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-   -   SP exhaust on Strada (/showthread.php?t=35549)

Douglas851 31-Aug-2006 17:01

SP exhaust on Strada
 
Just thought I would tell you of my thoughts after fitting an SP exhaust to my '94 Strada.
I was always unhappy with the standard exhaust, even after fitting Laser race cans. The engine would rev quite freely, but struggled once it got passed 9000 revs. Fitting a FIM chip helped but still not much happened at high revs.
In fact even on the track it was not worth revving passed 9500, it being better to change up.
A few weeks ago I finally got round to swopping the exhaust for an SP one I got the end of last year.
The change in behavior was dramatic. The exhaust sound is much deeper all through the rev range, but more importantly the engine will now reach 10500 quite easily under acceleration and with no apparent loss in the mid-range.
Apart from the exhaust and FIM chip the engine is completely standard.

I would say it is the best performance mod you can do to the standard 888.

Rob B 31-Aug-2006 17:45

Doug,

Is it a 50mm all through system?

Rgds, Rob

Douglas851 31-Aug-2006 17:48

Yes, a complete SP system.

The standard 45mm downpipes fitted with Laser race cans made very little difference, apart from the noise.

Jools 31-Aug-2006 17:54

Hmmmm....not sure why they would make such a difference to the rev limit. I know that freer flowing cans help the breathing, but my 888 strada revs like a rev hungry thing on standard pipes and on the high level cans I have for it.

Are you sure that there was nothing wrong with it beforehand?

pibbow 31-Aug-2006 20:03

Well I've spent all day fitting an Ex Raymond Roache full 50mm system inc nest of vipers! I'm having trouble with a small blow from round the header inserts any ideas on how to stop them. I've had the whole lot off three times and fettled it but still no joy.

Peter

Jools 31-Aug-2006 21:55

Quote:

Originally Posted by pibbow
I'm having trouble with a small blow from round the header inserts any ideas on how to stop them.
Peter


Duct tape? :lol: Anyway, some of us spend our lives trying to get a small...no let's not go there!

Seriously, I read somewhere that you could get some heat-proof sealant that stays reasonably elastic - so I'm not talking about that epoxy stuff they wrap round blown exhausts, it's stuff that doesn't bake rock hard or glue your system together forever. Trouble is, I can't think for the life of me what it's called

Douglas851 31-Aug-2006 22:27

Quote:

Originally Posted by Jools
Hmmmm....not sure why they would make such a difference to the rev limit. I know that freer flowing cans help the breathing, but my 888 strada revs like a rev hungry thing on standard pipes and on the high level cans I have for it.

Are you sure that there was nothing wrong with it beforehand?



There has been no change to the rev limit, it is just that the amount of power it makes over 9000 makes it worthwhile holding on to the revs before changing up. It is not so noticeable in the lower gears, in fourth and above it makes all the difference. Before anyone says 9000 in fourth is quite fast this was on the back straight at Snetterton!

Anyway the deeper exhaust note would have made it worthwhile on its own.

I also read the Moto One Performance website reports very carefully before deciding to buy a 50mm system, see http://www.moto-one.com.au/performance/ My reading of this was that for 100hp you really needed the 50mm headers, incidentally the ST4 runs 50mm headers to achieve its 102hp. This is also supported by the analysis in Ian Falloon's Ducati Desmoquattro Performance Handbook that mentions the correct ratio for exhaust valve diameter vs header diameter, which comes out at 50mm for the 888. Obviously there are many other factors that affect power, but there are not many you can bolt on yourself in an evening.

weeveetwin 31-Aug-2006 23:38

In my experience the Strada reaches its rev-ceiling and flattens off much earlier than the SP - even when fitted with race cans/open air-box & chip.

I've always put this down to the different state of its engine tuning - but maybe it has more to do with its more restrictive exhaust?


(Having said that, the Strada feels much more lively with race cans fitted than it does without).

Mr.R 01-Sep-2006 20:07

Hi,
I use LOCTITE 5699 Flange Sealant spareingly,it seals my 50mm system on the 851/916sp,the race pipes on my 950 full race bevel and the spannies on my tz's in the past. Leave it to set overnight before fireing it up then you should be ok.It's also easy to take apart,i get mine from BSL.
50mm full systems are to big for a Strada 888/851's, you would need hot cams and larger exhaust valves to take advantage of the big bore header system fully,otherwise your more likely to get less power IMHO.

Steve Robins

Jools 01-Sep-2006 20:24

Yeah...I agree with Mr R.

I read through the moto-one stuff regularly to fuel my fantasies. If you read the exhaust thread carefully I think that Douglas851 is 5mm out on his sizings. What the moto-one article boils down to is:

888 Standard = 40mm = strangulation
ST4 Standard = 45mm = Good power & torque for not much cash
ST4 DP System = 50mm = No appreciable gain at the top end and a big hole in the torque curve

In summary it seems the 45mm system is the optimum unless you're gonna tune it further


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