BHP

[richie95]

Hi
i have a stock sv650s.... k3, whats can be done to maximise the BHP and tune that babay up....

richie :smt118

[fizzwheel]

A new end can will get you started. Then you have options depending on how much money you want to spend.

Air Filter will give a bit more
Full Exhaust system will give a bit more on top of that
Then you could get the stock ECU remapped or Fit a power commander that'll liberate a few more BHP.

After that your looking at rebores, and then it starts to get expensive and IMHO its not worth doing, theres only so much BHP the bottom end of the SV engine will take before it goes bang.

If you want a stupid amount of BHP its just not going to happen so if thats what you're after buy a bigger bike...

[yorkie_chris]

How fast can you afford to go?

Full system; £500

That is pretty much the first level of tuning, nothing else is going to give you any impressive gains, though boring the throttle bodies out a bit can add some grunt according to zadar.

[richie95]

i went on 'chewys' website, and he has these spocaers for the petrol tank so miore aitr gets in, he reckons this gives more BHP... any views?

[richie95]

i just spent 600 on helibars and ermax belly pan/hugger/undertray etc... so no spare money at present, but what is the best system?

[fizzwheel]

How much more BHP do you want to liberate from your engine ?

[richie95]

dont know, just wondering what you can get??

[fizzwheel]

dont know, just wondering what you can get??

That depends on how your budget. Theres no hard and fast answer.

[yorkie_chris]

i went on 'chewys' website, and he has these spocaers for the petrol tank so miore aitr gets in, he reckons this gives more BHP... any views?

Yes, but it's marginal.

How much power do you want?

[yorkie_chris]

dont know, just wondering what you can get??

110bhp, I think there's some French bloke has done it.

It's like warfare that though apparently. Short periods of sheer terror followed by long periods of rebuilding.

[fizzwheel]

110bhp, I think there's some French bloke has done it.

It's like warfare that though apparently. Short periods of sheer terror followed by long periods of rebuilding.

Nicely put :D

I think the best sensible mods you can make are

1. Full Exhaust system
2. Some kind of aftermarket air filter
3. ECU Remap or Power Commander

You're talking what I would consider a large amount of cash to do this though easily over £500 I would have thought.

I never bothered with my SV, I just fitted a race slipon can to make it sound better and left it at that.

[yorkie_chris]

Yes it's stupid money.

No point having a power commander though it could save you money on dyno time as you can adjust them yourself AFAIK.

Got a quote a while ago, M4 system for the curvy was going to be £550.


As has been said many times before. Spend the money on suspension.

[richie95]

whats the best slip ons.....
i can always trade for the fat sv1000s...

i saw a nice 'high level' M4 Exhaust on ta inta-web.... any views?

[fizzwheel]

whats the best slip ons.....


Have a read of the exhaust section for some more views

http://forums.sv650.org/forumdisplay.php?f=137

Again it depends on your budget... and what you like the look off...

[yorkie_chris]

There is no best slip-on. They all do the same thing and won't give any extra power.

[21QUEST]

Best way to maximise HP is to make full use of what you already got available...and the best bit about doing it that way?..... it's free :cool: :mrgreen:

If you want a fruitier sound, get a Remus Revolution(don't forget to leave the baffle in) and then refer to above ;)


Ben

[ThEGr33k]

whats the best slip ons.....
i can always trade for the fat sv1000s...



Swap it for a Falco ;)

115BHP at back wheel stock and 125 with a couple of resonably cheap mods... 145BHP & 85ftlb torque at back wheel with 1060cc kit. MUHA HA HA :offtopic:

With stock displacement 80bhp is about peak with cam, TB and exhaust work, plus the fueling sorting with a PCIII.

[yorkie_chris]

You can get more, but then you're prodding the bottom end with a big stick

[Dangerous Dave]

See my signature below for full blown tuning...

110bhp, I think there's some French bloke has done it.
Might be an English bloke as well soon, on the road too!

[Bear]

Best way to maximise HP is to make full use of what you already got available...and the best bit about doing it that way?..... it's free :cool: :mrgreen:

+1. Do you use all the power of your bike a lot? If so maybe look at getting a new one. If not...

Power gains on a bike like the SV cost a lot for very little noticeable power increase. You may be able to tell people that you have a bike with 5 BHP more, but I doubt you'd actually notice any difference. PBHP (psychological brake horse power) is an entirely different thing however...

