ACT Y piece & Sleeved Exhaust?

[pincher]

I was looking through this thread and noticed that there doesn't seem to be much love for the ACT Y piece & sleeved silencer combination. Why is that?

I have the sleeve already and was considering the Y piece for a bit more volume but am wondering if it would be a mistake?

[Pupp]

The biggest 'silencing' component in the exhaust is the dutbin cat. With that in situ, sleeved exhausts don't drastically alter exhaust volume. Get rid of the cat (or cats if the manifold ones are gone too) and a sleeved exhaust becomes too much.... mine was measured at 121dB (given a 3dB increase represents a doubling of sound pressure level in crude terms, and mine decatted with an oem silencer is now 98dB), are you prepared for a sevenfold increase in volume). Fun for about 5 minutes unless you're 12 and like loud tugboats

[Pupp]

Should add the stock silencer with a full decat sounds wonderful however, especially with a wappy cam

[Fire99]

Personally I think the early Pre-Cat Griffs sound fantastic and just nice volume wise, so I would imagine running an ACT Y piece with a standard exhaust (keeping the silencer) would give similar effects.

[Johno]

Pupp said:

The biggest 'silencing' component in the exhaust is the dutbin cat. With that in situ, sleeved exhausts don't drastically alter exhaust volume. Get rid of the cat (or cats if the manifold ones are gone too) and a sleeved exhaust becomes too much.... mine was measured at 121dB (given a 3dB increase represents a doubling of sound pressure level in crude terms, and mine decatted with an oem silencer is now 98dB), are you prepared for a sevenfold increase in volume). Fun for about 5 minutes unless you're 12 and like loud tugboats

Agreed. I've kept the OEM silencer and fully de-catted. No way would I go for anything else as they just don't sound any better IMO, they just sound really really loud and more agricultural. I don't like the tone at all but plenty of people seem to. I do around 10k miles a year and don't want to be deaf from doing it.

Have sat at the top of Ventoux listening to a fully de-catted 500 with ACT SS manifolds and Y piece thru cherry bomb it sounded amazing coming up, but the whole place stopped to try and see what the noise was (I doubt my appearance 60secs earlier was as quiet as it could have been)

IMO the V8's are plenty loud enough to get you noticed, so flagging your existence even more to the BiB's doesn't appeal to me either

Only change mine well get will be ACT's performance manifolds ceramic coated once my originals give up, but they've done 75k and seem (fortunately) reluctant to perish. I'll definitely keep the OEM silencer and when that needs replacing it'll get one with the full box.

It seems to me lots of people have plumbed for the cherry bombs/sleeved options and then de-catted and now are be-moaning Tim's Y piece when as Pupp has said, the biggest silencer in the system is the cat . . . Go figure.

[AJs Cerbie]

I don't agree with the above and would highly recommend the ACT Y-Piece to compliment the sleeved conversion.

I've personally never understood this reference to "agricultural" sound claimed, and certainly never heard any farm vehicle sounding like this.

Had mine sleeved the day I bought if on the way home, as it was way too quiet for me after having my Cerbera for 2.5 years prior fully decat'd.

If you want a before and after comparison as original topic asked, judge for yourself.

This is original cat and precats in place with sleeved conversion:

http://www.youtube.com/watch?v=eMOaXt6Uapg

This is ACT Y-Pice fitted in place of main cat with sleeved (precats still in):

http://www.youtube.com/watch?v=-SrXrymuw8A

Each to their own I guess, but I prefer the harsher and raspier sound with the ACT Y-Piece fitted and also the enhanced soundtrack / volume, which to me is what TVR is all about

[clive f]

AJs Cerbie said:

This is ACT Y-Pice fitted in place of main cat with sleeved (precats still in):

http://www.youtube.com/watch?v=-SrXrymuw8A

you are not doing yourself any favours by removing the main cat, BUT leaving the pre cats still in place, absolutely senseless IMHO:YES:

[AJs Cerbie]

I will be removing the precats if / when the manifold gaskets start to play up and leak, but for the time being I can't see any issues with leaving well enough alone in the manifolds and having Y-piece fitted.

[Pupp]

AJs Cerbie said:

I don't agree with the above and would highly recommend the ACT Y-Piece to compliment the sleeved conversion.

I've personally never understood this reference to "agricultural" sound claimed, and certainly never heard any farm vehicle sounding like this.

Had mine sleeved the day I bought if on the way home, as it was way too quiet for me after having my Cerbera for 2.5 years prior fully decat'd.

If you want a before and after comparison as original topic asked, judge for yourself.

This is original cat and precats in place with sleeved conversion:

http://www.youtube.com/watch?v=eMOaXt6Uapg

This is ACT Y-Pice fitted in place of main cat with sleeved (precats still in):

http://www.youtube.com/watch?v=-SrXrymuw8A

Each to their own I guess, but I prefer the harsher and raspier sound with the ACT Y-Piece fitted and also the enhanced soundtrack / volume, which to me is what TVR is all about

If the two manifold cats are still in place then that will attenuate the noise, so you will not be hearing the full glory (racket) that a full-on decat and sleeve job results in. It isn't pleasant in most day to day situations

[lewis s]

I will try and get a decent video later of my full decat (V8 Developments) and standard silencer for comparison

[clive f]

AJs Cerbie said:

I will be removing the precats if / when the manifold gaskets start to play up and leak, but for the time being I can't see any issues with leaving well enough alone in the manifolds and having Y-piece fitted.

the problem is you are not doing your engine any favours, by removing the cats you are in effect removing the 3 restrictions within the exhaust system, the biggest of these restrictions being the pre cats, its all very well wanting some extra noise, fine, but without the precats the engine breathes so much better especially as they are located within 7 inches of the front cylinders 1 and 2, hence the better response on the throttle when they are removed.plus the fact that your under bonnet temperatures will be reduced considerably, all big plus` for a healthy engine.

just hope that your precats are not partially clogged or you will get some serious problems

removing the main cat first is like unbloking your drains without unblocking the kitchen sink first!

[lewis s]

I managed to get a short video but unfortunately the quality is a bit st from my camera. Its just uploading onto youtube now

[lewis s]

Ok here is my lame effort

http://www.youtube.com/user/lewissharman100#p/a/u/...

And my video from last week which has a few good noises in it

http://www.youtube.com/user/lewissharman100#p/a/u/...

[Del 203]

pincher said:

Noise envy is a cruel .........

[pincher]

Del 203 said:

pincher said:

Noise envy is a cruel .........

[Johno]

I may say that noise is easy to do, getting the 'right' noise rather than just 'loud' noise is something I may be envious of. . .

Number 7's 4.3 Wedge is the best sounding TVR I know (hate to admit it publicly) . . The 4.3 Griffiths are better than the 500's, some of the 500's out there to my ears just sound harsh, loud and IMO sounded better when they were completely standard.

Each to their own. . .that's the great thing about TVR's.

Also, have to agree with the comments above, if you've not removed the pre-cats you're not appreciating the full effect of a sleeved exhaust with ACT Y piece. Can't quite understand why you'd leave them there, but I'm sure you'll shift em soon.

Here's BB's with ACT Stainless manifolds, no pre cats, ACT Y piece and Offords cherry bom conversion (sleeved in other words), I make an appearance at the end after getting it running . .. Imagine that coming up Mont Ventoux and Corniche des Cevennes at full chat, it was certainly entertaining to listen to

http://www.youtube.com/user/thegriffithpages#p/u/8...

or coming up Ventoux

http://www.youtube.com/user/thegriffithpages#p/u/7...