ignition timing

B

bigjay

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Hey guys, Bigjay from australia here. Got a technical question for you. Ok, i have a 09 hayabusa which i just started drag racing. It has brocks lowering links in the back and strapped at the front. Brocks street megaphone 4 into 1 system and brocks clutch mod and cushion kit. Powermod computer ( similar to power commander ). All dynoed at 201hp at the back and 125lbs/ft torque. We have removed about 8 pounds of weight from the back and added a modified brocks brick on the front end at 18 pounds of weight. The problem we are having is torque wheelies in first gear. Now the question..... IS TAKING A LITTLE IGNITION TIMING OUT AT 80 TO 100% THROTTLE AT PEAK TORQUE A BAD IDEA. We are basically trying to flatten the torque curve. The front wheel comes up at around 6 to 7 and with 15 lbs/ft of torque still to comes it goes higher. If we can flatten torque curve at 110lbs /ft it will come up a little but wont keep rising which means staying on the throttle. 18/44 stock wheelbase and foot shifted. Best of 9.49 at 150 mph. Cant get full throttle in first because of wheelies. Please help!!!!!!!! I love racing my bike but this is becoming frustrating.
Thanks everyone..... Jamie
P.S. If you need dyno sheets i can attach
 
Removing 15 ft-lbs of torque with timing is a lot. I've seen a motor lose 5 lbs of torque with moderate retard, but 15 is big. You could also add a bunch of fuel and fatten is up to 11.0 or so to keep the front down. To do that you would need map switching or ECU flashing. I assume you still have your secondary throttle bodies in place. That will help in first gear. Retarding a motor puts more exhaust heat into the pipe and exhaust valve, but within reason its not dangerous. Riding stock wheelbase is tough...
 
yes i still have the secondary throttle plates on the bike and it would take 2 or 3 minutes to hook up a laptop and put the timing back in. Adding fuel in that area sounds like a good idea.:goodidea:
 
Don't take timing out,you need to be less aggressive or not pop the clutch lever at the end of first...Video your launch and you will see what I mean..
 
Its not the end of first thats the problem. Its midway through first that the bike comes up causing me to roll out the throttle.
 
bigjay said:
Its not the end of first thats the problem. Its midway through first that the bike comes up causing me to roll out the throttle.
Click to expand...

so try to hold clutch back a bit more thru your launch again film it and you will see where your hand control is during the rise..
 
no its not the launch its once i get about 200 ft out. Leave the line well and start to roll on the throttle and then suddenly up she comes. I know stock wheelbase bikes are hard to run, but they have run 30's and 20's over here. If I keep the front down or at least manageable, I will too. I thought there may have been a way to maybe detune the engine a touch just to make the bike a bit docile to keep the throttle open longer.
 
How far does it come up? My best run the front came up about 1 foot and held it there, I hit 2nd gear and it slowly put it back down and the thing just took off.
 
yes i have thought about stretching. I have had 2 of the best riders ride my bike and both have trouble keeping the front down. It happened once to me and i couldnt see the finish line so it got pretty high. I thought there might have been a way to soften the engines power a touch.If it had 10% less torque in the peak area the throttle would be pinned sooner therefore running quicker.
 
Have you tried adjusting the rear shock? Maybe stiffer spring would help. stiffen the compression setting so you dont get as much weight transfer to the rear.
Once again I gotta say if ya got the $$ for it get the bolt on extentions and the longer chain and brake hose. Its the best way to keep the front down.
 
Extensions are a last resort. I love having a multi purpose bike. Ride to the track and run mid to low 9's and then go home and hit the twisties up the mountains. To get 200 had brocks street megaphone full system and powermod ( similar to powercommander but with many more options ) fitted. Ignition access had a lot to do with getting extra hp. But now it seems i may have a touch too much. We are very close. If we just had a little less torque between 6000 and 9000 the throttle would be pinned earlier and be much quicker. As i said a little earlier, the times to the 330 suck. Surely with all the technology available and the brains of a lot of riders who ride gen 2, there would be a way of massaging these engines to suit the chassis.
 
have you tried ecuedit? what about maybe short shifting into second when it starts to come up?
 
Stll only new in Oz. Few people have tried it and going slower. So maybe as it gets going times will quicken. Short shifting basically slows the bike and puts 2nd gear out of powerband. I know a standard wheelbase can run numbers. Mr Gadson in the US has proved it among many others. I thought there may have been a few in the states that have run good numbers at stock wheelbase who could maybe share some knowledge.
 
dragonbusa said:
200hp with just pipes and a pc?:whistle: ain"t nobody i know can make that clam
Click to expand...

1st off I would never take power out unless you are running super street or some like power and track just wont hold, so even 3" out would help dramatically and corners would still be easily done, and while off topic I agree 200 RWHP on a busa and 150mph trap speed being a bit off Seeing dyno sheets wont help me they could be anybodys, I am not here being a prick at all , maybe it was just the dyno you used back to topic If you pull power out ..yes you will pin the throttle faster but you will also lose the power on top so you might 330' faster but back half slower just my .02 Have fun though:thumbsup:
 
Permalink #4 and #8 or reread them again = 1+


The rest is practice/practice/practice. "If D/racing was easy, everyone would do it" :whistle:
 
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