Bonneville top speed bike help




biggar

Registered
A local acquaintance is building a big bore bike for top speed runs at El Mirage and Bonneville. He is not much of an internet person but a good guy who needs any and all info he can get. Top speed is the only priority here. Obviously getting as much hp as possible at the top end is what he's looking for, weight is not a problem, the more the better actually. He's got 60 lbs of lead shot in the swingarm right now!
The bike, a '99 'Busa, currently has a 1397 kit with 12.5/1 (I think) weisco pistons, Lightened Crank, Counterbalancer removed, Mild head porting, PC II, Small box mod (soon to be full box mod), Yosh Stage one cams, HMF big bird system, 18/40 gearing (soon to be 18/38 or ?) He went out to El Mirage about a month ago and went 185 through the timing lights on the lakebed. The dyno pulls last night netted a disappointing 190-192 hp.
I hoping for some suggestions to help this guy get at least 200 hp or so. What would help?
TRE?
Clutch mods or replacement parts (any and all that would help in this application)
Degree work on the cams for more top end? (torque and drivability are of no real concern)
Ram air seals? (I know this won't show up on the dyno, but there are some that do help at speed aren't there?)
Motor oil type?
Chain and sprockets?
Gearing suggestions?
Lowering bike? (dog bones? front end strapping?, clip ons and drop the fork through a bit?)
Double bubble windshield?
More aerodynamic helmet and suit?
Any and all other advice?
There's a decent budget for what needs to get done, we're just looking for good advice from some of you tuners and top speed guys.
Turbo is not an option right now because of class restrictions.
Thanks everyone for any help they can offer.
Gar
 

TJFAST

Registered
Remap it! Play around with different maps and dyno the maps. Why the extra weight, every 7lbs is a HP ?
cool.gif
 

Knebnr

Registered
You will probably have to bump compression up a point to 13.5 to 1  in order to top 200hp. You can always lower it after the record attempt. Your other choice is go bigger with the motor ie stroker crank bigger pistons but its getting real expensive now. I have 99 busa with 4mm over pistons and 3mm stroker crank 1497cc 207hp with 12to1 compression. You could also change to larger fuel injectors from Rc engineering they are calibrated and will deliver a lot more fuel than the stockers. Also you will need a higher volume fuel pump available from the same company. Good luck hope you achieve your goal...................Knebnr

Oh forget to say get the TRE. Also if there is no weight requirements make the bike as light as possible.
Clutch mods weld or get billet inner hub. heavier springs that should do the trick basket will hold up fine. degree the cams good for a couple of ponies.
Ram air seals don't know it that will help
Mobil1 synthetic 10-40 or 15-50
Lower is faster if allowed in the class.
Don't know on winshield try stock and double bubble


Ps: Busa's do not respond real well to gearing changes especially going taller. Stock Busa gearing will give you around 207mph if your target mph is higher than do a mild gearing change one tooth at a time to see what the bike will do......
 

Racer 222

The rider formerly known as Howlin_Mad
Donating Member
Registered
Big Gar,
Whats up? Are you still going to Laguna Seca? I am going. If the bike is out of the shop by then it will be going as well. Hope to see you at the track. No way I am camping...

Marc "Howlin Mad" :usa:
 

MET

The Watcher
Registered
18/40 should get you around 214 with that hp,l but it will take a long time to get there. 18/41 would get you about 209
 

Kento-Moto

Hayabusa Immortal
Donating Member
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wink.gif
i know these are serrious $ items but hows about Turbo & Nitrous? air shifter too.

biggrin.gif
 

biggar

Registered
Thanks for the replys. I'll keep checking back here and print this thread up in a couple of days then just let these guys run with whatever info is there.
Turbo and Nitrous is not an option right now due to class restrictions.
Marc, I am definitely going to Laguna Seca, the Bonneville bike is not mine. It's the one down where your bike is at.
Your bike doesn't look too bad. You just managed to screw just about everything up just a little bit. Big $$ to fix it though as all of that stuff will get replaced.
She'll be good as new soon!
Gar
 

biggar

Registered
TJFAST, the weight does rob accelleration but doesn't hurt top speed much if any. The biggest problem on the dry lake bed or the salt is wheelspin, not necessarily at launch, but at very high speeds believe it or not. That's why he's trying to keep the rear tire planted as firmly as possible by weighing it down.
Gar
 

race24x

Registered
Wow something doesnt seem right all of the artcles I have read the stock busa is faster than what they are getting out of there modified Busa is it a limited distance 185 actual is where the limiter kicks you out I havent opened mine up on radar or GPS yet but I have hit 185 on the speedo and it was still pulling I have hit that several times actually its where the busa seems to get scary if there is any wind at all I dont really have any ideas for you because I have never tried anything like that at the salt flats is there an elevation problem for the computer ? seems with that much HP you should go faster and how did guiness book get 198 out of there Busa wasnt it stock ????
 

biggar

Registered
The bike needs to go a GPS honest 210 or better on pavement to have any chance to break 200 on the salt. Lots of rolling resistance, a little elevation, and poor traction all work against you out there.
Gar
 

Racer 222

The rider formerly known as Howlin_Mad
Donating Member
Registered
Big Gar,
Well I am in!! I will be heading to Laguna Seca!! I am so excited!! I hope to have the bike back by then I hope!!!!! Well I will see you at the track!!

Marc "Howlin Mad" :usa:
 



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