Finding three tenths of a louzy second.

Scooter trash

Been Around the Block
I doubt anyone on this forum owns only one motorcycle, so this is for the ones that do the 1/4 mile still. My 450 Honda turned a 13.17 @ 99 mph in 1967 at high altitude. I'm going to install a high oil pressure pump mod to see if 95 psi will help, it might just slow it down too with all that oil flying around. The bike is a gen 1 zx14 with 14 lbs boost. launching a turbo is difficult as you have to leave almost at the rev limiter. There are old GS and KZ bikes killing me in the 1/8. It has 8" over, Shinko drag hookup, two stage lock up clutch. Just can't get those damn 3 tenths. More boost is likely to break the motor. No one knows everything, so input?
 

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Pull a vacuum on the crank case to reduce windage while adding oil pressure to make up for... windage. You'll see nice gains there.
 
Before I even read the other responses, the first thing I thought was how much does this guy weigh?? Good 60', many decent r/t. You want those 8's doncha?
 
jimmer said:
Foot shifting? Does it maintain the boost the whole time?

Have to shift at 9k which keeps us at the peak of torque and hp. Any higher and the trap speed drops off 5 mph. Rider suited is 230 lbs.
We're going to try 8500k and see how that goes. The fuel drops off because we need a 6:1 fuel pressure regulator.

At this hp we have already broke a sprocket holder bearing so more hp is breaky breaky time. Good thing the bearing lunched on the dyno. My buddy on his turbo Busa ran a 7.90 at 182 mph and hurt his rod bearing.

Here's the final rub, Cycle world gets 9.50 at 149 mph on a bike right out of the crate!!

The bike has 50,500 miles on it, adding more power means less riding and more trouble.
 

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Looks like it is still pulling strong at 10,600. It looks like you could easily shift at 10,000 and roll through the traps closer to the 10,600 mark. Have you tried this?
 
jimmer said:
Looks like it is still pulling strong at 10,600. It looks like you could easily shift at 10,000 and roll through the traps closer to the 10,600 mark. Have you tried this?

It pulls better at 9k, we've tried shifting up to 11k, shifting at around the torque peak works best. The hp at 10.5k looks better but it just doesn't work that way for some reason. At 8k it wants to pull you off the seat, then the thrust dwindles beyond that.
 
I'd think about shifting the torque curve to allow for higher RPM shifts, but I see that Brocks have peak torque at the same 8k revs and are managing better times with 100 less HP.

Maybe the answer is that you have too much power to get off the line hard enough. I wonder how it would run with less power......

And a lighter rider would really help too I guess. :-(
 
My swb 02 GSXR 1k ran 9.40's all day with decent 60ft times. Stock motor !! Something don't seem right. That thing should be flying. I'm sure me weighing only 150lbs helps too but..
 
You running total loss? (Temporarily) removing the charging system will allow the bike to rev faster and the alternator usually robs a little power, too.
 
It looks to me like there is no correlation between your reaction times and your 60' times, or E.T. for that matter.
That leads me to think there is something screwy around the launch, maybe clutch slippage.


p.s. Nice reaction times. (almost all anyway) ;)
 
Nothing matters with the motor if it isn't getting to the ground. What are the options for tire compounds with bikes? My experience drag racing is with cars. We ran a harder compound on our Bugs and softer compounds on our Roadrunners. We also gained a couple tenths on the Bug with a shorter shift, after everything else was dialed in. We ran a shifter that could be adjusted from 4" down to 1". The Roadunners were always autos, so the stall was a bigger factor in hooking up off the start. One thing with tires is that sometimes a controlled spin is a good thing. A dead hook can shake or cause the motor to bog.
 
With the two stage I raised the static pressure .025" x 5, the added oil pressure didn't do anything...maybe. There bikes with wheelie bars and slicks just making us look parked until the turbo get wound up at 185,000 rpms

When we run a 41 tooth rear the top speed increases to 157 mph, but the 60' goes in the toilet.
 

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Are you running a two step ? I cant imagine launching that high in the revs is needed. What is your boost at launch? Are you running a boost controller?
 
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