Is it ok to run a open down pipe during the winter? Some one told me today that it is dangerous to run it in the winter because your motor could suck up cold air. Is this true?

 

I don't see why it would be bad, I've run my cutout in the cold. How would the motor suck cold air up through the exhaust?

 

I dont know! Thats what some dude driving a wrx told me me heard

 

Thats kind of a myth for n/a cars and running short exhaust systems in the winter (ie headers or headers+ downpipe off the headers), but its something I wouldn't worry about in your case.

 

is this a joke!!!!!!!!

 

If you keep your foot in the throddle, how could cold air crawl up the tail pipe? Tell the dude that told you that that "He is a f'in idiot" per Choray. If he has any problems with that i'll slap his momma, and she will set him str8!
Yours Truely
Choray

 

.....sorry momma...

 

I've always heard this rumor/myth/whatever that if your exhaust is too short cold air could somehow get back up the exhaust and cause the exhaust valves to warp.

That's what I've always heard but I've never heard of it happening.

 

Time for some schooling.

It is possible for exhaust to be sucked back into the combustion chamber because of valve overlap. The VQ35 is especially prone to this (by design) because the exhaust valve closes at 8 deg after TDC. (For comparison, the VQ30 exhaust valve closes at 3 deg ATDC. ) The VQ35 uses late exhaust valve closing along with variable intake cam timing to accomplish exhaust gas recirculation without an external egr valve. Unfortunately, this is also why pieces of pre-cat can be sucked back into the engine.

 

THE WISE MAN HAS SPOKEN

 

Very good information..

 

well should I worry? I have very little valve over lap.

 

even if cold air is sucked in i see no possible way of it harming your motor.