Less Noise Please

[ukkid35]

I can't pass 105dB static now I have newish cats. I have the sports exhaust, so my options are:

Original back box
Track day silencers
Something else?

I was thinking perhaps replace the cats with cherry bombs - is that practical (and affordable)?

[scotty_d]

my car is going in to meercat exhaust's next week to have my sports system finished off and silenced de-cats made up not sure on cost yet but my car is as loud as your is just now bit much for daily use. want it a touch louder than standard but not much.

[robsco]

I have the world's quietest sports backbox ready to come off mine now...

Not sure how noisy it is though actually, but even with decats it's extremely quiet for a Cerbera.

[ukkid35]

Is there a difference between 4.5 and 4.2 rear boxes?

I've seen that ACT do Silenced De-Cats, will that be louder or quieter than Cats?

[Tafford]

There is a difference between early 4.2 back boxes and later 4.2 / 4.5 back boxes - the diameter of the pipes that join to the 51mm dia centre pipes is smaller. Later 4.2 back boxes are the same as the 4.5's and fit 54.8mm dia centre pipes I believe.

[ukkid35]

Thanks Tafford.

It seems that the Cherry Bomb De-Cats do actually exist

http://www.acs-pro.de/1_4.html

[grahamn]

Hi I have an SP back box and cherry bombs on mine. I can pass the 105 db test and the 98 db test with the aid of trackday silencers. If this helps.

Graham

[ukkid35]

So no Track Day silencers to pass 105? That sounds good, as I'm trying to avoid Track Day silencers as they do seem to sap top end power, unless someone can recommend something less restrictive than the ACT SI01 units.

Edited by ukkid35 on Friday 11th May 12:16

[Tanguero]

Linked de-cat and standard back box. Passes 101dBA @ 4500 rpm noise checks. Perfect combination.

[gruffalo]

ukkid35 said:

So no Track Day silencers to pass 105? That sounds good, as I'm trying to avoid Track Day silencers as they do seem to sap top end power, unless someone can recommend something less restrictive than the ACT SI01 units.

Edited by ukkid35 on Friday 11th May 12:16

I can't say I have noticed a huge difference in top end power, torque out of corners in massive with the full ACT Large Bore System and track silencers fitted:-)

[spongy]

how do the act pipes sound compared to the cheaper sports pipes...and do they perform much better.think the main pipe diameter is bigger,but they sound deeper.i always thought if you went toooooooo big on bore on a non turbo application this reduced back pressure which is not always a good thing.must admit i think the act ones will find their way onto mine in a few years

[Obiwonkeyblokey]

robsco said:

I have the world's quietest sports backbox ready to come off mine now...

Not sure how noisy it is though actually, but even with decats it's extremely quiet for a Cerbera.

I thought that about mine a 2001 4.2 and at Combe last year it was 96DB! very quiet. Its now 112.

[Byker28i]

grahamn said:

Hi I have an SP back box and cherry bombs on mine. I can pass the 105 db test and the 98 db test with the aid of trackday silencers. If this helps.

Graham

The SP backbox and cats should manage 98-99db. This was the original configuration when they advertised it as being capable of 98db and was certainly verified on my car. However their full system, with linked decats added another 10dB. They did produce some beautiful trackday silencers with a fake rear entry and the rear exhaust entry pointing downwards, but they wanted £650 for them.

In my testing cats usually add 8-10db of noise reduction, on any exhaust system but you get the heat build up. I have the ACT quiet system with silencing in the long centre pipes, the rear cans silencers and additional silencing in the tailpipes. On my car it's 96db at 4500 revs, 96-98 with the ACT trackday silencers on and I've been 88db with the cats in as well to make it onto Thruxtons track 90dB limit). Sounds muted though.

Only issue I have with the TVR original/SP design is it's a huge box. I get more road clearance/less weight with the ACT setup, plus ACT's customer service is second to none.

[a1rak]

ukkid35 said:

Is there a difference between 4.5 and 4.2 rear boxes?

I've seen that ACT do Silenced De-Cats, will that be louder or quieter than Cats?

I have these ACT decats and they make very little difference to a staight decat pipe.
I have to use trackday silencers but would like to upgrade to a quieterr system. Does anybody know who did the sports system where the rear backbox went from side to side and not two seperate length ways boxes

[Vixpy1]

I'm on the lookout for SP back boxes at the moment, so if anyone has any

[ukkid35]

So I ended up buying the centre section of this system from another PHer



http://www.actproducts.co.uk/shop/sj10c-cerbera-bi...

But despite the claim that it fit's both 4.2 and 4.5, I can't see how it possibly can. So I'm either going to try to sell it, or find out from ACT if I can buy the tails and get it all to fit properly.

Any suggestions very welcome.

[PuffsBack]

Join the club! Seems to be luck of the draw as to what fits and what doesn't. Even fitting them seems to evoke emotion! (could be 15 mins or could be 10 hours and I am a t$$$er for even suggesting trying to fit it myself)

With the sports pipes lying under the car they look to be a perfect fit but bet they arn't when I mount them!

Edited by PuffsBack on Thursday 19th July 09:39

[Tafford]

Paul - from my limited knowledge the system you have will fit both but you will need the correct length cats / decats to get it line up properly. If the system you have is the shorter 4.2 system you will need the longer 4.2 cats/decats and if it is the longer 4.5 system you will need the shorter 4.5 cats/decats. The flanged fittings that goes on the cats/decats seem to fit either size even though there is a slight difference in diameter between the early 4.2 / late 4.2/4.5 systems

[Byker28i]

That looks like the system I have fitted.As mentioned you just need the right size cat replacement pipes.
This is mine for my 4.2