Been to the track a few times. went again friday

[rxtreme7]

well ive been to the track a few times on the busa and i think im kinda stuck and want to know some pointers on getting my times down. my personal best so far is a 10.31 @ 136 on a day where track temp were WELL over 100. my mods include: lowered and strapped, 16T front sprocket, small air box mod, open headers with chrome tips, and a tune on the stock ECU (tuned on 93 octane), and 112 race gas when im at the track. oh and i weigh 265 suited.

i consistantly cut 1.80 60' by holding at 7k and slipping the stock clutch out. im normally wide open before the 60' mark and i dont have any wheelie issues.

now heres my question: I want to get to a 10.0 or 9.9 on the mods i have. is this possible? how can i shave another thenth off my 60' should i try reving higher off the line?

or do you guys think i just need more mods? I ride the bike as much as possible (12k miles in 6 months since i bought the bike) and i dont want some crazy gearing where im cruising at 75 mph with 6k in RPMs.

any suggestions or input welcome!

o and one more thing i dont go to the track ALOT but i do go about once or twice a month. and I also race on the weekends.......well, at other places lol.

 

[bisquit61]

I think you are doing good for a 265 pound rider. Change your rear sprocket to a 42 or 43 tooth. It will help your 60foot times. Concentrate on lowering your 60 foot times. I'm not a mechanic but you maybe losing performance with that open header. What kind of pipe are you using? All your other mods are right on. Get your 60ft in the 1.6s and you'll be in the ballpark

 

[rxtreme7]

what RPMs would i be at going 75-80 on the interstate with a 42 or 43 rear sprocket? dont forget i ride the bike everyday to work.

 

[Professor]

(rxtreme7 @ Aug. 06 2007,08:25) what RPMs would i be at going 75-80 on the interstate with a 42 or 43 rear sprocket? dont forget i ride the bike everyday to work.

With a 16/42 mine is around 5K about 75. I've been riding mine the last two weekend with 16/42 and it reminds me why I don't like it on the street. I normally swap to a 16/40 17/40 or 17/42 on the street when I change tires.

You should be 1000' or lower in elevation. I suspect you are down on power a bit from the fuel based on MPH. What 112 octane gas are you using? I think there are some that would be a much better choice. Have you ran it on the 93 it was tuned for and compared MPH? Most will actually run better on 87-89 octane pump gas. There are may race fuels that will produce more power. Some are a PITA to work with or expensive (VP MR-9)


octane it not a measurement of power producing ability by itself. 112 is excessive for a stock busa and may be too slow burning to make good power at your low compression ratio.

Extended arm? I would expect it to wheelie if stock length at a 7K launch. You are correct about needing to get the 60' down. I am usually in the mid 1.6x range and run pretty consistant 10.0s

A 1.70 60' should get you in the 10.12-10.18 range.

 

[rxtreme7]

thanks for the info. i didnt notice any change in mph with or without race gas. i just thought id put it in for safety. the swingarm is stock length and the clutch is also totally stock so i dont think im leaving as hard as i could....i dont wanna mess up the clutch lol. but i do wanna get my 60' down. what rpms do you leave at professor? i assume you have the brocks clutch mods?

 

[Ludicrous Speed]

I usually run consistent 1.65-1.70 sixtys, and I am about 280 suited. I am set up very similar to you, except that I have full stock pipes and a 43 rear.

You can go faster with the mods you have now, I would work on getting your sixty foters down a little bit more.

I run 87 octane in my bike at all times. 112 is hurting you.

Another thing to think about: Last friday, I ran a friend who is setup very similar to us, but he has a Hindle pipe. I out sixty him by 3 hundreths, and he drives around me at half track. I run a 6.56 and he goes a 6.41. The weight difference is a lot of your ET. He weighs 185 to my 250.

 

[Professor]

(rxtreme7 @ Aug. 06 2007,14:19) but i do wanna get my 60' down. what rpms do you leave at professor? i assume you have the brocks clutch mods?

I usually launch between 4000 and 4500 depending on track conditions and what I'm trying to do with my reaction time as high as 5500 testing the last race after I added some weight. I'm running the hub mod but a stock cushion setup.