More low end torque question

[RussellJ]

Im more of a low RPM riding kind of guy. Whats the best way for me to get some more torque in the lower RPMs? A tune is next on my list for engine modifications. Any other cheap ways to get some more torque without getting into cam work? Im also wanting to get a V&H header but ive heard that will hurt my low end torque also so i may not be going with that.

 

[kromdom]

gearing change via sprocket swap

 

[RussellJ]

gearing change via sprocket swap

Like going down a tooth or two in the rear? And the effect of gas mileage would be noticeable im sure.

I just want to weigh everything to see if the extra torque would be worth it. The busa is my daily driver

 

[kromdom]

post #2 here helped me understand: https://www.hayabusa.org/forum/general-bike-related-topics/137999-gearing.html

another good site: http://www.gearingcommander.com/

 

[RussellJ]

post #2 here helped me understand: https://www.hayabusa.org/forum/general-bike-related-topics/137999-gearing.html

another good site: Gearing Commander: Motorcycle Gear Ratio Calculator for Sprockets RPM Speed Chain

That does help alot. So if i went up 2 teeth in the back i shouldnt see too much of a fuel mileage change. Ill do some org searching cause i know a bunch of people have gone up in teeth and they will be some mpg numbers around here somewhere

 

[Rainbow7]

Russell, I went -1 + 2 on my '06. It gives much better acceleration down low.
I also have a set of FP Velocity Stacks (all long) which helps with midrange power, plus I've had my ECU flashed to put more power there.

 

[RussellJ]

Russell, I went -1 + 2 on my '06. It gives much better acceleration down low.
I also have a set of FP Velocity Stacks (all long) which helps with midrange power, plus I've had my ECU flashed to put more power there.

Velocity stacks are so expensive

ECU flash is going to come as soon as im back riding again and the weather in NC is bearable for a few hours trip.

You went up alot of teeth then... going down 1 on the front is equivalent to up 3 on the rear so you went up 5 total so to speak. Whats you fuel mileage like average?

 

[Rainbow7]

Velocity stacks are so expensive

ECU flash is going to come as soon as im back riding again and the weather in NC is bearable for a few hours trip.

You went up alot of teeth then... going down 1 on the front is equivalent to up 3 on the rear so you went up 5 total so to speak. Whats you fuel mileage like average?

V Stacks aren't too expensive. - eBay, dude.

Fuel economy isn't great...but who buys a Busa for fuel economy?

If you really want something that you can ride at low rpm's, perhaps you should have a look a a B-King rather than a Busa?

 

[RussellJ]

V Stacks aren't too expensive. - eBay, dude.

Fuel economy isn't great...but who buys a Busa for fuel economy?

If you really want something that you can ride at low rpm's, perhaps you should have a look a a B-King rather than a Busa?

Fuel economy doesnt matter too much to me i just wonder cause just how i am. And no i dont want a damn BKing i love my busa
The busa really doesnt like the 25mph speed limit on base

 

[Fastfrog007]

Im up +2 -1 with a heavy azz 240 rim outback, havent noticed fuel mileage go down drasticly. Plus, with more power down low you'll be ably to use 4th instead of 3rd ect... dropping your R's thus getting better mileage.

Sprockets are pretty easy to sell and not lose much if you dont like em

 

[afterhours]

sprockets will not give you more torque....or HP.

adding teeth to the rear sprocket will do the exact opposite of what you are trying to accomplish.

example:

say with your current gearing you can cruise at 65 mph in 6th gear, at 5000rpm......
you add 3 teath to the rear sprocket and now....
you can cruise at 65mph.....but the rpms are now 7500rpm.....

the bike will accelerate better, not because it somehow makes more HP or Torque. The bike will accelerate better because you are now at 7500rpm, and the engine is making signifigantly more HP and/or torque than when you are at 5000 rpms.


to get more HP/Torque low in the rpm range you should leave it stock, and if you got the bike used check to see if the previous owner did the airbox mod. aftermarket exhaust and airbox mod will give more HP/Torque in the upper rpms, but you will lose a little at low rpms....

will the B-King cams drop in? that might be a low dollar swap for more torque.

