Stage 2 cams (again) - dynos!

[johnnyrod]

If we haven't done this one to death.... did the cam swap at Christmas (thanks Northwind and Itching to go Joe for the info beforehand), got it on the dyno on Saturday morning....

http://www.johnnyrod.co.uk/dyno3.gif
(170kb)

and this is the bit I really like...
http://www.johnnyrod.co.uk/svvs748.pdf
(6kb)

max power figure for the 748 is 90bhp which comes from revving a bit further than the SV.

Brm brrrrrrrrrm!

PS I know it's not the most scientific, but putting it all in Excel made it easier to overlay.

[GSXR Carlos]

wow, how much?

[jonboy]

Fab torque curve ;).

I wonder how much this will affect reliability?


.

[Skip]

Fab torque curve ;).

I wonder how much this will affect reliability?


.
Northwind is always pulling his to bits - so I guess not! :lol:

Sounds like an interesting upgrade - is it really just as easy as swapping the cams - no other parts required??

[Mike1234]

Good curve although displaying uncorrected dyno figures is absolutely no use to anyone as we cannot interpret the numbers to anything meaningful.

Have you got the corrected figures to hand?

[northwind]

Yup, I'm with Mike, do you have a before/after? I changed too many bits at the same time, so when I do get it dynoed again there'll be no way of telling what's cams, what's the filter, etc... Bit of a shame but it all went a bit wrong.

But y'see the good bit? The way it doesn't have a peak anymore, just a climbing line to the end? That's why I like the cam swap so much. IMO a broader peak is better for a street rider than sheer power at a point, and this mod can basically remove the tail-off completely. (there's still a a higher peak,but it'd be at about 10,000rpm or above) It almost certainly does cost midrange and low end, but not so much as to bother me (and I use the midrange a lot)- still stronger with the ignition advancer and cams than it is stock anyway.

'Tis nearly as easy as just swapping the cams- K3> intakes into het intake side, and your old intakes into the exhaust side (none of the exhaust markings will line up, but that's not a problem) You'll also want a set of cam chain tensioner adjuster gaskets- they're sort of reusable, but there's no point in cutting that corner. £135 or thereabouts all in. (if you have a rattly tensioner, it's a good time to replace it too).

Best practice would be to replace the buckets as well, as that's a matched wear deal, but I didn't bother- high mile SVs show no significant cam or bucket wear even after 100K, so a certain of accelerated wear doesn't concern me too much to be totally honest.

It's possible you'll need to change the shims too, if your post-install clearance check isn't good- seems that most people don't need to, I didn't.

Reliability... Well, like anything else, more power = more strain. But it won't turn your engine into a ticking time bomb, put it that way. I might have my bike in bits constantly but I've never had to go back to the cams since I did it ;) Almost any amount of tuning will reduce your engine's lifespan, but we're talking here about a motor that'll do 150,000 miles without heroic maintenance or any rebuild work. A marginal decrease in longevity isn't something I worry about in the least, personally.

Compared with, say, a 700cc kit, the reliability impact is trivial... And compared with a full system, filter and rejet, the cost is trivial. It's a good mod. But remember, if you get it wrong you'll bend all your valves :shock:

And if anyone with a K3> is thinking of doing the same with the cammed model's intakes in their exhaust side, I've got a set in the garage, £50 including the buckets ;)

[johnnyrod]

Mike - not sure how the correction bit works, this is what one run on a dyno I've not used before gave me. Here are the previous ones:

http://www.johnnyrod.co.uk/dynoruns.pdf

"Stock" is really with the Akropovic full system but no rejetting, run at JHS as a baseline. "PDQ" is with Akro pipe, K&N, Dynojet kit and JHS ignition advancer (and 2nd/3rd gear retarder disconnected, for what it's worth) as set up by PDQ. "Cams" is after the cam swap, not made any other engine mods, run by Chris Gunster in Grimsby. Does that help, or what are you after for correction? I gave the guy the bike and he ran it, and we looked at fuelling, I don't know a lot else.

Swapping job was pretty easy, checked all clearances afterwards and they were spot on, have also heard this from other people who have done the same job. Fuelling seems to have been unaffected by the cams (which is a surprise), it does run a touch rich 5000-6500 on full throttle (about 12:1 in stead of the 13:1 optimum) but I was told it was unlikely to worth getting that sorted, and part-throttle was spot on all over.

And it sounds different, and goes different!

[northwind]

The sound :) I meant to say about that. Hotter exhaust cams = fantastic overrun sounds. Lovely. Also a bit loud, it was the cam swap that made me sell my ridiculously offensive Kenz Sport twin system ;)

[SV650Racer]

When i get mine done i will post my dyno sheets of before and after both from the same dyno. Fingers x if all goes to plan should be done end of Feb.

