Let's see your dyno charts.

[rossinio]

I got the SV650S dynod at the Hein Gericke open day thing using the portable dynojet dyno. I asked the guy how accurate it was and he said it was the one they use to calibrate their other dynojet dynos around the country. I'm not sure how much of that is marketing but at least its something!

Here is the picture, 72.76hp and 45.14lb/ft seems a little high so not sure how accurate it is. It's worth noting the dip at 5.5k, I can definitely feel that when accerating quickly and am now seriously considering putting the bike on a Yoshi box to lean out the mixture and smooth out that dip (is it for emissions regulations?).

Click to get a bigger picture.

http://img204.imageshack.us/img204/4410/sv650dyno.th.jpg (http://img204.imageshack.us/my.php?image=sv650dyno.jpg)

[rictus01]

OK here's one for you

http://img410.imageshack.us/img410/7250/img183w.jpg

Cheers Mark.

[muffles]

Here's my recent one (power ATW):

http://img10.imageshack.us/img10/7769/img0757ewl.jpg

It's already big :p

[lukemillar]

OK here's one for you

http://img410.imageshack.us/img410/7250/img183w.jpg

Cheers Mark.

Is that an SV, Mark? :wink:

[rictus01]

Is that an SV, Mark? :wink:

Did I say it was :smt102...........;)

actually it's not even a performance run, but a fuel/ air mixture one, so down on topend.

[Jamiebridges123]

, I can definitely feel that when accerating quickly and am now seriously considering putting the bike on a Yoshi box to lean out the mixture and smooth out that dip (is it for emissions regulations?).


Probably is mate. :) :twisted:

[muffles]

Is that an SV, Mark? :wink:

Mine is :-dd

[lukemillar]

Mine is :-dd

Don't tell me........ - an end can and a desnorkelled filter? ;)

[muffles]

Don't tell me........ - an end can and a desnorkelled filter? ;)

Just end can, my friend ;)

[ThEGr33k]

LOL at this thread! :D

Rictus, you got the actual Dyno run files? IF so get rid of the MPH thing on the bottom... Doesn't help anyone! :p


Oh and I take it the smaller ones are part throttle runs?

Which brings me to, why is it that full throttle at lower revs = less power than part throttle? Too much air in or somehow less or what :-?

[ThEGr33k]

It's worth noting the dip at 5.5k, I can definitely feel that when accerating quickly and am now seriously considering putting the bike on a Yoshi box to lean out the mixture and smooth out that dip (is it for emissions regulations?).


You need to get yourself a real Dip at 5K :p

Top line is chip and open Exhaust... Middle is chip and open exhaust with baffle. Bottom is stock chip and baffle.

Got a new chip and open airbox so will get another run soon. :)

http://www.apriliaforum.com/forums/attachment.php?attachmentid=104321&stc=1&d=1237892011

[yorkie_chris]

Just end can, my friend ;)

What no TRE mod? :-P

[plowsie]

What no TRE mod? :-P
Or R6 throttle grip for that matter. :smt081

[yorkie_chris]

Which brings me to, why is it that full throttle at lower revs = less power than part throttle? Too much air in or somehow less or what :-?

Gas velocity not giving enough turbulence for proper mixing, changes in the resonances through the inlet tract. Could be lots of things.

[ThEGr33k]

Gas velocity not giving enough turbulence for proper mixing, changes in the resonances through the inlet tract. Could be lots of things.

Does it do it on all engines?

[dizzyblonde]

I'd show mine if only vista would tell me where its hidden the scan! or indeed if the damn thing has been sent to comp from scanner!

[muffles]

What no TRE mod? :-P

Or R6 throttle grip for that matter. :smt081
Just the end can and plenty of stick-on carbon fibre :p

[yorkie_chris]

Does it do it on all engines?

No some will be different. If you've got flatslides on then its almost a given though.

[gettin2dizzy]

There's a lot of technology to stop that now. AFAIK Yamaha do some fancypants vairable length inlet tract.

Bit naff if you ask me :lol:

[yorkie_chris]

And some of these la-di-da EFI bikes use secondary throttle valves...

[ThEGr33k]

Im running Fuel injection... so no problem with old carbs.

There's a lot of technology to stop that now. AFAIK Yamaha do some fancypants vairable length inlet tract.

Bit naff if you ask me :lol:

They also have fly by wire where you give it full throttle but the butterflies dont open fully untill 9K revs, id imagine this is to do with this same thing.

And some of these la-di-da EFI bikes use secondary throttle valves...

And above. I guess what you got to do is learn what throttle works best at what rev's... not really that hard :D

[yorkie_chris]

Im running Fuel injection... so no problem with old carbs.



And above. I guess what you got to do is learn what throttle works best at what rev's... not really that hard :D

Just greasy wop electrics instead.

If you ever get chance to have a go on a big IL4 with flatslides on it then it's an experience in throttle control, because with those using lots of throttle at low revs is a big no-no.