 

[Merlot]

Using aluminium rear sprocket will help since its lighter good for the rotary mass

 

[Kaptain Kanji]

sprockets will not give you more torque....or HP.

adding teeth to the rear sprocket will do the exact opposite of what you are trying to accomplish.

example:

say with your current gearing you can cruise at 65 mph in 6th gear, at 5000rpm......
you add 3 teath to the rear sprocket and now....
you can cruise at 65mph.....but the rpms are now 7500rpm.....

the bike will accelerate better, not because it somehow makes more HP or Torque. The bike will accelerate better because you are now at 7500rpm, and the engine is making signifigantly more HP and/or torque than when you are at 5000 rpms.


to get more HP/Torque low in the rpm range you should leave it stock, and if you got the bike used check to see if the previous owner did the airbox mod. aftermarket exhaust and airbox mod will give more HP/Torque in the upper rpms, but you will lose a little at low rpms....

will the B-King cams drop in? that might be a low dollar swap for more torque.

Afterhours is entirely correct on the torque analysis. As with most bikes, when you pull off the stock cans and reduce the restriction, you shift the torque band upwards in reference to the RPM band. If you want gobs of low end torque, put the stock cans back on your bike. Without this restriction, there's really no way to shift the torque band back down where you need it.

 

[Spkrdctr]

If your Busa doesn't like 25mph in first gear on base, then I would go down 1 tooth on the front sprocket, it will help quite a bit. I have a BKing and I actually have gone up a tooth on the front sprocket and I have to clutch it at 10mph as it will not run that slow! It also gave me some great gas mileage. I do a lot of freeway riding and I get up around 40mpg when taking it easy, and about 18mpg or less when I get on it harder. I would not hesitate to change the front sprocket and try it out. Well, worth doing.

 

[StromBusa]

Gearing will not change the torque of the bike but it helps move it in relation to your speed.

 

[sixpack577]

-1 front is only equal to +3 rear on paper, the bike "feels" as if it has more torque with just the +3, the -1 has the opposite effect, even though they both obviously raise the rpms. The real world feel of the bike is different. Go with just +2 or +3 rear, it'll give you what you're looking for. A -1 is cheap enough to add and try for yourself too, if you don't like it take it back off.

 

[Commuta_Busa]

In reality your engine doesn't need to produce any additional torque. As an example, if you were to rev it up into the "meat" of the torque curve before releasing the clutch you would notice how uncontrollable the torque from the engine is when you release the clutch. Granted at 2k rpm there is little torque available. Your ridding style is a large influence on the perceived lack of engine torque. Now if you wanted to your engine to produce more torque at a lower engine rpm that can be done through cam timing.

As for fuel economy, well if you want more torque it'll influence the fuel consumption.

Many times when people want that extra low end punch the quick solution is swapping sprockets. This gets your engine quicker into the "meat" of the engines torque curve. If you were to do this and continue to use the same cruising speed/mph as you previously did then the engine would run at a higher rpm which has an influence on your fuel consumption. Is it drastic, no. Your mpg won’t go from say 40 to 15. Can it go from 40 to 36 is possible. Your throttle control is the biggest influence on the mpg. Many people who like that low end torque feel can be more ham fisted than others. This kind of throttle control lowers your mpg.

Also, the "feel" you experience is the rear wheel thrust. Rear wheel thrust is achieved from engine torque / rpm / gearing. The more aggressive gear the more thrust.

Go +2 in the rear or -1 in the front and you'll feel the difference thrust. Once you've acclimated to the new setup it may not feel as aggressive any more. Hope on a 600 and you'll recognize how much thrust the busa really has.

 

[Merlot]

After trying 16 F and R 42 and 17 F R 42.I prefer 17 F R 42 with aluminium sprocket,best set up for me.Not realistic for set up 1 for long distance touring and the wear and tear on the tyres,chain and sprockets is much higher.Due to overtaking vehicles at high speed.

 

[flynlow]

When I went +3 on the rear, the difference in mpg wasn't really noticeable. But the pep was! Don't forget if you change ratios, a speedohealer will be needed. Which is also a good time to get a timing retard eliminator (TRE).

 

[Spkrdctr]

I'm going to go down -3 on the rear sprocket when I have to change the chain some day in the future. The bike has so much low end power that I can't use WOT in first gear on the street. I do a lot of freeway and it hauls ass on I-75. I took it easy last night with a Harley friend and got 45+mpg (between 45 and 50). Plus the bike likes running at 85 to 120 and faster all day long. On a naked, I top out at about 125mph as you start getting some serious wind speed if your sitting straight up just cruising at that speed.