red targa

A friend of mine with C4S w/after market turbo charger (Lotec) was in front of me driving at a fast pace on Sunday. I saw fire coming out of his tail pipes a few times.


I think it happens when he was slowing down, and changing gear. It looked pretty cool, but I am wondering whether his engine or exhaust might be damaged because of it.

We got off the highway, switched cars and I tried to repeat the phenomenon by downshifting from 3rd to 2nd @ 4,000 rpm. But I couldn't do it. I heard that it may be due to unburnt gas in the exhaust coming thru the hot tailpipe and got re-ignited again.

Does anyone know why this might happen?

Surj-993C2S

You mean like this:

Chris W. - '96 Targa

Gee, I just hope you caught that hatchback/station wagon in front of you...



-Chris

JPS

I've heard that is the aftermarket "tailgaiter / soccer mom eliminator", but I haven't been able to get a part number...

graham_mitchell

That photo looks so much like a lion charging a limping gazelle! You just know that death is seconds away... Great pic

red targa

Hi guys,

Thanks for the added comments. But so far, no one has commented on the possible cause & effects.

Is it something to be concerned about?


Thanks,

ZCAT3

Nope - a turbo Porsche running without cats will do this when the turbo is hot. It usually occurs on downshifting as exhaust gasses with unburned fuel are forced out past a red hot turbo and ignite. My 930 does this - it is very cool to see and is normal. It generally does not damage the car.

Surj-993C2S

Unfortunately it wasn't me driving, this pic is off of my mini DV camera - it was at a trackday at Donnington where we shared the track with a couple of Porsche Racing teams.

The 'Pink Gazelle' ended up in the gravel soon after...!

Rick Lee

I dunno. I'd worry about a rich mixture.

ZCAT3

Well it better be a bit rich when you are under boost or watch out - in any event, ask any turbo tuner out there ahd they will tell you this is normal for a turbo running without cats.

red targa

Thanks for informative comments.

So, this means my friend's turbo-charged C4S maybe running without catalytic converters?

If his car has cats then there shouldn't be any fire coming out of the tailpipes?

996FLT6

And without cats you can use the leaded gasoline say octane 118 : ). Great on the track with better mid-high rpm but kinda loud for the street and smellls like the dickens. Regards. Mike