NITROUS OXIDE ( nos / n2o ) advice forum

I am planning to fit a nitrous kit to my Nissan 370z, using two injectors

I would prefer if possible to fit the injector in the plenum or upper manifold rather than the hoses before the throttle body as is more conventional

The plenum looks like this and I could fit the nitrous injectors close to where the TB bolts on, hard to see but at the back side of the square bit, this would give a nice path into the plenum.



Now I understand this is usually a not a good idea due to the risk of nitrous burbs or backfires but on the 370z VQ37VHR engine the throttle plates remain open when the engine is running and the air flow is controlled by the complex valve timing arrangement (There is no intake cam on the VQ37)

Video here (skip to 107 to get an idea of how this works)

https://www.youtube.com/watch?v=DOUPW91fVbI

I currently have switchable maps enabled on my car so it would be easy to employ a dry system using two venom injectors and add the fuel/timing corrections through the map but I wonder if a dry system is the better option here? The fuel pump is of the non returnable type and the injectors are 380cc with a fuel pressure of around 50-55psi

I would be looking for around a 50-75hp increase on an engine producing around 350hp currently


Any thoughts or suggestions

Welcome to the forum!


Because of the angle in which the TB inlets are in relation to the plenum, you're going to have to use a direct port system. This will prevent the cylinders in the back from receiving the most nitrous and the forward ones getting the least. If you were to restrict your HP level to 50 or 55, you can get away with using 2 injectors a few inches from the TB elbows. The nitrous/fuel plume needs some time to "cloud" so that it can be mixed properly while it is drawn into the cylinders. These problems don't exist with direct port on this intake.

Secondly, even if you were to go dry there would still be an issue with using just two injectors as I've mentioned and it would be even worse unless you use a direct port dry as the cylinders receiving more nitrous will be lean and the others rich. Furthermore, you have to be really good at tuning the fuel part of the map when the nitrous is engaged. An alternative is to use 2 dry injectors far away from the intake to allow the nitrous to disperse in the intake, however this will reduce engine response once the nitrous is activated. Venom injectors are very narrow and highly directional with their discharge so Crossfires would be the best bet.

With the exception of the alternative case, you're going to have nitrous components in open view in order to function correctly.

I look forward to seeing your results after using WON nitrous!

On such manifolds you can use a single Crossfire per TB up to about 100 HP so you shouldn't have any problems with your requirements. We've already got a few customers with your kind of engine/induction system, doing very well with a WON system of this config.

However, it would be better and easier to locate the Crossfire's in the filter side of the TBs, as that gives the nitrous more time to mix with the air and helps to distribute it more evenly.

For your further information, using ANY nozzle other than a Crossfire would FAIL to achieve anything like even distribution, especially if located engine side of the TB.

You were on the right track [as usual ] and as always we try to locate the Crossfires in the best place, which is usually the flexible hose that feeds the TB's.
This layout (and most others) would suffer the kinds of problems you voiced concerns about if a US brand nozzle was used (ANYWHERE), as they have such a narrow plume that will bias ONE cylinder more than any other but that's not the case with the Crossfire, because of its fan shaped plume, which I designed SPECIFICALLY for this kind of application.