[bronze svrider]

got my sv650 k3 too 85 bhp which i think is half decent:cool:

[21QUEST]

got my sv650 k3 too 85 bhp which i think is half decent:cool:
What did you get done to acheive that? ;)


Ben

[bronze svrider]

twin pipe conversion full system by laser found here http://forums.sv650.org/showthread.php?t=68747&page=133

power comander upgrade on air filter oil filter etc

[21QUEST]

Cheers but if that's all it has had done, then no way is it making 85....not with having a 33bhp ECU 'n all :smt003 ;)


Ben

[yorkie_chris]

Lol.

Was the dyno owned by the same people who fitted the cosmetic pipes for you?

[Viney]

Best advice, is loose some weight from you not the bike.

Upgrade the brakes and suspension, then you can out handle and out brake everything else, then get some advanced training. Then and only then start with the bike :)

[Alpinestarhero]

+1. Do you use all the power of your bike a lot? If so maybe look at getting a new one. If not...

I was about to ask the same thing :D There's no point in splashing out loads for more power if you are not using all the power you got already.

(on a personal note, I find the 70 odd bho of a stock SV is more than enough for Her Magesty's highways. I finally got the chance to hold the throttle wide open in fourth gear for the first time on full power the other week, and decree'd that my motorcycle is more than fast enough...and I didn't get above 9000 rpm)

As others have said, there are some relativly easy modifications you can do (ECU, full exhaust system i.e. can and downpipes, just an end can won;t do alot, maybe a better air filter) and then there are some more difficult ad more expensive things you can do (cam upgrades, big-bore engine modifications etc). The point is though the SV isn't about copious amounts of power; its a little bike best suited to twisty B roads and A roads, where having confidence in your bike and yourself accounts for much more than how many horses you got underneath you :D

I would recommend sorting the handling out. The SV handles fine, but when you start pushing it can get difficult. Front fork internals, new rear shock (even if its from another bike e.g. ZX-6R shock), and - if you got the cash - lightweight wheels

Of course, its nothing if you can't ride for poo, like me :D

Matt

[lukemillar]

Lol.

Was the dyno owned by the same people who fitted the cosmetic pipes for you?

Maybe the same people who sold him the Ohlins front-end! ;)

[neio79]

Just wasting money if you are going to spend thousands on engine mods to not sort the suspension and brakes to handle the extra.
and TBH, you are only ever going to gain probably 5BHP at most at the rear wheel with a fullsystem, filter and PC.

I know its not directly comparable as the Kwak is an IL4, but a bloke with the same bike as mine had a full Akky system put on PC III set up and filter to only gain 6BHP over stock.

That cost about 2K to get done and works out a lot perBHP in my opion.

Best to do just an end can air filter and sort the handling out. If you really want a massive BHP gain buy a different bike.

[ThEGr33k]

See my signature below for full blown tuning...


Might be an English bloke as well soon, on the road too!

Yea but thats with the 750 kit? Or bigger even?

[ThEGr33k]

Just wasting money if you are going to spend thousands on engine mods to not sort the suspension and brakes to handle the extra.
and TBH, you are only ever going to gain probably 5BHP at most at the rear wheel with a fullsystem, filter and PC.

I know its not directly comparable as the Kwak is an IL4, but a bloke with the same bike as mine had a full Akky system put on PC III set up and filter to only gain 6BHP over stock.

That cost about 2K to get done and works out a lot perBHP in my opion.

Best to do just an end can air filter and sort the handling out. If you really want a massive BHP gain buy a different bike.


+1. The reason I went for a big twin is I like the idle low RPM power, I like to shove it in a high gear and just ride the midrange, something I couldnt do with the SV. I often short shift as if you use all the power in 2nd youll be breaking the law and in first youll be doing a mono... infact thats hard not to do if you give it some, the front starts to rise at 3K RPM :rolleyes:

The beauty of the SV is that you dont have to short shift, you can thrash the first 3 gears and only just be breaking the law. The SV has a VERY good road engine, arguably more than enough. Spend your money where it counts and with the SV thats the suspenders and breaks. :cool: Sort these and youll have a FANTASTIC road bike! ;)

[Alpinestarhero]

The beauty of the SV is that you dont have to short shift, you can thrash the first 3 gears and only just be breaking the law. The SV has a VERY good road engine, arguably more than enough. Spend your money where it counts and with the SV thats the suspenders and breaks. :cool: Sort these and youll have a FANTASTIC road bike! ;)

Definatly :D When I rode out with my dad soon after being derestricted, I kept up well - the only times he dissapearred was when the road opened up and we both pinned the throttles. In 95% of all riding, you won't be using all an SV has to offer, let alone something more powerful.

