NITROUS OXIDE ( nos / n2o ) advice forum

I entered my car in the 3rd round of the streetlegals in Drachten, Holland yesterday.
I had missed out the 1st and 2nd round so was eager to improve on my times from last year. Had high hopes from my 100 bhp nitrous shot.

Wether conditions:
Not ideal, 25 degrees Celsius, high humidity, and a stiff headwind on the track.

Track conditions:
As poor as poor can be. There is always a professional dragevent from the Explosion dragster organisation one week prior to our streetlegals, so in the meantime, rain, dust and oil mix together nicely to ruin the traction.
This time it was so bad that some of the hardcore racers managed to break gearboxes, shafts, etc, which caused several delays.
Only the guys with slicks or drag radials had decent grip.

I always make a couple of in car videos from my runs:

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My first run. I had forgotten to uncork my exhaust cutout. Luckily my catback stayed in one piece. Minimax at 30% with a 5 second ramp. Front tyres at 2.5 bar. Lots of wheelspin in 1st and 2nd. I found out I couldn`t flatshift through the first two gears on this track due to excessive torque steer, I had to keep the steering wheel with both hands otherwise I would be all over the place. Wished I had a LSD now.
A disappointing 14.765 E.T. I was shocked.

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My third run. I forgot to switch on the camera for the second run. Lowered tyre pressure to 2.2 bar. Minimax 30% at 7 second ramp. Exhaust uncapped. Bottle pressure was rather high at 1050 psi because of the exposure to the sun.
14.639 E.T. with a sleepy 0.554 reaction time.

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Fourth run. I was up against a buddy of mine with his ratty turboed Nova with 400 bhps. Minimax 30% at 6 second ramp. Bottle presure was down to 900 psi. Tried a 80 fuel jet instead of the 90 fuel jet. Engine picked up a bit in the midrange, might be responsible for my best time that evening, a 14.455 E.T. If it wasn`t for my lousy 0.553 reaction time I might have broken into the 13`s with that run.

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Had a good 0.032 reaction time this run.
Appaling 2.642 60ft
14.760 E.T.

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0.023 reaction time, my best that evening.
2.619 60 ft.
14.737 E.T.

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Bottle starting to get empty. 1000 psi in bottle. Changed back to the original 90 fuel jet. Somehow scored my highest topspeed at 167.83 km/hr.

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As a comparison a video from last year when I was naturally aspirated.
14.49 E.T. at 158.9 km/hr.



A few timeslips from yesterday:

This gives and indication of my trapspeed through the lights. Was off against someone in a 550 bhp r33 Skyline. If you solely look at the speed I`m not far behind.
I just need a better launch technique and improved traction to get a better E.T.
I compared my times to that of others and my 167 km/hr topspeed indicated a 13.7 E.T. with better launch and traction, so I know it`s possible for me to break into the 13`s.



My best E.T. that day. My best time last year was a 14.49 E.T. naturally aspirated, so a 0.04 second improvement with an extra 100 bhp nitrous shot on tap is pretty poor in my book.

The 4th and last round of the streetlegals is coming August, and I plan on changing my launch technique with the nitrous radically. I guess I`m still used to a natural style of driving by revving the snot out of the engine and flatshift my way through the gears.
I plan on setting the nitrous activation point very low, 2000 rpm or so, and let the torque from the nitrous carry me through 1st and 2nd gear in hopes of improving my 60 ft time and 100 ft time without the tyres breaking traction, I think this is the area where I`m loosing a considerable amount of time.

Video of my run against some other guy (half of the starting field consists of HondaCivics)
http://www.youtube.com/watch?v=ebC8_UilmZY

Well there must be something wrong.
Does the system flow?
Is it too rich?

I had the same problem with too low Bottle pressure = too rich.

Did you perform a static test that day?

It`s functioning alright, but it`s indeed a bit on the rich side. My lc1 controller showed 11.2-10.4:1 at 950 psi with a 90F/200N jetting in 3rd and 4th gear.
Oddly enough, with the 100 bhp shot, 1st and 2nd gear are in the 12.5-12.0:1 range.
Don`t know why that is, perhaps because the engine is still partially in closed loop.

Static test is not possible on my car because of the DBW throttle and the I-vtec system on my Honda, but I do road tests with my LC1 controller.

Too bad you can´t do a static test.
This is a pretty good indicator for me. (Have no Bottle heater and have to change the jets if it´s too rich)
I only have some random logs but i also had a rich reading on a good run. But only in the upper rpm range. Like 10.2 from 4000 to red line.
What does the spark plugs say?
The old guys say: "Do what the Plugs tell you!"

Greetings Thomas

Euh.., to be honest, haven`t looked at the sparkplugs yet. The last time I checked they looked okay. Discoloration right in the middle of the ground strap, no little specks on the porcelain, lightish dark ring on the lower porcelain side, black soot on the base ring, first two threads have discoloration. In other words, just what it ought to be.
I hate pulling the spark plugs, it seems I have to dismatle half the car in order to be able to reach them. I`m using the NGK BKR8EIX b.t.w, regapped them from 0.75 to 0.85mm.

