quite bad when I give it a rev and let off.

I have a rev 2 but a ct20b turbo has been put on.

Is there any turbos which will directly drop in? Planning on getting a standalone ECU and larger injectors soon and hoping for around ~400 horses.

Might as well just make the upgrade now. Everything else has been done in prep for more power.

Thankd

If its chattering there is a problem with the BOV or else some fool removed it.

If its still making full boost and not blowing visible smoke out the back, the turbo itself is probably fine.

MR2DI4 wrote: ↑09/09/19 3:52 If its chattering there is a problem with the BOV or else some fool removed it.

If its still making full boost and not blowing visible smoke out the back, the turbo itself is probably fine.

No this is more of a metallic rattling not compressor surge. If my BOV was stuck shut or removed it would be making that STUTUTUT sound. As much as I love it... I also like my turbo. I see no smoke out the exhaust at all.

I plan to keep using this turbo until its on it's last legs anyway.

I just heard from a friend that there are a lot better turbos out there now. I mean the ct20b is over 25 years old. So if i'm gonna replace my turbo at some point then I plan to get something a little newer. Not that there is anything with with the ct20b, it's a great snail but since i'm going for more power i'd like something with a little more huff.

Thats a shame, the CT20b is still a great turbo but like the CT26 you need to rebuild it once during the life of the car.

Once the compressor wheel touches the compressor housing for any great length of time its pretty much stuffed.

Rebuild it before there are signs of a problem with it and its cheap, just a few seals and floating bearings that is possible to do yourself if you have some mechanical skills.

"CT20b" and CT26 are useless if your goal is ~400bhp though.

You won't find anything that's quite as simple as bolt on, but the stock exhaust manifold is OK up to those levels and you can get adapters to fit a bigger turbo. You'll still need to sort oiling / cooling (if applicable) and a custom downpipe. As well as the ECU upgrade, you will also need to upgrade the fuelling, and you will be taking a massive risk doing this on an engine with stock internals. It really needs forged pistons minimum.

I heard the pistons are good up to 500 horsepower thats why I chose 400 as a target. I know I need more fueling etc. I have that sorted already. I just need the ECU so I can run the bigger injectors. Everything else has been upgraded. Fuel pump, radiator, intercooler etc.

I didn't know there was adaptors for larger turbos though. Ill have to look into it.

Right now just running my turbo at max. 1.28bar around 300 horsepower. Then the turbo is running out of puff. AFR is staying about 11.5 under full boost. Engine is loving that. Upgraded head gasket etc ofc.

Where did you read that the standard pistons can take that? Anything over ~350bhp is a risk on stock pistons.