NITROUS OXIDE ( nos / n2o ) advice forum

As unfortunate as it is, I'm learning what components are the weakest in this car and I'll rectify them in time. The good news is that this car really loves nitrous, of course besides the obvious ignition and clutch problems. Especially since other cars with junk kits tend to have issues of the more "permanent" nature...

I pulled out my coil pack and plugs for inspection again.

The only thing I noticed were the plugs are showing wear from use and the gaps opened up. With all of the commuting I do with this car, I'm not surprised at the current level of wear. However, the increased gaps could be enough to cause problems igniting the charge on boost and nitrous. I attached a pic for reference showing the visibility of the "V" in the NGK copper plugs I am using: you can see the difference. Also note that when gapping some plugs, the gap isn't always even, which requires a smaller gap than normal. To illustrate, Instead of an even gap like this ( || ), you get this ( |\ ).

For my car, I went down to 0.025" at its smallest end and the larger end is more like 0.028" but it's too difficult to measure.

I hope this cures my nitrous miss. Not that it matters with my clutch woes, but knowing why my engine shudders has me going nuts!

An increased gap will certainly make it much harder for the spark to get across it, so reducing it should certainly improve things.

It doesn't really matter that the gap isn't parallel as the spark always jumps across at the narrowest section, it just means that section will wear out a little quicker than it would if the gap was all even.

My point exactly, by gapping a little tighter the wear won't open the gap as much, which reduces the likelihood of misfire.

As suspected, just a regap was needed.

Just as an additional note: 99.9% of other nitrous kits wouldn't give a spark plug the opportunity to wear out normally since they usually end up breaking or melting them!

VERY TRUE and to add to that, my advice on plugs is to use a style that puts the least amount of metal in the combustion chamber.

This concept is supported by the fact that NGK offer a range of plugs with the code ECS which has a very short ground strap, which they happen to recommend for nitrous use.

In STARK contrast to my advice, Zex for example sell this JUNK;
http://speednik.s3.amazonaws.com/legacy ... G_7577.JPG
Which has a LOT more metal TO MELT than even a stock road plug, WHICH IS PLAIN STUPID!!!!

Not only that but they are making TOTALLY FALSE claims that sparks jump FROM all 3 electrodes (inferring that this happens ALL the time), when that is IMPOSSIBLE. Unless a vehicle is fitted with an MSD ignition system (and even then it may still be the case), the spark will jump between the centre electrode and whichever point on ANY of the 3 electrodes that is closest to it. It will only jump to one of the other electrodes when it has worn the closest one making the gap bigger than to another electrode and that won't be for months rather than nanoseconds.

It's absolutely DESPICABLE that US 'companies' are free to propagate such LIES, just to improve their profits.

One final point while on the subject of spark plugs, I've heard FOOLS claim that it is better to use a plug that melts easier (lower NGK number) with nitrous, as it acts like a 'FUSE' but that is TOTALLY THE WRONG THING TO DO. While it is correct that it will act like a 'fuse' in that it will melt before any other part in the engine, unlike an electrical fuse it WON'T save the rest of the motor from melting unless you INSTANTLY SHUT DOWN THE ENGINE THE INSTANT IT MELTED, which is obviously impossible to do.
In the absence of being able to shut it down INSTANTLY, the molten metal from the ground strap, is VERY LIKELY to end up trapped on the exhaust valve seat, where it will prevent the valve shutting and allow air to leak in on the next induction stroke. This then creates an excessively lean area in the same location as the very hot metal from the plug, which leads to pre-ignition and detonation. Finally on this matter, if anyone is unfortunate enough to melt a ground strap but the engine 'APPEARS' to be running OK after a new plug has been fitted, do yourself a BIG favour; 1) You shouldn't have fitted a new plug in the first case, 2) Before doing anything else you should have the engine either put through a LEAKDOWN TEST or better still have the head removed and the valve seat areas checked for trapped plug debris.

This could save you MAJOR expense the next time you run the motor.

BTW, those new plugs I put up are for the Lexus: they use the same plug type.

Trev,

I performed a fuel pump capacity test as seen in this video here: FUEL PUMP TEST

The plastic bottle shown is a 500 ml bottle and it was filled to the max in 10 seconds time with no jet inside the Pulsoid. I suspect that these computer controlled fuel systems have more powerful pumps than older style hydraulic pressure regulated systems. You'll see that the pump ramps to attempt to maintain fuel system pressure and while flowing 250 hp worth of fuel, the pump still maintained 30 psi of pressure. I was quite impressed with the amount of fuel the pump put out while still maintaining pressure and keeping the engine running.

After that test, I installed a 100 jet in the fuel pulsed and retested. I measured 150 ml worth of fuel with the car at idle, and then 175 ml worth of fuel after a road test for the same period of time with a good load of boost. There was no loss in fuel pressure with the 100 jet. So I am confident that this fuel system would support a 100 hp increase of nitrous as the car stands, which would surprise a lot of unsuspecting targets.

Excellent.

Very well presented.

I notice that you're using a throttle activated micro switch but the Max has an integral throttle position sensor switch, which means you only need to find the appropriate wire from your cars position sensor and connect it to the Max, to achieve much more reliable activation and potentially benefit from a range of advanced control features.

Check out the Max instruction pages for more details.

I kept the microswitch because I cannot find the wiring manual for this car. I want to use the tach signal as well to tie it into the Maxy, but I don't know which ECU output it is . Until I find one, I'll stay with the microswitch: it works very well for the current power level.

It appears that I can use a tachometer adapter that will convert the multi-coil pack signals to ones the Maxy can use. It costs some money so this setup will have to wait.

You should be able to just connect the signal wire from one coil to the Max to get an rpm signal and all you need to do to find the correct throttle wire, is stick a meter probe in to each connector and measure the voltage/resistance while operating the throttle. You need the wire that shows a change of either zero to 5 volts or 5 to zero.

See if this will help for the throttle...

Thanks Jeff!


The Sonic is finally getting a clutch upgrade and it's currently in progress. I just gained access to it and I'll continue this week to finish it up so that I can possibly increase the power from 25 to 40, depending on the outcome of a few tests. I'm also considering an electric exhaust cut-out to bypass the restrictive exhaust to further increase performance without ditching the stock quiet system.

This car will certainly convert a large number of skeptics!

So far, the original clutch actually looks pretty good. It is a low mileage clutch with only moderate standing take offs but it really does look quite fresh. Even the pressure plate looks really good and it still has its machined surface as if it were new; the same goes for the flywheel as well!

I guess it simply couldn't take the extra torque my car puts out on the nitrous... all of which won't be a problem much longer!

The 3 main causes of clutch slip are;
1) Inadequate grade of friction material
2) Inadequate spring pressure
3) Incorrectly machined surfaces on the flywheel and/or the pressure plate

You can't do a great deal about the first 2 but a clutch will usually handle at least 20% more power, if the flywheel and pressure plate are correctly resurfaced.

The new clutch and pressure plate units are aftermarket with a much higher torque capacity than stock.