61 replies to this topic

[MiniMartyn]

I reaaalllyyy love the sound of a mini when you lift off the throttle going down hill (usally in 2nd) and it pops and crackles. unfortunatly mine doesnt do it... Does anyone have any ideas for me? baring in mind i dont really want to break anything.

Cheers

[samsfern]

you mean burbling on the overrun. They dont normally do it if their running and setup correctly. Mine does, but my engines quite far from standard.

[Ethel]

If you don't want to break anything don't try 'n do it.


Cars with race cams do it because both valves are open at once allowing unburned fuel to go right through into the exhaust, where it ignites.

[Christoff-Mpi]

My mpi pops and bangs when it's cold and the chokes out but then again it's a decat, it didn't do it when it had a cat. There's a trick you can do turning the ignition on and off whilst revving the car but I'd personally not try it.

[MiniMartyn]

Okay thanks guys... So basically to do it propperly wer talkin serious money? Cheers

[SimpleSimon]

When I was younger, we used to make the mini's backfire. Basically, rev the engine then flick the ignition off and back on. As you flick the ignition off, "blip" the throttle.
As I said though, this was a fair few years back. We also used to ignite the fumes at the end of the backbox on our mk1 fiesta as it ran so rich when the choke was out.

But as advised above, the best way to do it, is spend a lot of time and money building a decent engine.

[DAVEY_C]

i use to have an 850cc ministox car, standard engine, welded diff but with a straight through exhaust... no backbox but it had a cat pipe, it use to pop and bang as long as we played with her and the rumble was savage,

i loved the sound of her and for an 850 she went like stink....

[CobraV8]

All you really need for the popping sounds is a less restrictive exhaust and extractors.

[Sprocket]

The fueling needs to be rich with a low value ignition advance, only really achievable with programable engine management. I have had some amazing pops and bangs, even flames on over run when I turned over run fuel cut off to tune the bottom line on the fuel map

[Cerberus]

Mine is a standard 1275, with a stage one kit, no CAT and single box exhaust system. My ignition advance, when idling is about 8 degrees (with strobe).

And it pops and crackles on the overrun.


As CobraV8 said, easiest thing to do is put a freer flowing exhaust.

My Fiesta MK6 used to do it when I'd only changed the back box for a SS one.


It obviously won't bang really loud or spit flames, but it burbles really nice.

Edited by Cerberus, 17 October 2010 - 01:37 PM.

[BennerW]

My 1998 MPI cooper pops and bangs alot on overun, Its standard apart from a maniflow manifold and a Fletcher twin rear box.

Especaiily when its cold in the morning and I go down a series of small hills in 2nd or 3rd or when I approach a roundabout and change down.

Ben

[TimmyG]

just put a cherry bomb on with no other silencers and it will pop and crackle on overrun and sound awsome! you will not break your car!?? most carb'd cars will do this, it is just silenced out usually thats all. Modern fuel injected engines tend not to do this as the fuelling is shut off altogether on overrun.

[Cooperman]

Can't understand why anyone would want their car to do this. Very strange. It's best if the car runs properly, surely.

[me madjoe 90]

Can't understand why anyone would want their car to do this. Very strange. It's best if the car runs properly, surely.

Im with this guy, only time i think it sounds good is on turbo cars with anti lag.

Even then its not exactly practical.

[Cerberus]

Can't understand why anyone would want their car to do this. Very strange. It's best if the car runs properly, surely.

I'm pretty sure even if a car is running properly, it can still pop through the exhaust.

As mentioned, fuel injected cars don't do it as much as carb'd cars.


I suppose, on a standard mini, it probably 'shouldn't' do it, but its not really a problem or anything IMO.