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-   -   Increasing the bhp (http://forums.sv650.org/showthread.php?t=60060)

sprocket 13-05-05 01:32 PM

Increasing the bhp
 
Just wondering what are the ways of increasing the bhp on the SV. I've looked at full exhaust systems, ie the apkrapovic system is supposed to add around 6bhp, then on top of that you could add a dynojet kit for a possible 10-15% increase. Im guessing the next thing would be a big bore to either 750 or 850.

What else can be done apart from this ... anyone done any of this?

Grinch 13-05-05 01:40 PM

If I was you I'd look at changing the Can, getting the bike Dyno'd, race airfilter, and other little tweaks bofore you go the rebore way. I think a few people on here have also done the ignition advance which adds a couple more Bhp.
You could also look at JHS Racings 650cc with high compression and special cams which gave them about 80 bhp. But its a few bob.

riktherider 13-05-05 01:45 PM

change the cams adds a bit, and the obvios one NOS, but thats a sort of last resort. if you have the money, you can pick up a new set of carbs if is it the older version for about 1500, but it is a lot more.
this site does a lot of mds for the sv http://www.jhsracing.co.uk/start.htm

Ceri JC 14-05-05 11:04 AM

I've seen big-bore kits for 700, 750 and 800. Not heard of an 850.

I looked at it, but judging by the insurance quotes you get for such heavy modification, as well as the cost of the kits (especially the 800)/fitting you could part ex your sv650 and get an SV1000 for the same price.

sprocket 14-05-05 03:23 PM

ah but the 1000's not a twin :D wouldn't get a bore done just yet anyway, probably look at exhaust system better fillter, dyno and advance key to start this could give above 10 bhp extra.

jonboy 14-05-05 03:51 PM

Quote:

Originally Posted by sprocket
ah but the 1000's not a twin :D

:?:


As for trying to increase the 650's power, it's expensive and unreliable. Much better to chop it in for a thou - also a world apart in terms of suspension too.

I would also think the insurance might be cheaper for a thou as opposed to a heavily modified 650.

.

Richie 14-05-05 03:54 PM

Re: Increasing the bhp
 
Quote:

Originally Posted by sprocket
Just wondering what are the ways of increasing the bhp on the SV. I've looked at full exhaust systems, ie the apkrapovic system is supposed to add around 6bhp, then on top of that you could add a dynojet kit for a possible 10-15% increase. Im guessing the next thing would be a big bore to either 750 or 850.

What else can be done apart from this ... anyone done any of this?

Buy a bigger bike... It'll be cheeper in the long run

northwind 14-05-05 03:55 PM

I'd have to call bull**** on any system alone adding 6bhp... Properly jetted with a filter that's reasonable, but a system alone will mainly just mess up your fuelling.

Ignition advance does very little for top end as well, it just brings on the torque earlier. Still nice for road riding hough, and very cheap. There's a lot of reports of it actually reducing top end on a tuned bike.

K3> intake cams and carbed intake cams into the exhaust side in a carbed bike is cheap power, with no setup time... Probably better to use Megacycle or JHS cams but they cost several times more. Putting a carbed model intake cam into the exhaust side of a K3> should help too, not tried that obviously...

I'd probably steer clear of big-bore, more power and more weight at the top end = much more stress at the bottom end, and the SV crank's the limiting factor. For a street bike personalyl I think it impacts on long-term life too much. Hayabusa pistons and thin gaskets/skimmed barrels give a compression boost and less moving weight, but that's a lot of work for not a huge amount of power. Big bore's fairly cheap if you can do your own work, though.

You could probably make a bit of power and response with top end work as well, but I've not really looked at that yet.

The sad truth is, tuning an SV for power's expensive and not especially effective... I've done it, because I enjoy the work as much as the ride, but if you don't you have to look at it objectively... A full system, jet kit (or teka/yosh treatment), filter and dyno time is going to run you £400 used, up to mabe £800 new, for example. That's £800 better put towards suspension and brakes, or towards your next bike, IMO.

Definately work on the suspension before you look at the engine too, if you ask me... If you want to look at it simply in terms of riding fast, I'm absolutely sure I got faster as a result of the Ohlins rear, brake work and front end upgrade, than I did as a result of the extra 10bhp I've got on the bike. Rider upgrades will be more cost effective too...


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