Servo

I want to run a boost activated exhaust cutout on a turbo downpipe. My goal is to have the cutout open at 5psi so that I can have a nice quiet system for cruising and minimal restriction under hard acceleration.

My question is; how will dumping a ton of hot exhaust gas right near the oil pan affect the handling characteristic in a road course environment?

My main concern is losing downforce or overheating the rear tires accelerating out of a corner. What do you guys think?

Weston

Nate, I don't think I'd worry too much about it causing additional lift... it can't help things, but I really don't think it's enough volume to make a noticeable difference. I'd be much more concerned about it heating the oil and frying any rubber or plastic that may be around the area. I ran a wastegate dump in front of the oil pan for years and didn't really have any problems, but then again, that was only a small portion of my exhaust volume. I'd make the cut-out as far back as possible... keep in mind that it wouldn't be unusual for a rulebook to require the exhaust to terminate behind the passenger compartment.

Servo

Ah, I hadn't thought of that rule aspect of it. Do you recall what sanctioning bodies require termination behind the passenger compartment?

SicNA94TegGsR

QUOTE=Servo]Ah, I hadn't thought of that rule aspect of it. Do you recall what sanctioning bodies require termination behind the passenger compartment?[/QUOTE]

Most of them do.

mc-integra111

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Servo &raquo;</TD></TR><TR><TD CLASS="quote">Do you recall what sanctioning bodies require termination behind the passenger compartment?</TD></TR></TABLE>

MC, NASA, and SCCA for sure. My guess is that even track days may have supplementals that include that rule.

Servo

Ok, so I at least need a pipe w/ a turndown after the passenger compartment.

Would you guys think that far enough back to avoid heat soaking the rear tires? I understand what you're saying about your dump tube, Wes, but this will probably be 95% of the flow from a 300whp engine.

stealth430

For your safety, make your exhaust run end after the driver compartment. Exhaust will enter the cockpit if you end it after the oil pan. You will be inhaling this at large amount. Imagine jogging behind a bus. Your footwell will also be super hot and you can burn yourself even through your shoes.

There is no measurable gain in lift or downforce if the exhaust exits right after the pan with our production based car.