a exhausting question

[adamsky01]

i have a 940 i need a new exhaust i am opting for stainless the car is a 2 litre turbo do i go for one silencer or 2 the guy in the shop seems to think it would be nice to have one instead of 2 i am not sure

[mharriso]

Previous comments, and perhaps general consensus is that if you have a turbo impellar and a cat then there is only need for x1 straight through (absorbtion) silencer, deffo x1 if baffled.

If no CAT then perhaps x1 baffled silencer only or x2 straight through (absorbtion).

I guess it depends how much noise you want to make...

with the turbo impellar inthere, i don't believe there is such an issue with exhaust length / volume tuning to scavenge the cylinder at resonant frequencies.... so the option come down to noise and back pressure....how much or how little of each your after, and the real gains available...

as an intertesting side point, i recall mumerous tuners stating standard CATS present no real perfromance restriction until you are around the 100bhp per litre mark, i.e. flowing a fair amount of gas... in case you were thinking of chucking the cat.....

let us know how you go and how it sounds...

[adamsky01]

Originally Posted by mharriso

Previous comments, and perhaps general consensus is that if you have a turbo impellar and a cat then there is only need for x1 straight through (absorbtion) silencer, deffo x1 if baffled.

If no CAT then perhaps x1 baffled silencer only or x2 straight through (absorbtion).

I guess it depends how much noise you want to make...

with the turbo impellar inthere, i don't believe there is such an issue with exhaust length / volume tuning to scavenge the cylinder at resonant frequencies.... so the option come down to noise and back pressure....how much or how little of each your after, and the real gains available...

as an intertesting side point, i recall mumerous tuners stating standard CATS present no real perfromance restriction until you are around the 100bhp per litre mark, i.e. flowing a fair amount of gas... in case you were thinking of chucking the cat.....

let us know how you go and how it sounds...

im afraid the cat went a few years back i dont want to be to loud i just would like a nice per

[mharriso]

my missus has a nice "per" too... so i know what you mean....

if the cat has gone then suggest x 2 straight through, though these will need repacking periodically... sound good though......

hey try one and get them to make it with a removaable section so you can insert another if its too much......

if you get sick of the noise you can always add a small baffle on the end won't effect performance unless you are at high rpm.....

[IC]

Thread moved to the appropriate forum.

[terrywilde07]

I had a 63mm straight throught tube from the turbo to the rear bumper... No CAT, No Boxes

The turbo quietens down the exhaust anyway, it was fitted to 2 of the 940 Wentworth Turbos that Ive had (2.0L HPT B200's) & they were well within the sound limits and went through 2 MOT's with no problem

sounded excellent, deep toned burble, & was a hell of a lot cheaper without the boxes

[adamsky01]

thanks guys ok look like im going with 1 got o sound better than whats on there now there is so many holes in the sys i got now i have used coke cans to seal holes up so its time to replace

[caveman]

Originally Posted by terrywilde07

I had a 63mm straight throught tube from the turbo to the rear bumper... No CAT, No Boxes

The turbo quietens down the exhaust anyway, it was fitted to 2 of the 940 Wentworth Turbos that Ive had (2.0L HPT B200's) & they were well within the sound limits and went through 2 MOT's with no problem

sounded excellent, deep toned burble, & was a hell of a lot cheaper without the boxes

and it was legal?? i might go for one like that!
cavey

[terrywilde07]

Originally Posted by caveman

and it was legal?? i might go for one like that!
cavey

yes it was legal.... it passed 2 MoT's & passed the sound level check at 87dB and the maximum permissible which, I think, is 95dB.

it was actually quieter than most of them boy racer back boxes you see on them little 1.6 Saxo's & Corsa's parked up in the town centre car parked of a friday evenin

That was while the 8 valve B200 was putting out 295bhp after lowering the compression, new stronger mains & big end bearings, comp head gasket, re-mapping the ECU & boosting the turbo to 23psi, along with a few chassis/suspension tweaks. Sounded great when there was the odd crack from the tail pipe on gear changes at high rpm

well... I used to work for a Motorsport team & thats what I did to my trusty old Volvo to keep up with the other spanner men in their, scoobys & various GTi's, & you can't work for a race team & not 'tickle' you own car now can you

interestingly enough.... I did see an old 740 at Rockingham circuit with a 6.6 Pontiac engine shoe horned under the bonnet, & it was a private car used for towing... not a track car