Smoke on track: next steps?

[btweedd]

2002 911 C4 Cab; 6 speed; US; 27,000 miles

Hi All

I'm trying to diagnose an intermittent problem that has occurred at two tracks since last summer during my participation in DE events with PCA.

In high speed right-hand turns (only right turns so far) I can get a cloud or puff of smoke depending on specific lap, RPMs, etc. It happened once at Watkins Glen, on the second day (first day without incident). Then it was fine for a day at New Hampshire International Speedway. Then this summer at Mt. Tremblant, again, it occurred, but not every lap. I have read postings and spoken to several folk. I know that this is a known issue but I think I've already done all of the obvious "fixes" that I've read/heard about.

This is what has been done so far: 1) it has the revised dipstick that follows a TSB for 02 models therefore running about 1/2 liter less oil - also, I am making sure that, when fully hot, the dipstick reads about 1/3 quart shy of full - just to ensure it is not overfull; 2) it has the x-51 oil pan mod with improved baffling; 3) after it happened at LCMT I went to Montreal between days and had an oil/air separator replaced.

With all that, it still happened the next day but perhaps with more of a puff than cloud. I also was short shifting some to see what happened - and to salvage the track day - and that seemed to improve it. I'm off to New Jersey Motorsports Park in a week or so for three days of driving.

What am I overlooking? Are there incremental things I can do?

Does this suggest long or short block issues? (And then, of course, do I have to buy a whole new engine? Ugh)

How should I continue to assess this issue? What are the decision-points?

I hate to blow smoke in people's faces and I sure don't want to sell the car with the other mods I've already done.

I have a good tech professional working on this but he is also unsure how to proceed...

Any thoughts most welcome. Thanks in advance.

[PAULSPEED]

Sounds like you are doing a lot of g's in the turns. You

probably need to turn the car into a race motor. Can you

turn the motor into a dry sump. On the west coast I

would cal TRG. On the east coast I would phone Farnbacher

Loles. Both shops turn street cars into race cars. Sounds like

you are running JRZ suspension with racing tires. The baffle plates

only help with twistie turns. The long bank turns should produce

some smoke. My guess is that you are seeing smoke on the turn leading

on to the long straight at Watkins Glen.

Paul

[btweedd]

Thanks Paul

At Watkins Glen, before any mods were done at all, I was in Turn 5 right after the Inner Loop/Bus Stop, a carousel-type curve where, yes, I was pulling some Gs, but then again, oddly, the day before, no smoke, and on street tires and stock suspension. Currently, I'm running Bilstein PSS9 suspension - at Mt. Tremblant it was on setting #7, relatively stiff - with GT3 anti-sway bars and Michelin Pilot Sport Cups.

Any thoughts as to why it would be intermittent? Except for inconsistent driving on my part?

Do you happen to know if the dry sump that TRG offers is a kit? or a custom install? And any idea of price? Obviously I'll need to do the research but just looking for guidelines...

If there are any other ideas out there, I'm sure interested...

Again, thx.

Sounds like you are doing a lot of g's in the turns. You

probably need to turn the car into a race motor. Can you

turn the motor into a dry sump. On the west coast I

would cal TRG. On the east coast I would phone Farnbacher

Loles. Both shops turn street cars into race cars. Sounds like

you are running JRZ suspension with racing tires. The baffle plates

only help with twistie turns. The long bank turns should produce

some smoke. My guess is that you are seeing smoke on the turn leading

on to the long straight at Watkins Glen.

Paul

[PAULSPEED]

I put a H&R sway bar on the rear and

that shaved off 4 secounds a lap. I was getting

smoke in the long bank turn at Button Willow

Raceway.

Maybe a not so expensive fix would be adding a higher pressure

oil pump. The guys at TRG know there stuff. Let us know

if there is an answer.

Paul

[btweedd]

are you saying that the sway bar eliminated the smoke?

I put a H&R sway bar on the rear and

that shaved off 4 secounds a lap. I was getting

smoke in the long bank turn at Button Willow

Raceway.

Maybe a not so expensive fix would be adding a higher pressure

oil pump. The guys at TRG know there stuff. Let us know

if there is an answer.

Paul

[PAULSPEED]

No. The sway bar made the car run on rails. On a long

fast banked turn, the oil will slide to the outside part of the motor.

The crankshaft will not be able to dip into the oil and splash it

up into the motor. The puff of smoke is a result of

too much oil on one side of the motor and no oil on the other side.

I would look at tracks that do not have banked turns.

Paul