Relevant mods:

FP Green
Forge 20psi WGA
Ported stock ex. manifold & hotside & O2
3" downpipe & 3" cutout

I installed cams recently and took my intake off to repaint it. I checked my turbo while I was in there and realized that there was a decent amount of carbon buildup around the inside of the turbo inlet. It was around the blades and it seemed pretty significant (although I was able to rub some of it off).

1.) Is the carbon buildup indicative of major turbo problems?

Also, I noted since some quirks since the cam install:

2.) The car seems much more sensitive to knock, even on E85 + meth

3.) Even @ 100% WGDC on the stock BCS with a custom pill, @ 7000rpm I'm logging 27psi / 260 load / 42 lb/min. I should be able to push it more than that... maybe the BCS can't bleed air away fast enough???

The car seems fast and I'm logging 430whp in DLL, but something doesn't feel right... for the amount of mods and the fuel I'm using, it just doesn't seem right.

Thanks in advance

 

260 load cells sound pretty low

 

I've never seen much carbon on the inlet/compressor side of the turbo. Do you have your pcv wented back into the intake still?

 

yes but I have an oil catch can in between

 

I highly doubt it's carbon buildup; where would the carbon come from? It's most likely a little oil from the PCV mixed with some dirt making it past the air filter. Should not be a problem at all.

With regards to the knock issue, where is it knocking in the rev range? I would guess that if the cams have more overlap, that may be the reason for the increased knock. You're trying to cram a LOT of flow through that small turbine housing, so there's bound to be a lot of backpressure in the exhaust manifold. With increased overlap, you may be getting more reversion leading to your knock issue. Just a guess.

 

one thing to keep in mind, carbon build up in the combustion chambers from blow by from rings or from a catch can that isn't doing it's job, will lead to higher knock counts....

Have you pulled your plugs and checked them to see if your cyls have any abnormal buildup?

Good luck!

 

260 load at 7,000 RPM does not sound weak to me ( I am at ~230 calculated @ 7K on a std. 9 turbo)...I can't believe you are at 27psi @ 7K though (5 psi more than me)...

What cams did you install? Did you change your MIVEC map at all (probably need to)?

 

The cams are FP 4R, I did play with MIVEC using DLL as a reference and it seemed to like full advance (28.8) all the way up to 6500 and then start dialing back.

The 27psi is verified with a JDM MAP. This is a FP Green remember.

I pulled the plugs the other day, they looked good, light brown with no buildup of any kind or any damage. I regapped them a bit tighter but they are still stock IX plugs so perhaps I need a colder range plug.

I ordered Denso IKH24's and I'm gonna try a MBC to see if maybe the stock BCS just can't cope with bleeding away enough air.

I know my turbo is capable of flowing 46 lb because last year I had a small boost leak and load was much higher (280 @ 7000RPM)

 

Thats your problem right there. Too much advance.

 

I'll play with MIVEC more, but according to FP:

 

I don't think FP has tuned cars in real world conditions to know the full extent of the Mivec system.

Pull back advance after 4000RPM gradually.