NOS questions

So I've never messed with NOS before so it's a somewhat intimidating learning curve.  The Zoomboni came with a fully plumbed kit and full bottle the size of an 80 cf scuba tank (i suspect they are sourced from the same supplier actually).

It appears there is a toggle switch to arm the system, a purge button to clear the pipes, and a micro switch on the throttle body that engages at full throttle.  Does this sound right?  Is the TB mounted switch the preferred method of engagement over the F&F style steering wheel button?  What do I need to know about such a setup?  Are there any big "gotchas" waiting to bite me in the butt?

A WOT switch is definitely better than a thumb button, especially as someone new to nitrous, because that way you don't run the risk of accidentally staying on the spray when you let off the throttle, which will result in usually result in a big bang.

The purge is optional and mostly found or higher end wet kits, or ricers wanting to make a show. I like the throttle mounted switch, I've had a couple of systems, on challenge cars, still have a cheap wet kit I thought about tossing on the miaturd. If it's a dry kit you want it as far from the throttle body as possible and if it's a wet kit you want in the intake past the throttle body. Pay close attention to the jet sizes and start small, you can probably guess how I learned that lesson.

In reply to NickD :

Ah, that makes sense.  Cool

But it does seem like it makes the throttle response kinda wonky.  Throttle goes 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%......150%.  Again I haven't driven it and maybe in a straight line it doesn't really matter so much but it looks like it may become a handful in a hurry.

In reply to evildky :

Wet kit being the one with an extra injector dumping fuel into the system?  Yup, it's that type.

I have a feeling that Mr. Grimes didn't mess around and this is a really well set up system but I don't thing it was ever actually run (the drags got rained out back in 2009).

So why is there a rule against NOS at autocross?

KyAllroad (Jeremy) said:

 

So why is there a rule against NOS at autocross?

I always wondered if the Saleen Focuses (Focii) that came with it, you could get away with it an autocross because it came equipped with it? Probably not, but it'd be a fun argument with the tech inspector. 

Also, what the hell is this Zoomboni? I've seen several mentions of it, but no photos or explanation (or I missed it, entirely possible, I miss all the fun stuff here) and I'm really curious.

In reply to NickD :

https://grassrootsmotorsports.com/articles/2007-a-zamboni-odyssey/

It now resides in my garage and is getting ready to tackle next season of autocross as an E mod.

In reply to KyAllroad (Jeremy) :

Ahh, back on that 302 Miata life, I see, but now with 100% more zamboni

Only real "gotchas" at this point are tuning related. Probalby worth checking to see what jets are in it and making sure they make some sense. I generally always test a new setup with the bottle valve closed to make sure all the safeties work as should. Hit WOT should turn nitrous and fuel solenoids on and with no nitrous you should feel it bog rich. After that open the bottle and start tuning. <50hp stock plugs, one colder at 50 and every 50 till 150 then keep the same ones. Timing is another story but it's a long one and more details would help.

But it does seem like it makes the throttle response kinda wonky.  Throttle goes 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%......150%.  Again I haven't driven it and maybe in a straight line it doesn't really matter so much but it looks like it may become a handful in a hurry.

There is such a thing as a progressive controller but if you're adding a small shot to a low power car going straight and level then you probably have more than 50hp of 'traction headroom' in all but 1st gear.  On a dragstrip you probably wouldn't engage nitrous until second and then then throttle would be "150%" for the whole rest of the course other than manual trans upshifts. 

The only nitrous setup i ever installed was a WOT switch  and an rpm switch so that it wouldn't spray below 4000rpm even if WOT. Again, not an issue on a drag run where you'll never be below 4000 rpm in most cars except during the launch, but for any other use it's worth considering.