[JessHerbst]

The torque curve explains why this bike is so pleasant to ride.

https://www.cycleworld.com/story/bikes/royal-enfield-int650-dyno-test-2022/?utm_medium=syndication&utm_source=flipboard

The HP number is not impressive, and that is kind of the point. With a torque curve like that and 6 speeds, HP is not the end all so many people believe.

[iblastoff]

is it really all that rare in modern midrange bikes?

Both of my Ducati scramblers are very linear in power delivery but has 73hp. Xsr700 and sv650 all have similar linear delivery. Shrug.

The re650 is definitely the best LOOKING of most new bikes out there though. But performance? Hell no.

[JessHerbst]

is it really all that rare in modern midrange bikes?

Both of my Ducati scramblers are very linear in power delivery but has 73hp. Xsr700 and sv650 all have similar linear delivery. Shrug.

The re650 is definitely the best LOOKING of most new bikes out there though. But performance? Hell no.

If you were looking for a Performance Bike, you bought the wrong bike.
 If you want good ride-ability, looks and solid construction, you got the right bike.

[iblastoff]

If you were looking for a Performance Bike, you bought the wrong bike.
 If you want good ride-ability, looks and solid construction, you got the right bike.

i never look for performance in a bike tbh. my very first bike was a 150cc with 14hp and it was awesome. i've had 250cc bikes with very similar hp. both were great outside of highway riding. super light and easy around town.

i wouldnt even call the ducati scramblers to be performance oriented either. its literally the cheapest ducati you can get and its just a very LIGHT bike.

for how much the RE650 weighs (i'd say my gt650 is almost 100lbs heavier than my modified ducati scrambler which is about 410lbs wet and now closer to 350lb after mods), i think it should have at least 50-60hp.

the gt650 is a fun ride. but its also very sluggish, especially in urban riding and taking off at green lights. every previous bike i've had takes off way quicker and i am NOT a speed demon. i can only attribute that to the weight of the bikes, or lack of HP.

would more HP make the GT650 less sluggish off the line? i would assume so. or it needs to lose a whole lot of weight, which there arent many easy options to do on this bike besides pipes/slipons (which i've already changed out from the super heavy stock ones).

the gt650 also just 'feels' super heavy, especially when trying to move it around or backing it into tight parking spots, which i have to do in the city all the time. its just odd how easily i can manoeuvre all of my previous bikes vs the gt650. the weight distribution seems super weird.

the one great thing about more expensive bikes is parts tend to be more modular. for example i can remove the entire passenger rearset from my ducati and lose almost 20lbs from it, which i did. can't do that on the GT650 since its just cheaply welded to the frame.

i stilll love the gt650 but i've yet to find the 'perfect' bike for me.

[John Mullen]

That's why the pistons and cam I put in my Interceptor has made it the perfect machine.  Running about 60 HP and 55 lbs of torque now, there's nothing to want for.  It's a shame RE doesn't offer this set up.  I have to sell my dream bike so someone will sure find a smile on their face during their first test ride.  I remember the great torque curve from stock and you're right Tess, it's amazing.  It's just that now mine is 135% of that.  I sure hate to see her go.  But at 73 now, I need to be a grown up about it. I need stay healthy and take care of family.  But I'll always feel like chiming in after someone says they wish they had a little more power.  I got to ride that dream machine! 

[JessHerbst]

That's why the pistons and cam I put in my Interceptor has made it the perfect machine.  Running about 60 HP and 55 lbs of torque now, there's nothing to want for.  It's a shame RE doesn't offer this set up.  I have to sell my dream bike so someone will sure find a smile on their face during their first test ride.  I remember the great torque curve from stock and you're right Tess, it's amazing.  It's just that now mine is 135% of that.  I sure hate to see her go.  But at 73 now, I need to be a grown up about it. I need stay healthy and take care of family.  But I'll always feel like chiming in after someone says they wish they had a little more power.  I got to ride that dream machine!

John,
 I do agree that Royal Enfield should offer a version with higher performance tuned engine.
 Obviously they could, you did.
There are probably two dozen financial & marketing reasons why they don’t.
 Maybe the Royal Enfield Continental GT 650 race series is scratching that itch for those in the company that agree with us, but could not get management to produce such a bike.

[Yinzer]

If you were looking for a Performance Bike, you bought the wrong bike.

I think RE should make a liter bike w/ 350hp for the US market.
Call it the Compensator
 

[NVDucati]

I think RE should make a liter bike w/ 350hp for the US market.
Call it the Compensator

Ouch.

[YellowDuck]

I've said it before but....I literally bought this bike because it has barely adequate hp.  Keeps me out of trouble riding on public roads.  Sport bikes make me naughty.

I don't judge anyone for modifying their bike for increased performance - that can be a really fun journey.  But there is also a lot to be said for just buying the bike you want in the first place, and then just riding the thing.  Especially if you are at a place in life where free time is not as plentiful as you might like. 

