Low end power

[jumjum01]

I have a stock gen1 hayabusa with full akrapovic system. I would like to improve low end power. I dont want to change the gearing, so don't suggest sprocket change.
I have been looking at gen2 crank swap and hi comp pistons, but cannot find any dyno sheets or hp numbers for these mods alone.
I have done airbox mod with 4 long trumpets with no noticeable difference.

 

[michael parris heuberger]

I have a stock gen1 hayabusa with full akrapovic system. I would like to improve low end power. I dont want to change the gearing, so don't suggest sprocket change.
I have been looking at gen2 crank swap and hi comp pistons, but cannot find any dyno sheets or hp numbers for these mods alone.
I have done airbox mod with 4 long trumpets with no noticeable difference.

Hi. Head port, cams, and pistons about 210 to 230 HP. Why do not want to change sprockets? I have changed my front and rear and in the transmission I have changed 1st gear and 5th and 6th gears.

 

[Bumblebee]

I have a stock gen1 hayabusa with full akrapovic system. I would like to improve low end power. I dont want to change the gearing, so don't suggest sprocket change.
I have been looking at gen2 crank swap and hi comp pistons, but cannot find any dyno sheets or hp numbers for these mods alone.
I have done airbox mod with 4 long trumpets with no noticeable difference.

Changing out the cams will give you more low end...other than that, a gearing change will be the best bang for the buck.

If money is no object, getting a big bore is the way to go although reliability becomes an issue.

 

[jumjum01]

Hi. Head port, cams, and pistons about 210 to 230 HP. Why do not want to change sprockets? I have changed my front and rear and in the transmission I have changed 1st gear and 5th and 6th gears.

I like the stock gearing.. 200+hp is nice, but how much HP at 2500rpm, 3000 rpm, 3500rpm, 4000rpm?

 

[jumjum01]

Changing out the cams will give you more low end...other than that, a gearing change will be the best bang for the buck.

If money is no object, getting a big bore is the way to go although reliability becomes an issue.

Many of the dyno sheets I have been able to find, where cams and exhaust have been upgraded, the HP numbers is lower than my bike below 7000rpm, but higher after 7000rpm which is not what I am looking for
Dont bigbore's have reputation for overheating and starting issues?

 

[Bumblebee]

Many of the dyno sheets I have been able to find, where cams and exhaust have been upgraded, the HP numbers is lower than my bike below 7000rpm, but higher after 7000rpm which is not what I am looking for
Dont bigbore's have reputation for overheating and starting issues?

They do indeed...the best way to get what you are looking for is probably going with a turbo...

An in line 4 can only give so much low end torque.

 

[jumjum01]

They do indeed...the best way to get what you are looking for is probably going with a turbo...

An in line 4 can only give so much low end torque.

I know it might be asking a lot from the busa's i4 engine. But when coming from a SV1000 bigbore bike the busa feels a little "slow" in low/mid rpm. But the i4 engine is much smoother and you can go all the way down to 1500rpm in 6 gear

 

[michael parris heuberger]

Many of the dyno sheets I have been able to find, where cams and exhaust have been upgraded, the HP numbers is lower than my bike below 7000rpm, but higher after 7000rpm which is not what I am looking for
Dont bigbore's have reputation for overheating and starting issues?

Hi. Yes they do. I have a Gen 1 with a Gen 2 crank, but I still use the 20mm pins. I have custom JE pistons at 10 to 1 custom Corrello rods and custom Web cams with oversize valves with Incone valves. The bike will be turbo with NOS It also has all carbon fiber bodywork.

 

[bigoltool]

I know it might be asking a lot from the busa's i4 engine. But when coming from a SV1000 bigbore bike the busa feels a little "slow" in low/mid rpm. But the i4 engine is much smoother and you can go all the way down to 1500rpm in 6 gear

Coming from an SV1000 and the Busa feels slow in comparison? Something aint right.

 

[Bumblebee]

I know it might be asking a lot from the busa's i4 engine. But when coming from a SV1000 bigbore bike the busa feels a little "slow" in low/mid rpm. But the i4 engine is much smoother and you can go all the way down to 1500rpm in 6 gear

The SV has it's power delivery a little lower on the rev range as many twins do. The in-lines like their revs.

That being said, if you lined up next to an SV1K on your Busa and went for broke, there'd be no contest, the Busa would eat it for breakfast.

An SV puts out 69 ftlbs (7200rpm) compared to around 100ftlbs (6700rpm) for a gen 1

I think turbo is the direction you are needing to go if you are finding your bike to be flat...before going that route you'll want to ensure your engine is healthy.

 

[ottafish]

Sell it, buy a Gen 2 or even a 3.
Failing that, you want more low end grunt, bit of headwork will help but the biggest kick will be adding cc's to the engine. For me, I'd go cc's over a turbo any day..
I've gone +2 on the rear and it woke the bike up. And only added 250rpm or so to cruising

 

[bigoltool]

Sell it, buy a Gen 2 or even a 3.
Failing that, you want more low end grunt, bit of headwork will help but the biggest kick will be adding cc's to the engine. For me, I'd go cc's over a turbo any day..
I've gone +2 on the rear and it woke the bike up. And only added 250rpm or so to cruising

No replacement for Displacement!

