Performance modifications and gas consumption

[jellyrug]

I believe everyone here knows I have kept my Busa bone stock. My main reason for that is because I don’t ever intend selling it and wish to preserve the original, exactly as Suzuki sent it to the showroom. It will probably end up as a collector’s item during my time here on earth and if not hopefully once I am gone someone will appreciate that and keep it as a collector’s item.

So let’s talk about gas consumption:

I recently posted a ride at 50mpg doing a long ride but with a number of short sprints some up to 160mph, I got challenged by a fella saying that is BS. Another poster mentioned that he had the same mpg before a pipe and a tune, but then it went down to 40mpg.

The calling BS fella recently did a long trip on a Honda CBX 1000 and was posting that he averaged 24mpg. First, anyone with a reasonable automotive background would know that is terrible. A 1,000 cc motor averaging 15 - 20kw of of power use during a normal ride, (a small portion of maximum) burning that amount of gas is about as inefficient as it gets. If we do a bit of research, some of those bikes got up to 40mpg back in the day, which is still not much to brag about. Were it me, I would probably use. CO data logger and first move the carb needle circlips up, after rebuilding them. Or look at jetting. Suffice it to say, I would be embarrassed to post those numbers.

Gasoline has an energy content of 33,526 kJ per liter.
A good design ICE has around 40% thermal efficiency today, some these days have achieved 50%.
The rest goes into wasted heat from the exhaust and the cooling system, as well as unburnt fuel out of the exhaust. So looking at that little Honda motor (I can attempt to calculate this but let’s guess) its thermal efficiency will be below 10%. Where does that energy go? It can’t possibly be heat from the motor, as it will glow red at that rate. Most of it will be unburnt fuel going out the exhaust. What does that do? Two things, it fouls up the motor, making things even worse, as well as washing a whole lot of oil off the cylinder walls, with a major reduction in engine life.

Reading all the posts here on the forum, I have always noticed that modified Hayabusa's have poor gas consumption and that this myth is accepted in lieu of increased performance. Automotive design and manufacturing was once my life as an employee with a prestigious German manufacturer and later as an aftermarket guy for mostly European sports cars. I can tell you for sure, it should be the other way around. If you don't believe me, below is a link, perhaps you will believe someone else.

Take the simple example of a pipe and a tune. First, the cats are gone, so there is a whole lot of heat coming out of the energy from your gasoline which is no longer lost. Second, you have better flow through the motor, less restriction, so the motor should be more efficient. It follows that for the same riding conditions maintained before and after your tune, you should have improved fuel consumption.

I think most here don't appreciate the effort that goes into factory ecu programming and cam design focussing on valve lead and lag and what it takes to get that perfect in the factory, when it comes to high performance motors. As simple as a factory exhaust change to a different pipe throws all that out the window, as the flow is now totally different.

Anyways, in short, when I did this as a living, if I increased performance with a decrease in efficiency (More gas for normal use similar output or at the same MPH), my boss would have sent me back to the drawing board.

Again, if you don't believe me, here is a link and if you google I am sure you will find a lot more from folks who are into this professionally.

https://flatironsrally.typepad.com/faq/2007/12/what-effect-wil.html

 

[WuzzaCBXRider]

I’d like to see where that ‘CBX 1000 fella’ said that he averaged 24 mpg.

Some ‘fella’ may not be able to find that bit of misinformation and he also didn’t take into account the SIX carbs, no EFI, or the motor being air cooled, no radiator, or that the bike weighs around 600 pounds or, that it’s 42 years old.

 

[sixpack577]

My 49mpg was all done riding very conservatively, which was because I vividly remember it rained 16 of the first 21 days that I had it(got an '08 as a new leftover in '09), and rained more the 4th week.
Any high speed was gradually built up to.
I changed exhausts a couple times, and ended up with a full-dual Akropovic with cf mufflers, a BMC race air filter(for easy cleaning), and flashed the ecu, which changed the opening rate of the secondary throttle plates and amount of fuel available(not the air/fuel ratio, that was never touched), there was more timing below 6k rpm, and the fans came on 10°F sooner.
I never had the engine dyno tuned, as it ran great just as it was.
I also rode the bike very hard, high in the rpm's, through corners, and many, many miles of wheelies, sustained high rpm.
I also changed the gearing from 18/43 to 18/46, so the rpm's were up by 600rpm's vs stock at the same speed(I also used a Speedohealer).
I traded the bike at 17,500 miles, running great.
I ran across the buyer earlier this year, as he was selling it on Marketplace.
He had it since I traded it, and said that it still ran great at over 77k miles, and that it never had an issue.
I got 40-42 mpg highway, or cruising, but my knee dragging, wheelieing, and general ham-fisted riding ate tires, that I kept around 36psi hot, front and rear, and at times 32 and 34 psi hot, so bigger contact patch and more drag.
All these things contributed to much worse mpg than I started out with, but mpg was never something that really concerned me.
Had my air/fuel been tuned, the tire pressure been higher, and the gearing left stock, I would think that the mpg would have been about the same as stock, or at least close to it.

 

[jellyrug]

I’d like to see where that ‘CBX 1000 fella’ said that he averaged 24 mpg.

Some ‘fella’ may not be able to find that bit of misinformation and he also didn’t take into account the SIX carbs, no EFI, or the motor being air cooled, no radiator, or that the bike weighs around 600 pounds or, that it’s 42 years old.

See post your post #3. Memory issue, your end?

Heading out in the morning | Trips and Touring

I’ll visit my son and his family mañana and then head to the coast 25 miles from his place, and then north. Possible turnaround spot will be Port Angeles WA. If so, that will be Thursday. Should be back next Monday. It will be 97 here when I leave and 65 at the Pacific. Sure hope I can...

www.hayabusa.org

People age, they get slower, their cognisance change. Machinery is either defective, or it operates as it was designed to. No reason for a 42 year old bike to be taken care of so it is in perfect condition.

Hope that helps, not the sharpest knife in the drawer, right? I normally let these things go, but you challenged my ride post, so sorry for giving you facts which you cannot deny.

 

[HayaWakened]

Gen 2 (2014), with aftermarket header, PAIR delete and 1 tooth down front sprocket
average MPG past 8 months: 35.86
It's always been around this number since 2019, when purch used w/ 10k Mi ODO
Highest MPG (2019 - Present): 47.31

I've always assumed that fuel type + enviro can affect these numbers, meaning riding a bike in SoCal is not the same as riding a bike in another region, all other factors being equal. I could be wrong

 

[Bumblebee]

I find fuel consumption figures to be a relative thing.....there are so many variables to change these figures that all they can hope to be are baseline figures....some get better mileage, others get less and it takes very little to skew mpg/km/L.

For instance on the race team I was on, we had two identical 1985 GSXR 750 factory race bikes (tires, pressures, mods), we as riders were pretty much the same weight and size, but they got different fuel mileage....we thought it was because I was more aggressive as a rider so we switched bikes in training and the bikes got the same mileage as before the switch.

 

[WuzzaCBXRider]

24+ mpg was an 80-85 mph “rip” during a 100+ degree day for about 245 miles not the 2,000 mile trip average which was in the mid 30s.

As for “Machinery is either defective, or it operates as it was designed to.” Well, no shiiite Sherlock. Any other jewels of information?

And this? “No reason for a 42 year old bike to be taken care of so it is in perfect condition.”. Makes no sense.

Sorry about your diminishing “cognizance”.

 

[jellyrug]

24+ mpg was an 80-85 mph “rip” during a 100+ degree day for about 245 miles not the 2,000 mile trip average which was in the mid 30s.

As for “Machinery is either defective, or it operates as it was designed to.” Well, no shiiite Sherlock. Any other jewels of information?

And this? “No reason for a 42 year old bike to be taken care of so it is in perfect condition.”. Makes no sense.

Sorry about your diminishing “cognizance”.

LOL, you said I did not take into account the six carbs and no efi earlier.

Actually I suggested to you how to fix those six carbs to make your bike operate as it was designed to. You either missed that or you have no idea what those carbs look like inside. I do BTW.

Let me help you a bit further, there is no reason for a 42 year old bike to be repaired or serviced so it is in perfect condition and it does not burn 24mpg at 80mph, which is nothing for that bike. Shite, I can do that all day long on my dirt bike and it gets around 62mpg at that speed. It's a Husky TE610ie, should you wish to call more BS.

For more help, you can do 85mph on a motorcycle with a 15hp motor, so if you are burning that much fuel below using 20hp, I would be embarrassed to share the data in public.

 

[jellyrug]

I find fuel consumption figures to be a relative thing.....there are so many variables to change these figures that all they can hope to be are baseline figures....some get better mileage, others get less and it takes very little to skew mpg/km/L.

For instance on the race team I was on, we had two identical 1985 GSXR 750 factory race bikes (tires, pressures, mods), we as riders were pretty much the same weight and size, but they got different fuel mileage....we thought it was because I was more aggressive as a rider so we switched bikes in training and the bikes got the same mileage as before the switch.

I’m sure those two 750’s were not original 100% stock, could be where the difference co
came in. Or the motors had different wear conditions, one worse than the other.

I focus on gas consumption to see what is happening inside the motor, as compared to brand new, out of the box. To make sure everything is right.

Another way of doing that, is oil analysis new and then later to compare fuel dilution in the oil. It will immediately tell you if your injectors are not spraying as they should, or if something is changing in the motor. Monitoring gas consumption will tell you more though.

What I tried to highlight in this post is that just changing a pipe and a tune, gaining a few hp, but losing efficiency (mpg) means you have gone backwards.

Way past my best before date, but if I had to manufacture and sell pipes, this is what I would do:

Get a Busa motor and hook it up on a stand to a dyno at the crank, the dyno equipped with all the hardware and software needed.

Have stock profile camshafts manufactured, rigged up to change valve lead and lag ( cam timing) adjusted on the fly while the motor is running. (Will cost some money)

Make the pipes, there is absolutely no rocket science to pipes, all we want to do is reduce turbulence as much as possible and reduce noise using perforated sections with a possible backing. The only complicated thing about pipes is Marketing.

Run this setup, with the first activity being achieving optimum air flow through the motor, by adjusting valve lead and lag, under several differing loads and engine speeds. Follow with air/fuel and timing through the ECU, repeat cams, repeat ECU until the best condition is achieved.

Following the above, have cams manufactured to the profile of what worked best during testing, and sell the cams, pipe and ECU flash as a total package. Much better hp, plus efficiency, meaning at same load fuel consumption will actually improve, more mpg. It will also ensure that there is no loss of reliability long term.

I have a buddy who builds race motors, full CNC shop, not on the forum. He is pretty busy does a lot of Busas. Discussed this with Rick, but he does not want to spend the money and has more business than he can handle. 95% of Rick’s business focuses on the drag racing scene. So he is not interested in investing for best on the street.

 

[michael parris heuberger]

I’m sure those two 750’s were not original 100% stock, could be where the difference co
came in. Or the motors had different wear conditions, one worse than the other.

I focus on gas consumption to see what is happening inside the motor, as compared to brand new, out of the box. To make sure everything is right.

Another way of doing that, is oil analysis new and then later to compare fuel dilution in the oil. It will immediately tell you if your injectors are not spraying as they should, or if something is changing in the motor. Monitoring gas consumption will tell you more though.

What I tried to highlight in this post is that just changing a pipe and a tune, gaining a few hp, but losing efficiency (mpg) means you have gone backwards.

Way past my best before date, but if I had to manufacture and sell pipes, this is what I would do:

Get a Busa motor and hook it up on a stand to a dyno at the crank, the dyno equipped with all the hardware and software needed.

Have stock profile camshafts manufactured, rigged up to change valve lead and lag ( cam timing) adjusted on the fly while the motor is running. (Will cost some money)

Make the pipes, there is absolutely no rocket science to pipes, all we want to do is reduce turbulence as much as possible and reduce noise using perforated sections with a possible backing. The only complicated thing about pipes is Marketing.

Run this setup, with the first activity being achieving optimum air flow through the motor, by adjusting valve lead and lag, under several differing loads and engine speeds. Follow with air/fuel and timing through the ECU, repeat cams, repeat ECU until the best condition is achieved.

Following the above, have cams manufactured to the profile of what worked best during testing, and sell the cams, pipe and ECU flash as a total package. Much better hp, plus efficiency, meaning at same load fuel consumption will actually improve, more mpg. It will also ensure that there is no loss of reliability long term.

I have a buddy who builds race motors, full CNC shop, not on the forum. He is pretty busy does a lot of Busas. Discussed this with Rick, but he does not want to spend the money and has more business than he can handle. 95% of Rick’s business focuses on the drag racing scene. So he is not interested in investing for best on the street.

Hi. I had an HD 1340cc 10 1/2 to 1 pistons .600 lift cam ported heads and 42mm Mikuni carb. On a long trip 1600+ miles. I took about 1 gal less each fill up that a stock HD. But the other guy on the HD was about 125 lbs more than me.

 

[Bumblebee]

I’m sure those two 750’s were not original 100% stock, could be where the difference co
came in. Or the motors had different wear conditions, one worse than the other.

I focus on gas consumption to see what is happening inside the motor, as compared to brand new, out of the box. To make sure everything is right.

Another way of doing that, is oil analysis new and then later to compare fuel dilution in the oil. It will immediately tell you if your injectors are not spraying as they should, or if something is changing in the motor. Monitoring gas consumption will tell you more though.

What I tried to highlight in this post is that just changing a pipe and a tune, gaining a few hp, but losing efficiency (mpg) means you have gone backwards.

Way past my best before date, but if I had to manufacture and sell pipes, this is what I would do:

Get a Busa motor and hook it up on a stand to a dyno at the crank, the dyno equipped with all the hardware and software needed.

Have stock profile camshafts manufactured, rigged up to change valve lead and lag ( cam timing) adjusted on the fly while the motor is running. (Will cost some money)

Make the pipes, there is absolutely no rocket science to pipes, all we want to do is reduce turbulence as much as possible and reduce noise using perforated sections with a possible backing. The only complicated thing about pipes is Marketing.

Run this setup, with the first activity being achieving optimum air flow through the motor, by adjusting valve lead and lag, under several differing loads and engine speeds. Follow with air/fuel and timing through the ECU, repeat cams, repeat ECU until the best condition is achieved.

Following the above, have cams manufactured to the profile of what worked best during testing, and sell the cams, pipe and ECU flash as a total package. Much better hp, plus efficiency, meaning at same load fuel consumption will actually improve, more mpg. It will also ensure that there is no loss of reliability long term.

I have a buddy who builds race motors, full CNC shop, not on the forum. He is pretty busy does a lot of Busas. Discussed this with Rick, but he does not want to spend the money and has more business than he can handle. 95% of Rick’s business focuses on the drag racing scene. So he is not interested in investing for best on the street.

The two 750s had all the exact same modifications done to them...it shows that even the same bike with the same modifications (or none) will get different mpg for varying reasons.

In the days of carburetors tuning meant changes to jet sizes and moving needles which would increase fuel consumption which is the same today only we do this electronically......gen 2/3 Hayabusas come lean from the factory due to emission constraints...any change to this will cause an increase in fuel consumption but I don't figure it to be a huge increase...what burns more fuel is riding habits more than modifications.

In the days of 2 stokes, part of tuning was in the expansion chambers. now with 4 strokes it is all about how they scavenge exhaust with flow rates.

 

[jellyrug]

The two 750s had all the exact same modifications done to them...it shows that even the same bike with the same modifications (or none) will get different mpg for varying reasons.

A Six Sigma Black Belt, will totally disagree with you.

 

[Bumblebee]

A Six Sigma Black Belt, will totally disagree with you.

I could say it's a beautiful sunny day outside and somebody somewhere would disagree with me so no worries.....just as long as I know it, that's all that matters to me.

 

[jellyrug]

I could say it's a beautiful sunny day outside and somebody somewhere would disagree with me so no worries.....just as long as I know it, that's all that matters to me.

It’s a beautiful sunny day here also. At least we agree on something. You are the lucky one though, I have to work, no time to enjoy the sun through my dark tinted visor.

 

[LC4CARL]

50 is terrific. I usually start looking for gas at 200 miles. By then I'm ready for a Twinkie anyway.

Remember the old time Marathon MPG event from Popular Mechanics or something? They got some great numbers out of those old '60's tech cars. I may put a vacuum gauge on the Busa...

 

[Bumblebee]

It’s a beautiful sunny day here also. At least we agree on something. You are the lucky one though, I have to work, no time to enjoy the sun through my dark tinted visor.

It WAS sunny then just as I was cutting my second lawn, some dark clouds rolled in and light sprinkles started...I managed to get home and c lean up the tractor and as I was backing it into it's storage barn, the rain really started.....and now it's pouring out....

 

[sixpack577]

It WAS sunny then just as I was cutting my second lawn, some dark clouds rolled in and light sprinkles started...I managed to get home and c lean up the tractor and as I was backing it into it's storage barn, the rain really started.....and now it's pouring out....

Our 2 and a half month drought has turned out as expected, rain showers or storms about every other day now...just enough to make it really humid, but the dry days have been really nice.

 

[Bumblebee]

Our 2 and a half month drought has turned out as expected, rain showers or storms about every other day now...just enough to make it really humid, but the dry days have been really nice.

Same here, my wife and I collected a lot of rain water in barrels and 5 gallon pails.....now it will probably rain until fall......

I mentioned to the wife that every year we do the same thing and end up with lots of collected rain water at the end of the season.....

 

[sixpack577]

Same here, my wife and I collected a lot of rain water in barrels and 5 gallon pails.....now it will probably rain until fall......

I mentioned to the wife that every year we do the same thing and end up with lots of collected rain water at the end of the season.....

Still never a bad thing to have.
We need new gutters, and the boards and vinyl behind them.
We agreed on getting one of the big 200 or 300 gallon white plastic water tanks, the square ones for farming that come in the aluminum cage, to put under one of the downspouts on the back of the house to collect the rain water.
I'm going to level a spot for it and pour a concrete pad when it cools down.

 

[Bumblebee]

Still never a bad thing to have.
We need new gutters, and the boards and vinyl behind them.
We agreed on getting one of the big 200 or 300 gallon white plastic water tanks, the square ones for farming that come in the aluminum cage, to put under one of the downspouts on the back of the house to collect the rain water.
I'm going to level a spot for it and pour a concrete pad when it cools down.

We were thinking about this as well but it would mean a complete re-jigging of our eavestroughs which we don't want to get into as they are working very well right now and we figure if we mess with them, they will leak or worse....

We have 4 60 gallon rain barrels and 20 5 gallon pails full right now and I also have a 25 gallon tow behind water trailer that I can fill with the garden hose if need be......there have been a couple times last summer where I needed to use the 25 gallon trailer to water with as all the others were empty....