Sounds like ive got a plastic bag???
 

Hi all, ive got a My96 WRX with a Scoobyecu and Prodrive back box - its been mentioned to me a coupla times (m8's cars following/bystanders) that when im accelerating under full load that the car sounds like its got a plastic bag rattling/rustling about? Is it just the back box note or has this happened to anyone else - it was doing it b4 and after the ecu changes, sounds good on idle/when revving any ideas??? cant find anything loose underneath!

Hi Graybr,
Have you heard it?and if so which area of the car is it coming from?
Some cars suffer from the wastegate being clogged,but that sounds more like someone blowing over a bottle! And also if the heatshield is cracked that vibrates and rattles(or at least that is what my old car did!)
Are you going to the Sunseeker Rally?
Regards
Dean

no ive not really heard it, all ive heard is a noise a bit like the tyres digging in/biting from my point of view (which i dare say they are), no obvious noise from the engine bay, if the heat shield is cracked thas no worry as its coming off for a decat pipe in the next few weeks. Have you heard much on the Janspeed D/pipe, i know most go for the H & s but janspeed is just up the road plus i had them make a system for another car and they did a good job??

I have got a H&S downpipe and would certainly recommend them.But I am sure Janspeed also do a fine exhaust.
There is also a guy in Wilton that makes exhausts.I think it's called Torque Technics and is next to UKLF.(But then you probably know that!)
Cheers
Dean

Cheers Dean

Graybr

This is a "characteristic" of Prodrive BBs. I think a better way of describing it is an aircraft taking off!

I can't recall the reason, but its something to do with it being a balanced resonator box or somesuch. That is, its been well designed/made to be highly efficient.

I'm sure someone more knowledgeable than I will assist you as to the precise reasons it sounds that way, but its nothing to worry about.

i was drove a p1 with a scorpion bb on it. it was a full decat IIRC, but it sounded unlike any other bb i'd heard. sounded just like what your describing. like a sort of aeroplane takin off only not quite as loud. cant remember the name of the bb now, but i'll try to find out if it helps?

cheers, PTMD i searched under everywhere, but alas have just in the last few days had a heat shield rust through (see new thread) which far out rattles the exhaust - happens in 3's doesnt it so whats next???? might have to go for another back box though a bit throatier i think, but cheers again, G

Nowt wrong with the sound m8 - I rather like it TBH as its quiet when you're just pootling, then makes old ladies dive for cover when you floor it :D