[Jock Alert]

Question for you turbo Gurus out there....

Been running .9 bar (occasionally) on a stock turbo, and I believe stock internals (although I have no idea) on an RB20 DET.

Sometimes she does that pleasant pop, bang, flamey thing out the tailpipe on gear change, or on the rundown. (on stock boost, but mostly on .9 bar).

Now, today I was out down a few quiet roads being followed by a mate, and he said she was a bit smokey. Now, he hasn't got a clue about cars, and I daren't let him drive it so I can see for myself so my question is thus...

Along with the pops and flaming yadda yadda, is there likely to be anything like smoke coming out (ie unburnt fuel) occasionally when running hard?

Engine is running sweet as ever so I don't suspect and problems, but I am a bit concerned.

Never run over 1.0 bar (and that was once by accident).

Help! (again!!!)

 

[Sarky_FCUK]

Question : > Now is it grey smoke, white smoke, blue smoke.

My money is on Overrun thats when you get smoke puffs.

 

[Jock Alert]

I have no idea what colour to be honest.....

BTW... Define overrun.....? By that do you mean when I lift off the throttle but stay in gear?

 

[Skip]

Could be unburnt fuel vapour...

No idea really! but apparently mine does that when I am giving it everything its got and change gear...

 

[Jock Alert]

CHeers Skip, thats what I had suspected but didn't wanna pin my thoughts on it completely....

Maybe I should replace them plugs!

 

[grebo]

If it's unburnt fuel vapour then it'll be very white. If it's got a blue or black tinge then it's gonna be oil.

Has your oil consumption gone up at all recently ?

Could also simply try running your fingers over the deposits in the end of the exhaust - does it feel at all oily ?

 

[Jock Alert]

Shall carry out some exhaust stroking later.....

Not needed to top the oil up ever, so hopefully thats ok.. Just had a change so shall monitor closely.

 

[Sarky_FCUK]

are you running an aftermarket ecu or changed your a/f ratios Jock, if so , could just be running rich, my old fruit.

 

[grebo]

Any chance the oil was overfilled at the recent change ?

 

[Jock Alert]

Possibly... Put about 4.7 litres in I think ,but it just reaches max on the dipstick.

 

[Sarky_FCUK]

silly point, but car was on a flat surface and not a slope whilst filling oil up ?

 

[Jock Alert]

Flat as a pancake. Front end raised about half an inch, just enough to get my socket stuff onto the sump drain.

And I don't think its a silly question, an old mate of mine thought the oil pan needed removed to change the oil!

 

[Sarky_FCUK]

just a thought. Dont think it can be anything serious, if it gets worse however thats a different story, but I woudl just keep an eye on it.

 

[Jock Alert]

Had a feel at the tailpipe and its a healthy black soot, no oily residues.... Oil level is good, nice and clean too. Have to get someone with half a clue to follow me when I am booting it and have a look.

 

[b]

Who would be able to keep up ? Dangerous game chasing the dragon

 

[Jock Alert]

Heh heh! Indeed buster....

Sarky, just re-read the thread and missed your question about A/F ratios and ECU yesterday....

Using the stock ECU but an S-AFC. I increased the fuelling at various points in high throttle positions to eliminate a flat spot I was getting at around 5000 rpm....... Maybe just a little too rich?

 

[grebo]

Sounds that way. From your inspection of the exhaust pipe certainly doesn't sound like it's burning a lot of oil.

Think it could be time for a dyno run !

 

[Jock Alert]

Indeed... Been long overdue!

 

[Sarky_FCUK]

TREV Hi-jacker, start a new thread and I will answer your possible problem with an answer.

Thanks.