blow off sound in brumby

brumby_pete · Post by **brumby_pete** » Thu Jan 31, 2008 8:28 pm

i put a $75 cannon on the brumby for shits and giggles and it sounds that good its not funny. really didnt expect it to sound so good. when im being a tosser and rev her right up and let off the throttle really quickly i get this blow off valve sorta sound. it only happens if i really rev her up though. ive looked around the engine bay to see if i could find anything and i found a valve thing inside the air box inside the section the oval filter encloses. i dont have any probs with it but i'd like to know why it does it. its only happened since i put on the cannon so i dont know. any ideas on what it is would be awesome.

Cheers.

Post by **Alex** » Thu Jan 31, 2008 9:12 pm

you need to put some resonators in your system. Is it like a crackling really quick popping noise?

alex

Matatak · Post by **Matatak** » Thu Jan 31, 2008 9:52 pm

the best answer u culd get. is -

u have an EA81T with a BOV already on it

but i doubt it.

but yer i agree with Alex.

steptoe · Post by **steptoe** » Thu Jan 31, 2008 10:40 pm

hey, how come the asterisk police let you spell shits clearly ?

Gannon · Post by **Gannon** » Fri Feb 01, 2008 5:32 am

brumby_pete wrote: i found a valve thing inside the air box inside the section the oval filter encloses.
Cheers.

So obviouslly you dont have an EA81T

The valve is something to do with emissions, i doubt it would make the noise.

As said above, probably small backfiring in the exhaust

Sti_Brumby · Post by **Sti_Brumby** » Fri Feb 01, 2008 7:52 am

it's not the anti - back firing vavle is it? top right hand corner.

My brumby used to make that noise

BRUMBI · Post by **BRUMBI** » Fri Feb 01, 2008 7:56 am

when i was putting my weber on my brumby i took all the emission contorl stuff of one by one, there is a vacume hose that gose to a valve caled an anti-backfire valve when you disconect one side of it and rev the car it would make a blow off sound, maybe one off these hoses have come off,

its up around here...

BRUMBI · Post by **BRUMBI** » Fri Feb 01, 2008 7:59 am

must of been writing that at the same time, its pritty easy to find its mounted very high and has about a 20mm hose going into it on one side that i can remeber

brumby_pete · Post by **brumby_pete** » Sat Feb 02, 2008 3:02 pm

Alex wrote:you need to put some resonators in your system. Is it like a crackling really quick popping noise?

alex

ok ive done some serious reving haha and its not that sort of sound at all. its more like a constant gush of air. it continues to have the gushing sound if i keep it around the redline area. i think i called it a BOV sound cause i only kept the revs that high for a moment. another thing ive noticed is when im in third and i slow down by going into second and just let the compression slow me down, particularly in second, i get that crackling quick popping noise and it does it heaps of times before it gets to low revs and it stops. that particular sound reminded me of an anti-lag system. a cop actually pulled me over yesterday to check if it was a turbo. (not allowed to drive turbos as im on the new P plate laws). what might these sounds be???

cheers.

Sti_Brumby · Post by **Sti_Brumby** » Sat Feb 02, 2008 3:23 pm

free flowing exhuast tend to do that on the ea81's. Specially you have fitted a straight through cannon.

Dutchy · Post by **Dutchy** » Sat Feb 02, 2008 3:42 pm

brumby_pete wrote:ok ive done some serious reving haha and its not that sort of sound at all. its more like a constant gush of air. it continues to have the gushing sound if i keep it around the redline area. i think i called it a BOV sound cause i only kept the revs that high for a moment. another thing ive noticed is when im in third and i slow down by going into second and just let the compression slow me down, particularly in second, i get that crackling quick popping noise and it does it heaps of times before it gets to low revs and it stops. that particular sound reminded me of an anti-lag system. a cop actually pulled me over yesterday to check if it was a turbo. (not allowed to drive turbos as im on the new P plate laws). what might these sounds be???

cheers.

I get the same backfire and gush of air in my car but its an ea82, but i have done nothing to the exhaust. Ive always wondered wat it was.

Post by **Alex** » Sat Feb 02, 2008 4:57 pm

simply because you said it does it at high revvs when downshifting makes me think you need a resonator for SURE! my car use to do it.

i'll go make a quick vid of my car now

alex