afterfire or backfire?

Minicobra1 · 12-31-2009, 03:56 AM

Yes, it is somewhat normal, Berk CBE + Berk HFC gets the burble too.

My Mini Cooper does it too, check out the video on this one:

A couple links on articles, not sure how accurate they are:

Exhaust Burble Causes | eHow.com

eBay Guides - Exhaust Pipe Diameters

Modshack · 12-31-2009, 10:45 AM

Quote:

Originally Posted by Minicobra1

A couple links on articles, not sure how accurate they are:

Exhaust Burble Causes | eHow.com

eBay Guides - Exhaust Pipe Diameters

Yeek...More bad info on the internet. I wouldn't put too much stock in either of those 2 links though there is a little truth in the second.

Most cars, due to emissions, now have complete fuel cuts when you close the throttle. This immediate transition to lean will cause the burble and snapping depending on exhaust design and back pressure. On my old ('08) Corvette you could tune this out with software by turning off the fuel cut and allow some fuel and combustibility into the system even on closed throttle. The more even burn did away with the burble and snap/crackle..It was all very tunable. Opening or closing the Exhaust flappers had an impact too.

spearfish25 · 12-31-2009, 04:40 PM

Quote:

Originally Posted by Modshack

Yeek...More bad info on the internet. I wouldn't put too much stock in either of those 2 links though there is a little truth in the second.

Most cars, due to emissions, now have complete fuel cuts when you close the throttle. This immediate transition to lean will cause the burble and snapping depending on exhaust design and back pressure. On my old ('08) Corvette you could tune this out with software by turning off the fuel cut and allow some fuel and combustibility into the system even on closed throttle. The more even burn did away with the burble and snap/crackle..It was all very tunable. Opening or closing the Exhaust flappers had an impact too.

Race cars burble like crazy. I assume they don't care about emissions though. Is it more exhaust design then?

Anyone getting burble with the Stillen CBE and Berk HFCs together? I have the Stillen CBE alone and there is only a hint of burble.

gumpy · 03-09-2010, 04:59 AM

Quote:

Originally Posted by spearfish25

Race cars burble like crazy. I assume they don't care about emissions though. Is it more exhaust design then?

Anyone getting burble with the Stillen CBE and Berk HFCs together? I have the Stillen CBE alone and there is only a hint of burble.

Yeah I'd love to know what type of exhuast gives you the lift off crackle. I don't necessarily want a louder exhaust but a freer flowing one with over run crackle and pops would be awesome.

spearfish25 · 03-09-2010, 08:54 AM

Quote:

Originally Posted by gumpy

Yeah I'd love to know what type of exhuast gives you the lift off crackle. I don't necessarily want a louder exhaust but a freer flowing one with over run crackle and pops would be awesome.

I think the mufflers really kill the burble. When I did the muffler delete with stock cats still on the car, the over run crackle was absoluletly awesome. If the WOT acceleration wasn't so darn loud, I'd have kept the muffler delete for the over run burble alone. Man, was it cool.

gumpy · 03-09-2010, 04:08 PM

Quote:

Originally Posted by spearfish25

I think the mufflers really kill the burble. When I did the muffler delete with stock cats still on the car, the over run crackle was absoluletly awesome. If the WOT acceleration wasn't so darn loud, I'd have kept the muffler delete for the over run burble alone. Man, was it cool.

Ah so the exhaust did get unreasonably loud did it?

12-31-2009, 03:56 AM	#1 (permalink)
Minicobra1 A True Z Fanatic Join Date: Nov 2008 Location: Orange County, CA. Posts: 1,205 Drives: 370Z Tour, Spt, 6mt Rep Power: 646	Yes, it is somewhat normal, Berk CBE + Berk HFC gets the burble too. My Mini Cooper does it too, check out the video on this one: A couple links on articles, not sure how accurate they are: Exhaust Burble Causes \| eHow.com eBay Guides - Exhaust Pipe Diameters __________________ 370z Tour\| Spt Pack\|Navi\|BERK CBE\|Berk HFC's\| Eibach Springs\| Hotchkis Sway Bars\|SPC Camber Arms\|15mm Ichiba Wheel Spacers\| 19"Factory Nismo Wheels-Matt Black\|Stop Tech Rotors\|TWM Shifter\|3M Tint\|Black Fangs\|Black Rear Valance\|JDM Fog Light\| MY BAND-www.myspace.com/petroleum