The Penalty Box

The 668 Sport, as well as a number of other models produced before and contemporaneously, is fitted as standard equipment with a two into one into two exhaust system.  There is a stainless steel 'expansion box' fitted under the engine.  This 'expansion box' has been referred to variously as a 'constriction box' and a 'penalty box', as removing it and fitting a Laverda designed X-piece will improve engine responsiveness and smooth out the engine at lower revs.  To fit the X-piece requires cutting the original header pipes by around 20-25 cm (8-10 inches).  There is a Laverda EPROM upgrade which should be fitted at the same time as the  Laverda X-piece.  Additional benefits are a reduction in weight - the stainless box weighs in at around 5 kg, I'm told - and an improvement in engine note.

Louder Cans

Laverda supplied carbon fibre skinned Termignoni exhausts on the 650 Formula.  As far as I can tell, these are not very much different from the standard Lafraconi stainless cans inside, and offer no great performance boost, although they do seem to sound a bit louder.  Some people have taken their standard cans and carefully 'deskinned' them, removed a reasonable amount of the interior, and then put the skins back on.  This makes things louder and should, by reducing back pressure, aid exhaust gas extraction and by inference aid cooling of the head.  Another option would be to have new cans made, preferably of a lighter material.  The standard cans are pretty heavy.  You will need to have them made complete with pipes to the crossover of 'penalty box' as, unlike many other modern bikes, they are not fitted to a flange.  Of course, you could get replacement pipes and cans made that included such a flange mounting system, so you could choose from a range of different cans.... 

An after market solution is the Bora cans.  From Chaz:-

"[T]he Bora does work on 668s/650s - I considered having it done on the Diamante before I decided to go for the [750] Formula. I haven't been able to track down a web site or e-mail address for Bora yet but, if you want details, try calling Baines racing in the UK on 44 1327 858916 or A&M on 44 1462 483211".

Two into One Exhaust

Another option is fitting an after market exhaust system.  The M4 Exhaust two into one system has been strongly recommended by Ferdinand who fitted it to his 668 Ghost Strike - here's what he has to say about it:-

"All I can say is jeez what a difference! I am talking about the new M4 two into one exhaust I have recently implanted into my little Ghost Strike. I have gained power in almost all the powerband. Where once (stock) I had to pop the clutch to get the front end up, now it goes up on roll on. This is even before enriching the fuel mixture! All in all, a great investment... although like most European setups, there was some modification needed. One minor area was that the pipe would NOT FIT! Not on the left side mount, as intended by the manufacturer. With this in mind, my cohort and myself took on the job of moving the exhaust from left side to the right mount. With some proper adjustment and a great welder, it did the trick. The pipe now clears all the obstacles once experienced by left side mounting. (rear set and kick stand obstruction) William Ow should have a set of JPEGs taken of my bike and the pipe for all to look at in the future. I also plan to dial in the mixture next week and perform a dyno test sometime in the future." (1)

The M4 page includes a very promising dyno chart for the 668 Ghost Strike, so obviously it is possible to improve on the standard Laverda exhaust system.  It is interesting to note that the latest Laverda 750 model, the Super Sport, has a two into one exhaust system as standard.

For photos of the RHS exit version on Ferdinand's bike, follow this link.


© Steve Carr, 2001-2007

Site created February, 2000.  Last modified Friday, May 15, 2009

Return to 668 Tech start page

Last updated
30 May 2005