[Keef Sparrow]

I think RE should make a liter bike w/ 350hp for the US market.
Call it the Compensator

Interestingly either the Indian owner or the British R&D head of Royal Enfield (can't remember which one but I think it was the British guy) has said in an interview that RE have the resources and technical expertise to produce a World class Panigale type V4 Supersports bike - if they wanted to. I think they would sell next to zero in India which is where nearly all their world sales are - so it's not likely to happen.

[pedro__]

My uncle cb750 heated like hell on red lights,  less hp actually has some advantages.

Just to throw that out.

[iblastoff]

My uncle cb750 heated like hell on red lights,  less hp actually has some advantages.

Just to throw that out.

i think it has more to do with engine configuration than HP. i have a ducati thats actually LESS hp than the RE650 but it gets WAAY HOTTER feeling because its an L twin and is situated right underneath your seat.

[iblastoff]

That's why the pistons and cam I put in my Interceptor has made it the perfect machine.  Running about 60 HP and 55 lbs of torque now, there's nothing to want for.  It's a shame RE doesn't offer this set up.  I have to sell my dream bike so someone will sure find a smile on their face during their first test ride.  I remember the great torque curve from stock and you're right Tess, it's amazing.  It's just that now mine is 135% of that.  I sure hate to see her go.  But at 73 now, I need to be a grown up about it. I need stay healthy and take care of family.  But I'll always feel like chiming in after someone says they wish they had a little more power.  I got to ride that dream machine!

i agree that 60HP would be ideal for this bike! thats not asking for 'performance'. it just seems the more sensible amount of power for the weight of this bike.

[JessHerbst]

i think it has more to do with engine configuration than HP. i have a ducati thats actually LESS hp than the RE650 but it gets WAAY HOTTER feeling because its an L twin and is situated right underneath your seat.

If it is an air cooled L twin that makes sense. The rear cylinder gets ‘cooled’ by hot air coming off the front cylinder.

[lavrentyuk]

This debate reminds me of an old East German MZ advert.

"All the speed you need".

There is something to be said for that.  Going fast on a slow bike is always far more fun than going slow on a fast one.  Any modern Japanese 600 ish bike has far more performance than I can ever sensibly use on a public road in mid Wales.

The Interceptor works here - has fun on the A roads and unclassified mountain roads too.  It tours.  It looks good for posing on the Prom in Aberystwyth.

It is all the bike I need and much of what I want too.

[John Mullen]

See what you started Tess?  There's sure no shortage of opinions when it comes to absolutely anything about motorcycles.  Like you said Tess.  In this heat, all I can do being stuck indoors, is read about all the different ways we have to value our precious Royal Enfield's.  It's good entertainment.  Long live the Queen!

[JessHerbst]

See what you started Tess?  There's sure no shortage of opinions when it comes to absolutely anything about motorcycles.  Like you said Tess.  In this heat, all I can do being stuck indoors, is read about all the different ways we have to value our precious Royal Enfield's.  It's good entertainment.  Long live the Queen!

There are also no shortage of opinions on the first letter of my first name, but indeed it is ’J’, just like John!
Jess

[John Mullen]

Oh come on now.  If you agree to change it to Tess, then I wouldn't sound like the absent minded fool I really am.  And you would laugh if you only knew how many times I go over my posts, looking for errors before I hit the post button.  Oh well.  I think you're great Jess and I'm sorry about that.

[GravyDavy]

I've said it before but....I literally bought this bike because it has barely adequate hp.  Keeps me out of trouble riding on public roads.  Sport bikes make me naughty.

I don't judge anyone for modifying their bike for increased performance - that can be a really fun journey.  But there is also a lot to be said for just buying the bike you want in the first place, and then just riding the thing.  Especially if you are at a place in life where free time is not as plentiful as you might like.

You are not alone. I really like that my Interceptor is happiest running at speeds that won't land me in jail. I have ridden far faster bikes that aren't in their element under 100mph or much more. It was very frustrating keeping them throttled back. 

[JessHerbst]

Oh come on now.  If you agree to change it to Tess, then I wouldn't sound like the absent minded fool I really am.  And you would laugh if you only knew how many times I go over my posts, looking for errors before I hit the post button.  Oh well.  I think you're great Jess and I'm sorry about that.

You can call me Tess anytime John!

[Mort]

You can call me Tess anytime John!

I think you mean Tohn.

[Warwick]

Another post justifying horsepower
cheers and beers
Warwick

[JessHerbst]

Another post justifying horsepower
cheers and beers
Warwick

Well, it started out praising torque…

[iblastoff]

If it is an air cooled L twin that makes sense. The rear cylinder gets ‘cooled’ by hot air coming off the front cylinder.

Definitely air cooled haha. IMO when it gets really hot here, city riding is impossible on it cause it gets so hot waiting at lights.

That’s definitely one thing the RE650 has. I really don’t feel much heat coming off of it even on the most nuclear days.

