R3R exhaust collector box, popping

[Martin]

hello all
Replaced my R3R exhaust with straight through end cans and straight through cross-over, plus in-box K&N, got it dyno'ed accordingly. F/A was set at 13.5. the performance and smooth running is perfect.
The problem is popping on deceleration, its got to a point where I find it so irritating that im about to swap out the cross-over back to the restrictive OEM cross-over box, this will stop popping as its increased metal mass does not get as hot as the cross-over pipe and therefore does not ignite unburnt gasses so reduces popping. Anyone had similar ?
incidentally what is the purpose of the OEM cross-over box which contain plates to route the gas indirectly - I can only surmise its for further noise reduction or to stop decel popping ?!
cheers

 

[dougl]

hello all
Replaced my R3R exhaust with straight through end cans and straight through cross-over, plus in-box K&N, got it dyno'ed accordingly. F/A was set at 13.5. the performance and smooth running is perfect.
The problem is popping on deceleration, its got to a point where I find it so irritating that im about to swap out the cross-over back to the restrictive OEM cross-over box, this will stop popping as its increased metal mass does not get as hot as the cross-over pipe and therefore does not ignite unburnt gasses so reduces popping. Anyone had similar ?
incidentally what is the purpose of the OEM cross-over box which contain plates to route the gas indirectly - I can only surmise its for further noise reduction or to stop decel popping ?!
cheers

With your freer flowing mufflers, changing the crossover may not do it. Have you had the fuel retuned? 13.5 is ideal at WOT but the popping problem is at zero throttle under load. You can try to tune this out by adding fuel in the L tables using TuneEcu. It's much easier to do with a PCV.

 

[Martin]

i replaced straight through cross-over back to the original collector box and the popping is down to zero, im happy with slightly reduced power, maybe running slightly rich, with zero popping - the popping with cross-over on closed throttle was incessant and irritating.

the bigger collector box doesnt get as hot, the straight through pipe got VERY hot. still dont know the collector box' official function, i guess sound reduction.

 

[Rick McC.]

i replaced straight through cross-over back to the original collector box and the popping is down to zero, im happy with slightly reduced power, maybe running slightly rich, with zero popping - the popping with cross-over on closed throttle was incessant and irritating.

the bigger collector box doesnt get as hot, the straight through pipe got VERY hot. still dont know the collector box' official function, i guess sound reduction.

I believe the "plates" you speak of are the catalytic converter.