My MCS with Borla Race burbles when you let off the gas and use compression braking. So does everyone else's.

I could understand it with carb-fed engines. But with FI, why is there excess gas coming through the exhaust valves which I am guessing causes the burbling.

If you have that figured out, then why, if the A/C is on, does burbling totally disappear? Totally. Crest a hill at redline in second, take you foot off the gas, and coast down. Nothing. Not that I am complaining, I just don't understand why.

Vince

 

The MINI runs extremely rich. The would account for the excess fuel and vapors getting through the exhust valves. It's also what causes your exhaust tips to go from polished to black in 2 blocks!

 

Moorlockx,

I am not surprized that they are tuned rich. Protects their warranty butt. You pay in gas and performance and it runs a bit cooler although fuel is a fairly poor way to get cooling. As for the compressor (a/c that is), same air/fuel mix but slightly more drag. Sure does quiet things down though.

Ciao,

Vince

 

I first noticed the burble with the addition of Milltek header. Although Unichip leans out the mixture, the burble still exist. I'm also curious as to what actually caused the burble? :smile:

_________________

 

As dave's above, my Milltek catback burbles with a Unichip MINI04 program.
love the sound.

 

I would be upset if there was no burbble, I love that sound.