NITROUS OXIDE ( nos / n2o ) advice forum

The transducer is likely to be more accurate than any gauge and as long as you have repeatability of the readings (which you will with a transducer), it doesn't really matter if it's not fine tuned to exactly the correct pressure.

FYI the Max has the facility to adjust the reading to match the exact pressure but the cost of another device that is KNOWN to read an exact pressure would be insane.

There's certainly NO substitute for experience and I'm always happy to share mine with my customers, just a shame there's so many free loaders out there who read my site, who are smart enough to steal some of the knowledge but not smart enough to realise they need to buy my products, for the knowledge to perform to it's maximum potential.

I am now hooking up the nitrous button. I need to use a manual button to activate the nitrous system. The bike runs full throttle about 95 % of the time. I only want to activate the nitrous after I am settled into a tuck. And then I usually wait for a track marker. Like the 3/4 mile or the 1/2 mile marker.

Since I have no Throttle switch I was thinking of using the terminal R10 Throttle input. The switch I use is a simple contact switch mounted under my thumb on the handle bar. My question is what should I use for the input? 6 volts from terminal R4?

Might I suggest that you activate the Max prior to the launch (a simple on off switch would do it) or better still at the launch using a clutch activated swithc and rely on;
1) The gear activation option
in conjunction with
2) The RPM activation option

This would allow you to set the Max to activate in whatever gear you intend to fire it in and above whatever RPM you decide on.

Set appropriately this would allow you to go through the gears you don't want to use nitrous in and then get comfortable prior to activation in the desired gear and when ready, nail the throttle which would cause the rpm to rise and once it exceeds the selected rpm the system would activate.
Once you shut off the throttle the rpm will drop or if you pull in the clutch, the system will switch off.

I just cant do it that way.
First I have no room for a throttle switch and I don't have a clutch switch. And I really don't want nitrous coming on before sixth gear. The shifting on this bike has to be done carefully. It is sloppy by race standards.
And there are a lot a times when I will miss a shift just shifting to early or late.Or just blow the run for what ever reason you can think of. No use wasting the bottle charge, I can just go around and get in the VERY long line. Then try again. If I use some nitrous then I have to go back to the pit and start over with the bottles and all. So the go go go button is just simple and reliable,

But I do want RPM windows. Like the nitrous to cut off above 14000 RPM and not come on below 9000 rpm for safety.

As i understand it, you should still be able to set max for gear activated window cut out nitrous. If you have a switched 12V supply which you switch on prior to run. Feed the max a 2nd 12v signal via the clutch switch to activate gear change, then as soon as you get 6th gear the nitrous will arm and fire once yr in 6th. If you blow yr run prior to 6th, back the throttle off to keep revs outside of window range and no nitrous firing so straight round to back of queue.

To be honest though, if your gear change is that sloppy id get it sorted so as not to waste valuable racing time. I appreciate yr not against the clock like us drag boys, but every slow gear change is a loss of valuable forward momentum, so you could be costing yourself 5mph by the stripe just through dubious gear changes

Steve

It's not that the shifting is sloppy. The trans is not undercut. If it pops out of gear or finds a false neutral while nitrous is spraying it will send the engine to 20000 rpm.
I am just not comfortable with nitrous activating with out my say so. I have been drag racing for a long time. This is not drag racing . I could send you a text message mid track and get your reply at the finish line.

Can you give us a step by step resume of what you've previously done during a typical run please?

I check the switches and nitrous psi and that the bottle is open also. I check that the fuel valve is open and camera is running. Also I make sure the dash is reset.

I put it in first gear and when the starter gives the OK I rev to full throttle at 10000 rpm I start to let out the clutch once the clutch is out and the rev hits about 12000 I shift to second with just a blip of the throttle and I use the clutch. After I am in second I quick shift to third again using the clutch . From there it is safe to go to forth without the clutch. Just blip the throttle and shift into forth. This is about 1/4 mile in and close to 100 mph. I will speed shift into fifth and watch the rev till it climbs to 11000 or more then into sixth gear. Now I shift my body back as far as I can and I am about to the 1/2 mile marker sitting just below 110 mph and about 11800 rpm and that is it . I ride down the track watching the tack reach for 12000 rpm . With the nitrous I can start to spray. If the system worked it pulled faster and faster till the line. But most times it would nose over and I would get out of it

So you ONLY use nitrous in top gear from 11,800 rpm.

