want a little more power
02-08-2008, 06:12 AM
#32
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My superhawk put 103/63 down. I felt pretty happy about this, considering I am running "highway gearing" (taller gearing than stock). If I changed to a 16:43 setup, I would pick up a little. The thing that I do know, if flyweight is bad for HP, then wheels are a big deal. If you want to be the fastest on the road, get lighter wheels, and the lightest tires. Say good by to ---road tires and hello to "i hope i get 3000 miles from this set". The dyno will show hp to the ground. You aren't increasing engine power, just making bette use of it.
If you look at the cost of wheels, about $3000. Cost of cams and pistons $1000. Having someone machine flywheel, $100+ Port and polish, er $$$. Price of acceleration, cheaper to do engine work, price of a bike that handles COMPLETELY different, relatively cheap in comparison.
I still vote tires and wheels, just cause they can make a huge difference. For example: audi a4 1.8t with lighest available wheels and heavy rubber ran 3 seconds slower around blackhawk farms then same vehicle, with only DIFF rubber. All we did was change the tires, nothing else, for 3 seconds. That is a huge difference. Braking, accel, turning are all going to be more responsive.
If you look at the cost of wheels, about $3000. Cost of cams and pistons $1000. Having someone machine flywheel, $100+ Port and polish, er $$$. Price of acceleration, cheaper to do engine work, price of a bike that handles COMPLETELY different, relatively cheap in comparison.
I still vote tires and wheels, just cause they can make a huge difference. For example: audi a4 1.8t with lighest available wheels and heavy rubber ran 3 seconds slower around blackhawk farms then same vehicle, with only DIFF rubber. All we did was change the tires, nothing else, for 3 seconds. That is a huge difference. Braking, accel, turning are all going to be more responsive.
02-08-2008, 06:39 AM
#34
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My superhawk put 103/63 down. I felt pretty happy about this, considering I am running "highway gearing" (taller gearing than stock). If I changed to a 16:43 setup, I would pick up a little. The thing that I do know, if flyweight is bad for HP, then wheels are a big deal. If you want to be the fastest on the road, get lighter wheels, and the lightest tires. Say good by to ---road tires and hello to "i hope i get 3000 miles from this set". The dyno will show hp to the ground. You aren't increasing engine power, just making bette use of it.
If you look at the cost of wheels, about $3000. Cost of cams and pistons $1000. Having someone machine flywheel, $100+ Port and polish, er $$$. Price of acceleration, cheaper to do engine work, price of a bike that handles COMPLETELY different, relatively cheap in comparison.
I still vote tires and wheels, just cause they can make a huge difference. For example: audi a4 1.8t with lighest available wheels and heavy rubber ran 3 seconds slower around blackhawk farms then same vehicle, with only DIFF rubber. All we did was change the tires, nothing else, for 3 seconds. That is a huge difference. Braking, accel, turning are all going to be more responsive.
If you look at the cost of wheels, about $3000. Cost of cams and pistons $1000. Having someone machine flywheel, $100+ Port and polish, er $$$. Price of acceleration, cheaper to do engine work, price of a bike that handles COMPLETELY different, relatively cheap in comparison.
I still vote tires and wheels, just cause they can make a huge difference. For example: audi a4 1.8t with lighest available wheels and heavy rubber ran 3 seconds slower around blackhawk farms then same vehicle, with only DIFF rubber. All we did was change the tires, nothing else, for 3 seconds. That is a huge difference. Braking, accel, turning are all going to be more responsive.
02-08-2008, 07:37 AM
#36
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Depends on the type of dyno. On an inertia dyno, yes. One that measures reaction torque and RPM, no.
I am putting a down payment on the RC51 I built at the end of this month. Permission for it to cross the border into my compound starts next January. Meanwhile, I'm collecting parts.
I am putting a down payment on the RC51 I built at the end of this month. Permission for it to cross the border into my compound starts next January. Meanwhile, I'm collecting parts.
02-08-2008, 01:25 PM
#38
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autoteach is right.
i got to feel pretty fast among the 'B' group of street riders at track days.
Now I'm going ot be on a track bike, with a bunch of racers with time and money for track days, on a bike that's built for the track.
I was pretty good in the B group. Passed a lot of faster bikes. Now I'm going to school.
No illusions about that!
i got to feel pretty fast among the 'B' group of street riders at track days.
Now I'm going ot be on a track bike, with a bunch of racers with time and money for track days, on a bike that's built for the track.
