Second hand exhaust or new?

[Banjo47]

Ive posted this also on the Caterham forum, but I'd like to know if exhausts deteriorate over time. I have a Roadsports whose exhaust was broken in a race last season and I replaced it for the last race with a second hand one. Would there be any difference in power if I fitted a new one? Obviously in racing every little helps and I'd like to know the definitive answer please. Thanks

[crankedup]

Just first to mention I'm no expert, however if you have changed the exhaust for a different type/style silencer boxes/altered route, then it is almost certain the back pressure will have been affected. In this case you will need to retune the engine to suit this altered back pressure. The margins are really small however. Wait for a more knowledgable answer too before doing anything.

[Banjo47]

Thanks, but the replacement exhaust is exactly the same as the damaged one it replaced (although older). So the question is exactly that. Would a new one make more (or less) power than one that had been on the car for 20,000 miles lets say.

[crankedup]

A new replacement identical to old system will not make any difference worth noting IMO. My Son races (200bhp)Superbikes and sticks on replacement pipes as and when, as long as he has'nt changed the dynamics of the replacement system he knows the bikes performance will be unaffected either way.A change of air filter for example would have a far greater affect on power delivery and engine breathing than straight exhaust replacement.

P.S. I'd love to have a go racing the Caterhams or its ilk

[Banjo47]

Thanks Cranked up. That confirms what I suspected. If your son races on a budget as I do, its £150 for a second hand unit versus £650 for a new one! As for the Caterham racing, its just bonkers and very competitive, but fun, identical cars, the first 20 on a grid seperated by a second after qualifying makes for very close racing. I'm not sure about the knee down lark your son does though. I recently sold my MV Agusta Brutale but I wouldnt dare do the bike stuff seriously!

[crankedup]

Oh yes the racing is on a budget for sure, what racing comes cheap, none. You sold my dream bike the Brutali!! not that I expect to be riding anymore, old age and all that. Have a great new season, if and when you do Snetterton let me know and I come and watch, have a natter.
David.

[Banjo47]

Havent had the list of races yet but Im sure well be at Snett. Be good to meet you!

[crankedup]

[richardb.jones]

Interesting - my logic suggests that a used exhaust will flow better than a brand new one, as exhaust deposits will potentially fill any pits or weld lines that create air turbulance. I though it was a well known fact that an exhaust 'note' changes (usually for the better) for this very reason once 'run in'. Whether this creates any noticeable power increases I'm not sure..

[Banjo47]

Thanks Richard. I think you may have a point. Also we have to run with catalytic converters in our series and that could deteriorate. I have been advised previously if there is a "racing incident" and the cat converter is damaged - they are quite delicate - they should be replaced. This of course is the problem with racing in a car with the exhaust on the outside!