Reliable 85bhp from a Curvy?

Originally Posted by yorkie_chris

Personally, I'd be looking for a set of flatslides for best hassle to gains ratio.

Flatslides bring their own problems. We are talking about a road machine here to it has to be user friendly. Once the CV carbs are modified they work really well.
james

Originally Posted by andrewsmith

It was something I looked at last year. But it was based on using a blown motor. With your exhaust system get the bike dyno'd prior to tuning the motor.
From memory Rictus had a 700 kit in a curvy and it liked to drink oil.

As a side, get onto JHS Racings website as they're doing a set of forged pistons for 200

We are also having a special at present on conrods. http://www.jhsracingstore.co.uk/PBSC...ItmID=15374278
But please do remember we have loads of parts which we never advertise as we just don't have the room nor time to. Just contact us we will try our best for you.
james

[andrewsmith]

Originally Posted by jhsracing

We are also having a special at present on conrods. http://www.jhsracingstore.co.uk/PBSC...ItmID=15374278
But please do remember we have loads of parts which we never advertise as we just don't have the room nor time to. Just contact us we will try our best for you.
james

I wish I had the cash to stick a set of rods and pistons and a set of naughty cams in

We are the European distributor for Spears Racing parts & have been winning Supertwin championships here in Ireland for some time now.
We can easily reach 85 plus bhp with reprofiled cams, Spears/CP standard bore, high compression pistons, Carrillo A beam rods - lighter than H beams & good for 90bhp per rod, heads gas flowed & set up on dyno.
There is no machining of heads or cylinders required.
Flat slides are the answer if you are looking for maximum power, but aren't as flexible as CV's.
Feel free to give me a call if you want a chat about your engine.

Brian
www.moto-tech.biz
2014 Adelaide Masters Champions.

[rowdy]

Originally Posted by jhsracing

Dyno power outputs that's a big subject !


ALL dyno's will have a degree of positive and negative feedback but what I have seen is that operators of Dynapro dyno's seem to be very quick to run down the Dynojet dyno but do seem to forget these are the industry standard within the motorcycle trade. (that's my view)
As to power output from a k3 sv650 machine your figure is acceptable and where it should be at but a lot of factors can be brought into play,such as tyre pressure, chain tension, air temp and air supply and exstraction of the dyno room. There is loads of data on this subject on the net if you want to do some research.
hope this helps
james

was chatting to a mate the other day and he was saying you can gain 1bhp depending on the chain used, and could feel a drop in power when the chain needed adjusting. As I mentioned, the guy that was operating the dynapro was the guy that made them, so I guess he would think they are better than dynojet dynos, but he wasn't bragging about his dyno or slating any other at the time. As for the power mine was making, he said he had dyno tested a lot of sv's at mini twin events and that mine made good power and was at the limit for legality were it to be a mini twin race bike.

Originally Posted by johnnyrod

Around 5-10% sounds about right, but as James says, there are a load of corrections and influencing factors, plus you do a set of runs back to back and you'll get a variation in numbers straight away. What you're after is optimising the performance and the seeing the gains with the mods, rather than aiming for a specific number.

Rowdy, peak power is usually just around the redline, as the torque curve is fairly flat, hence the power curve (torque times revs) climbs all the way. Even the drop-off at higher revs is slow compared to the rate of revs rising so the power curve continues upwards. You should have had a printout, but you can see plenty on t'internet anyway for various SVs.

James I've still got a K&N, not the first gen crap one, the next one, what sort of difference (%) do you reckon the BMC RS is worth?

It would have been nice to have had a printout, but like you say it was not about chasing numbers, just to fine tune the bike to the exhaust.
A friend of ours had just got a dyno from mark, primarily to test engines for go kart racing. The wife had arranged for me to ride up to Steve Jordan and get a full m4 fitted for a birthday present, and then to take it back down to our friends to have mark come over with his box of tricks, plug it into the ecu and fettle it, and to show our friend how to use the dyno, so wasn't able to get before and after figures.

[yorkie_chris]

Originally Posted by jhsracing

Flatslides bring their own problems. We are talking about a road machine here to it has to be user friendly. Once the CV carbs are modified they work really well.
james

They sound awesome and have a lot of character. I've never had some on an SV but did have on an exup thou, they were ace once you'd got the hang of starting them.

Can you get CVs to give that same instant response? I've never managed to.

You won't get the same response from CV's as you can from well set up flat slides.

Brian
www.moto-tech.biz
2014 Adelaide Masters Supertwin Champions.

Oh yes you will. The cv carbs as I said have to be modified to get great results without sheading loads of money.

Originally Posted by rowdy

was chatting to a mate the other day and he was saying you can gain 1bhp depending on the chain used, and could feel a drop in power when the chain needed adjusting. As I mentioned, the guy that was operating the dynapro was the guy that made them, so I guess he would think they are better than dynojet dynos, but he wasn't bragging about his dyno or slating any other at the time. As for the power mine was making, he said he had dyno tested a lot of sv's at mini twin events and that mine made good power and was at the limit for legality were it to be a mini twin race bike.


It would have been nice to have had a printout, but like you say it was not about chasing numbers, just to fine tune the bike to the exhaust.
A friend of ours had just got a dyno from mark, primarily to test engines for go kart racing. The wife had arranged for me to ride up to Steve Jordan and get a full m4 fitted for a birthday present, and then to take it back down to our friends to have mark come over with his box of tricks, plug it into the ecu and fettle it, and to show our friend how to use the dyno, so wasn't able to get before and after figures.

To be honest just fit the full system and don't touch the ECU it does not return the results and you are only changing the basic fueling.
jh

[yorkie_chris]

Originally Posted by jhsracing

Oh yes you will. The cv carbs as I said have to be modified to get great results without sheading loads of money.

What do you modify on them?