Diameter of exhaust?

[A900ss]

I've decided to go down the exhaust sleeving route and rather than pay someone to do it for me, I'm going to do it myself and what cash I 'save' from doing it myself, I'm going to spend on tools. (For the past 15 years I've had company cars so my tool collection isn't great at the moment).

Can somebody tell me the diameter of the perforated pipe that I need to remove in the rear box? I assume its 50mm but if somebody knows, that would be great.

Thanks.

[Big Al.]

IIRC 53mm o/d.

[Julesprivate]

I believe it's 2" (so around 50mm) so you'd need something just over that ID to slip over - and they're around 16" long IIRC

[jamienshelly]

Remember to get as much wadding back into the box before re-sealing the box else it will sound even more like a tractor at tickover.

[Julesprivate]

jamienshelly said:

Remember to get as much wadding back into the box before re-sealing the box else it will sound even more like a tractor at tickover.

Not sure how that would do anything if the replacement pipe isn't perforated...

[rigga]

Cuts down the reverberations in the chamber of the silencer.

[Julesprivate]

rigga said:

Cuts down the reverberations in the chamber of the silencer.

yeah, I guess that makes sense...

[A900ss]

Thanks all.

2 inch it is then.

I was going to pack it out with wadding as I have heard of reverberations coming through the cabin if you don't.

Thanks again.

[Alun450]

The cars very loud with the sleeved pipes I'd look for the best material on the planet to compress into it, noise out the back not noise in the cabs what you want, mind you they sound damn awesome sleeved. Let us know how you get on. I've got a heap of grinders but no welder!?! I get the feeling welding that paper thin steel back up might need an experienced hand!

[grngriff]

A900s

Hi I've got a spare sleeved exhaust if you want to try it,only took it off last weekend as mine is fully decatted
And too loud for me,
Your more than welcome to have it,

Pete

Sorry just realised mines a griff yours a chim so different I think

Edited by grngriff on Saturday 4th May 23:15

Edited by grngriff on Saturday 4th May 23:17

[Alun450]

I've been thinking of putting wider bore pipes on to a standard pipe from the silencer box onwards to the rear. Has anyone got any idea what this would do to the power curve/ and sound!? I've often thought the tail pipes could fit the cut outs better! Big/ wider is good! I suppose I should just change the tail pipes!

[jamienshelly]

After welding in the sleeves I just forced all the wadding back in and made sure that when sealing the box the wadding was tight against it, I have a lovely exhaust note and the noise inside is not overly loud, and thats sleeved and pre cats out, and I want a decat y piece for the tunnel runs etc but apparently the mortgage and gas bill are more important.

[clive f]

Alun450 said:

I've been thinking of putting wider bore pipes on to a standard pipe from the silencer box onwards to the rear. Has anyone got any idea what this would do to the power curve/ and sound!? I've often thought the tail pipes could fit the cut outs better! Big/ wider is good! I suppose I should just change the tail pipes!

I did this on my old griff, I didn't go bigger on the pipes exiting the silencer because of ground clearance issues, but changed the wheelbarrow handle type pieces for 3" diam pipe, sounded nice, but the big advantage with going to that size was being able to make some inserts to go right into the ends just to tame it down a bit when needed, these took 10db off which helped on long journeys, as its easier to silence an engine the further away from the engine you can get your silencer.
made no difference to power, so long as the inserts were not in the tail pipes

http://tinypic.com/player.php?v=14nhcea&s=3

the noise is a bit different on this as I`d just fitted equal length manifolds.

[chris1972]

You may find this useful:

http://www.youtube.com/watch?v=TcsE74VZcto

[chris1972]

clive f said:

http://tinypic.com/player.php?v=14nhcea&s=3

the noise is a bit different on this as I`d just fitted equal length manifolds.

That sounds awesome Clive!

[A900ss]

chris1972 said:

You may find this useful:

http://www.youtube.com/watch?v=TcsE74VZcto

I have seen that but thanks anyway Chris.

[Alun450]

Nice Clive, I've got a contact today who Chromed stuff and makes exhausts, I like him already, going to find his secret location,it's in a shed that's all I'll say, now the inserts, that might be the answer to my problems, how to get a good sound without choking it on a trackday. I had a special exhaust for my old Jag, did away with rear boxes, it was terrible at 2000 revs', pathetic and in fact barely faster, the back boxes are massive and silence the car completely yet as there so far back don't offer much resistance! I put the old ones back on.

It's like a saxophone if I played it your ears would hurt if Stan Getz played it your parts would fizz. Same instrument different sound entirely!

I have such mixed feelings about the sound, sometimes I think damn it needs to be louder then other times I'm embarrassed how loud it is! If I lost the depth in my low rev band sound I'd be gutted though. Sod pops and bangs if it's a lighter if louder noise!! Anyway isn't pops and bangs a sign it's running rough, lol. pre ignition or........

[Else]

What we need is a valve in the silencer operated from inside the car so we can choose quiet or loud at will!

You can buy the valves but integrating it into the pipework would be a challenge.

[Else]

clive f said:

...............he noise is a bit different on this as I`d just fitted equal length manifolds.

I'm interested in those manifolds, do you have any pics?

[clive f]

Else said:

I'm interested in those manifolds, do you have any pics?

old write up here, http://www.pistonheads.com/gassing/topic.asp?h=0&a...

pic here. and no I don't make these anymore.