[Cazzy_R]

RE now outsell Kawasaki and Suzuki in the UK.
They don't need to change their USP to make flattering numbers on a dyno print out, their sales figures speak for themselves.

[ATXConti650]

That 3K to 5.5K RPMs is where I like riding.

[iblastoff]

RE now outsell Kawasaki and Suzuki in the UK.
They don't need to change their USP to make flattering numbers on a dyno print out, their sales figures speak for themselves.

there is no doubt these bikes are selling. but this is kind of a meaningless stat without context. suzuki is barely a motorcycle company anymore. kawasakis big sellers in the UK are basically the higher end ninja 1000's. royal enfields main sellers in the UK are the 350s. obviously the cheaper ones are gonna sell at more volume. honda has consistently been the top seller in the UK, but thats only because a huge volume of those sales are cheap honda scooters.

if you break it down further to the 650cc segment, RE isn't even the top seller there (triumph trident is). on top of this, you have varying manufacturers in constant fluctuating stock over the past nearly 3 years. so we have no idea what true numbers actually look like if things were back to 'normal' times.

[whippers]

if you break it down further to the 650cc segment, RE isn't even the top seller there (triumph trident is). on top of this, you have varying manufacturers in constant fluctuating stock over the past nearly 3 years. so we have no idea what true numbers actually look like if things were back to 'normal' times.

The Triumph Trident isn’t in the same capacity range in the UK. In June the Trident was the best seller 651cc - 1,000.  The RE twins are 648cc. Until the advent of the Classic 350, the Interceptor was usually the best selling bike in modern classic segment.

[lucky phil]

If it is an air cooled L twin that makes sense. The rear cylinder gets ‘cooled’ by hot air coming off the front cylinder.

You need to review what a Ducati twin looks like Jess. Does this look like the rear cylinder is getting blasted by heat off the front cylinder?

Phil

[JessHerbst]

You need to review what a Ducati twin looks like Jess. Does this look like the rear cylinder is getting blasted by heat off the front cylinder?

Phil

Honestly Phil, yes. It looks like that to me.
That front cylinder is in line, ahead of second. The air is going to flow over & around it and be heated before it reaches the second.
 Am I missing some amazing air flow or design trick that negates this?

[Intybe]

You can see what Phil means if you draw a horizontal line across the top of the first cylinder. Above it is empty space through which fresh air flows to the second. Great design, makes much more sense than harleys in this regard. Thx for pointing it out, Phil

[lucky phil]

Honestly Phil, yes. It looks like that to me.
That front cylinder is in line, ahead of second. The air is going to flow over & around it and be heated before it reaches the second.
 Am I missing some amazing air flow or design trick that negates this?

Yep as Intybe pointed out plus the front cylinder fins also direct the air downwards to an extent as they run parallel to the cylinder axis. The cylinders are offset to one another due to the side by side big end arrangement. Most of the air that hits the front head and travels down the cylinder axis then hits the crankcases and gets pushed out sideways and down the sides of the engine. Here's what real cylinder shielding really looks like on an engine renowned for it plus no cylinder offset with knife and fork big ends. The Ducati also has superior cylinder cooling to a Parallel twin as well.

Phil

[Hoiho]

Not like this then... 976cc V-twin

[Tbone13]

40 HP at the rear wheel is pretty good.  I had a 1988 Honda Hawk GT650. Liquid cooled, OHC V twin.
With a professional rider a magazine at the time got one into the high 12s at 103 mph in the quarter.
The bike was expensive (for that time) at $4100. All aluminum chassis and gas tank, single sided swing arm, great brakes, etc. 400 pounds if memory serves. The engine was basically a fore and aft version of the old CX 500.
My bike cranked out 37.5 HP on a dyno run in the heat of summer.
So 40- that ain't bad.

[whippers]

40 HP at the rear wheel is pretty good.  I had a 1988 Honda Hawk GT650. Liquid cooled, OHC V twin.
With a professional rider a magazine at the time got one into the high 12s at 103 mph in the quarter.
The bike was expensive (for that time) at $4100. All aluminum chassis and gas tank, single sided swing arm, great brakes, etc. 400 pounds if memory serves. The engine was basically a fore and aft version of the old CX 500.
My bike cranked out 37.5 HP on a dyno run in the heat of summer.
So 40- that ain't bad.

Sounds a bit low for a Hawk.  Interesting bikes.  The engine is based on the VT500 motor.  the 3 valve SOHC engine was built as a hedge by Honda as they felt Americans wouldn't embrace the CX500 OHV shaft drive model

[Jack Straw]

Dyno results are just perfect for guys who love to argue with pieces of paper

[Tbone13]

Sounds a bit low for a Hawk.  Interesting bikes.  The engine is based on the VT500 motor.  the 3 valve SOHC engine was built as a hedge by Honda as they felt Americans wouldn't embrace the CX500 OHV shaft drive model

The VT500 was based on the CX 500, too.
I thought it sounded low also. I remember it had a flat torque curve and was a fun ride. I didn't race it, I just liked how it could straighten out any curve with ease.  It would get away from a friend's 750 Suzuki 4 if the road was curvy enough.  As far as numbers, with Dynos it is best used for a baseline for mods, not as a comparison to all bikes since they are inconsistent one to the next.  It felt at least as powerful as my 68 TR6. It rushed from 60 to 90 like a scalded dog. It topped out about 112 IIRC.
This was over 30 years ago.
 

