I think that I have heard my car backfire a few times since I had my HKS exhaust installed. I was wondering what can cause an exhaust to backfire.

It seems to happenen when I accelerate to redline and let off the gas. (ie. when I need to get into the next lane from a dead stop after the light turns green. When being given bad directions.)

Any info would be appreciated.

Thanks

 

That's pretty common with a low restriction exhaust system. It's just a little reversion (reversal of airflow) that occurs when you get off the throttle suddenly at high rpm. The engine actually isnt' firing when you get off the the throttle (No fuel is injected), ot it isn't a big deal. Actually, the sound is considered kind of cool by some folks.

UL

 

I

 

look for exhuast leak if you want it to do it less. Otherwise it won't hurt much except for maybe the gasket at the leak. Check those connections; aft of CAT, also right and left legs for tightness.

 

I was planning on checking for loose nuts/bolts anyway. Now, I have one more thing to do tomorrow.

So if there really is no harm, then I shouldn't be that worried. It just sounds really loud, like a gunshot. I wonder what the people around me are thinking.

Thanks again for your input.


CDELENA,
Did your car have the Mugen exhaust on at the John Eagle TWS event?

 

[QUOTE]Originally posted by joe_s2k
[B]..It just sounds really loud, like a gunshot. I wonder what the people around me are thinking. ..CDELENA,
Did your car have the Mugen exhaust on at the John Eagle TWS event?

 

Not that it is the same, but my s4 had the same problem, but it went away after new gaskets were installed.

 

My 5zigen backfired VERY loud on the freeway a couple times last summer. It was probably a combination of things. I was accelerating slowly and it was over 110 degrees out. Also, there might have been a slight leak somewhere. Since then I've had to remove and reinstall the exhaust several times to change the clutch, diff, and other stuff, so if there was a loose connection, it's been fixed. Anyway, it hasn't done it since. But when it did, it sounded like someone threw a big ass boulder at the back of my car. pretty damn loud.

 

Sounds like an air leak from improper seating of the exhaust gasket. Four questions:
1) Did you use a new gasket with the header?
2) Did you replace the nuts?
3) Did you torque in the proper sequence?
4) Did you retorque after several thermal cycles?

Oxygen will reignite if there is an airleak in the exhaust path. The above four elements are the leading causes of exhaust leaks on aftermarket systems.

 

header? who's talk'n header?