I was pretty good in the B group. Passed a lot of faster bikes. Now I'm going to school.
No illusions about that!
02-08-2008, 02:01 PM
#39
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autoteach is right.
i got to feel pretty fast among the 'B' group of street riders at track days.
Now I'm going ot be on a track bike, with a bunch of racers with time and money for track days, on a bike that's built for the track.
I was pretty good in the B group. Passed a lot of faster bikes. Now I'm going to school.
No illusions about that!
i got to feel pretty fast among the 'B' group of street riders at track days.
Now I'm going ot be on a track bike, with a bunch of racers with time and money for track days, on a bike that's built for the track.
I was pretty good in the B group. Passed a lot of faster bikes. Now I'm going to school.
No illusions about that!
I raced in the CMRA for 2 years on my gsxr 750. Not much could touch that bike on the track or street for that matter. I raced it on the weekends and rode it to work m-f and don't get me wrong, it was a race bike. I had 2 bodies and no lights, only rode during the day.
I am just used to riding with friends and being able to pull any of them. I may just have to loose 30 lbs of rider and get a set of forged alum wheels.
How did you have to modify your gsxr wheels. I did find some for an rc51 but don't know what the differences are between those and vtr wheels.
02-08-2008, 04:49 PM
#41
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The rear wheel should be very similar. Maybe some spacer changes.
The front rotors are completely different. Different rotor hub diameter and offset.
But then, the Super Hawk doesn't really start working unitl you put RC51 forks on it.
Make it fast, and the limitations start to show. I put legs under it, before I put a motor in it. Actually, I did both at the same time. You're going to want better brakes too. Not so much on the street, but definitely on the track.
At the track, it's more the rider, than what he's riding. I passed some really fast bikes and also got passed by racers on SV650s. It alway felt good to pass a GSXR/CBR/R600 on the inside and pull away from a 999/998 on the straights. A race-prepped bike will make a big difference, but I am still going to get schooled in the A group. I look forward to the education. I was ready to move up when I threw my bike in the ditch.
I didn't modify GSXR wheels. I was told they are not interchangable with Honda wheels by the sales rep at TAW ( the Marchesini distributor). People all ove the web are saying that the bolt-on adapters are the only difference. Not true, according to the 1 rep I talked to. Maybe she didin't know. Just a warning not to go headlong down that road without more information.
The front rotors are completely different. Different rotor hub diameter and offset.
But then, the Super Hawk doesn't really start working unitl you put RC51 forks on it.
Make it fast, and the limitations start to show. I put legs under it, before I put a motor in it. Actually, I did both at the same time. You're going to want better brakes too. Not so much on the street, but definitely on the track.
At the track, it's more the rider, than what he's riding. I passed some really fast bikes and also got passed by racers on SV650s. It alway felt good to pass a GSXR/CBR/R600 on the inside and pull away from a 999/998 on the straights. A race-prepped bike will make a big difference, but I am still going to get schooled in the A group. I look forward to the education. I was ready to move up when I threw my bike in the ditch.
I didn't modify GSXR wheels. I was told they are not interchangable with Honda wheels by the sales rep at TAW ( the Marchesini distributor). People all ove the web are saying that the bolt-on adapters are the only difference. Not true, according to the 1 rep I talked to. Maybe she didin't know. Just a warning not to go headlong down that road without more information.
02-08-2008, 06:16 PM
#42
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Ok, I misread your post on the previous page. I re-read and understand now. I don't think I could stomach 3k for magnesium wheels, but 1800 is doable. Especially since I work in an aerospace machine shop with full plating capabilities. IE...anodize whatever color I want for free. I would love to find a set of magnesium USED.
02-08-2008, 07:53 PM
#43
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If you can find a supplier, a company called PVM make wheels that fit the VTR1000f directly.
Forged magnesium or forged aluminium. The aluminium ones I was looking at would be around $2200, but thats if you bought them fromt he UK. I'm sure a USA supplier would be a better deal.
Forged magnesium or forged aluminium. The aluminium ones I was looking at would be around $2200, but thats if you bought them fromt he UK. I'm sure a USA supplier would be a better deal.
02-09-2008, 12:17 AM
#45
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Oh, but you don't understand. I can't have it just sitting in my garage all winter.
Taking it apart and making it better is at least half the fun of owning it.
Fixing the washing machine, tuning the skis and snowblowing the driveway just don't have the same appeal! I tried getting obsessed with bicyces and climbing again, but that didn't work either.
