Changes to Back Pressures

[Dai Capp]

Anyone got any ideas what, in real terms, the changes to back pressures are by sleeving the exhausts on the Tuscan and whether this could have a detrimental effect on the running of the engine.

This is loosely linked to the constant throttle misfire threads that have been knocking around. I wondered whether sleeving and consequent back pressure changes may have something to do with it.

Also, does anyone know the difference in construction between a standard can that has been sleeved and a Carbon Can Co can...

Cheers

DC

[simon-c]

The standard cans have a perforated tube of 54mm o/d and I presume everyone who sleeves standard exhasuts uses 50.8 plain tube as this is a good fit inside.
This means that the inside diameter is now 48.4.

Carbon Can Co cans use 57.15 o/d plain tube, this has an i/d of 54.75 which is 3mm larger than standard.

I think sleeving standard cans may significantly alter the back pressure more than fitting Carbon Can Co cans.

Has anyone out there got the equipment to measure flow rates of standard sleeved cans and Carbon Can Co.

Simon

[Dai Capp]

Interesting, sounds like it would be better to move to CCC cans rather than sleeve, but would the changes to back pressure through sleeving have a detrimental effect on the running or would the greater pressure be absorbed by the silencing wadding...

Any help etc...

DC

[whitey]

the factory whinged at me for sleeving my exhausts back in Dec 00, blaming that on my engine problems. Yeah right, been fine ever since they re-built the engine !

The factory cars, with the Sp6 engine are always having different exhaust combinations on them, so I doubt it makes much effect at all.

[St george]

Now this raises another question. I have had problems, perhaps thanks to a good time at Keevil, with the exaust breaking where the cans join the back box.

I also know talking to other owners that I am not alone in this.

Is there a difference in weight between tuscan cans and others? Does the back pressure change such that it puts more strain on the join?

Also see other thread: www.pistonheads.com/gassing/topic.asp?t=47648&f=5&h=0

Thoughts?

Terry

>> Edited by St george on Thursday 17th July 18:06

[Nick Elliott]

CCC cans & standard Tuscan cans are about the same weight.However adding 16" of SS tube to the standard cans I am sure would add a bit more strain to the exhaust.Even thin walled T316 tube would add about 0.75 KG per side.

Nick

[all black]

ive had no problems with mine after they were sleeved.

I looked at having a de cat but was advised against it by andy at apm for the back pressure reasons