Nitrous question?????

[M Wright]

I've spent the last several hours reading posts here on piggybacks.

I have an odd application a little different than anything I could find. I am looking to use this unit to only control secondary injectors.

My problems start here. The secondaries are installed for a big nitrous kit on a dragbike. I need it to build fuel over time, not off of throttle position and rpm.

Problem 2 This bike revs to 11300.

Can the Megasquirt be made to work on my application? Any help would be appreciated.

[78Spit1500Fed]

The secondaries are installed for a big nitrous kit on a dragbike. I need it to build fuel over time, not off of throttle position and rpm.

If the purpose is to provide additional fuel when the Nitrous system is actuated, you absolutely must know the throttle is at WOT. Apart from that, the RPM and the Manifold Absolute Pressure would be used to determine fueling.

"Building fuel over time" means what? Increasing fueling at some arbitrary time interval, in preparation for the nitrous? Please explain.

Problem 2 This bike revs to 11300.

Not a problem.

Can the Megasquirt be made to work on my application? Any help would be appreciated.

I believe it can, we just need to nail down the details. Fill us in and we'll see what floats.

-Brian

[BottleFed70]

I do not understand why the secondary injectors need to flow more over time (I assume you meen in regards to engine RPM). If the amount of N2O injected does not change, then the amount of additional fuel injected shouldn't change either.

If you need to "inject more fuel" at higher RPM then you are probably compensating for a fuel system that cannot keep up to engine demands.

[M Wright]

Thanks for your prompt reply. I agree nitrous will not be activated until WOT.

Here is the typical scenario on the dragbikes I build. The bike sits on the line at approximately 3500 rpm. Starting lights go down and we pin the gas, and let the clutch fly. When the WOT manual switch is activated my nitrous controller starts pulse modulating my nitrous kit of approximately 150hp.

The Nitrous controller starts pulsing the solenoid at 20% with a 4 to 6 second build time to 100% depending on the track conditions.

What I want is to for the Megasquirt to see WOT and then start running my secondary injectors on a ramp. If the throttle is released I want two options. (Pause fuel and resume at that place, or reset) Basicly I want a time based ramp. Start with xx pounds of fuel and

I'd like to see it something like this
TIME FUEL
(Sec) (Lbs/hr)
0.25 XX.XX
0.50 XX.XX
0.75 XX.XX
1.00 XX.XX
1.25 XX.XX
1.50 XX.XX
1.75 XX.XX
2.00 XX.XX
l
l
etc
l
l
V
15.00 XX.XX

[M Wright]

I do not understand why the secondary injectors need to flow more over time (I assume you meen in regards to engine RPM). If the amount of N2O injected does not change, then the amount of additional fuel injected shouldn't change either.

If you need to "inject more fuel" at higher RPM then you are probably compensating for a fuel system that cannot keep up to engine demands.

I know I wasn't very clear. These motorcycles generate 250hp on motor, and run very well on motor 8.2's @163 in the 1/4 before the nitrous

We put 150hp dry nitrous on them and they fly. The problem is we have to map them so rich for this amount of nitrous they will barely run on motor. Hence the secondary fuel injectors. I put 05 GSXR 1000 throttle bodies on this one. they are larger than the Hayabusa, and 8 24 pound injectors.

[Enthalpy]

What are you doing to reduce timing while hammering the engine with the bottle?

[M Wright]

What are you doing to reduce timing while hammering the engine with the bottle?

http://secure.cartsvr.net/catalogs/cata ... prevnext=1

[jsmcortina]

You could get a Megasquirt for that money, but can it control your ignition too?

There is nitrous control in the MS1/Extra code
http://megasquirt.sourceforge.net/extra

but it doesn't do PWM output or fuel ramping.
I have used it to control two stages on my 12sec car.

James

[M Wright]

I am very impressed with the capabilities of the MegaSqeirt, and I don't want to offend anyone here. We spend a lot of cash on our motors, and the factory system works well. I have used alternate systems in the past such as DFI and EFI. The factory sensors always prove to be problems. I don't want to spend another summer trying to get a motor to run as well as the stock system. I am simply looking for a good piggyback fuel controller. I know this unit has the capability, I just need help with the code to make it work the way we need.

Thanks for everyones help.

[M Wright]

Anyone?