[ThEGr33k]

Causes flooding at a guess?

[yorkie_chris]

No opposite.
You familiar with Bernouillis eqn at all?

[dizzyblonde]

Standard end can, very old air filter with family of spiders, standard jets, check out the year it were done!
http://i205.photobucket.com/albums/bb45/loubi650/dynorun.jpg

but you don't really need the one that goes with the Art can, re-drilled jets, and a de-snorkelled air filter...too boring, and I don't have it now anyway!

[yorkie_chris]

Mine with main jets 4 sizes too small and an air leak has smoother torque than that lol

[sv-robo]

Haven't had the rr dyno'd myself(yet) but the previous owner had & reckoned it was putting out 127bhp.

[dizzyblonde]

Mine with main jets 4 sizes too small and an air leak has smoother torque than that lol

I reckon it were the spiders that did it:D

[ThEGr33k]

No opposite.
You familiar with Bernouillis eqn at all?

Nope...

Haven't had the rr dyno'd myself(yet) but the previous owner had & reckoned it was putting out 127bhp.

I have to be honest mate... I think he was more than likely talking out of his back side! R6's, the newest ones with full Zorst and PC3 are putting down about 110bhp at the wheel Gixxer 750's are putting down about 130bhp. So unless yours has some pretty serious work done Id guess about 100-105bhp at the wheel. Not that it matters mate, its how it feels, how you enjoy it :D

http://www.youtube.com/watch?v=M9NKYLtYUu4

http://www.youtube.com/watch?v=r7AVB5MaXZk

[yorkie_chris]

Nope...

Basically if you've got a flow of fluid and constrict it, its velocity must rise to get the same volume through a smaller gap. This causes a pressure drop, and is how a carb works. The venturi is the constriction so the pressure drop above the needle jet sucks fuel up and atomises it.

So if you've got flatslides on and whack the throttle open, the gas velocity through the carb drops so much that it doesn't suck any fuel up and the engine bogs. Hence why many get accelerator pumps to give a squirt of fuel as the throttle is opened.

CVs get around it by having the slide controlled by the gas flow keeping the velocity and hence the vacuum around the fuel "suck up" area relatively constant.

[ThEGr33k]

Basically if you've got a flow of fluid and constrict it, its velocity must rise to get the same volume through a smaller gap. This causes a pressure drop, and is how a carb works. The venturi is the constriction so the pressure drop above the needle jet sucks fuel up and atomises it.

So if you've got flatslides on and whack the throttle open, the gas velocity through the carb drops so much that it doesn't suck any fuel up and the engine bogs. Hence why many get accelerator pumps to give a squirt of fuel as the throttle is opened.

CVs get around it by having the slide controlled by the gas flow keeping the velocity and hence the vacuum around the fuel "suck up" area relatively constant.

Ah right a name for it, I understand that, makes sense. I can see why the CV's came along, how long since flat slides were used?

[yorkie_chris]

Still used now for some stuff. On the GSXRs they used flats for all the slabsides until the slingshot came out in 88.

They still use flats now on tuned motors and huuuuge ones like lectrons for drag racing.

[ThEGr33k]

Still used now for some stuff. On the GSXRs they used flats for all the slabsides until the slingshot came out in 88.

They still use flats now on tuned motors and huuuuge ones like lectrons for drag racing.

So whats the advantage? Great fuel flow or something?

[yorkie_chris]

Bah any carb can flow more fuel than you need.

They're great for airflow. Very low restriction, so great for power. And a hell of a lot lighter than EFI. Also easy to tune.

[ThEGr33k]

Bah any carb can flow more fuel than you need.

They're great for airflow. Very low restriction, so great for power. And a hell of a lot lighter than EFI. Also easy to tune.

Well its just drag machines need fuel flow, air flow is a given with some of the blowers they stick on them... BIG **** :cool:

[yorkie_chris]

Yes if you consider boost = air in the cylinders. This is not true.

Static pressure is NOT the same thing as mass flow.
By making a better flowing head, carbs etc (if we're on about blow-through) then the boost psi is actually reduced for the same airflow. Generally if you run a turbo at lower boost for the same mass flow, then you put less heat into the mix.
Cooler mix means you're further from detonation limit, meaning you can crank the boost up a bit more.

Also guys running draw-though. HSR42 is common carb. This is a flatslide carb, and on a drawthough setup you've still only got atmospheric pressure pushing the charge into the turbo, so a better flowing carb means more power.

[lukemillar]

Or R6 throttle grip for that matter. :smt081

:winner:

Genius! How could I forget the ultimate SV BHP mod :p

[Jamiebridges123]

I can relate to what you're saying Chris about opening the throttle too much..

5th gear on my SV, pulling from 30. Open the throttle (it's an R6 one, that's an extra 50bhp right there) and it goes. But if I let off to say, 70% it'll pull much harder till I get higher in the revs..where obviously if I open it more it'll move quicker! :rolleyes: