Large guy, slow times

Reaper337

Registered
So after a relatively embarrassing first ever attempt at drag racing a stock hayabusa, I am working on how to improve my times. I have searched and found great tips regarding lowering straps, launch techniques, etc. What I would like to know is how much difference rider weight makes. I weigh about 280 - 290 suited. What kind of ETs should I expect to see if everything else is done correctly?
 

RYC1966

Donating Member
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wind it up and fan out the clutch...280 is what you are working with...practice and seat time is worth way more than the price of admission...figure out when it will blow out the back tire = bad track / to much power / bad tire.....or lift the front ...to much power / good track conditions. If you want to race don't hesitate and keep improving...hit the track as much as you can afford
 

Jacobs

OEM Parts/Accessory guy
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Well first off, what year Hayabusa? When you say stock.. is it 100% showroom stock or is there any performance mods done?
 

In10SS

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I can't imagine being more than .2 higher once your technique is sound, bike optimized to put it down, and gearing adjusted so you're at the peak when going through the traps. Maybe a little more if you are trying to save the clutch a bit.
 

RYC1966

Donating Member
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high 10's are easy for a heavy duty stature...scare yourself a few times and then look at the et slip...look at the front half and back half times....if you get a poor launch still wind it out...the numbers on the slip will tell you whats up as far as what the bike is doing...you can take the best front half and the best back half and under best conditions you could run it...et or mph... Keep up on the chain a bunch of hard hits move pieces parts...jumping a tooth is not good...
 

Got-Busa?

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You should be high-10's without to much trouble. They say .10 = 10lbs but that depends on may things but can be a good estimate for you.

What are you running now?
 

Quicker Gixxer

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I just raced my Busa for the first time last week... It's better to be cautious at first until you get an idea of what to expect. Don't worry about your times..those will get better. I started at 9.29 (8th mile) and got down to low 7's before the night was over. I started launching at 3k or so..then 4k...then up to around 5 while slipping the clutch more. The bike surprised me..it was more stable than I expected and I have more confidence heading into next weekend. Hopefully my strap will be here by then...practice makes perfect :laugh:
 

Reaper337

Registered
Thanks for the info. As embarrassing as it was the best I could do first time out was 12 flat. The bike is stock for the most part. I have done the airbox mod, yoshi bolt ons k&n filter and had 114 octane, which I later read would do nothing with out a tune. Everything else was stock. I was hoping to learn from some other riders at the track, but as it turned out I was the only bike there. This friday hopefully will be a different result.
 

Dennis

Registered
Sounds like you have a Gen-1. That isn't a bad time for your first time out with your conditions. Forget the 114 and put in the lowest octance pump fuel you are comfortable with (I use 87 on my Gen-2 when not spraying). As mentioned, practice, practice, practice. It's all about seat time.
 

Robusa

Registered
You need to use your weight to your advantage. When I was teaching motorcycle safely I would ask the negatives of being on a bike over a car. One of the first responses was always bikes are smaller,,,,,,it is true but that is also an advantage at times. You need to learn to use your weight as a positive its only a 1/4 mile and the launch to 100 someone smaller and less weight will have obstacles you will not have if you learn to distribute your weight at different points on the bike during your race. Just try different configurations and you will figure it out.
 

Robusa

Registered
You should be high-10's without to much trouble. They say .10 = 10lbs but that depends on may things but can be a good estimate for you.

What are you running now?

This makes no sense so 100 LB means 1 second? So if I weigh 250 and run 9 sec 1/4 lose 100 lb's I now run 8 sec? This is not even close to accurate from my experience or from recorded history. This would mean if you run a 1 second 1/4 mile you can lose enough weight to run a 0 1/4 mile.....Now thats a record, and awesome!!
 

GNBRETT

Registered
This makes no sense so 100 LB means 1 second? So if I weigh 250 and run 9 sec 1/4 lose 100 lb's I now run 8 sec? This is not even close to accurate from my experience or from recorded history. This would mean if you run a 1 second 1/4 mile you can lose enough weight to run a 0 1/4 mile.....Now thats a record, and awesome!!
maybe you didnt read what he said. he said "but that depends on may things". thats pretty common knowledge in the car and motorcycle world of drag racing.

and where are you getting 1 second? it's .10

u can also add weight and drop ET. adding weight to the back could help ur vehicle hook up and gain ET due to a better 60 ft. addn weight to the front could help keep the nose down if you are wasting energy coming off the ground out of the hole.

it also depends on where the weight is. f=ma, it's a straight linear relationship. as you lose weight ur acceleration will increase proportionately.

its a general formula. there are too many variables. the lighter the bike the more of a % change will occur with a 100lbs.
If you took 100lbs off a 550 lb. motorcycle it would have a much greater effect than 100lbs off a 5000 lb. truck.

If u lose weight and therefore lose traction then that wud also factor into the formula. again location plays a dominating role. for every 1lb of rotating mass that u reduce u take approx 8 lbs. of weight off your vehicle. 100 lbs of rotating weight wud have a drastic effect. u losn 100 lose wud hav far less effect.
 

sportbikeryder

Registered
Reaper, you open each of your posts with how embarassing it was to go to the track.
If you are worried about being embarrassed, stay home.