Look at the current 1000cc bikes, capable of 100+ mph in first gear alone; that's one engine not going to visit the redline too often!

[ThEGr33k]

Definatly :D When I rode out with my dad soon after being derestricted, I kept up well - the only times he dissapearred was when the road opened up and we both pinned the throttles. In 95% of all riding, you won't be using all an SV has to offer, let alone something more powerful.

Look at the current 1000cc bikes, capable of 100+ mph in first gear alone; that's one engine not going to visit the redline too often!

Indeed. In the corners where 99% of the fun is imo the SV is pretty good, Ive kept up with all sorts of sporty bikes and out ridden some... sort the suspension and brakes out and man they will be a real giggle! :cool:

[bronze svrider]

well had my bike dynod rollin road whatever its called on a seperate occasion and it is doin 85bhp so....................

[ThEGr33k]

well had my bike dynod rollin road whatever its called on a seperate occasion and it is doin 85bhp so....................

What Dyno was it? It could be giving you a predicted 85 at the crank... That would be believable, 85 is HARD to attain on a SV unless head work is done. :(

[Dangerous Dave]

twin pipe conversion full system by laser found here http://forums.sv650.org/showthread.php?t=68747&page=133

power comander upgrade on air filter oil filter etc
Sorry mate, I have been tuning SV's for a long time now and I do know for a fact that you won't get a true 85bhp from the mods you listed. It may say it on the Dyno print out but that doesn't mean it is true.

The exhaust for a starter is non-performance enhancing, flows no better than OEM.

[Dangerous Dave]

Yea but thats with the 750 kit? Or bigger even?
I meant, see my signature to see what tuning modifications can be done.

Oh... and it is now a little bigger than 750cc

[ThEGr33k]

TBH mate you might as well have made your own engine... or you will have once you are done :p

[sixstring]

Anyone seen this?
http://uk.youtube.com/watch?v=KdTa43CRfqU

All the proof you need to see that an SV can hold it's own against bigger bikes.....


I wish I could ride like that!!!

[Dangerous Dave]

TBH mate you might as well have made your own engine... or you will have once you are done :p
I pretty much have, its a eight year old 750 which I have had all its life and it is getting one lass spruce up. Power to weight and handling it is an unbelievable V-twin!

[ThEGr33k]

Id LOVE to make my own engine... A V-twin Oval cylinder beast. :D make it rev like a Jet turbine :p

[Dangerous Dave]

Id LOVE to make my own engine... A V-twin Oval cylinder beast. :D make it rev like a Jet turbine :p
Sounds good!

[ThEGr33k]

Sounds good!

Yes... it sounds great... making it work no doubt will take more effort. I dont know muhc about engine design, never mind oval cylinder's lol. :( Just got to win the lottery. :)

[bronze svrider]

Sorry mate, I have been tuning SV's for a long time now and I do know for a fact that you won't get a true 85bhp from the mods you listed. It may say it on the Dyno print out but that doesn't mean it is true.


i gave the bike to rizla suzuki to do the power comander exhausts filters etc and when i picked the bike up they gave me the print out lying bsartads lol well its still 33bhp atm any way lol

[Dangerous Dave]

Thats Crescent Suzuki for you, even their SV specials made less power than they stated!

[bronze svrider]

Thats Crescent Suzuki for you, even their SV specials made less power than they stated!


really interested in what the bike is doing now lol well when the proper ecu is in

[ThEGr33k]

I wouldn't worry to be honest... compared to the 33bhp it will feel like a ROCKET ship :D

[Tim in Belgium]

Definatly :D When I rode out with my dad soon after being derestricted, I kept up well - the only times he dissapearred was when the road opened up and we both pinned the throttles. In 95% of all riding, you won't be using all an SV has to offer, let alone something more powerful.

Look at the current 1000cc bikes, capable of 100+ mph in first gear alone; that's one engine not going to visit the redline too often!

Depends with who on what, where and when you ride, I'm finding the SV engine lacking when out with my R1/GSXR/Mille/Blade mounted mates, but that makes it all the more satisfactory when I manage to keep them in sight.

[yorkie_chris]

really interested in what the bike is doing now lol well when the proper ecu is in

It's probably doing more than 33 now anyway.

[Grinch]

One million bhp...

[neio79]

Anyone seen this?
http://uk.youtube.com/watch?v=KdTa43CRfqU

All the proof you need to see that an SV can hold it's own against bigger bikes.....