[whippers]

The VT500 was based on the CX 500, too.
I thought it sounded low also. I remember it had a flat torque curve and was a fun ride. I didn't race it, I just liked how it could straighten out any curve with ease.  It would get away from a friend's 750 Suzuki 4 if the road was curvy enough.  As far as numbers, with Dynos it is best used for a baseline for mods, not as a comparison to all bikes since they are inconsistent one to the next.  It felt at least as powerful as my 68 TR6. It rushed from 60 to 90 like a scalded dog. It topped out about 112 IIRC.
This was over 30 years ago.

No the VT500 is a completely different engine.  It is a SOHC 3 valve V twin whereas the CX500 is a transverse pushrod 4 valve unit.

[ideola]

40 RWHP / 47 BHP (factory reported) = 15% driveline loss
That's a useful ballpark figure, which extrapolated, means I'm in the vicinity of ~87 BHP on Project MLG and ~64 BHP on The Rocketeer.
 

[lucky phil]

No the VT500 is a completely different engine.  It is a SOHC 3 valve V twin whereas the CX500 is a transverse pushrod 4 valve unit.

Not only that but ones a 52 degree longitudinal V twin and ones an 80 degree transverse V twin. About the only thing they have in common is they are both 2 cylinder 4 stroke V twins.

Ciao 

[Wrenchjockie]

TBone
 “The engine was basically a fore and aft version of the old CX 500.”

Not even close. Not unless you consider a pushrod 4 valve motor the same as an overhead cam 3 valve motor.

[NJ Mike]

Actual Dyno results.

I have yet to pick it up, but I feel real good about what I see based on how it ran when I dropped it off.

Tuned by cracking the stock ECU. From my tuner: "So lots of changes to lambda targets, fuel trim per cylinder and cylinder correction factors.Plus ignition timing, also there are some restrictors we remove. We also tuned individual cylinders as left to right were way different. I do find tuning individual cylinders when I can that makes more power and better throttle response which makes the engine more efficient too. The ignition we adjust both cylinders together, not separate, only added 3 degrees. What is best about a custom tune, like what we did is less parts so less potential failures plus we can do so much more with."

If anyone in the NY metro area needs a tune, his name is Steve Saucier, and he's the service manager at Hudson Valley Motorcycles and he does custom tuning. Mostly on Ducati's and BMW's, and most anything else with two wheels and a motor. steve@hvmotorcycles.com

[whippers]

Actual Dyno results.

I have yet to pick it up, but I feel real good about what I see based on how it ran when I dropped it off.

Tuned by cracking the stock ECU. From my tuner: "So lots of changes to lambda targets, fuel trim per cylinder and cylinder correction factors.Plus ignition timing, also there are some restrictors we remove. We also tuned individual cylinders as left to right were way different. I do find tuning individual cylinders when I can that makes more power and better throttle response which makes the engine more efficient too. The ignition we adjust both cylinders together, not separate, only added 3 degrees. What is best about a custom tune, like what we did is less parts so less potential failures plus we can do so much more with."

If anyone in the NY metro area needs a tune, his name is Steve Saucier, and he's the service manager at Hudson Valley Motorcycles and he does custom tuning. Mostly on Ducati's and BMW's, and most anything else with two wheels and a motor. steve@hvmotorcycles.com

looking good

[Hoiho]

Actual Dyno results.

I have yet to pick it up, but I feel real good about what I see based on how it ran when I dropped it off.

Tuned by cracking the stock ECU. From my tuner: "So lots of changes to lambda targets, fuel trim per cylinder and cylinder correction factors.Plus ignition timing, also there are some restrictors we remove. We also tuned individual cylinders as left to right were way different. I do find tuning individual cylinders when I can that makes more power and better throttle response which makes the engine more efficient too. The ignition we adjust both cylinders together, not separate, only added 3 degrees. What is best about a custom tune, like what we did is less parts so less potential failures plus we can do so much more with."

If anyone in the NY metro area needs a tune, his name is Steve Saucier, and he's the service manager at Hudson Valley Motorcycles and he does custom tuning. Mostly on Ducati's and BMW's, and most anything else with two wheels and a motor. steve@hvmotorcycles.com

Looks like it might use a bit more gas now. AFR is highest at 7500 - going have to ride everywhere at redline for best economy 

[NJ Mike]

Looks like it might use a bit more gas now. AFR is highest at 7500 - going have to ride everywhere at redline for best economy 

I'm sure fuel mileage will take a hit. I was averaging 60 mpg, with a low of 56 and a high of 70. And that's with the hi-compression 650 pistons, the Kent/Hitchcocks cam, open head pipes and S&S cans with the baffle. The stock motor got worse gas mileage, more like an average of 55, with a high of 60.