Go out and have fun and worry about one person, you.

If you want to know what a 290lb person could run on a no-bar hayabusa, I'd say 7.60's are possible, probably lower. Not saying it is going to happen, or that you are going to build an all out 75" flat slick turbo bike, but it could certainly be done.

Now for a practical response...
Fill it up with plain old 87 octane pump gas.

Turn both the upper and lower damping adjustment screws on your stock shock all the way in. It still won't really be enough damping, but it is a start.
You probably need to add preload to the spring as well. Have someone measure a point from the rear of the tail to the grouns with you straddling the bike, and then with you sitting on the bike with your weight to see how much it moves. You may be nearing the end of travel with just your weight on it, although it may still have head-room since it is a stock length arm. If it is moving more than about 1.5", try tightening upo teh preload on the rear spring. Still probably won't be enough, but again, it is a start.

Make sure you are geting the bike to wide open throttle as soon as possible and hold it there. It is often easier to rotate your hand/wrist forward and get a "bigger" grip on the throttle to do this. You can lift your right elbow up to shoulder height and grip teh throttle, then drop your elbow and tuck it in while twisting the throttle at the hit to ensure it is getting open and staying there.

How are you shifting the bike (technique)?

Are you spinning or lifting the front at all? If so, lower the bike and change out to a more agressive rear tire, or tweak the tire you have a bit.

What tire on the rear and pressure?

Easiest thing you can do is change the gearing. Try a 16 tooth on the front for starters with the stock 40 on the rear, should set you back less than $30 if you put it on yourself. If you want to buy a new chain, I'd try 16/45 or 17/48 or so at your weight.

John
 

PADEROLIS

Registered
Don't beat yourself up; my very first run in the 1/4 mile resulted in a time of 16 seconds!! I got nervous and stalled the bike but not before the front tire moved enough to start the clock! Oh and yeah it's on video! lol
 

Karl_1052

Registered
My first time at the track, I was running in the 12s for the first few runs.
There was a guy who was on a Harley sportster with a wheelie bar and slick.
He saw he was quicker than me, so he wanted to beat a busa, so we lined up, and I launched harder than I had previously, cause there was no way any Harley was going to beat me, and I ran a low 11.

I am a fat bastard too(270lbs with leathers) and I usually run low 11s-high 10s. I don't give a **** what others think, I go out to have fun.
I might go out tomorrow to see if I can beat my best et(10.84) or my best mph(139.xx).

Even running in the high 10s, I am nowhere near wheelieing, or spinning, so I know there is still lots in the bike(obviously).

Just take it easy, and have fun.

Sign up on a local bike forum and see if anyone else wants to go, and give you pointers.
 

frisbee

GODSPEED RACING
Donating Member
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Strap your front wheel down , lower your tire pressure to around 20lbs., keep your revs upfor the launch around 4000, stay low on the bike, once the light turns green ... get to full throttle ASAP! And have fun !!
 

Reaper337

Registered
Thanks for all the advice. I went out this weekend and I was able to turn an 11.5 quarter with a .069 ET. I strapped the front end, launched at about 4k, and shifted without the clutch. Everything worked well.

One of the things I am still having trouble with is getting my feet up to the peg after launch. I started with my left foot up already so as not to miss a shift point, but I'm almost half way down the track before I can pull the right foot to the peg.

All in all it was a great time. My friends son asked me what it felt like. I honestly couldn't explain it to him.

I have a lot more I want to do with it, but 11.5 is a good place to start. Thanks again!
 

Karl_1052

Registered
I find it is sometimes easier to have someone to race against who is faster than you. Sorta like a rabbit you have to chase down.
Eventually you will catch them and pass them.
 

Got-Busa?

Donating Member
Registered
Do NOT run 114 octane fuel in your bike! If you have a Gen-I run 87 if it's a Gen-II I recommend 93 but many run lower. 114 does nothing but reduce power and has been proven many times to hurt performance with your mods.

It will take time, just practice and be safe. You might watch some videos on youtube if you don't have anyone local to help you. Lots of good videos with footage or RPM and track in one video that may help you a little with your start.
 

Robusa

Registered
maybe you didnt read what he said. he said "but that depends on may things". thats pretty common knowledge in the car and motorcycle world of drag racing.

and where are you getting 1 second? it's .10

u can also add weight and drop ET. adding weight to the back could help ur vehicle hook up and gain ET due to a better 60 ft. addn weight to the front could help keep the nose down if you are wasting energy coming off the ground out of the hole.

it also depends on where the weight is. f=ma, it's a straight linear relationship. as you lose weight ur acceleration will increase proportionately.

its a general formula. there are too many variables. the lighter the bike the more of a % change will occur with a 100lbs.
If you took 100lbs off a 550 lb. motorcycle it would have a much greater effect than 100lbs off a 5000 lb. truck.

If u lose weight and therefore lose traction then that wud also factor into the formula. again location plays a dominating role. for every 1lb of rotating mass that u reduce u take approx 8 lbs. of weight off your vehicle. 100 lbs of rotating weight wud have a drastic effect. u losn 100 lose wud hav far less effect.

I guess thats why I race on pavement and not paper. Paper means nothing.
 

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