I wish I could ride like that!!!

all i see on that video is it getting spanked everytime its out of a corner.

The bike he is folowing and getting caned by on the straights for the first half is a 2007 ZX6-R ;):cool:

[ThEGr33k]

all i see on that video is it getting spanked everytime its out of a corner.

The bike he is folowing and getting caned by on the straights for the first half is a 2007 ZX6-R ;):cool:


Ahhh the vid did look like a fake... :p

Tim those 1000's do have a lot of mid range, just think at like 6-7K rpm them make more power than the SV ever can and they have another 5-6K of revs to go. OTT on the road imo... thats why I aint too bothered. 1000cc V-twin/SS600 is more than enough.

[Alpinestarhero]

I wouldn't worry to be honest... compared to the 33bhp it will feel like a ROCKET ship :D

I can second that; You know how a restricted bike dosnt pull after 8000 rpm, it just vibrates and makes alot of noise?

Full power SV will keep pulling, boy is it fun

:rave:

[Grinch]

I had a guy really cane it on a w reg bandit this morning at a set of lights, as he pulled away it looked like the back wheel was just on the edge of spinning up. I let him get on with it, I can shift but I like to keep my tread for a little bit.

[Alpinestarhero]

I had a guy really cane it on a w reg bandit this morning at a set of lights, as he pulled away it looked like the back wheel was just on the edge of spinning up. I let him get on with it, I can shift but I like to keep my tread for a little bit.

Same here; I try and be careful with the throttle...I don;t know how much 70 bhp will shorten the tyre life by, but more than 33 bhp will. Also, it'll help preserve my chain life....and petrol life

But it is fun to burn off away from the lights, specialy coming off hangar lane gyrotary and onto hangar lane itself. I popped my first wheelie there :D

[Grinch]

I mean I don't mess about most of the time, but there are a few about that I think... mmmh, bit heavy for me. Along with the near miss as I car turned into my lane, and the van nudging me this morning (I did kind if push my way in) I had enough excitment for one morning.

[ThEGr33k]

I set off the other day just normal like getting upto motorway speed (out of a layby on the A64) and up pops the front nice and gentle up it comes started to come up at like 3000rpm... felt wierd because normally I dont give it much in first, I still wasnt to be honest. Ive had the front come off the ground in 3rd before, not a lofty one but leaving the floor all the same...

I wouldnt worry about the SV's power it wont do anything like spin up unless its wet. well mine never did anyway. :) I still got like 65-70mpg on full power and the tyres didnt wear a great deal more, the chain I adjusted like a few times in 25K miles. Scottoilers are ace!

[Tim in Belgium]

......

Tim those 1000's do have a lot of mid range, just think at like 6-7K rpm them make more power than the SV ever can and they have another 5-6K of revs to go. OTT on the road imo... thats why I aint too bothered. 1000cc V-twin/SS600 is more than enough.

Yeah may be a little OTT but still very useful ;) The SV is not the be all and end all of road bike engines, personally I can't wait to get something with a little more oomph where I can use skill rather than just twisting the throttle back to the stop everywhere. Don't get me wrong the SV is a great little bike that will do all sorts and I'll probably miss it a bit when it has gone, one of the reasons I've kept it 3 years. But 70 bhp (roughly) isn't always enough when it's just a fun machine for me.

[bronze svrider]

I can second that; You know how a restricted bike dosnt pull after 8000 rpm, it just vibrates and makes alot of noise?

Full power SV will keep pulling, boy is it fun

:rave:


my pointy the power cuts out at 6k rpm !!!!!! but my bike goes quieter not louder but agree with the vibrations lol

[northwind]

Yeah may be a little OTT but still very useful ;) The SV is not the be all and end all of road bike engines

Depends what you like... The only time I've ever felt mine's lacking is on track, on the road it's just spot on for me. I don't like big power bikes, it makes it too easy, I like to feel the engine work and at my pace, any litre road bike just isn't even trying :D which can be quite nice, but I prefer it the other way round. Having said that, I loved the 06 R1 I rode for its laziness, obviously if you turn it up it's a missile but when you roll it off it's just lovely.

[Dangerous Dave]

Depends what you like... The only time I've ever felt mine's lacking is on track, on the road it's just spot on for me. I don't like big power bikes, it makes it too easy, I like to feel the engine work and at my pace, any litre road bike just isn't even trying :D which can be quite nice, but I prefer it the other way round.
+ 1, I think the SV is suited to the roads and if ridden properly can easily hang and pass with the bigger bikes. Power isn't the SV's problem, it is its handling out of the crate.

