Why bite it (tongue)?
I was thinking a A/F monitor would be a great tunning tool to have long before all this happened, This just put it higher on the list of priorities. Santa are you listening?
Give me a call if you have more to say[img]i/expressions/face-icon-small-happy.gif[/img]

OK mabye later I really am going to sleep now.

 

Alright, I have come to my conclusion. First I must say, all my nitrous experience up to this point was with the boonies system, and it works completely different than any other system.

What I think was wrong, was I leaned out, and started detonation, and didnt have enough octane to fight the detonation. I think this was cause by failures in two parts. One, the lack of knowledge I had pertaining to the boss noss system, and second the temperature drop.

First, imo, you need to tune your carbs, and your nitrous on the coldest day you plan on riding, if you want to be safe. If you want to run more octane than is needed, than i think you can flirt alittle with the temps. My reason is the nitrous is consistant, it never changes. But the carbs do. So like what happend to us, we were tuned for 80 degree weather, and the temps dropped 40 degree's. So the carbs went lean, the nitrous pushed the same amount of fuel and nitrous through that was needed, but it eccentuated (spell?) the lean condition. It made it act like it was twice as lean as it was. Then since I was running as little octane as I could, it could not fight the detonation occuring and damage was done.

So to combat this, I will retune my bike whenever temps change alot. I will also tune in the evenings when its cooler to give me a bigger margin of safety. I will also add more octane to help incase it does start to detonate. Now I think the mix I was running was sufficient for Nates bike, but thats my opinion. If the temps hadnt had fallen so far, i dont think he would have had an issue. But with more octane, like Marky had stated, he would have been saved.

I like to thank a few people that helped me find the results I did find. Eric (Mr HP), Marky, Nate, you fine folks on here, the internet, my goats, chickens, the pigeon that wont leave my roof, the neighbors dog, the neighborhood cat for leaving them fine tracks all over my black truck, the sun, for being so dang hot right now, and the WEATHER, for creating this fine mess that has got me here today.[img]i/expressions/face-icon-small-happy.gif[/img]


I do want to say one thing about the Boss Noss. Now that I fully understand its perameters, I am fully confident in running it. What I like the most about it, is that whenever I push the button, as long as there is nitrous in the bottle, I am going to get the same hit everytime. So tuning for the hill will never be so simple, knowing its consistant everytime. I will have this on the dyno here shortly, and will post the results afterwards. For those racers looking for a good system for tuning, this is the one to have. No need for heaters, and no worrys about the bottle pressure. It works off flow, so it dont care what temp it is, so run it from 30 below to 100 degrees, as long as your jetted according to your needs, it will give you what you want.

Marky, its all good like I said, no need to get so defensive. I like the kit, and never once said otherwise. It's a learning experience for me, that could have been avoided with more knowledge.

 

I wont even make the attempt to sound like i know anything about nitrous and how it works but i do have something to add.I have always jetted my motors on the rich side because of the great temperature variances that we have on the dunes here in Oregon.In the winter it can be as cold as 35-40 and in the summer it can be 80-90 which is a huge difference.Yes i am losing some performance by running too rich for the warmer weather but i have been doing this for almost thirty years now with good success.I am learning more all the time about nitrous but as i said i dont know much yet .It may be a while before i feel comfortable using nitrous but it sounds like when everything is dialed in and working correctly it is a very good way to go for performance.For those of you that have had motor problems i feel your pain.

 

Thanks duneit. We had them same temp swings overnight. Thats what caused all our problems.

 

Jed if the temp drop caused all your guys problems why did none of us locals spraying have any problems all weekend we all run 50/50 110 with 91??

 

I too have no Nos experience, but have some things to add and ask,

I run 14:1 compression at sea level with 110 octane, and at Utah/Idaho I mix 2/3 110 and 1/3 90 for around a 103 octane. Many hundreds of miles of extreme high reving with this fuel at tip top performance with no issues, and dr9 plugs btw. You guys are running 12:1 and I don't know what difference Nos necesitates for octane level but I can't imagine needing more than 100, please educate me of why you think 110 is necesary with 12:1 on Nos.


