Black Smoke On Boost

[smoothR33]

Hi all,

I have a problem with black soot on my rear bar. It has always had a bit on the back, car is white, but has gotten worse since buying the car 6000km ago. I wash it take it for a 20min drive and it is covered again.

I have had the AFR checked and they were supposedly spot on. The cat still seems to be working properly as it doesnt smell like raw fuel.

What else could be causing this? It seems to do it worst when I take 2nd gear to the redline, I can visibly see the smoke out the back.

Car is:

96 33GTS-t

FMIC

PFC

Split dump to 3 1/2 after cat

HKS Pod

Bleed valve at 12psi

Any suggestions would be appreciated, thanks.

Edited July 17, 2007 by smoothR33

[burgO.]

whens the last time you changed the oil?

[smoothR33]

1000km ago with Motul Chrono 300v 10w40, I havent done the plugs since I bought the car though

[MBS206]

Do them then

Sounds like it isn't burning fuel correctly.

[lineskee 33]

running rich, get the power fc tuned to reduce the amount of fuel goin in. just my opinion. i have the same issue. my white bar is fairly black these days too

[NYTSKY]

When i was driving my car around after i installed the FC(untuned) i used to get black soot on my rear bar too.

Is it tuned?

[tacker]

Has to be the tune, or a leaking injector or two or a dodgy fuel pressure reg.

anyway your AFR must be way out to be seeing black smoke out the back of your car while moving. How do you know that the AFR as ok?

Edited July 17, 2007 by tacker

[SiR_RB]

you may possibly have a gutted cat, i no that this is common when the insides of the cat are bashed out....could maybe just need a tune as others have said

[mad082]

you may possibly have a gutted cat, i no that this is common when the insides of the cat are bashed out....could maybe just need a tune as others have said

+1

my mate has (we are pretty sure) a gutted cat or callapsed cat and his car is filthy on the rear. his afr's are 12.0:1

[R33GOD]

i have to polish my rear bar once a week to get rid of it lol

[blind_elk]

anyway your AFR must be way out to be seeing black smoke out the back of your car while moving. How do you know that the AFR as ok?

I've been behind a stock 32 GT-R and a modded 33 GT-R (PFC), and they both exude a lovely black cloud when "nailed".

Stop running to red-line in second, and you might at least reduce the problem!

[turboedsloth]

paint your car black or rear bar black then you wont notice it as much

[ardie]

^^^ +1

i use the soot to cover the small scratches i got when i reversed in2 a bush.

if i were you id check the cat, will only take 10 mins, iv got a straight through system and it loves spitting black clouds