I should be in a better power territory, and with the previous AFR I was too lean and getting detonation in specific situations, like at 5k or so in gears 4-6 when giving it more gas on a hill. This should be cured, according to Steve. I'll gladly take a slight hit on mileage for a better running motor. Hopefully I won't be any worse than stock.

I'll give post a follow up as soon as I can pick it up.

[Blazes Boylan]

Actual Dyno results.

I have yet to pick it up, but I feel real good about what I see based on how it ran when I dropped it off.

Tuned by cracking the stock ECU. From my tuner: "So lots of changes to lambda targets, fuel trim per cylinder and cylinder correction factors.Plus ignition timing, also there are some restrictors we remove. We also tuned individual cylinders as left to right were way different. I do find tuning individual cylinders when I can that makes more power and better throttle response which makes the engine more efficient too. The ignition we adjust both cylinders together, not separate, only added 3 degrees. What is best about a custom tune, like what we did is less parts so less potential failures plus we can do so much more with."

If anyone in the NY metro area needs a tune, his name is Steve Saucier, and he's the service manager at Hudson Valley Motorcycles and he does custom tuning. Mostly on Ducati's and BMW's, and most anything else with two wheels and a motor. steve@hvmotorcycles.com

Thanks for the contact info.  Ossining is only an hour north of me  Sweet!

[NJ Mike]

Thanks for the contact info.  Ossining is only an hour north of me  Sweet!

He does tuning as his own business, and his shop is in Chester NY. He'll give you the info when you get in touch with him.

[Starpeve]

My experience in modding engines ( minor compared to some here) is of vague disappointment. There always seems to be a trade off, which usually I’ve been unhappy with.
A perkier engine with less practicality, for instance. I did up one V8 listening to pros, and ended up with no bottom end grunt, but high RPM power. Why? Who the fuck wants a V8 with no bottom end? My fault for being unclear, I suppose. But introducing more variables of failure into a situation has become anathema to me.
I admire your pursuit, and wish you luck, whilst following your work with interest, but not for me. 👍

[NJ Mike]

My experience in modding engines ( minor compared to some here) is of vague disappointment. There always seems to be a trade off, which usually I’ve been unhappy with.
A perkier engine with less practicality, for instance. I did up one V8 listening to pros, and ended up with no bottom end grunt, but high RPM power. Why? Who the fuck wants a V8 with no bottom end? My fault for being unclear, I suppose. But introducing more variables of failure into a situation has become anathema to me.
I admire your pursuit, and wish you luck, whilst following your work with interest, but not for me. 👍

That's why I went with the cam I did, it didn't have a negative effect on the bottom end. And higher compression pistons gave me a nice boost everywhere. But I do get a nice hit in the fun zone without it being at all peaky. I'm really stoked with the results, and that was before the tune. It's a very linear and tractable motor, with a lot more grunt to drag my fat ass up hills and around a line of slowpokes.

[whippers]

That's why I went with the cam I did, it didn't have a negative effect on the bottom end. And higher compression pistons gave me a nice boost everywhere. But I do get a nice hit in the fun zone without it being at all peaky. I'm really stoked with the results, and that was before the tune. It's a very linear and tractable motor, with a lot more grunt to drag my fat ass up hills and around a line of slowpokes.

so you have full exhaust, cam and high comp pistons right not big bore?  Also rekluse clutch?

[RecoilRob]

My experience in modding engines ( minor compared to some here) is of vague disappointment. There always seems to be a trade off, which usually I’ve been unhappy with.
A perkier engine with less practicality, for instance. I did up one V8 listening to pros, and ended up with no bottom end grunt, but high RPM power. Why?

Torque is mostly a function of displacement and little can be done (besides force feeding) to greatly increase the peak value without increasing the size of the motor.  Because horsepower is a calculation of torque x rpm if we can't increase the torque...the next easiest way to make more power is to rev it higher.  As long as the revs are increasing faster than the torque is falling...the HP will increase.

It's very common for the 'HP' version of an engine to have LESS peak torque than a lesser version of that same engine due to the camshaft timing being optimized for high rpm use.   The 'trick' (if it exists) is to make better power higher up in the rpm range without destroying the bottom end....and the cams available for the 650 are successful in this effort.   Increasing CR will also bump the torque across the board if it's done properly at the expense of needing better fuel to stay alive.

The 4 valve head really is a game changer when it comes to making power across a broad power band.   A similar displacement 2 valve engine can make about the same top end power...but needs a LOT more cam timing to equal the flow of the 4 valve head.   This means the 4 valve engine will run right with the 2 valve up on top but also have a lot better behavior down low because it doesn't need as much cam timing.

