Rb20 help! noob!

[lg54]

Hello all,

I've had my rb20det in my 240sx for about 5 months now.

Since the begining, I've had my boost set up to 5psi. Recently, I've been messing around with it. I opened my boost control a bit. When I went to test, I gave it gas and saw my boost gauge climb up to 15psi. I looked at my rearvie mirror and saw a cloud of white smoke. I stopped and put my boost back at 5psi.
Note: white smoke happened only at heavy boost (15psi) not when I'm at 5psi.

Questions..

- why the white smoke? What to check?

- did I blow my turbo seals?

- would I be able to run at 11psi with a tune?

Thanks a lot! Sorry I'm sort of a noob!

[Tantwoforty]

lets hear a little more about your setup
ecu
injectors
stock turbo?
do you have a wideband?

step one is to get a wideband, i would never touch the boost untill i have a wideband installed its probably the most important tool you have.

the smoke being white sounds like coolant, meaning it may have leaked into your turbo or through your head gasket.
you can do a compression test to test the head gasket, you can also pressure test your cooling system.

just my 2c.

get a wideband before upping boost.
be careful!

[lg54]

Thanks for the quick reply.

As for my set up, its all stock. Just a rb25 turbo.

I do not have a wideband, planing to get one.

Did a compression check and all where around the 160 -150 area but #6 was around 140.

If my head gasket was bad, which one would it be? How would I check this?

The curious part is that when it boosts at 5psi, no smoke what so ever..

Thanks for all the help!!

[Tantwoforty]

hmm, your compression test shows 6 is low so that could be where there is a small crack in the gasket or something that when it sees higher boost it forces coolant into the engine and burns it. and thats your smoke.

IF that is infact the problem its not smoking at 5 since it isint enough pressure to push it through or suck it in rather.

again this is just theory

What did you turn your boost up with?

Im thinking its head gasket or turbo seal.
i assume the turbo is water cooled as well as oil cooled since its stock.

by any chance did you smell it when it was smoking?

you should pop off a few intake tubes and see if you find oil or anything funny looking.

check the oil and the plugs ect..

im just rambling off ideas at you here hopefully someone with more experience with rb's can chime in
but again, you have to get a wideband before upping boost so you can watch A/F and remain in a safe mix.
i have seen too many engine blow up from just what you did, and 5 to 15 is a pretty big jump