Twin tail pipes

[Guest]

Has anyone tried the twin tail pipe mod shown below (hopefully). Recognise will need extra silencers for track use, but should be easier to bolt on when required than to side exit.

Did it give any noticeable power increase, or just lots of noise?

 

[Alex Postan]

I had one of these on my 2.7 RS and it was fabulously rude - on the 1998 Pyrennees Rally we christened it the "3 valley exhaust" because when you fired it up, startled pigeons would take to the air three valleys away.

BUT! I later did a back to back with it on Bob Watson's rolling road. The standard SSSIs with stainless single exit silencer gave seven more bhp.

On Saturday, a Lambo Murcielago came by us in Pall Mall with a demon sports exhaust - only the Carrera GT or a 917 can sound as good - every window rattled, every pigeon flew and the last of the winter's leaves dropped off all the trees in St James's Park.

 

[pmjt]

ORIGINAL: IanD

Has anyone tried the twin tail pipe mod shown below (hopefully). Recognise will need extra silencers for track use, but should be easier to bolt on when required than to side exit.

Did it give any noticeable power increase, or just lots of noise?

I took one off a 2.0S I owned and there was a veeeery small dip in power - the noise was incredible, if a little hard on the ears after a while - it's sitting in my garage waiting to be used at some time in the future []

p

 

[vic cohen]

Great fun , flame spitting and all lost 3 bhp on my 3 0 rs , Loss of back pressure for a start .....................for extra performance , not noise and flame , Megaphones !

 

[Guest]

thanks guys, I think I'll forget that mod. Does anyone have any alternatives for a back box to which I can easily add extra silencing for tight noise circuits, and then remove when nobody cares.

In my experience the standard silencer with SSIs and a 10.3CR on a 2.9RS engine (93mm barrels) is marginal at most circuits and too loud at many. Right now I've an extra repackable silencer welded on the back, but looks horrendous.

See Prepfab are offering one on their excellent website ( .http://www.prepfab.co.uk/) ..anyone tried it?
Incidentally I've used these guys for some work/bits for my rally Mexico and am very impressed by their fabrication skills.

 

[early 911]

I made one of those exhausts using a £30 second hand exhaust (and following those instructions) . . . no increase in power.

Kept all 3 pipes (i.e. two new one and the exisiting one) open. To reduce the noise I simply put two red bull cans and a jubliee clip of the two smaller pipes. Mostly I run with all 3 open . . . . its been on there a couple of years now. I like it . . but the neighbours don't [].