Cant wait 8)

btw its a thunderbike not a minitwin SV650 so tuning is allowed!

[Robw#70]

Mike - not sure how the correction bit works, this is what one run on a dyno I've not used before gave me. Here are the previous ones:



Still doesn't say much, 3 graphs at 3 different dyno's!

Nick at PDQ always uses EEC correction, not sure about the others but at least they're all Dynojet.
If you look at the top of the graph (original printout) it should say, it will be three letters:-
EEC
SAE
DIN

cant remember the rest

[Robw#70]

When i get mine done i will post my dyno sheets of before and after both from the same dyno. Fingers x if all goes to plan should be done end of Feb.

Cant wait 8)

btw its a thunderbike not a minitwin SV650 so tuning is allowed!

How far are you going with it?

Got a bit carried away with mine, was all going well, working on it being 160-165kg Until I weighed it the other night It was 145kg :shock: :shock:

Admittedly it had no pistons or cams, but the exhaust, coolant and extra 5l of water were put on it.

I think it might end up with a big chunk of steel bolted underneath or std cams, ive stopped spending money on it now, but its still a pile of bits, hope its ready for the first one, allbeit multicoloured, If not i'll be hiring/blagging a bike for snett.

[SV650Racer]

How far are you going with it?

Got a bit carried away with mine, was all going well, working on it being 160-165kg Until I weighed it the other night It was 145kg :shock: :shock:

Admittedly it had no pistons or cams, but the exhaust, coolant and extra 5l of water were put on it.

I think it might end up with a big chunk of steel bolted underneath or std cams, ive stopped spending money on it now, but its still a pile of bits, hope its ready for the first one, allbeit multicoloured, If not i'll be hiring/blagging a bike for snett.

Wow sounds good, thought mine was light at 153kg wet and all together!. Mind you am now working on getting some more off it now it doesnt have to be minitwins legal.

Just looking at getting it upto a safe 80bhp not much more as dont want to have a bike that needs anymore attention than a minitwin.

I am sure more things might get done throughout the year dependant on the bank balance :wink: ..cant wait to get out there though!.

You up for comming to Croix and entering the Forza's..me and Will are thinking about it! 8)

[johnnyrod]

Okay checked out the dyno sheets:

stock/JHS: EEC
PDQ: EEC Horespower
cams/Chris Gunster: not sure will find out some time.

The torque figures for the two non-stock runs are almost identical at the bottom end/lower midrange, and my trouser dyno tells me there's no change there. Will be interested to see the results from SVracer using the same dyno. I was pretty chuffed it was going quicker so thought you'd like to see, and the fuelling doesn't really need adjusting, I know using different dynos isn't ideal for comparison but how big a difference can there be in measuring the same thing?

[PeterM]

Good work. It's a great mod isn't it?

We had a bit of a southern Australia SV get-together recently & I really noticed (so did everyone else) the lovely over-run sounds from my bike compared to others. 8)

[xj/frosty]

I did the JHS stage 2 cam/dynojet/advance key/M4 pipe thing on my 02 race bike
on the dyno Shes pulling a reliable 80hp (dynojet dyno readings)
Under our race rules Im NOT allowed to modify my airbox or fit an aftermarket filter.
Under racing conditions its very much a case of --the same but more -the curves havent changed but theyre just higher
She's overfueling a bit at the bottom end--but what the hey-She spends no time down there

[r4ce_e3nd]

instead of making another new thread about it, I will continue here with my questions... :D


I just read about the cam-swap (K3-intake into curvey-intake end intake to exhaust) and I am already very interested. :lol:

but, some questions. I've read that the swap isn't very hard to do. I recently checked the clearence of the valves myself, so that I can do. the only thing is how do you know you've put the cams in the right place/angle..... because I don't want to brake my valves :?

I will also install the ingition advancer key at the same time. I have already a K&N + modified air-box (extra holes) + dyn-jet stage II + open exhaust. I will propably need to tune my carbes (I don't know much about those animals), right? but because I don't know much about it, I will let this done by my local tuner, who has a machine to measure the bhp's (tell me the name pls :lol: ). know, with the current set-up I have 74bhp at the rear wheel, will I get the 80bhp, with the right tuning? :? (please say yes :P )

about the install for the ignition key advancer: can someone post me a pic about the tool I have to use to remove the fly-wheel, because I have NO clue what it looks like...

and last but not least, where can I buy the intake cams of a K3> model? I read somewhere that I can buy them in America for $200, or does someone know a place in Europe for more or less the same price?
maybe on ebay, but didn't find nothing today.


gracias :wink:

[northwind]

You can buy them from any Suzuki dealer, it comes to about £130UK. The cams have timing marks on the ends, so fitting the intake cams are fairly simple. When you put the old intake on the exuahst side, your markings won't line up but you can work out how they should be by simple comparison to the old exhaust cams- what you're basically doing here is making sure the lobe is in teh same place. You turn the engine over by hand (with a wrench on the end of the crank) before you fire it to make sure nothing's clashing.