[ThEGr33k]

+ 1, I think the SV is suited to the roads and if ridden properly can easily hang and pass with the bigger bikes. Power isn't the SV's problem, it is its handling out of the crate.

I agree. If it wasnt for the suspension it would be great. :cool:

[Dangerous Dave]

I agree. If it wasnt for the suspension it would be great. :cool:
...and it is far cheaper to upgrade the suspension than to part-ex for a whole new bike with similar characteristics and qualities.

[ThEGr33k]

...and it is far cheaper to upgrade the suspension than to part-ex for a whole new bike with similar characteristics and qualities.

Indeed... What would you part-ex it for thats similar though? :confused:

[northwind]

Indeed... What would you part-ex it for thats similar though? :confused:

To get a suspension upgrade and similiar engine? A 748 with a really ropey engine :D

[ThEGr33k]

To get a suspension upgrade and similiar engine? A 748 with a really ropey engine :D

I think it was a joke about me getting the Falco... lol. Didnt part Ex anything though :)

[Tim in Belgium]

...and it is far cheaper to upgrade the suspension than to part-ex for a whole new bike with similar characteristics and qualities.

Yep, cheaply upgraded the suspension (front springs, oil and hagon shock), and now it's the lack of power, which is why I'll be getting something else when I move. But admittedly this lack of power is only when pushing on hard, or when at altitude!

[Dangerous Dave]

Indeed... What would you part-ex it for thats similar though? :confused:
Closest thing to an SV, nothing as it is unique.

now it's the lack of power, which is why I'll be getting something else when I move.
Would a near 110bhp stripped down SV (not an over weight 1000) be a consideration?

[Tim in Belgium]

I would briefly consider it, but will end up going the 675 Daytona route no doubt, depending on how easy they are to find in Holland.

[lukemillar]

I would briefly consider it, but will end up going the 675 Daytona route no doubt, depending on how easy they are to find in Holland.

Man of good taste, Tim! :wink:

[Grinch]

Part of me dreams of the 750 cc kit for my other SV, but I think I would need to fit it and I don't have the knowledge for that.
Not even sure if you can still get hold of them.

[ThEGr33k]

I would briefly consider it, but will end up going the 675 Daytona route no doubt, depending on how easy they are to find in Holland.

I gotto say out of all the ss600 thats the one id choose... :D

[rowdy]

A cautionary warning. I got a full race m4 and a k&n and had it put on a rolling road and fettled with. It put out 72bhp atw which equates to near 80 atc. I have heard that anything over 80bhp and the crank is in serious danger . I can confirm this as a couple of months ago the crank snapped. However the bloke that dyno'd my bike (k3 model) said that mine was one of a handfull that left the factory with the wrong rev limiter setting (11400 instead of 10400) so this also had a detrimental effect on the engine.
Hoping to be back on the road this week.

[Dicky Ticker]

no disrespect intended to anybody
I know we all like tinkering with our bikes but major rebuilding of an engine to gain the maximum possible increase is quite complicated and IMHO for the sake of a few horse power on the SV with standard suspension hardly worthwhile. The money involved would be better put to another bike which has the required performance or alternative do the easy mods and spend money on the suspension giving you a bike that you can push to its limits

[Grinch]

no disrespect intended to anybody
I know we all like tinkering with our bikes but major rebuilding of an engine to gain the maximum possible increase is quite complicated and IMHO for the sake of a few horse power on the SV with standard suspension hardly worthwhile. The money involved would be better put to another bike which has the required performance or alternative do the easy mods and spend money on the suspension giving you a bike that you can push to its limits

But where's the fun in that...

[Dicky Ticker]

" competent tinker":)

[Dangerous Dave]

no disrespect intended to anybody
I know we all like tinkering with our bikes but major rebuilding of an engine to gain the maximum possible increase is quite complicated and IMHO for the sake of a few horse power on the SV with standard suspension hardly worthwhile. The money involved would be better put to another bike which has the required performance or alternative do the easy mods and spend money on the suspension giving you a bike that you can push to its limits
I agree, even though it is the opposite to what i have done (is almost 40 considered a few horse power?).

As we all know the suspension is the only thing that really needs looking at with the SV650.

[yorkie_chris]

Would a near 110bhp stripped down SV (not an over weight 1000) be a consideration?

Whoa cool, is that what yours is putting out now? Any idea what it's like for reliability (I know you have a strong bottom end... lol)

I would briefly consider it, but will end up going the 675 Daytona route no doubt, depending on how easy they are to find in Holland.

