Discussion
Anyone have any pictures of their sports exhaust, particularly ones with the 2.5" or 3" tails. Eye level pics when fitted would be good 
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I think the 2.5" straight through may be too loud as the felines are absent. So I think I'm leaning to the 3" ones with the extra silencers built into the back from Tim at ACT but can't remember seeing any pictures of them on a Cerb, and search isn't helping
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Another query is; whilst the extra silencing should keep the general noise down (good) does it muffle the pops and bangs excessively (bad
)
. I think the 2.5" straight through may be too loud as the felines are absent. So I think I'm leaning to the 3" ones with the extra silencers built into the back from Tim at ACT but can't remember seeing any pictures of them on a Cerb, and search isn't helping
. Another query is; whilst the extra silencing should keep the general noise down (good) does it muffle the pops and bangs excessively (bad
) 
HarryW said:
I'm leaning to the 3" ones with the extra silencers built into the back from Tim at ACT
Harry -funnily enough I've also been talking to Tim about the 3" pipes
As well as the 'built-in' silencing there is also the option of adding extra trackday silencers to them to get through the noise restriction test. Be nice to see some pics...
Interestingly, when I approached JP about a year ago to make sports systems with 3 inch bore they said they couldnt do it as the only suitable silencers they made were 2.5 inch internal pipework so no point other than aesthetics of the tailpipe (ie no extra flow). have JP now started making 3inch silencers then? Would be cool if they do cos i have a project for them 
Autonotiv said:
So harry, have you now brought a cerb then?
Keep up at the back http://pistonheads.com/gassing/topic.
, just need to sell the S 
v8_oatz said:
trackcar said:
have JP now started making 3inch silencers then?
Hi Joo! I'm no expert and I'm sure he'll be along directly to correct me but:
[sticks neck out]
I think it's a 3" diameter tail-pipe accomodating a 2.5" silencer
[pulls neck back in]
Bugger if that's the case cos that means no extra flow. getting 3 inch perforated pipe seems to be a bit of a problem
HarryW said:
Autonotiv said:
So harry, have you now brought a cerb then?
Keep up at the back http://pistonheads.com/gassing/topic.
, just need to sell the S Let us know when the engine is done. unless it has been done already?
So will it be at the H&C next thurs?
HarryW said:
Not sure what if any extra flow is had from going from 2.5" to 3" but would be interested in the result
Harry, if you are talking just about going from 2.5" to 3" inch on the tail pipe (section after the back boxes) then I would say that there would be very small if any gains.
A Std / Sports System comprises of
Intermediates Pipes (cat back) at 2.125" (2 1/8th)
Rear pipes into back box at 2.125"
Back Box (internal) at 2.125"
Tail Pipes out of back box at 2.125 into 2.5"
ACT Big Bore System
Intermediate Pipes (optional) at 2.25" (2 1/4)
Rear pipes into back box at 2.25"
Back Box at 2.25"
Tail Pipes out of back box 2.25" into 3" (silencers optional)
My System
Intermediate Pipes (yet to be fitted]) 2.5" (2 1/2)
Rear pipes into back box at 2.5"
Back box at 2.5" into 3"
Tail Pipes out of back box at 3" all the way.
The noise level does increase but it is very deceptive. Everyone who knows my car has commented that since fitting the new back section of the exhaust that the car "sounds" quieter, however this is only because the sound is now much deeper and bassier. There are also power improvements to be had by going to a larger bore system, however this will vary from car to car depending on whsat system they had fitted previously and which system you opt for. There isn't an "optimum" bore size to go for, although there may be an "optimum" noise size
Have a read of the thread I posted a couple of weeks ago about my new exhaust, this explains that improvements can be had, but in order to see it you would have to have a custom system made up, however the ACT system will also add a slight performance improvement as well as sound improvement.
I think the ACT big bore system will be your best option, but see if you can listen to one with and without silencers.
www.pistonheads.co.uk/gassing/topic.asp?h=0&t=282272 performance improvements......
www.pistonheads.co.uk/gassing/topic.asp?h=0&t=280171 pictures
Edited by Cyclone1 on Saturday 8th July 07:36
Autonotiv said:
HarryW said:
Autonotiv said:
So harry, have you now brought a cerb then?
Keep up at the back http://pistonheads.com/gassing/topic.
, just need to sell the S Let us know when the engine is done. unless it has been done already?
So will it be at the H&C next thurs?
If I'm at the H&C next week it'll be in the S/Touring, not expecting the Cerb to done this side of August, waiting on some touring car pistons from Germany at present
.Cyclone1 said:
Lots of good stuf :thuumbup:
Cheers for that Jules, I'll ponder what to do, as said/alluded an off the shelf ACT big bore is favourite at present.
I went bespoke on the S (including headers) and dont' really feel like taking the lead on this one, although I could be tempted
.HarryW said:
Autonotiv said:
HarryW said:
Autonotiv said:
So harry, have you now brought a cerb then?
Keep up at the back http://pistonheads.com/gassing/topic.
, just need to sell the S Let us know when the engine is done. unless it has been done already?
So will it be at the H&C next thurs?
If I'm at the H&C next week it'll be in the S/Touring, not expecting the Cerb to done this side of August, waiting on some touring car pistons from Germany at present
.shame, will be good to see/hear it
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