I have heard soo many people that say " you will blow your motor if you spray under 3k rpm" but so far none of them have been able to back it up with any proof, so I have to ask if anyone else has ever heard this b4?? and if it is true why?? because it just dosent seem to make sense to me!

I have window switch and its set for 3200-5600 rpm because ofthis rumor ans so far I have had no troubles.

so does this rumor have any truth to it?

Thanks.

 

Nitrous adds alot more shock to the rotating assembly at lower rpms, even most nitous companies will tell you not to activate thier systems below 3000 rpm as engine damage may be the result. That being said, I know lots of people who engage thier nitrous at the starting line myself included.

 

Too much cylinder pressure = KABOOM. If you are spraying a 100 shot for example, you are going to get 100 HP regardless of RPM. If you recall the formula that HP=Torque*RPM/5252, you can figure out how much torque that 100 shot will produce at any given RPM. The lower the RPM, the more torque you're going to make.

6500 RPM = 80 lb-ft
5252 RPM = 100 lb-ft
3000 RPM = 175 lb-ft
2000 RPM = 263 lb-ft
1000 RPM = 525 lb-ft
825 RPM = 636 lb-ft

So as you can see, at low RPM's the N2O is producing an increduble amount of torque, which means that cylinder pressures are also incredibly high. Even purging the nitrous through the engine at idle WITH NO LOAD can collapse ring lands and cause some pretty nasty damage, though it sounds pretty cool. I would imagine that spraying out of the hole the engine speed would be above 2-2.5K the whole time, so though there is a greater risk of damage, it probably won't happen. Now, if you're idling along with an M6 and spray it you'll probably have a few broken engine parts. I have my window switch programmed to come on at 3600 and off at 6200. Any lower activation RPM than that and traction becomes a complete joke.

 

Would it be safe to spray below 3000 rpms with say a smaller shot via a progressive controller?

 

Yes.

 

It is not that you will blow the motor up, it is just greatly increasing your chances. And is not needed. Also the smaller the shot the sooner it can come in, just like a progressive unit.
Ricky

 

well it can happen,the main reason for the 3000 and up rule is, at that rpm level the engine is pulling in more air and that will help atomize the fuel,n2o as well as in coming air,it also does not shock the bearings and rings as hard.
as for a smaller setting it allows you to hit it earlier cause their is not much "HIT" with a smaller pill,hope this helps!

 

NX RECOMEND SPRAY ABOVE 2K. i 'M SPRAYING AT 2100 150 SHOOT WITHOUT PROBLEM IN THE PAST I HAD 2 BACK FIRES BUT BECAUSE I DIDN'T USED WINDOW SWITCH, NOW I HAVE ONE 2100 ON 6000 OFF

 

i run 200 starting at 2000 rpm in first gear right off the bat. drops from 13.40 to 11.81. yes, it puts more stress on the engine, the lower you hit it. now, of course, once i put a converter in, i won't be able to do that anymore without blowing the tires off.

 

Iv never used a window switch, ive always had my dry kits set up on a WOT switch and sprayed it off the line all the time. I would just nail it off the line nitrous and all and never backfired or anything. Mabey becaus at WOT the rpms are already up there. However with my wet kit i know is more prone to back fire so i will probabily be getting a window switch to come on between 2300-6100 rpms or so.

 

Yeah I would suggest at the very least 2500 rpms, and if you are gonna dyno your car wait till at least 3500 rpms, because the dyno puts more of load down low, then the track or street. Therefore increasing your chances of a kaboom

 

Not sure if it was addressed but jsut skimming...

are you running a wet kit, I heard something about a fuel puddling at low RPM shots, which leads to backfires.

 

Yes I am running a wet kit it's a NOS 5151 intended for TPI motors but it also works on a LT1 with some fitting.

 

refer to CLICK ME this thread CLICK ME for yet another quality thread by NXricky on the topic of fuel puddling. basically on LT1's and most fuel injected vehicles, its highly unlikely

to nxricky

 

nitrous, eh.......window switches, eh.........hmm...I'm learning here. I am researching N20 before I but. You guys help a lot! thanx.