Sometimes I wish I wasn't so obsessed with these things, but I just have to go with it.
Taking it apart and making it better is at least half the fun of owning it.
Fixing the washing machine, tuning the skis and snowblowing the driveway just don't have the same appeal! I tried getting obsessed with bicyces and climbing again, but that didn't work either.
Sometimes I wish I wasn't so obsessed with these things, but I just have to go with it.
02-09-2008, 05:19 AM
#46
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luckily in Texas, I get to ride ALL winter. It was only 34 degrees this morning and I rode to work.
mikecronis: Sometimes, somepeople just can't leave well enough alone! I am one of those people. There is always something you can do to make things better.
I will look into the PVM wheels. Thanks.
mikecronis: Sometimes, somepeople just can't leave well enough alone! I am one of those people. There is always something you can do to make things better.
I will look into the PVM wheels. Thanks.
02-10-2008, 03:37 PM
#47
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My engine have hi comp JE pistons, ported and finished intake and exhaust, finished and polished combustion chambers, balanced conrods and crankshaft, BMC race filter, Dynojet kit (US spec), two short trumpets on both carbs and GPR street legal slipons (with db killer) and stock headers.
You can see my dyno chart on the forum gallery.
Bye
02-10-2008, 03:59 PM
#48
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Best I've seen is 140bhp from the RUMI built race bike.
Rumi Superbike VTR specs: 140bhp, 163Kg, Moriwaki and Robby Moto Engineering parts, WP suspension front and rear, Arrow pipe, Marvic Penta Magnesium wheels, reinforced rear swingarm, 520 chain, CF airbox, Brembo brake parts, engine heavily modified.
Rumi Superbike VTR specs: 140bhp, 163Kg, Moriwaki and Robby Moto Engineering parts, WP suspension front and rear, Arrow pipe, Marvic Penta Magnesium wheels, reinforced rear swingarm, 520 chain, CF airbox, Brembo brake parts, engine heavily modified.
It was dynoed by italian magazine SuperMotoTecnica in june 2001
02-10-2008, 04:53 PM
#49
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Just reading this thread. With mods very similar to what Azzkicker posted and what RCVTR had done before, I got very similar numbers. I did not mill the heads but used HiComp pistons, stage 1 cams and cleaned up the intake ports. The lower curve was the mods with slipons, the upper curves were after full exhaust and some hrc tuning parts. It all started stock at about 100hp.
15% on a bike making 100hp is a VERY noticeable difference and really changes the character of the bike, but keeps it completely rideable in all conditions. It is expensive per hp, but as has been said here, most of us do it because we love working on them, get obsessed chasing improvements or want to keep learning something about how they tick. bang for buck, I think the suspension mods are best yield, but the added power sure makes it a blast to ride.
bill
15% on a bike making 100hp is a VERY noticeable difference and really changes the character of the bike, but keeps it completely rideable in all conditions. It is expensive per hp, but as has been said here, most of us do it because we love working on them, get obsessed chasing improvements or want to keep learning something about how they tick. bang for buck, I think the suspension mods are best yield, but the added power sure makes it a blast to ride.
bill
02-10-2008, 06:45 PM
#50
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Riccardo, that number seems a bit hight compared to others I've seen. I'm not saying you haven't done an excellent job (or whomever did the work). I'm sure you/they have. It's just that there are a lot of variables in dyno testing, and my info comes from a known (to me) source.
You have lighened the crank and flywheel, which changes the inertial mass of the engine. Lighter wheels, chain etc. will also effect drivetrain inertia. Was any calibration done to account for this? And how long was the sweep time? The most accurate measurement occurs in the absence of acceleration. Although by the seat of the pants, lower inertia = more power
I'm not really trying to argue, so much as learn more about testing.
And I am sitting in a hotel room in Narva, Estonia and can't sleep.
Hopefully someone can add to my limited knowledge.
cheers,
Rand
You have lighened the crank and flywheel, which changes the inertial mass of the engine. Lighter wheels, chain etc. will also effect drivetrain inertia. Was any calibration done to account for this? And how long was the sweep time? The most accurate measurement occurs in the absence of acceleration. Although by the seat of the pants, lower inertia = more power
I'm not really trying to argue, so much as learn more about testing.
And I am sitting in a hotel room in Narva, Estonia and can't sleep.
