What are some safety mechanism I can use, switches ?

[alaskanbowtie]

I'm getting the Holtzman 20g./sec. single nozzle on my Apex and I'm wondering what is availble for safety back ups ? I know of the full throttle switch, do you run a fuel guage after the solenoid to verify your fuel pressure when in use? I've done this on some of my cars in the past how about on sleds? Anything else fuel pressure relay/shut off ?

 

[HAMMER]

Does Barry recommend any "safety" items with his kit ???

Fuel Safety: If the nitrous/fuel mixture enters the intake track before the carbs/throttle bodies a WOT switch or Progressive Nitrous Controller is more of a convenience (on lower hp systems) than a necessity because the carbs/throttle bodies will control how much nitrous/fuel mixture gets to the engine if you unintentionally activate the system... If the nitrous/fuel mixture enters between the carbs/throttle bodies and the engine there is a much greater chance of "kaboom" if you unintentionally activate the system... For 99% of the snowmobile systems out there you can safely activate your system manually (button) using common sense, I prefer this method in the applications I have used on my sleds... Many automotive nitrous companies sell adjustable low fuel pressure safety switches for both standard and EFI systems... You can adjust them to disable the system at a set fuel pressure... They remove electrical power from the nitrous solenoid to prevent lean conditions when fuel pressure gets below a certain set point... You could also use a "window switch" that will provide an open or closed circuit based on the engine being between two RPM values that you chose so that you'll only flow nitrous within a set range of RPMs.

Solenoid Safety: According to most of the nitrous solenoid manufactures solenoids are designed to "fail in the closed position" so that shouldn't be a concern.

Bottle Safety: Most bottle "burst safety discs" are rated at 3000psi so that shouldn't be a concern either.

 

[NOS-PRO]

AB - Holley brand makes a fuel switch that shuts the system down, if it gets below 5 psi., and I use them on the big NOS systems I put on cars for people. The fuel pressure on the FI sleds are 40 psi, so I didn't install one. I trun the system on, (without the nos bottle on), and then with all activation switches on, I hit the button, while driving the sled a couple times, to squirt fuel into the engine. When the engine starts to bog, I know that fuel is entering the engine, and I tell my self it is o.k. to let off of the button, and pull over, and turn the bottle on. I have an activation swith mounted on the dash, and then the button on the left thumb side of the handlebar. I tried the throttle activated, but like it better over on the left, cause i can keep control of it better. I can hit or let off of the button in different traction areas.

 

[kinger]

"Fuel Safety: If the nitrous/fuel mixture enters the intake track before the carbs/throttle bodies a WOT switch or Progressive Nitrous Controller is more of a convenience (on lower hp systems) than a necessity because the carbs/throttle bodies will control how much nitrous/fuel mixture gets to the engine if you unintentionally activate the system... If the nitrous/fuel mixture enters between the carbs/throttle bodies and the engine there is a much greater chance of "kaboom" if you unintentionally activate the system... "

I don't understand this???

What are you you trying to prevent injecting nitrous with no fuel? If so then how does the throttle bodies help with that?

 

[alaskanbowtie]

yes, safery switch to prevent activation without fuel

I was wanting to know what all options I have for safety, basically so if I'm riding all day and have been hitting the butom occasionally and then the fuel solenoid or mechanism for mixture malfunctions how can I safe guard the sysytem so it senses this and won't activate. But after great talks with Holtz and ICE I've decided the likely hood of this happening is like winning the lottery.

 

[HAMMER]

I don't understand this???

If you activate most systems at low rpm with nothing between the nozzles and the engine...kaboom...sort of a informational precursor to mentioning the WOT switch or window switch to activate the system... Not necessarily a fuel exclusive remark... Sorry if my ramble was confusing.

With the carbs/throttle bodies blocking/restricting the nozzles/charges path to the engine, rpm goes up a few hundred, but no kaboom.

With my old BoonDockers system I would "fog" my airbox on the starting line (hold the button down for 1 or 2 seconds) the RPM would go up 200-300rpm, and talk about a hole shot, whueeee!!!

Should be able to do the same thing with my current SC and the little "dry shot" I setup for next season... Bump the button a couple times on the starting line "fog" the charge air tube/intercooler, grab a handful, and as soon as the nose starts to settle down I can get back on the button if it's a close run... I don't really need it out of the hole with the SC but I am curious to see what effect it has and if I can hold traction... I installed it mostly for long-steep-deep-pulls to help keep the intercooler temps down and add a bit more oxygen at 8000+ altitudes.

 

[kinger]

I see this assumes you have a button and not a WOT switch. I gotcha thanks for the good info.