Some Curvy engine tuning advise needed.
 

Hello all,


Dutchy here planning on adding a Leo Vince SBK E-approved slip-on onto my street use only '02 Curvy (mainly for sound reasons, but any gain in power is welcome). I was also considering to look at the jetting side of things (my throttle response is very on-off at low loads and rpm) and if I was doing that any way I might consider the cam swap as well. According to this article (http://www.geocities.com/catpoopman/sv650_snorkel.html) desnorkeling is not advised for slip-on only. I don't want to spend to much money on it, so what would I be looking at:

• Leo Vince SBK slip on (245 euro)

• Main jet's from 137.5 to 140 mm (Part Number N102.221-140, 10 euro)

• Pilot Jet's from 15 to 17.5mm (MIKUNI PN: KVM28/486-175, 10 euro)

• Cam swap (150 euro)
• 2.5 turns on the A/F screws, 2 shims under needle

So questions would be:

• Are the above assumptions correct?
• Any comments on the Leo Vince exhaust choice?
• Correct in assuming air filter desnorkeling won't help much with an E-approved slip-on?
• What kind of hp gain to expect from a K&N filter?
• Drawbacks on a race filter for street use?
• Jet sizes make sense (142.5mm main better)?
• Cam swap useful for this set up, or additional modifications needed to make it worthwhile?
• Some say that the intake to exhaust part of the swap doesn't do much, any thoughts on that?
• Is 6-8hp gain (1.5 hp exhaust, 1.5 hp jetting, 3-5 hp cam swap) a reasonable expectation with these mods?
• For about 415 euro I'm get a much nicer sounding bike, smoother throttle response and a stronger engine throughout the rev range?
• Any suggestions where to get these part for main land Europe, webshop, dealer?
• Anything I need to know before proceeding?

I would be very grateful if people could shed some light on some of the above questions.

Re: Some Curvy engine tuning advise needed.
 

H'mm The wisdom on the ORG says you won't get anything from the K&N filter, you'd be better off getting a BMC race filter i you want any gains.
Neither are you going to get anything from just adding a slip on can, it's the header pipes that stiffle the engine, so an M4 system is what you need.

Cam swap will give you more HP, and the cheapest way on you're 02 curvy is to replace the inlet cams with the exhaust cams from injection model.

I'm sure you'll get a more comprehensive answer from some one else.

No point trying to add to much extra power as the bottom end can't cope with too much extra power

Re: Some Curvy engine tuning advise needed.
 

You could do it.

But the catpoopman site is a load of catpoop for jet sizes. No idea why unless he lives below sea level. With a desnorkelled OEM or a BMC race RS (best one) probably jets 150 - 160.

Leave the mixture screws alone. Leave the needle alone until AFTER you have selected the best main jet. Otherwise you will chase your tail for DAYS until your head eventually falls off.

Having done similar myself, I would do the cam swap, fit the slipon, and leave the rest alone until you can get a decent full system.

Re: Some Curvy engine tuning advise needed.
 

Any drawbacks to using a race filter over a street one?

Yeah, perhaps find a good not too expensive second hand one, thanks.

But according to that site, desnorkeling is not much use with a standard or slip-on exhaust?

Sounds like a plan.

Well I could get a full sustem now, just that I don't want to spend too much on it. Any ways thanks for the answers.

PS. BTW what about Gladius intake cams on a Curvy, I heard the have even more lift than the Pointy ones?

Re: Some Curvy engine tuning advise needed.
 

One more question: did LeoVince ever make a full system for the 99-02 SV650(S)? It's not listed on their side and I'm having a hard time looking for 2nd hand ones too.

Re: Some Curvy engine tuning advise needed.
 

i think dave2004 had a full system on his bike

Re: Some Curvy engine tuning advise needed.
 

LEave the pilots alone as well. No need to change them.

Re: Some Curvy engine tuning advise needed.
 

Yes they did, and it is possibly the best out there.

Unless it is US spec. UK one comes with 17.5 pilots, USA model got 15s I tihnk, and a different needle.

Re: Some Curvy engine tuning advise needed.
 

Ok thanks, I'll keep searching then. I also understood they provided the best output and apart from that I prefer the mat finsh look as well. Matches very nicely with the frame in my view. Just hope that those older models allow the logo to be removed too.

One would expect a Dutch market model to have the same as the UK's, but no a big issue I understand, thanks.