Worth mentioning, maybe, that I have a spare set of carbed model intakes still, which would be cheaper than K3 intakes, but less godo to be fair.

The rotor puller is more or less a big hardened bolt... Nothing too clever.

You drilled holes in your airbox?

[svrash]

,,,You drilled holes in your airbox?

Yeah :? :? Why?

As for the K3> cams, if anyones got a set let me know 8)

I've put a set of intake cams on the exhust side and the over run noise is worth doing it, i think it give more power at the top of the rev range but i have no dyno charts to prove, just that i keep running in to the rev limiter :oops:

[r4ce_e3nd]

ok, that was a stupid question, about the fitting of the cams, I should have touhgt about it... but thanks anyway ;-)

,,,You drilled holes in your airbox?

Yeah :? :? Why?


I didn't do it, my tuning-guy did that and I trust him on this one... but the holes ar befor the filter :!:

As for the K3> cams, if anyones got a set let me know 8)

hey! I was first! :twisted:

[svrash]

ok, that was a stupid question, about the fitting of the cams, I should have touhgt about it... but thanks anyway ;-)

,,,You drilled holes in your airbox?

Yeah :? :? Why?


I didn't do it, my tuning-guy did that and I trust him on this one... but the holes ar befor the filter :!:

I've cut the hole right back, as far as the filter, more of a exaggerated de-snorkle-do-da

[northwind]

I didn't do it, my tuning-guy did that and I trust him on this one... but the holes ar befor the filter :!:


Cool... So what exactly did he do?

[r4ce_e3nd]

are there any negative concequences about the mod? I've heard that you will need to check the clearence of the valves more often and with a better tollerance than standard...


I didn't do it, my tuning-guy did that and I trust him on this one... but the holes ar befor the filter :!:


Cool... So what exactly did he do?
he drilled wholes in the plastic that covers the filter. I don't know how many he drilled and the size, but I think 6 or 8 and diameter of 8-10mm. he also was so kind of turning alumunium pieces to raise my tank and this looks very nice (befor I used washers) :)

[johnnyrod]

No reason to check clearances any more often than usual. Check the clearances after you fit the new cams, my experience (and a lot of others' too) is that the same shims did the trick.

There is a thread on www.svrider.com forums with lots of info on this. There are alos pics of the cams with timing marks, but to double-check I also worked out the marks myself by looking at the lobes.

If the carbs were right before the cam swap then they should be fine afterwards, but get a dyno run anyway, as you want to see the extra power, and confirm that there aren't any carb issues hanging around. You'll see a big difference if you're fitting the ignition advancer at the same time, it'll be a totally different bike. Both mods make it louder too.

[northwind]

Ah, that makes sense. So it's basically similiar to the desnorkel mod... But with drilled holes instead of entierly removing the snorkel.

As far as consequences... As far as I'm aware, there aren't any as far as clearances are concerned. The higher lift and duration affect what happens when the valves are open, the clearances are most critical when the valves are closed. If the clearances were wildly out then I suppose there'd be a risk of your valves tap dancing on the cylinder heads, but not dramatically more than stock- and we're talking ridiculously bad setup here, not just "a bit out". SV heads are quite roomy :)

[r4ce_e3nd]

thanks for the advice!

which realy concerns me is the fact that it will make it louder, because I subscribed me for a trackday on our circuit Zolder and they have very tight dB-limits (max 94 dB if I remember well) and last year I had a warning with the setup I know have (with a 2nd warning you can go home :? ): K&n dynojet and MIVV exhaust + dB-killer. but, the fact is that I need to replace the damping-stuff of the exhaust because I noticed some darkning of the carbon-fiber and it gets louder and louder, which means the damping-stuff is burning up. maybe I will go with the stock exhaust to be safe...


I will check svrider.com too :wink:

[r4ce_e3nd]

got these timings from someone, maybee someone can use them, because I'm not familiar with these things:

SV 99-02
in: befor UDP 28°/after LDP 62° (lift 8.1mm)
out: befor UDP 43°/after LDP 24° (lift 6.1mm)

SV -03
in: befor UDP 33°/after LDP 66° (lift 8.7mm)
out: befor UDP 55°/after LDP 66° (lift 7.3mm)

UPD: upper dead point (I don't know the exact translation, but it's the position of the piston)
LPD: lower dead point

greets

[r4ce_e3nd]

ok, I've done it :D

I feel a real boost starting at 7-8000 rpms and those cam chain tensioners are sneaky little *******s...

soon the ignition advancer, but first I have to get the right bolt to remove the flywheel (is this the correct word? :? ), an M20 x 1,5 right?

I will also do a dyno-run to see the difference.