Nitrous Control- Hardware Question?

wes kiser · Post by **wes kiser** » Sun Aug 19, 2007 7:18 am

Since this feature isn't in the stable release, I thought this was the appropriate forum to ask in, if not please move.

In the documentation, it states that it is possible to use the "complementary" IAC output to drive a relaty if the current limit is not exceeded. Does this mean to hook up IAC1A to one side of the relay's coil, and IAC1B to the other side of the relay's coil (avoiding the additional simple transistor circuit)? If so , do you still install the diode accross the relay's coil? I was going to attempt to install nitrous on the car next weekend, and just wanted to know.

Post by **jsmcortina** » Sun Aug 19, 2007 7:28 am

What it means (but untested) is to use IAC1B connected to the relay coil (and the other side of the coil to 12v.) I would still use the protection diode.

As this feature is new I would suggest some cautious testing. If using a wet system, try it out with the nitrous bottle off. If using a dry system, fill the line then shut the bottle off.

When the system activates you'll get a lot more fuel than required and should get a small hit from the nitrous, then it will go mega-rich.
Review your datalogs to confirm that the timing retarded as expected etc. etc. then take the testing up a level.

James

wes kiser · Post by **wes kiser** » Sun Aug 19, 2007 7:55 pm

I was likely going to test it with an empty bottle, and the pressure switch dummied out at first, to ensure it went very rich, and pulled the timing.

In my case, I also am not using much nitrous (probably just a 50 shot to get the turbo spinning), so it really will not go all that mega rich with an appropriate fuel shot. I am going dry to try to hide as much of the system as possible (hopefullly all of it).

Jon k · Post by **Jon k** » Sun Aug 19, 2007 8:01 pm

Is the above mentioned method of hardware configuration the only method available?

What I mean is, because I don't know much about the nitrous setup, is this method something new/improved versus a conventional way? Or, is this it, and nitrous just isn't fully supported yet?

Post by **jsmcortina** » Mon Aug 20, 2007 1:33 pm

Jon k wrote:Or, is this it, and nitrous just isn't fully supported yet?

Please explain.

James

Jon k · Post by **Jon k** » Mon Aug 20, 2007 3:10 pm

jsmcortina wrote:
Jon k wrote:Or, is this it, and nitrous just isn't fully supported yet?
Please explain.

James

Basically - is nitrous fully supported by the MS2/E firmware as of right now? And, if so, what's different about the original posters setup?

Post by **jsmcortina** » Mon Aug 20, 2007 3:14 pm

It is fully supported, but nobody has tested it.

Different from what?

James

Jon k · Post by **Jon k** » Mon Aug 20, 2007 4:28 pm

jsmcortina wrote:It is fully supported, but nobody has tested it.

Different from what?

James

Nevermind I am confused.

Is there any reason it wouldn't work? That makes me nervous!

Post by **jsmcortina** » Tue Aug 21, 2007 2:43 pm

Jon k wrote:
jsmcortina wrote:It is fully supported, but nobody has tested it.James
Is there any reason it wouldn't work? That makes me nervous!

None.
I tried it on the bench and all looked good. BUT!!!!!! As with any nitrous install, exercise care. Too much gas at the wrong time will surely nuke a motor. In my time I've cracked and melted a couple of pistons (or is it three?)

James

Jon k · Post by **Jon k** » Wed Aug 22, 2007 6:53 am

jsmcortina wrote:
Jon k wrote:
jsmcortina wrote:It is fully supported, but nobody has tested it.James
Is there any reason it wouldn't work? That makes me nervous!
None.
I tried it on the bench and all looked good. BUT!!!!!! As with any nitrous install, exercise care. Too much gas at the wrong time will surely nuke a motor. In my time I've cracked and melted a couple of pistons (or is it three?)

James

Ok I will be careful.

For what its worth, if I run a wet shot, I shouldn't really have to worry right? Use MS to trigger the nitrous, 50 - 75hp wet shot (fuel and gas) and it should be good to go?

Post by **jsmcortina** » Wed Aug 22, 2007 2:50 pm

You should always have some "worry" when using nitrous. You need to retard your timing and don't enable the system at the wrong time.

