I need some help cant figure it out

[gap4652]

I have an 08 busa and am runnin 6.0's on the 1/8th @ 123-126mph and 9.10's to 9.20's on the quarter from 154-156mph I have a dry setup with a fast FI box and a 2 dial schnitz set @ leaving 32% and going to full in 1.5 sec. My 1/8 mile times do not change whether I am runnin on the nitrous or on the motor. My 1/4 mile times drop back to 9.30's-9.40's on motor around 146-149mph. Why am I not gaining in the 1/8th on the nitrous. 3 different good riders same results. Thanks for any help

 

[jspin]

sounds like either your nitrous solenoid isn't opening, you have really low bottle pressure, or that fast FI box is giving you so much fuel that you aren't gaining any power. how do the plugs look? how does your pipe look after a run after a nitrous pass compared to a motor pass?

depending on what size nitrous jet, my bet is the fast fi box is giving you way too much fuel.

 

[Draco1340]

I'm not terribly familiar with the MPS Fast FI box, but I suspect that when it switches to full rich the N2O takes a couple of tenths to start flowing, and then it is only running at 40%. The bike might be running stinking rich for the first second, so that any benefit in the 1/8 is counteracted by being a bit boggy out of the hole. If you look at the 60 fts, are your 60 ft times better or worse on spray. If there worse, that's probably the problem. One thing to try is activating in second, and ramping up very quickly (50% to 100% in .5 to .7 seconds). You should have plenty of power on an 08 to pull a 1.45 short with the proper chassis. I don't think spray will help that much in first with the setup you have.

 

[Moparict]

I'm not terribly familiar with the MPS Fast FI box, but I suspect that when it switches to full rich the N2O takes a couple of tenths to start flowing, and then it is only running at 40%. The bike might be running stinking rich for the first second, so that any benefit in the 1/8 is counteracted by being a bit boggy out of the hole. If you look at the 60 fts, are your 60 ft times better or worse on spray. If there worse, that's probably the problem. One thing to try is activating in second, and ramping up very quickly (50% to 100% in .5 to .7 seconds). You should have plenty of power on an 08 to pull a 1.45 short with the proper chassis. I don't think spray will help that much in first with the setup you have.

I agree with the above. My chassis set up stinks and I found I could go faster delaying nitrous till second gear. I brought it in at 50% and ramped up to 100% in 1 second. Worked great. I did find that if I delayed the ramp up speed that I would gain mph. I never figuered that one out. Good luck to you.

 

[Draco1340]

The only way I have seen a strong running N2O setup work in first gear is with a progressive wet system. That way the fuel and spark are tuned relatively optimal and the fuel isn't switched on with an alternate map or a full rich FI box. I am probably opening myself up to a hundred alternate opinions on this, but try activating your dry system in second, or switch to a wet system.