Very nice bike, a little too focussed for my tastes though.

[Dangerous Dave]

Whoa cool, is that what yours is putting out now? Any idea what it's like for reliability.
109.6 bhp with 63ft/Ib and so far so good, had a little look around inside after a few hundred miles and she seems sweet (bit early to really tell I Know).

I know you have a strong bottom...
Pervert... :p

[northwind]

A cautionary warning. I got a full race m4 and a k&n and had it put on a rolling road and fettled with. It put out 72bhp atw which equates to near 80 atc. I have heard that anything over 80bhp and the crank is in serious danger . I can confirm this as a couple of months ago the crank snapped. However the bloke that dyno'd my bike (k3 model) said that mine was one of a handfull that left the factory with the wrong rev limiter setting (11400 instead of 10400) so this also had a detrimental effect on the engine.


At the end of the day, engines break, stock motors can break cranks if you're unlucky. That 80bhp guideline everyone beats about is wheel not crank... And also, to be fair, no more than a very simple rule of thumb. If you had a high revver that'd threaten the valvetrain more than the crank... It's very hard to ever say why an engine fails, from one incident, it could be the tuning, or it could be a little teeny tiny manufacturing flaw that's been waiting for the perfect moment for 5 years.

For balance, mine runs at just shy of 80 at the wheel and it's stock from the pistons down, has done for 20000 miles, everything from trackdays to spending most of a day at 90mph on motorways, with nothing but standard maintenance. It might explode tomorrow but there's no particular reason it should. Bigbores add a fair bit more stress of course, not just more bang but more weight.

Why do it? Because it amuses me. Obviously it'd make more sense to get a faster bike but I'd just mod it too, this way I'm doing it to something cheap :D

[ThEGr33k]

109.6 bhp with 63ft/Ib

Impressive! You got the Dyno for that?

What CC is it on ATM?

What exactly have you done? Any info you care to share will be well recieved. Im always interested in this stuff. :D I might be doing the 1060 mod one day... :rolleyes:

Also wondering what is it that seems to limit the rev's of V-twins... Is it getting the air in and out I.E. valve area not enough or is it a machanical restreint? The 999 WSB Ducs were apparently pushing 14500RPM...

[rowdy]

At the end of the day, engines break, stock motors can break cranks if you're unlucky. That 80bhp guideline everyone beats about is wheel not crank... And also, to be fair, no more than a very simple rule of thumb. If you had a high revver that'd threaten the valvetrain more than the crank... It's very hard to ever say why an engine fails, from one incident, it could be the tuning, or it could be a little teeny tiny manufacturing flaw that's been waiting for the perfect moment for 5 years.

For balance, mine runs at just shy of 80 at the wheel and it's stock from the pistons down, has done for 20000 miles, everything from trackdays to spending most of a day at 90mph on motorways, with nothing but standard maintenance. It might explode tomorrow but there's no particular reason it should. Bigbores add a fair bit more stress of course, not just more bang but more weight.

Why do it? Because it amuses me. Obviously it'd make more sense to get a faster bike but I'd just mod it too, this way I'm doing it to something cheap :D
The fella that dyno'd my bike made it run leaner than standard and I was wondering if that has made the bike run hot which in turn has caused the crank to snap, either that or I'm just unlucky

[neio79]

Just out of curiosity, the people who have tinkered to the extent where they have got signifigent HP increases. How much money have you spent doing so??


If its thousands , do you not think you would have ben better just changing the SV for a better bike to start with.

Its a bit like me trying to get the 6R to perform like a 1000, it would be cheaper and eaiser to go and trade in for one.

[Dicky Ticker]

As a matter of interest what is the general consensus of HP and Torque that makes an ideal road bike for commuting,touring and the odd blast? I am not talking track/racing use but general everyday use with a cumfy bit of performance for when needed and bearing the cost of fuel reasonable fuel consumption
My ideal seems to be about 100bhp and 95n.m.torque

[Tim in Belgium]

I think it all depends on the torque (and therefore power) delivery, it's the shape of the curves as well as the outright max figures.

[jambo]

Also wondering what is it that seems to limit the rev's of V-twins... Is it getting the air in and out I.E. valve area not enough or is it a machanical restreint? The 999 WSB Ducs were apparently pushing 14500RPM...