[NVDucati]

Torque is mostly a function of displacement and little can be done (besides force feeding) to greatly increase the peak value without increasing the size of the motor.  Because horsepower is a calculation of torque x rpm if we can't increase the torque...the next easiest way to make more power is to rev it higher.  As long as the revs are increasing faster than the torque is falling...the HP will increase.

It's very common for the 'HP' version of an engine to have LESS peak torque than a lesser version of that same engine due to the camshaft timing being optimized for high rpm use.   The 'trick' (if it exists) is to make better power higher up in the rpm range without destroying the bottom end....and the cams available for the 650 are successful in this effort.   Increasing CR will also bump the torque across the board if it's done properly at the expense of needing better fuel to stay alive.

The 4 valve head really is a game changer when it comes to making power across a broad power band.   A similar displacement 2 valve engine can make about the same top end power...but needs a LOT more cam timing to equal the flow of the 4 valve head.   This means the 4 valve engine will run right with the 2 valve up on top but also have a lot better behavior down low because it doesn't need as much cam timing.

Well said!
Another "trick" is the EXUP valve. Initially, a Yamaha innovation and now, patent expired, found in a lot of brands.
It bridges those issues that you correctly describe and I'd be surprised if some aftermarket exhaust system doesn't offer one for our twins soon.
The EXUP goes almost unnoticed considering how widely it is used.
https://classic-motorbikes.net/brilliant-biking-inventionsthe-exup-valve/

[iblastoff]

damn anyone know any modding/tuning experts in ontario or the GTA specifically??

i want to explore squeezing out more HP on my gt650, whether its a full big bore or 'just' cams/pistons etc.

[NJ Mike]

so you have full exhaust, cam and high comp pistons right not big bore?  Also rekluse clutch?

Yes, full exhaust, cam and high comp 650 pistons. And a Rekluse clutch.

I didn't want more displacement for a variety of reasons that mostly centered around the idea that the engine would then be beyond the design parameters of the frame, brakes, suspension and throttle bodies, thus necessitating an order of magnitude more investment of time and money. And then there's the added complexity of making that pile of parts work together.

I wanted a bit more torque and HP, and based on what I see on my graph, I got what I set out to do. Same pleasant demeanor of a stock bike down low, and a steady build to +9 ft lbs of torque and +19 of hp over the stock engine in a very smooth progression. Mission accomplished.

On my own, with my limited skills and my small pile of crappy tools, I'd have left it mostly stock. But having Wrenchjockie as a friend, instigator and facilitator of all things mechanical, I slowly lost my ability to resist. That and the fact that it would slow down on steep uphills while trying to pass coal trucks in WV while loaded with me and my gear, I convinced myself that it was a safety issue. I can be very convincing to myself, because if safety was really the issue, I should just go slower. But really, who wants to go slower?

[NVDucati]

Yes, full exhaust, cam and high comp 650 pistons. And a Rekluse clutch.

I didn't want more displacement for a variety of reasons that mostly centered around the idea that the engine would then be beyond the design parameters of the frame, brakes, suspension and throttle bodies, thus necessitating an order of magnitude more investment of time and money. And then there's the added complexity of making that pile of parts work together.

I wanted a bit more torque and HP, and based on what I see on my graph, I got what I set out to do. Same pleasant demeanor of a stock bike down low, and a steady build to +9 ft lbs of torque and +19 of hp over the stock engine in a very smooth progression. Mission accomplished.

On my own, with my limited skills and my small pile of crappy tools, I'd have left it mostly stock. But having Wrenchjockie as a friend, instigator and facilitator of all things mechanical, I slowly lost my ability to resist. That and the fact that it would slow down on steep uphills while trying to pass coal trucks in WV while loaded with me and my gear, I convinced myself that it was a safety issue. I can be very convincing to myself, because if safety was really the issue, I should just go slower. But really, who wants to go slower?

Big Congrats!
Success should only and always be measured against the original goal.
Good job.

[whippers]

Well said!
Another "trick" is the EXUP valve. Initially, a Yamaha innovation and now, patent expired, found in a lot of brands.
It bridges those issues that you correctly describe and I'd be surprised if some aftermarket exhaust system doesn't offer one for our twins soon.
The EXUP goes almost unnoticed considering how widely it is used.
https://classic-motorbikes.net/brilliant-biking-inventionsthe-exup-valve/

I had an 1988 FZR400 EXUP racer. The cycling of the exup valve upon turning the key sounded so trick back then. I think that was the first model to have an exup valve.

[whippers]

Yes, full exhaust, cam and high comp 650 pistons. And a Rekluse clutch.

I didn't want more displacement for a variety of reasons that mostly centered around the idea that the engine would then be beyond the design parameters of the frame, brakes, suspension and throttle bodies, thus necessitating an order of magnitude more investment of time and money. And then there's the added complexity of making that pile of parts work together.

I wanted a bit more torque and HP, and based on what I see on my graph, I got what I set out to do. Same pleasant demeanor of a stock bike down low, and a steady build to +9 ft lbs of torque and +19 of hp over the stock engine in a very smooth progression. Mission accomplished.