What point/distance are you measured from and for how long?

Yes from top gear and top rpm. The power band tops out at about 12000. The revlimit is 14500rpm . For my goal of 125 mph I need 13000 or better. I would like to spray 1/2 mile about 25 seconds . But I usually only spray from the 3/4 point about 10 secounds.

If your powerband tops out at 12,000 why not raise the gearing so you achieve your top speed at 12,000

Also why are you only using the nitrous from such a high rpm?

BTW I'm not saying you are doing anything wrong, just wondering why you do it the way you do, just in case there's anything I can contribute to help you achieve even better results.

I understand your need to understand my methods. I have been developing this bike since 2008 and some things I do out of habit, some from hard learned lessons.
Any input you have will be greatly appreciated.

The fun of racing a motorcycle that has no power is finding the gearing that will make the best speed.
let me take the nitrous out of the figures because I have not had results I can effectively document. But running all motor. I have over a hundred passes at Maxton alone. What I found is.Or what I do is. Go on the dyno(that will happen next Tuesday ) find the power band peak. Then use a formula to figure out the speed that the power will allow. You have to be realistic. I have done this enough to know say 30 hp will go 105 mph. and I make 34 hp at 12500 rpm. I will then use another formula and figure out what gear ratio will get the rpm at that speed. I then go one tooth up from there and take it to the track.
The test is to make one pass in 6th gear and another in 5th . If it is faster in fifth than you have it over geared. One tooth can drop this motor out of the power band and it will go through the trap at 98 mph at just over 11000 rpm. The difference between a record and a blow run is less than 500 rpm. So if I can get 1000 rpm . I am flying.

Once I have a consistent power out put I can then work on the aerodynamic aspect of the Land speed racing game. But I have to get the power consistent first. In 2009 using a stock motor I went from the original 102 mph top speed and got to 112 mph and over 106 on every pass.The top speed for any 250 four stroke was 108 mph at that point. Jarl and I have made great strides since then.

No I have not used nitrous on the dyno. I use a dyno jet 250
My plan is to break in the engine on the dyno . Then make a couple passes on the 1/4 mile track then do the static test and then test the nitrous on the dyno.

I spray for 1/2 mile about 20 to 30 seconds

The difference between a nitrous run and all motor run would be a 16 tooth front sprocket instead of a 15 . And I pull some timing for the nitrous.

I change the gearing to help keep the RPM lower . The engine makes power from 8500 to 13000 after that it drops off . I just want to push the motor in sixth gear to the point it reaches in the lower gears

OK on all that.

Is the aim to achieve the highest possible terminal speed as you cross the mile line and not an average over a mile distance?

Correct, the top speed after one mile run up is measured in the last eighty feet. The speed increase after 100 mph is very gradual so getting going like a drag race start is good .But because the top speed is low I am up to that speed in about a half mile . From there I just try to tuck hold still and go straight .

this is an average run. You can hear the nitrous hit. It just goes BLAAAA and no real speed increase.
http://youtu.be/IBxr0-sJL_E


Up until this year I have competed in a points race. This year there is no points race and since it is a new track .There are no records. For the first time I don't have to run.
This gives me time to test and tune


This is what I would hope a good 20 hp shot of nitrous would look like.

In answer to your original question;
Yes, you should switch it with the 6V output as you suggested and you'll also need to turn on the 'trigger load' option in the inputs menu - menu > system > inputs.
Full revised Max V2 instructions will be added to our products instruction page later today.

The surge in power was from me pulsing the button. If I stay on the button the engine will blow up. So I just push the button and gain a couple mph . Then let off and do it again. Gain some loose some down the track.

