Does 5mm make all the difference?
 

Hi all, back to the age-old exhaust debate again...

I'm considering a very lovely 996bip with a 45mm system and termis...

...only thing is i've seen an odd one with full 50mm system and i wonder - honestly - what is the difference purely from a sound and throttle response/power point of view?

Am i as well with the standard bike c/w 45mm or should i buy a 50mm system just for the sound effects... or am i just talking ****e!!!?

Let the debate commence..... :bouncy:

Who am I to comment as my 996 has a 54mm but my 998 only has a 50mm system. My 955 also has a 54mm system with the 748 that i'm building having a 45/50mm set up. They all look and sound good and with the right chip matched to them they all perform well.
My 916 only ever had a 45mm system with carbon Termis and a Senna Chip, it made a tad over 104bhp on the MotoRapido Dyno and not only sounded sweet but went very well on the roads and track

im running a 45/5omm which looks good and sounds awesome

i think a few mm does make a difference as i beleive the factory racing 998's used to run 60mm's and they wouldnt run larger exhausts if it wasnt for a very good reason

kev, how much louder do your 54mm sound to the 50's,is it a different kind of noise or just louder

cheers

dave

Skidlids just how many bikes do you have?

I make it 13 bikes of which 7 are Ducatis plus enough spares for another

The 54mm system gives a deeper sound, not any louder than some of the smaller systems as I usually try to stick to the ACU noise limits incase I want to take them racing.

A few more than me then.

12 more than me then, thats some collection you have kev. are they all in good working order or like 3 of my old mans that havent turned a wheel in over 20years

Up and running at the moment we have the

998, 996, 600SS, 750SS, R6, GSXR600K2, CBR600FV

Complete but not running is the M620Sie (blooming imobiliser)
Almost finished is the ZXR400L
The 748 and 955 should progress well over Xmas/January
Leaving the TL1000S and the Harris Magnum living in Boxes for a while longer

If only work didn't get in the way of things, but then again I need the money it pays

I think it goes - bigger bore = more top end horsepower
Narrower bore = more mid range horsepower
Bigger bore also equals more noise - have a look at pics of Chillis pipes on his 998.5 - big pipes, smaller outlets to keep within noise regs
I run 45 - 50mm on my 996 - made 127.6bhp on the Moto Rapido dyno
My 916 with same exhaust made 106.8bhp on the Moto Rapido Dyno, so from Skidlids figures the extra bore looks like it's worth 2 or 3 horses - although other factors in the engine and transmission would easily affect these figures

I think there's a bit about this on Doug Lofgrens site http://www.visi.com/~moperfserv/916comp.htm

[Edited on 10-12-2005 by Webcore]

According to the termi website the 57mm, 60mm & 63.5mm exhaust kits are only available for the 998S, and not for the standard 998?