Hopefully someone can add to my limited knowledge.
cheers,
Rand
02-11-2008, 06:02 AM
#52
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Its funy, the rumi bike had the same issues that my bike had. When I made my custom exhaust, it had toooooooo much flow for the jetting overlaps and I ended up with a hole at 6500rpm. It looked exactly the same on my dyno sheet. It was easier to fix then one would think. I had a packing error on my exhaust and blew an endcap at 80mph into a farmers field. I used a shifter cart endcap, 1" outlet, to fill the void. It cam alive and the first time I got on it in first I smashed into the rev limiter. This only works because we don't have tru duals, especially my for my setup.
02-11-2008, 03:45 PM
#53
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I don't know what to say!!!
I've dynoed my bike 3 times on the same dyno at sea level.
First time, in 2004, I read 105,9 hp at 8700 rpm whit stock exhaust, BMC race filter and Dynojet kit (European Spec).
I think that this value is reliable compared to the Stock VTR's dyno runs I've seen. They are all between 103 and 105 Hp, both the ones done by Dynojet and those done on the Dyno I used.
Two years later, in 2006 with the big engine work done, I read 117 hp at 9000 rpm, but there was an electrical problem on the rear cylinder that caused a slight misfiring.
Next year, with electrical problem solved, I've done my "ultimate" dyno run reading 119 hp at 9000.
The only inertial change I've done is a 520 chain kit in 2007.
Probably I've been very lucky doing my porting-finishing-polishing-grinding job!
That's all I can say.
I've dynoed my bike 3 times on the same dyno at sea level.
First time, in 2004, I read 105,9 hp at 8700 rpm whit stock exhaust, BMC race filter and Dynojet kit (European Spec).
I think that this value is reliable compared to the Stock VTR's dyno runs I've seen. They are all between 103 and 105 Hp, both the ones done by Dynojet and those done on the Dyno I used.
Two years later, in 2006 with the big engine work done, I read 117 hp at 9000 rpm, but there was an electrical problem on the rear cylinder that caused a slight misfiring.
Next year, with electrical problem solved, I've done my "ultimate" dyno run reading 119 hp at 9000.
The only inertial change I've done is a 520 chain kit in 2007.
Probably I've been very lucky doing my porting-finishing-polishing-grinding job!
That's all I can say.
02-11-2008, 04:40 PM
#54
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On that note - does anyone have a spec for machining the flywheel? I wanted to do this the last time I had mine apart. The balancing holes drilled in it got me scared, the last thing I want is an engine vibration (a bad one that is). I've seen pictures of the Moriwaki flywheel but that doesn't really help much. I don't have the ability to balance the flywheel after machining either. Any info would be greatly appreciated.
02-11-2008, 07:32 PM
#55
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Riccardo, it sounds good. Did you make major changes to the port sizes? Port and valve sizes are the main differences between the RC51 and VTR heads, and the differences are substantial. The RC51 makes ~120 RWHP stock and up to ~140 with stock cams. My porting was prety conservative and I did not have the resources to do more development. Good job!
Jamie, I was worried about that as well, but was told I would not notice the change in balance. I didn't. My engine purred like before. No noticable vibration. A 1/2" reduction in flywheel diameter will also not adversely affect the tractability around town.
If you do balance it, I believe you will want to balance the pistons, pins, rods, crank and flywheel together. I'm sure it would be better rebalanced after changing pistons, but it will be happy, if you don't. I was surprised by that. Bob was interested in helping me to stay within my budget, and everything he said turned out to be right.
Jamie, I was worried about that as well, but was told I would not notice the change in balance. I didn't. My engine purred like before. No noticable vibration. A 1/2" reduction in flywheel diameter will also not adversely affect the tractability around town.
If you do balance it, I believe you will want to balance the pistons, pins, rods, crank and flywheel together. I'm sure it would be better rebalanced after changing pistons, but it will be happy, if you don't. I was surprised by that. Bob was interested in helping me to stay within my budget, and everything he said turned out to be right.
02-11-2008, 10:12 PM
#57
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It ddoes all add up. Here's a comparison of an RC51, done by JHord at www.hordpower.com with stock cams.
Full Yosh, Thorsten airbox, ported heads, VP fuel, PC3R, Carmo extended rev limit, Wiseco high-comp pistons, Carrillo rods, Falicon Supercrank, etc. (vs. 100% stock bike)
Full Yosh, Thorsten airbox, ported heads, VP fuel, PC3R, Carmo extended rev limit, Wiseco high-comp pistons, Carrillo rods, Falicon Supercrank, etc. (vs. 100% stock bike)
02-11-2008, 11:59 PM
#59
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