View Full Version : what is the most approprite exhaust size for a 998s engine?
for example running with revised cam timing and approprite ecu?
what is the most aproprite axhaust diameter to run with the above,
one place tells me 60mm the other tells me 57mm and that 60mm is too much?
It would be good to hear from anyone who has run either system, even better if youve ran both at differant times on the same bike.
im looking at buying a bigger system and anm not sure which to focus on?
Depends what your planning to use the bike for? Th bigger bore will breathe better but will knock out some midrange, usually about 5k ish.
The other thing you need to bear in mind is swingarm clearance. The 60mm will more than likely not fit with the stock arm. The 57mm will be tight!
Depends what your planning to use the bike for? Th bigger bore will breathe better but will knock out some midrange, usually about 5k ish.
The other thing you need to bear in mind is swingarm clearance. The 60mm will more than likely not fit with the stock arm. The 57mm will be tight!
its not for racing just trackdays. i have a mag arm so clearnce is hopefully no longer be an issue.
Was this prompted by the 60mm system thats just appeared on fleabay? ;)
Ive been wondering the same...
The guy who's selling the 60mm system says it doesnt come with the "short manifolds." Not quite sure what he means?
Was this prompted by the 60mm system thats just appeared on fleabay? ;)
Ive been wondering the same...
The guy who's selling the 60mm system says it doesnt come with the "short manifolds." Not quite sure what he means?
no but I have seen it.
more prompted by a 57mm system ive been offered, that fits the stretta motor. there does seem to be a few 60mm systems around if you look hard enough!
no but I have seen it.
more prompted by a 57mm system ive been offered, that fits the stretta motor. there does seem to be a few 60mm systems around if you look hard enough!
Are there? Tell me more!
skidlids
16-Dec-2006, 02:30
Was this prompted by the 60mm system thats just appeared on fleabay? ;)
Ive been wondering the same...
The guy who's selling the 60mm system says it doesnt come with the "short manifolds." Not quite sure what he means?
http://cgi.ebay.co.uk/Ducati-Termi60mm-System-TITAINIUM-EX-WORKS916-996-998_W0QQitemZ120065499598QQihZ002QQcategoryZ10448Q QrdZ1QQcmdZViewItem
The short adapters/headers will be the manifolds that bolt to the head and looking at the exhaust they will be Testastretta ones as the header pipes do not have the duel inlet as per 916/996.
And from previous experience with Testastretta manifolds for the 998 I doubt if you'll pick up a set cheap, so check with someone like Nelly, JHP or Moto-Rapido first and get a price.
Kev, do you mean standard 'Stretta manifolds? Like on a 996r or 998s?
skidlids
16-Dec-2006, 09:36
Standard ones on a S or R are only 50mm, the ones for the 60mm exhaust should be bigger, Dallas has a 63mm Exhaust for his tuned 998R and the manifolds are a lot bigger than standard, I think they taper out from the 4 bolt flange that bolts to the head to the full 63mm diameter of the down pipe
these manifold/headers are 680quid.
polarexpress
16-Dec-2006, 11:56
I guy I know in Italy owns a highly tuned 998S and a Termi 54mm full system as well as a Leo Vince 57mm full Ti system.
He uses his bike for both street and track and he says the 57mm system is only marginally better above 9.500 rpm. Apart from that narrow, but crucial, rpm segment the 54mm system is significantly better all across the midrange etc.
Don't fool yourself, though. If you're not into full-on racing you're not spending much time at the rev limiter end of the rpm band and therefore you should focus on allround power delivery instead of peak performance at the top end.
I think you need to ask yourself what you're really after. If it's the bling factor and you don't mind losing engine performance all across the board using a stock 998S engine then go ahead and buy the biggest, meanest system there is.
On the other hand, if you're actually planning on using your bike on the street when you're not attending the occasional track day and you want to maintain the allround performance qualities of your engine the way it is today I'd either stick with the system you already have or tune the engine a bit and aim for the 54mm system.
A large system like the 60mm or 63mm is only going to be useful, performance wise, if you are planning on tuning your engine to the level of a 996RS/998RS.
Yes, these systems allow the engine to breath freely but if your engine isn't capable of delivering the amount of gas flow these systems were designed for you'll lose engine performance instead of gaining power.
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