Wet Nitrous
Turbo Mini Forums

so can anyone share how one would go about a 5 port EFI turbo and n2o?

im thinking that the n2o would need a Fogger Nozzle in each port and two sets of Solenoids that are timed with the normal Siamese efi stuff so as to get decant AFRs ?

you only need one set of solenoids.

the number of nozzles required will depend how you intend to equip your engine with manifolds and throttles.

Me personally if I were to do it again but on a five port, I'd install one fogger type nozzlein the spacer block between the carb or single throttle on a decent standard type manifold.

As for timing it with any sort of injection, forget it, Nitrous is either on or off, or, pulsed via a progressive controller. Its not timed to any engine event.

ok so the solenoids are not fast enough to keep up with the injector events? or there is no way to configure the solenoids to work like fuel injectors?

i intent to have a manifold like pauls one with similar injectors bosses and runners but id have two injectors side by side and one n2o nozzle behind what im getting at is aint there a way to get equal AFRs with the 5 port on n2o by following the efi route for Siamese?

if i ran with nitrous id want a the most i can safely run so would need it well setup so as not to do damage. if not ill go spend the cash on the rest of the can/motor

With a nitrous port injection setup, I have no idea how you'd control it such that you have equal AFRs. As mentioned, the solenoids are not fast enough to control them like injectors. I guess you could inject in the plenum and that would give a better chance of self regulating to similar AFRs on each cylinders.

One more thing that might be a problem is to verify that you actually have equal AFRs. I'm not sure how the wideband sensors react to the presence of nitrous. You still have the same gases as air (N and O) but they don't have the same partial pressure so I don't know if that has an effect on measurement.

I think it's going to be a challenge to get the full benefit of sequential port fuel injection with the addition of nitrous injection. Maybe a dry setup could be made to work but that would mean very large injectors.

Jean

http://www.jbperf.com/

Well, after my last post I had a look around the internet and it seems that using wideband O2 sensors with nitrous is fine (I should have done that before posting...)

So using a dry nitrous setup would be the way to go. You'd need to tune without the nitrous first then use that as a starting point for your nitrous setup but with a much richer tune than that would suggest. From there you'd see how much adjustment you need to do to get back to sane and equal AFRs.

One thing that would be difficult to tune for though is if the nitrous injection has a significant impact on fuel travel time. This would change the needed injection timing and there is no way to compensate for this in the current code. And there's a good chance this would happen but it depends on how everything is positioned.

Jean

http://www.jbperf.com/

The problem with wideband and nitrous is not that it doesn't read, it is that Nitous oxide is not air.

In reality, AFR is not a measure of air, but rather its oxygen content. Nitrous oxide has a greater percentage oxygen than air. This means the AFR's you see on any gauge set for stoich at 14.7:1 are not representative when on nitrous. Things are complicated further by the fact that the engine does not just consume an air/ fuel or a Nitrous/ fuel, but rather a coctail of both in varying quantities depending on nitrous jetting. This again alters the target 'AFR'. If you are good at chemistry and maths, you should be able to work out what the total target AFR is for each nitrous jet used.

I tried explaining this to the guys on the Wizzards Of Nos forum, but they got lost easily which was a surprise.

When I ran a 50 shot, I was still on the lean side on nitrous when the AFR showed 10:4

Tob brutally honest, if you intend running nitrous on a five porter, I wouldnt bother with the difference in AFR's. Just run it richer, which is what any good Nitrous kit manufacturer would tell you to do irrespective of engine design.

i see quite a hard thing to get right dose running it real rich make an impact on performance?

might dump the idea me thinks

Colin,

I did mention in my first post that the partial pressure for oxygen and nitrogen was different when using nitrous so I do understand that part and I can see how that would affect measurements. I'm just surprised that no one seems to be saying that anywhere.

In any case, while I agree that keeping things rich is definitely what you want to do, not bothering with the unequal AFRs would be a mistake in my view because you could easily end up in a situation where you're running the outer cylinders too lean even with massively rich inner cylinders. That is exactly what I would expect of a wet setup which is why I would not use it myself.

So checking that the difference remains small would be a good thing even if you don't have the actual AFR. And a dry setup would allow you to do this up to a point.

http://www.jbperf.com/

So run the centers richer, simples.

Dry nitrous is a sure way to melt something though

On 3rd Feb, 2013 Sprocket said:
Dry nitrous is a sure way to melt something though

http://www.jbperf.com/