On my own, with my limited skills and my small pile of crappy tools, I'd have left it mostly stock. But having Wrenchjockie as a friend, instigator and facilitator of all things mechanical, I slowly lost my ability to resist. That and the fact that it would slow down on steep uphills while trying to pass coal trucks in WV while loaded with me and my gear, I convinced myself that it was a safety issue. I can be very convincing to myself, because if safety was really the issue, I should just go slower. But really, who wants to go slower?

Very nice to get 60hp at the wheel. I think you have S&S silencers which headers do you have? Also are the results with baffles in or out?

[FormerStar]

Because horsepower is a calculation of torque x rpm if we can't increase the torque...the next easiest way to make more power is to rev it higher.

If anyone is interested,  the formula we all know:

Horsepower = Torque (measured in lbs/ft) × RPM ÷ 5252


As mentioned earlier in this thread, to increase HP,  keep torque levels up into the higher end of the rev range.

How you accomplish that is the science. This part is just the math.





As usual,  little of substance from me. Have a nice day.

[RecoilRob]

It's surprising how many people aren't aware of how dyno's measure power output.   I often ask people a semi-trick question:  Can you directly measure Horsepower?  And...of course...everyone pretty much says SURE!!  You put it on a dyno and it measures the Horsepower...you dummy.   

But the 'trick' is the word 'directly'...which of course the dyno cannot do.  It CAN directly measure the torque output, and it CAN directly measure the RPM...but the Horsepower is a calculation derived from both of those direct measurements.

[whippers]

It's surprising how many people aren't aware of how dyno's measure power output.   I often ask people a semi-trick question:  Can you directly measure Horsepower?  And...of course...everyone pretty much says SURE!!  You put it on a dyno and it measures the Horsepower...you dummy.   

But the 'trick' is the word 'directly'...which of course the dyno cannot do.  It CAN directly measure the torque output, and it CAN directly measure the RPM...but the Horsepower is a calculation derived from both of those direct measurements.

Do you get many return invites to dinner parties? 

[NJ Mike]

Very nice to get 60hp at the wheel. I think you have S&S silencers which headers do you have? Also are the results with baffles in or out?

Yes, S&S with the baffles IN, it's too loud without them. I have the Hitchcocks headers, which are very nice brushed stainless and they match the mufflers, and weigh many pounds less than the original boat anchors.

[RecoilRob]

Do you get many return invites to dinner parties? 

Actually no...I'm a hermit and avoid as much human interaction as possible.

[NJ Mike]

I finally picked up my bike after having the stock ECU cracked with a new tune.

OMFG! It just leaps forward. I hardly have to twist the throttle and it just wants to go. Even while cruising, again it seems I hardly have to move the throttle and it always feels like it's pulling. And when I do whack the throttle open, it just goes a LOT faster and in a hurry. Oddly enough, with the extra power it's faster and yet seems more relaxed, like it's not working hard at all.

When the bike was stock it would eventually go faster, but not by much. I found myself hesitating and/or unable to pass or accelerate up hills without serious downshifting and planning, and even then, sometimes it would just run out of power and bog down. I could have lived with it the way it was, but a voice in my ear kept saying we could make it better. That voice, Wrenchjockie, can be very persistent, and he has the knowledge and tools to back it up with an actual ability to get the work done. And we did.

Steve was able to change the ignition timing and tune each cylinder individually, he said they were very different, and the result is that now it's smoother everywhere on the tach, and with all on and off the throttle transitions. There used to be a bit of a buzz in the left bar that would bother my hand and make it a numb, and now it's gone completely. He took the pile of parts we put on the bike and made them all work in harmony.

I'm so happy with the work we did, and with the result. It's all I could have hoped for, still friendly, civilized and linear as the day it rolled off the assembly line, but now even more so. It's making 60 hp and 47 ft lbs of torque. Similar power to my stock 1st gen SV650, but with almost 10 ft lbs more torque, and I don't have to rev the hell out of it.

Here is a list of changes made to hardware: S&S mufflers and 650 High Compression Pistons, Hitchcocks/Kent Stage II Cam, Hitchcocks headers and air injection delete kit, DNA air filter and air box snorkel delete plate, Recluse clutch, plus Wrenchjockie cleaned up the intake and exhaust ports on the head and honed the cylinders.

The tuner is Steve Saucier who is the service manager at hudsonvalleymotorcycles.com in Ossining NY. He runs his own dyno tune shop in Chester NY. If anyone is interested, you can reach him at steve@hvmotorcycles.com. He is deeply knowledgable and has decades of tuning experience.

After my next ride or two I'll report back with fuel mileage as compared to the previous iteration.

[NVDucati]

That is really great news! Congratulations !!!

[iblastoff]

awesome. 60hp sounds just about right for this bike. honestly probably what it should have been stock if they didnt try to conform to a2-license stuff.

