ZCboost

I've had my custom turbo set up installed for about 3 weeks now. I've been pretty easy on it so far because I'm waiting on my DSM 450 injectors. I have a wideband O2 sensor, so I've been able to feel boost now and then by letting off before it leans out too much. A couple times I've noticed that when I let off after hitting boost the car is puffing out a cloud of smoke. When I accelerate normally without hitting boost, it doesn't do it. Is this blowby?? If not, anyone have an idea what's probably doing it?
Note: it doesn't smoke while under boost, just after you let off the throttle. I had my bro drive the car and I watched from behind the car to see.

Hoosier Daddy

Does it smoke at idle? What color is the smoke?

ZCboost

Nope, at idle it's fine. I checked that too. It looks like oil smoke when I let off(bluish), so I'm wondering if the turbo is sucking in oil from somewhere when it switches back to vacuum???

Butcher

This could be a normal occurance. When you close the throttle there is a momentary richness because of the fuel being injected durring boost but no more air is entering. Get those new injectors in and just keep an eye on it

boosted_dc2

it could be this^^^ but i doubt it. is the turbo new??? whats the return line look like??? also if you can do a compression check then that would be helpfull too.

Landon

ZCboost

Awesome. Finally a sign of good news. I can't wait to get those injectors on there. The car is very impressive so far, and I haven't even been able to wind it out yet.

Actually, that is a good point. The set up is new to me because it's just been installed, but the turbo is a rebuilt Garett T3 Super 60. It looks really nice. My buddy who did the install with me(and has MUCH more turbo experience) said it was a really sweet unit.
I'll keep an eye on it for a while, see if it still does it with the larger injectors......

Butcher

One other thing that came to my mind is the ammount of oil pressure going to the turbo, assuming it is oil cooled. My friend turbod his 91 pontiac gta and had too much pressure going to the oil feed and blew out the seals. This doesn't sound like the case but I'm just throwing things out there for ya. I can tell you that in my SRT4 my exhaust tips are BLACK from all the on-boost driving I do

ZCboost

Hmm, that could be a problem. The turbo is indeed oil cooled. I have the oil sending line connected to the stock honda oil pressure sending unit. HOWEVER, it's actually leaking like a ***** right now. I have the proper fitting being shipped to me from Stan at fast-turbo.com. I'll have a new thread up when I install the proper fitting with pics.

Butcher

What I have seen done on other cars to control oil feed to the turbo is a brass fitting placed inline with a small diameter hole drilled out of the center for oil flow. Turbos don't need a lot of pressure, just a steady ammount of oil. Like I said, I doubt you are getting oil blow-by on the turbo seals since there is no oil smoke at idle and such.

ZCboost

That sounds like a good plan. I think I can probably fabricate a little piece like that myself. If it's a pain in the ***, anyone know where i can get one of them? The concept sounds pretty simple actually, sorta like a restrictor plate on an intake system. Just need to slow down that oil pressure a bit. Thanks Butcher. Good help man.

CUSTOMCONNECTION

MY TURBO LS DONE THE EXACT SAME THING...I USED FITTINGS AND LINE FOR OIL GUAGE KIT... MADE IT ABOUT 3 INCHES LONG ..STOPED 90% OF THE SMOKEING...BUT ITS HOMEMADE BUT EFFECTIVE.

Sinitron

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ZCboost &raquo;</TD></TR><TR><TD CLASS="quote">That sounds like a good plan. I think I can probably fabricate a little piece like that myself. If it's a pain in the ***, anyone know where i can get one of them? The concept sounds pretty simple actually, sorta like a restrictor plate on an intake system. Just need to slow down that oil pressure a bit. Thanks Butcher. Good help man. </TD></TR></TABLE>

ATPturbo.com sells oil restrictor fittings ... intended for ball-bearing applications.
If you have a -4an feed line, try the .060 fitting, it'll reduce some of the high volume.

lohatch

another thing could be your PCV valve. the valve is designed to open during vacuum(which is anytime the motor is running on an NA car) what the PCV does is sucks built up pressure from the crankcase and it flows back into the IM for emissions reasons. well when you go into boost it closes the valve. this means no boost pressure goes into your crankcase, **but this also means that the pressure inside there isnt being released anywhere, sometimes resulting it oil spewing out the valve cover. so if you have some blowby in your piston rings the oil may be forced upwards into the combustion chamber and is burnt. causing smoke during WOT or during boost. this is why guys run catch can setups. the PCV is a little plastic thing that it located in line between that black box on the back of your block and your IM. just do a search on PCV valve in the archieves and there is a lot of stuff. BTW my car smokes under boost too.

ZCboost

Ahh, another good thing to try. Thanks a lot guys. I'll have a look at all of these tomorrow morning, see if i can get it figured out.