 

[ottafish]

No replacement for Displacement!

Amen to that

 

[fallenarch]

I know it might be asking a lot from the busa's i4 engine. But when coming from a SV1000 bigbore bike the busa feels a little "slow" in low/mid rpm. But the i4 engine is much smoother and you can go all the way down to 1500rpm in 6 gear

No offense but I think you might be looking at this wrong. An engine is designed for a certain powerband from compression ratios to stroke, to bore, to intake configuration. It's difficult to reduce performance (which is essentially what you want) as aftermarket cam makers are going to focus on getting more out of the engine. Obviously, since you say a Busa is weaker than an SV you haven't run the Busa to 7-8K rpm in first gear - it's practically unmanageable.

You ride the bike to the power band. Keep the Busa between 7K and redline and it is a monster. Ride it between 2-5K and it is a bit lethargic. Gearing changes will shift that power band up or down a bit, which may make it easier to keep the bike in the sweet spot or leave enough RPMs on top for max speed.

If you have ridden an R6 it is fast but you have to rock the gearbox constantly as there is no bottom end at all. My BMW 1250 on the other hand starts the party at less the 2K but it's all over at 9K. The Gen 1 and Gen 2 are engineered for speed, they have respectable bottom ends but if you want to pull tree stumps try a Bandit.

 

[Mythos]

I like the stock gearing.. 200+hp is nice, but how much HP at 2500rpm, 3000 rpm, 3500rpm, 4000rpm?

It won't accelerate real hard below 3500 rpm if you're in third gear or higher. I doubt even going with shorter gearing will make a huge difference at that low of an rpm. I have a +4 rear sprocket on my other bike and it's noticeable at low rpm but not earth shattering until the engine gets up to at least 3000 rpm.

I don't even know if you can go WOT at 2000 rpm in the higher gears without the engine bucking and bogging. If you get a custom tune you might be able to do that if you don't want to shift down. My other bike will accelerate smooth from 2000 rpm at WOT in 6th gear but I tuned it myself on the road. It's still not quick at that low of an rpm but it runs good if I ever want to operate it like that.

 

[Berlin Germany]

the values of gen2 trans is the same like in the gen1 - so it makes no sense to fumble around there.

all values taken of the two manuals.

only at the end reduction ratio they differ a very very lill bit at 2nd and 3rd digit after the decimal-dot.

so what the heck

if you really want a lot more power don´t play around
but
invest a huge bunch of bucks (10-14K and more) and
- put a turbo (gear selectively controlled) in
- and
- and
- and

and for speed wide over 300 km/h / 220 mph put "longer" 5th & 6th gear sprockets in plus reduce the chain sprocket´s ratio.

 

[jumjum01]

The SV has it's power delivery a little lower on the rev range as many twins do. The in-lines like their revs.

That being said, if you lined up next to an SV1K on your Busa and went for broke, there'd be no contest, the Busa would eat it for breakfast.

An SV puts out 69 ftlbs (7200rpm) compared to around 100ftlbs (6700rpm) for a gen 1

I think turbo is the direction you are needing to go if you are finding your bike to be flat...before going that route you'll want to ensure your engine is healthy.

The busa is the faster bike, no doubt about that, and it pulls very hard higher rpm.
I currently own a SV1000 and the busa and ride both bikes. The SV is bigbore and 10+HP i most of the rpm range over stock and only weigh 179kg.
I did own a Bandit 1200 (121rwhp exhaust+headwork) before the SV, but the SV has allmost same power and weigh 45kg less.
Under 5k rpm SV pulls extremly hard. I was hoping to make the busa do the same with gen2 crank and hi comp pistons.

 

[WuzzaCBXRider]

Have you ever run the SV in the quarter mile? Time?

 

[The Big Red One]

The busa is the faster bike, no doubt about that, and it pulls very hard higher rpm.
I currently own a SV1000 and the busa and ride both bikes. The SV is bigbore and 10+HP i most of the rpm range over stock and only weigh 179kg.
I did own a Bandit 1200 (121rwhp exhaust+headwork) before the SV, but the SV has allmost same power and weigh 45kg less.
Under 5k rpm SV pulls extremly hard. I was hoping to make the busa do the same with gen2 crank and hi comp pistons.

Unfortunately you're dealing with 2 completely different types of engines, a v-twin versus an inline 4. V-twins make their power down low, inline 4's make it up higher (and more of it). There's no real way to change those characteristics.... your best bet would be to get a v-4, they're known for having a compromise of the power delivery of a twin and I-4.

 

[jumjum01]

Have you ever run the SV in the quarter mile? Time?

nope, unfortunately not