[Blazes Boylan]

Congratulations.  That’s great to hear.

[Keef Sparrow]

awesome. 60hp sounds just about right for this bike. honestly probably what it should have been stock if they didnt try to conform to a2-license stuff.

Yes, it's a shame they didn't make a version like this alongside the A2 license version - could have sold a lot more bikes.

[Intybe]

Congrats NJ. Well done! I'm so glad to hear it all came together and exceeded your expectations. And great that you give credit where credits due, to wrenchjockie and Steve your tuner. Working with people you trust and appreciate is so cool. May you enjoy many thousands of miles of smiles 🎉🥳

[NJ Mike]

Congrats NJ. Well done! I'm so glad to hear it all came together and exceeded your expectations. And great that you give credit where credits due, to wrenchjockie and Steve your tuner. Working with people you trust and appreciate is so cool. May you enjoy many thousands of miles of smiles 🎉🥳

Thanks! I was more like a not-so-innocent bystander to their work. My job was to decide which parts to buy and not drop any nuts into the crankcase. I can do all of the basic maintenance on my bike with fairly simple tools, but I know my limitations.

Wrenchjockie was trying to egg me on to more displacement, but I resisted and am glad I did because the mission creep at that point would have been wallet busting.

Compared to these guys, who are true mechanics with a wealth of knowledge, I'm just a guy with a wrench who doesn't know much at all. I'm very lucky that they allow a dolt like me to hang out with them. But I do know how a good bike should feel when I ride it, and that's what matters.

One of the reasons I got this bike was because it was so approachable from a mechanical standpoint. I understood that it was built to a price point and also that it had more potential. As it was box stock, it was better than the sum of its parts, and with changes to tires, suspension, visibility and ergonomics as the first priorities, performance came second. And all of the mods have made it better, but the original character of the bike remains intact, which is also what I wanted.

Maybe I'll polish it one day and make it prettier too. 

[NJ Mike]

It seems hot rodding the motor, and a proper tune, doesn't kill fuel mileage.

With the dyno tune and all the mods, my gas mileage so far is averaging 64 mpg, with a heavy throttle hand. The worst is 60 mpg, and the best so far is 68 mpg.

Since the mods, with the Power Commander and now with the ECU tune, mileage has bee as good, if not better, than with the stock motor. I was often getting mid 50's before any mods. With the stock motor I had to wring it out all the time, and now, what I need is just a slight twist of the wrist. I'm using a lot less throttle pretty much all the time.

And the bike is perfectly happy on backroads to putt along at 2500 - 3000 rpm, with a 16t front sprocket, and when I need more it just grunts it out. Fun.

[Wrenchjockie]

Amazing! 42% increase in HP, and still great gas mileage! And great rideability.
FWIW, 60 HP is what a stock R100 BMW Airhead put out.
Still waiting for a Nikasil 750 kit :-)

[whippers]

Amazing! 42% increase in HP, and still great gas mileage! And great rideability.
FWIW, 60 HP is what a stock R100 BMW Airhead put out.
Still waiting for a Nikasil 750 kit :-)

Surely there R100 60hp was at the crank not the wheel? I seem to recall the R80 was 50hp? When I was young and obsessed only with Japanese performance bikes I used to sneer at the R80 which in the mid 80s was already seriously an old man’s bike.  The other day I saw an older gent on a lovely white R80RS and thought I’d love to have a ride on that!

[whippers]

It seems hot rodding the motor, and a proper tune, doesn't kill fuel mileage.

With the dyno tune and all the mods, my gas mileage so far is averaging 64 mpg, with a heavy throttle hand. The worst is 60 mpg, and the best so far is 68 mpg.

Since the mods, with the Power Commander and now with the ECU tune, mileage has bee as good, if not better, than with the stock motor. I was often getting mid 50's before any mods. With the stock motor I had to wring it out all the time, and now, what I need is just a slight twist of the wrist. I'm using a lot less throttle pretty much all the time.

And the bike is perfectly happy on backroads to putt along at 2500 - 3000 rpm, with a 16t front sprocket, and when I need more it just grunts it out. Fun.

That’s high compression for you, big gains in efficiency

[NJ Mike]

That’s high compression for you, big gains in efficiency

Kinda what I was thinking before we even started. And really glad it worked. I think the Kent cam is a keeper too. When I just had that with the headers and stock pistons, the increase in power was enough to make the stock clutch slip.

If anyone else wants to do this, we have a spare head and cylinders. It's much easier to have a freshly honed set of jugs and a head with the valves, springs and shims pre-installed and ready to go. That way you pull the old stuff, change the pistons and slip on the new stuff and off you go. Bolts right on, 20 minutes tops. Not really, unless you're looking at utube.

If you throw money at someone, maybe they'll even hone the cylinders and smooth out the ports before you get them. Let me know.

And some people thought the hone job wasn't right, but I'm here to attest that it seems pretty darn good. No use of any oil over a few thousand miles, even while thrashing it in the mountains.