On the subject of temp change - I have been tuning to temp through the course of the year for years, here in Indiana I go from the 90's with 90% humidity like a rain forest to zero degrees and 15% humidity in the winter, and I ride in all of these conditions. Humidity is as big a deal as temp make no mistake, I make the same adjustment for a 30% humidity change as I do for a 30 degree temp change, and that adjustment is 2 main jet sizes. When I travel out to Utah and Idaho and raise 5,000 feet in altitude, you would think I need to drop 3 main jet sizes for altitude, but this is not always the case due to temp and humidity changes too, and when all said and done with first day tuning on trips out west I am usually only 1 or 2 jets different out there than at home mainly due to lack of humidity in the desert counteracting what I need to drop for temp and alititude.

But anyway, a 30 to 40 degree temp drop only makes a DS lean by around 2 or 3 main jet sizes assuming humidity did not change, and this is not enough for anything bad to be happening as far as all motor is concerned, but what kind of amplified effects is this going to have on a Nos system is what I am unclear on and wondering about?

 

Crapo, are you sure. Brindley completely lost his, your blowing smoke (just like we were) and derby lost his big bike. Thats three.

Hightower, without knowing the air density stuff, my best guess is it went from warm and dry, to cold and wet. It leaned out our bikes just enough to put them on the edge on all motor. Then we added nitrous, and that further enhanced our lean issue. How much? I really dont know either.

 

with a cold front coming in it can often be accompanied with higher humidity, getting cold makes the motor go lean, but going wet makes it go rich, and the two counteract eachother. no fancy science or math being applied here, just speaking from experience tuning in all of the above conditions. I know you didn't have a hygrometer with you or anything, maybe the humidity didn't change and only the temp did, but point being you would only have been 2 maybe 3 main jets off due to this weather change, if that.

I only bring this up because I do not understand why or how any Nos system could be so effected by such a small amount of mal-adjusted tuning. And I want to understand why and how because Nos is something I have pondered adding for well over a year now.

 

Hightower, thats a good question, and one I dont know. The bikes ran perfect the day before on 80 degree temps. One thing I will mention, is with all the other systems, they are regulated by bottle temps. So when the weather dropped, and they were out riding around with there bottles on the front of there bikes, they got cold, and bottle pressure dropped. So they naturally all went rich. And that could be what saves them during such an event. While the Boss system runs off flow, it dont care how hot or cold the bottle is, so you always are running in the same tune. So my take is, I might have been on the edge on all motor before this happened in warm weather, and could have been lean on nitrous at the same time (my fault for not making sure of these two things), so when the temps dropped, both went even leaner, and she got some deto going and the rest is history. Now my bike ran fine after this, just looked like a smoke stack by the time I made the ride back to camp.

 

Hightower,

You are exactly correct when it comes to Humidity. I actually dont know what the humidity was the previous days, or the following days. The factors are pretty interesting for sure on how they affect air/fuel.

Clearly, I saw both Nitrous Powered quads AND non-nitrous powered quads go down. Also I think Jed may have been at an acceptable jetting prior to the cold front moving in. However, I do think he was lean after it moved in. Jed isn't the only one that has been fooled by this - and certainly, being from the State of Utah, not many people want to ride ATVs in the cold. In Oregon, as I have mentioned before, going too lean in the cold is actually pretty common. You'd think more Oregon riders there would hear about it and watch thier jetting when they attempt to ride in those conditions.

Jed may have had some other factors contributing to his issue. Certainly using an pretty advanced ignition may have contributed. Add the fact that he may have been on the lean side of the acceptable limit, and a temperature drop of nearly 30 degrees which may have lowered his tuning elevation by 2300 feet and you have a potential for issues and moving from that barely acceptable jetting, to something thats not.

As far as the temp goes, its not something Jed would have known about. We simply dont see very many posts about how temperature is a factor in jetting. And, unlike Jed, you simply dont see many people talk about it. But, Jed is right here helping the DS guys trying to understand it.

Jed is right about the NOSS system. Its "air" from the Nitrous bottle is regulated and will not be affected by temperature. However, that being said, if the temp drops and causes the carb to be out of tune, nitrous wont heal that.