I believe the clutch was holding. I mis spoke . I should have said no real increase in speed. That run was below 108 mph

Just had a look at your video,none too shabby for a 250. However,I'm in agreement with Trev, def sounds like the clutch is slipping a bit soon as ya hit the button.
Steve

Hard to say for sure. I will put the camera in a place that records the dash, That will give some useful data. I was activating the system at about 11500 or so. With the 16 tooth front sprocket it is hard to get the engine to rev once the bike hits 90mph in sixth gear.
For timing I was at 28 deg I think, I will have to check but Stock is 35 deg , And I pulled it to 32 then 30 then 28. All with the same results. I tried 118 octane fuel and could not get the engine to start or run at all. Most of the time I was running 110.

I had very bad clutch slipping when I hit 121 in September of 2010. It was showed up on the dash RPM recorder also. At that time the Boss Noss system SEEMED to be working. I would hold the button for increasingly longer periods and the bike was going up to 120 with no problem But at 122 the clutch would slip a little and the speed would drop to 121. I went through the traps 3 times like that hitting the rev limiter at 14500.
The clutch I have now has VERY strong springs and I don't think it was slipping. There are no blue spots on the steels and the pack still measures out OK. I will see how it looks after the dyno tomorrow.

When I came back in April 2011 I felt like a had made improvements in the bikes aerodynamics and I had a better clutch with stronger springs. When I got on the button the bike pulled and then shut down with a Hole in one piston and the electrode missing from the spark plug. and the other plug white lean. So I cam back in May and tried it again after talking to Boss Noss and sending them the system back. I was hopeful the system would work. Same thing. A slight surge of power and then POP.
June I used a N/A motor . But In September when that video was taken I had figured if it starts out rich then goes lean, then by starting and stopping it would stay rich. It worked and I was able to race again in October.
The reason I had to do this was the points race. Every MPH over the existing record was worth 2 points. I finished in 6th place for 2011.

The new track will not have a points race for 3 to 5 years, So now I don't HAVE to race,If the bike is not ready I will just drink beer in the sun and watch Jarl race.

Well hopefully if it was clutch slip then it'll show on the dyno, if not, like you say, the camera should catch it. To be honest, i sounds like an old honda shifting with clutch (no insult intended) where they were a bit lazy re- engaging then once its there its good. It may just be an audible illussion with you on and off the button

I dont know if its the norm on smaller capacity machines, but that seems an awfull lot of timing to drop, but guessing this was trying to cure the holed pistons? From what you are saying, it sounds very much like you've suffered a bit of fuel lacquer or damage to a seal or something caused by fuel. I know 2 seasons ago i forgot to drain my nitrous system of fuel, only to find my fuel pulsoid had gummed up and wouldnt work. But at least now you have a new system so that shouldnt be an issue any more.

I think once you've used your WON system a few times and gained trust in it, you could really start pushing the boundaries, i wouldnt be suprised to see you and Jarl in the 130's very soon.

6th sounds a very respectable finish considering all the trouble you had, so congrats on that and best of luck with the upcoming season

Steve

I went on the dyno today,
I did not do everything I wanted to do, I was not prepared for the bore increase. The jets I have, though crazy rich for a 250 where lean for a 265cc engine. I have up to #122. We found a set of #128 jets and they where just a bit rich. Great for break in but not for testing. I will go back when I get proper jets and the nitrous system finished
The results I did get where very good. With 30 hp at 10,000 rpm and that was with 35deg of timing and a rich A/F, so OK.


Yes I was trying to help with the preignition/detonation by pulling the timing back, I tried everything.

This engine responds VERY well to timing increasing. I have run as much as 44 deg with race gas and rich jets.But with nitrous I will start with 35 deg. and work from there. I have seen 35 work for myself and another team.Unless there is a better number to begin with.
I used the stock 35 deg timing setting on the dynio today.

All sounds fine to me.

With timing it's always better to start retarded and EDGE UP towards the NA setting.