Nitrous engines

[J. Delaney]

QUOTE (Wayne Schofield @ Nov 6 2007, 11:44 PM) <{POST_SNAPBACK}>

It could be calculated fairly well actually, but I suppose jetting the fuel to match ambient conditions, and therefore bottle vapour pressure, would be easier with a wet system.....

Wow 15:1! That's not far from diesel territory.

[wistech]

QUOTE (wanablaze @ Nov 7 2007, 08:05 PM) <{POST_SNAPBACK}>

High compression motors love nitrous! Boost, not so much.

John, I'd recommend running a fuel pressure safety switch and a window switch. Colder plug with smaller gap, yes. As evidenced by the low bottle pressure seen @ Crandon, I'd strongly recommend an automatic bottle heater. You should be spraying when the bottle pressure reaches 950 psi (up to 1050ish). Any less and you'll be dumping extra fuel. Excessive pressure will lean the mixture out. When spraying, ideal AFR is typically lower (on avg between 11.3-11.8 to one). Make sure to invest in quality solenoids. A purge kit, nitrous filter and quality solenoids are always a good idea. If you're paranoid about solenoids sticking open, you can run two solenoids in a row. Do some research on "FJO Progressive controller." This device will act as a window switch, allow you to lock it out of certain gears, and you can adjust how and when the extra power comes on.

My suggestions are based on the fact that you are using a wet kit (computer will not adjust for the amt of nitrous it encounters) and are taken from what I've learned about "sprayin'" an LSX series motor. If you'd like I can pm you a link for more information.

PS 5 degrees does not seem like a lot of timing pulled for a high compression stroker with nitrous...

The system nitrous system functions perfectly so far for what I have done. From the info I have found backing the timing down 4 or 5 degrees is a safe place to start instead of stock.

[wanablaze]

Many of the accesories are there to ensure longevity. A system can function fine without them. For example, a fuel pressure safety switch will save your motor if your fuel pump fails or you're low on fuel. Good luck! I'm anxious to see the results.

[Speed 1B]

NX tech told me that even at 15:1 he doubted i would need to retard the timing at all...even with a 10-15 hp shot. He said as long as i followed his directions after we got the motor together he promised me i would have a foolproof, reliable system. The major deciding factor in where to put the timing is a compression check after assembly. He said the compression would let him know how to tell me i needed to set the system up. Just telling him the compression of the piston doesnt help becasue your cam timing comes into play.

[hogman]

QUOTE (cannondale27 @ Nov 6 2007, 08:27 AM) <{POST_SNAPBACK}>

I dont believe the Harley injectors will support 80hp reliably have to go bigger.He also would have to switch to MC1000 since MC500 is not tuneable enough currently.Kind of a shame though since the wet system he used produced a absolutly perfect AFR on Nitrous.

Just a FYI the harley injectors we are using have no problem running a 100hp 100ft/lbs torque harley so they should be more than enough for 80hp.

[cannondale27]

How come the Harleys offer bigger injectors even with thier Screaming Eagle kits which barely dyno 80hp?

[kdeal]

Duty cycle %

[cannondale27]

Yes anything 80% is considered unreliable.

[hogman]

QUOTE (cannondale27 @ Nov 13 2007, 08:19 AM) <{POST_SNAPBACK}>

Yes anything 80% is considered unreliable.

The injectors we are using are the 01-05 injectos. Screaming eagle didnt have different injectors untill harley changed the injectors in 06, and yes the 06 and later style injectors suck for higher hosepower engines. The 01-05 injectors will run 100hp without any problems. Also u have to remember that the harleys are using 2 injectors for 2 cylinders and each cylinder alone has more CCs than any cdale engine built. So if one injector can feed one bigger cylinder then 2 should be plenty to run a single cylinder.

[cannondale27]

The early ones are what we use.Will find out if they flow enough when Turbo gets used I imagine.Maybe the rpms and rate of acceleration of Harley vs Cannondale is also a factor.Anyone know how to check duty cycle while running?PowerCommander displays it on dyno while your tuning.So must be a way.Just dont want to run into tuning troubles on topend like we did with stock injectors.