The mass of the pistons and con rods flailing about are the biggest problem. A 1000cc 4 cylinder bike has 4x250cc cylinders, the pistons for this setup weigh less than the 2x500cc cylinders for a twin would. For every rotation of the crank each piston must rise, come to a dead stop, fall, come to a dead stop and return to the start point. At 10,000 rpm, it's doing 166 revolutions per second. Thats 333 stokes a second, or a complete change of direction every 0.003 seconds.

As Force = Mass x Acceleration, and a change in velocity is an acceleration, the higher the mass of the piston, the greater the force on the crank & con rods for a given RPM. This is why twins & singles of a given capacity rev lower than multis.

You can use stronger components that can take higher forces, the crank and con-rods on a WSB Ducati are likely to be made of rather exotic materials, and machined to close tolerances. The pistons will also be as light as possible, but none of that is cheap. And for a road bike the cost starts outweighing the benefit of an extra 1,000 rpm or so....


Jambo

[ThEGr33k]

The mass of the pistons and con rods flailing about are the biggest problem. A 1000cc 4 cylinder bike has 4x250cc cylinders, the pistons for this setup weigh less than the 2x500cc cylinders for a twin would. For every rotation of the crank each piston must rise, come to a dead stop, fall, come to a dead stop and return to the start point. At 10,000 rpm, it's doing 166 revolutions per second. Thats 333 stokes a second, or a complete change of direction every 0.003 seconds.

As Force = Mass x Acceleration, and a change in velocity is an acceleration, the higher the mass of the piston, the greater the force on the crank & con rods for a given RPM. This is why twins & singles of a given capacity rev lower than multis.

You can use stronger components that can take higher forces, the crank and con-rods on a WSB Ducati are likely to be made of rather exotic materials, and machined to close tolerances. The pistons will also be as light as possible, but none of that is cheap. And for a road bike the cost starts outweighing the benefit of an extra 1,000 rpm or so....


Jambo

Aye... I know that is a problem as well but, on mine it peaks power at about 9,250RPM but revs on to 10,500rpm. Why is it that they dont make it peak higher since they rev higher? How can you make it do that? More gas flow... or is that again piston weight causing it to peak early...

My engine is a relative long stroke when compared to other bikes... Mine is 97 x 67.5mm a Duc 1098 for example is 104 x 64.7 mm or a SV/TL 97 x 66mm. I suppose the shorter the stroke the easier to rev BUT the less torque you get at lower RPM... you have to chase the revs with the short strokes. I guess its finding the happy medium. :cool:

[Dangerous Dave]

If you had a high revver that'd threaten the valvetrain more than the crank.
+ 1

You got the Dyno for that?
Will post it up later...

What CC is it on ATM?
800cc, just need to finish the bike off so i can get it on the road.

[ThEGr33k]

Will post it up later...


800cc, just need to finish the bike off so i can get it on the road.

Cool, just wondering how the power curves and all that joy. Since you are creating not far off of the same power mine does its impressive. I guess it must peak higher than mine though in the rev range since mine has more torque.

So i wonder what bigger valves and higher lift cams gas flowed heads etc etc could help pull out of my motor. Could put a 03 RSV top end on it for 2mm bigger Intake valves. :D

What size valves you running on that then?

Oh and how the HELL are you going to insure it!?

[northwind]

Just out of curiosity, the people who have tinkered to the extent where they have got signifigent HP increases. How much money have you spent doing so??


Don't know if mine qualifies? I've spent, oh... £120 cams, £300 the full system and carb work, £50 for the ignition advance and gear selector kit. Plus a lot of time of course. And on the suspension (which is really where it makes a difference) something like £700.

On the one hand, yes, it's a bit daft spending £1200 on handling and performance mods on a £2500 bike. On the other hand, a new SV costs £4000. People happily spend £300 for fairing lowers or a slipon that does nothing but add noise, or £200 for sticky tyres they don't need...

There's 4 proper answers... One is that most folks don't start out planning to take it this far, it just grows, so you never think "I'll spend a grand on the engine", you think, "Ah well, I'll just fit a slip on... Now a filter... Oh, needs rejetted, might as well fit a race system... Hmm, cams are cheap..." One is that it's interesting to do it (I wouldn't ever have paid someone to do the work I've done on mine). One is that it's nice to have a nontypical bike.

But for me, it's that when I started there was no better bike. I don't like inline 4s, a 400cc V4 was too expensive and hard to find a good one, and there was no street triple/Aprilia shiver/etc. I thought about a 748 but tht has its problems too, not least being expensive (I could afford it but I'd be afraid of hurting it) I wanted a moderately powerful bike with a nice versatile engine and very good suspension and brakes, which was faired, and comfortable, and light weight... couldn't buy one, so I made it.. I suppose these days I'd buy a dorsoduro, maybe, or an F800S

Not everyone wants a race rep or a litre twin, is the short answer.