I also noticed that bottle pressure in combination with jetting plays a major role on my car when it comes to performance. Below 900 psi the car feels sluggish and won`t rev cleanly. Due to my exhaust cutout I can also hear whether the mixture is fat or not. I consider a pressure gauge and bottle heater mandatory if you want to get the jetting optimised.

Just a note, your reaction time doesnt count towards your et

So dont worry about the lights if your just going for a time.

A few quick points;

1) You should NEVER start a race season with such big jets, especially on such a bad track, you SHOULD ALWAYS start at 25 HP.

2) Lack of traction means that the results you've posted are NOT an indicator of how good or bad the system is performing or how accurate the mixture is, ONLY good condition and lack of wheel spin can provide that.

3) You should ALWAYS inspect your plugs after the first couple of runs at least (I did mine after every run) and you should kill the engine as soon as possible after shutting down at the end of the run - DO NOT DRIVE THE CAR OFF THE TRACK (coast off) AND DO NOT DRIVE BACK TO THE PITS. Failure to comply with these instruction make plug inspection virtually a waste of time.

4) If you been using smaller jets you would have undoubtedly run MUCH quicker times - bigger is not always best.

For the record, I used to run up to 750 HP of nitrous in my street car when I was using slicks but when I raced on treads I dropped that down to as little as 150 HP (between 3 stages) and regularly beat guys who were TRYING (unsuccessfully) to use MUCH MORE power than I was using. More than you can use is not only a waste but it will produce slower times. By starting low and working up, you can determine how much the car/track can use and achieve the best possible under the prevailing conditions.

5) Changing your launch/driving technique the way you describe and I preach, will undoubtedly improve your results but if you also act on the above advice as well, you'll do even better.

Don't forget I'm expecting GOOD things from you to show the Dutch racing authorities what my products can do.

BTW how did the race tech meeting go?

I also noticed something else, my fuel pulsoid stayed cool through the evening during my runs, but the nitrous pulsoid got pretty hot in the end.
I think it gradually picked up more and more heat from the intake manifold since it was so close to it.

I plan on relocating the nitrous pulsoid from the intake manifold to one of the shock towers in the engine bay. This will necessitate a longer feed pipe from pulsoid to distibution block, but I don`t think that will affect the system.

hahaha Oh Paul , Im sorry to hear you had to go through all that explenation and proving those dumb ass of what a good system the WON is.
You dont wanna know all the stupid stuff I had to hear from them last year, Until they saw the car perform....after that they never said a word again hahaha.

As Trev said, your car WILL perform MUCH better.Like I said in the other thread, if you want I can stop by and maybe offer some help.

I hope the weather gods will be good to me coming weekend in Wilhelmshafen. I will use that event to optimize my launch at low rpm assisted by the nitrous system. I plan on setting my window switch between 2500-7900 rpm, minimax at 30% with a 5 second ramp up time. This is on a 75 bhp shot. If that goes well I may even try a 100 bhp shot again.
I would be glad if I can get an official 13.9 timeslip. That will sweeten all the mishap I had this year.
One thing I`m really glad about is that the DHRA startercrew will make their appearance there with a real christmas tree. Last year the German organisers used some sort of traffic light contraption, no means of staging possible.

I'm sure you will get it soon enough.
wow 5 seconds...
traction is killing you

Best of luck Paul and I hope to see a good report when you find time.

Good luck Paul

Well, checked the weather forecast at the Wilhelmshafen area in Germany today at 6.30 am, and I think I shouldn`t have mentioned the weather gods because they steered a continuous amount of rain clouds directly at the airport there all day, the bastards.

So decided to stay at home, keep my bottle full and save it for the last event this season coming Friday the 17th in Drachten.

SHIT!!!

No worries Trevor. Drachten is my home track, and I think I can improve my E.T.`s this time.

I'll be there Paul
I'll stop by and say hi

See you there man.

I`m sad to report that the streetlegal drag event coming Friday at Drachten has been cancelled again because of the heavy rains this week. The track is not accessible, the surrounding terrain is soaked with water.

I hope the DHRA can organize another event somewhere else this month or in oktober, so I can make at least a few runs to try and improve on my times this year.

Paul, are you going to Bitburg this weekend??
"King of the Hill 2010"

We are going, so if you manage to go, let me know.

Nah Gino. My back doesn`t allow for long distances behind the wheel. Otherwise I would have entered there.
My nitrous antics are currently in hibernation until next year I`m afraid. I might change my nitrous setup however. There are some plans in the pipeline this winter:
-Hondata flashpro (hopefully Hondata will have the optional nitrous control by then)
-Switching from a single pair of pulsoids to a double pair, just for the heck of it.
-I ordered some semi slick tyres for next year to get more grip at launch
-I purchased a spare 6 speed transmission for a bargain. Still on the lookout for a used LSD.

Hope these mods will bring down my 60 ft times.