Saying that, I'm succesfuily running two stages of "160hp" and an additional "80hp" that comes in over 4500rpm. (Using MS1/Extra)

James

Jon k · Post by **Jon k** » Wed Aug 22, 2007 3:52 pm

jsmcortina wrote:You should always have some "worry" when using nitrous. You need to retard your timing and don't enable the system at the wrong time.

Saying that, I'm succesfuily running two stages of "160hp" and an additional "80hp" that comes in over 4500rpm. (Using MS1/Extra)

James

Is there a general rule of thumb for timing retard w/ nitrous? I am using only a 50 hp shot or so because I am wanting to spool a large turbo. What RPM is safe to inject at?

Post by **jsmcortina** » Fri Aug 24, 2007 1:52 pm

Something like 2-3 deg for 50hp I think.

On a my NA car I'm starting the first stage at 3000rpm, second at 4500.

Using only 50hp as a turbo spooler, you can likely get away with it earlier, but check with others who have actually done it first.

James

wes kiser · Post by **wes kiser** » Fri Aug 24, 2007 8:34 pm

Just added the suggested circuit to the squirt (using IAC 1b to directly drive the relay), and it appears to work on the stim. Hopefully I will be spraying tomorrow and can give some "real world" input on how well it works.

wes kiser · Post by **wes kiser** » Mon Aug 27, 2007 5:08 am

Tried it with nitrous this morning, as with the bottle closed the software seamed to work as expected.

It seamed to work well, except for some odd behavior (may be wideband related). When I tried it with what seamed to me to be a reasonable PW (3 at min, 2 @ max) it read way lean (14:1, but felt great). I richened it up alot, and it then read mid-12's on the wideband, and felt OK (but not as good as it felt too lean). I put some more fuel in it (at this point what seams to be an insane amount of fuel), and it bogged.

Is the PW you enter the actual PW, or is it scaled with the required fuel (by this I mean if you are running say, 4 squirts alternating, does it automatically divide the PW you enter by 2, or is the PW you enter). On the stim, and in my preliminary testing, it appeared to be the actual PW.

The reason I ask this, is to make the wideband read reasonable, I almost had to double my fuel when spraying, and for a 50 shot on a 400 hp car that is not reasonable. The only thing I can think of, is maybe it was already so rich to start with it was "rich missing" and reading lean. I am reluctant to pull fuel out though until I confirm.

Post by **jsmcortina** » Mon Aug 27, 2007 5:28 am

It is supposed to be a direct addition to the pulsewidth. This does mean that you need to be careful when changing other settings.

I'll check with Ken later whether there may be any impact from recent changes to EAE and stuff, but I think that is unlikely as nitrous should only be active at full throttle.

For info, my TechEdge wideband reads mid 11:1 when I'm on the bottle.
(For some weird reason though, the AFR is gear dependant... 1 ok/lean, 2 ok, 3 rich, 4 ok)

James

wes kiser · Post by **wes kiser** » Mon Aug 27, 2007 9:29 am

It works as you described. After more testing, I pulled fuel out, and it actually read more rich. My initial calcs had so much "safety" in them it was just that rich.

Post by **jsmcortina** » Mon Aug 27, 2007 9:37 am

Great! You'll be the first MS2/Extra nitrous user then.

Get some bigger jets and get that second stage running !

James

Jon k · Post by **Jon k** » Mon Aug 27, 2007 10:29 am

I am going to be running a wet kit and its my first nitrous endeavor. Only 50hp to spool we we discussed - will I need to add fuel if using a wet kit? I am just an over-thinker and conerned what a friend has told me that when nitrous comes on, it can be lean for a split second. If that's true it'd be nice to dab some fuel in there but I cannot see how this is an issue. Argh - I guess I have to figure it out!

wes kiser · Post by **wes kiser** » Mon Aug 27, 2007 2:49 pm

You could definately dab a little fuel in there, but I honestly wouldn't worry about it if it is a wet kit. This was also my first nitrous install. I have very large injectors, so I just used the extra capacity (I sized them for 450 hp on e85, 400hp on gas is cake).