[Grinch]

When I was looking at some of the peak load information about the SV made me realise I'd been riding it all wrong as most of the peak power is at 8k. Though sometime I'd been shifting at 10k, so its time for a riding style change, now I'm going to be trying to do my best to keep it that way. Did the same last night and seemed to get the move on alot quicker, might be in my mind, but then I can but try to better myself.

[jambo]

on mine it peaks power at about 9,250RPM but revs on to 10,500rpm. Why is it that they dont make it peak higher since they rev higher? How can you make it do that? More gas flow... or is that again piston weight causing it to peak early...

My engine is a relative long stroke when compared to other bikes... Mine is 97 x 67.5mm a Duc 1098 for example is 104 x 64.7 mm or a SV/TL 97 x 66mm. I suppose the shorter the stroke the easier to rev BUT the less torque you get at lower RPM... you have to chase the revs with the short strokes. I guess its finding the happy medium. :cool:

The bore and stroke affect the rev ceiling as you've seen, a longer stroke can give more torque but increases the strain on crank, con rods etc at a given RPM. A wide bore, shorter stroke motor is apparently harder to get nice fuel air mix in the combustion chamber at lower rpm. Having a large valve area exaggerates this due to the relatively slow speed of the air-fuel mix coming through them at low rpm, but helps flow at high rpm. Ducati are apparenty very good at designing large bore heads that work well. The valve area argument is why the VFR800 runs 2 valve head at low rpm, and a 4 valve head at high rpm.

As I understand it the main thing that affects most bike's power characteristics are the cams, which affect the duration of the inlet, and exhaust valve opening and, crucially the overlap time when both are open. This, together with bore, stroke, valve area all make an impact. An engine that makes power best at it's red line may compromise through the rest of the rev range.

Also you want to be able to rev, change gear, and still be up in peak power / torque, so need a decent spread.

I'll be honest this isn't something I know tons about and may have got some of this wrong, but this is how I understand it.

Jambo

[ThEGr33k]

The bore and stroke affect the rev ceiling as you've seen, a longer stroke can give more torque but increases the strain on crank, con rods etc at a given RPM. A wide bore, shorter stroke motor is apparently harder to get nice fuel air mix in the combustion chamber at lower rpm. Having a large valve area exaggerates this due to the relatively slow speed of the air-fuel mix coming through them at low rpm, but helps flow at high rpm. Ducati are apparenty very good at designing large bore heads that work well. The valve area argument is why the VFR800 runs 2 valve head at low rpm, and a 4 valve head at high rpm.

As I understand it the main thing that affects most bike's power characteristics are the cams, which affect the duration of the inlet, and exhaust valve opening and, crucially the overlap time when both are open. This, together with bore, stroke, valve area all make an impact. An engine that makes power best at it's red line may compromise through the rest of the rev range.

Also you want to be able to rev, change gear, and still be up in peak power / torque, so need a decent spread.

I'll be honest this isn't something I know tons about and may have got some of this wrong, but this is how I understand it.

Jambo

Indeed thats how I understand it... So i guess we cant both be far off. :)

I believe as the Piston gets bigger (bore) you get more wasted space which the valves cant fit so you end up trying to pull more air in than is possible if you go too large. A real git tbh. Maybe this is why the 5 valve came along but tbh I dont think the IL4's have a big problem as their Bores are small so the valves are relevantly large for the capacity. It would be interesting to see how a 5Valve head worked on a Large capacity 1000-1200CC engine where the benefit should be felt. :D Variable valve timing would be required though for low down power...

[yorkie_chris]

5 valves works, but not massively better than 4. The yam genesis engines are 5 valve, but the latest R1's have gone back to 4valve...

[jambo]

5 valves works, but not massively better than 4. The yam genesis engines are 5 valve, but the latest R1's have gone back to 4valve...
The motoGP Yamaha M1 went from a 5 to 4 valve head after Rossi joined the team apparently. Personally my thoughts were limited to "oh joy that's 20 shims" after I'd trudged through the Kawasaki's 16.....

Jambo

[ThEGr33k]

5 valves works, but not massively better than 4. The yam genesis engines are 5 valve, but the latest R1's have gone back to 4valve...

Aye but im wondering if it might help to use more of the space available on the bit Bore twins. A shame I cant engineer my own to see :p