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Hi,

Looking into doing water-methanol injection system and just want to double check I wont be causing any damage.

Just want to clarify the hoses located in the blue circle labeled 1 to 5 (disregard the red, using picture in another thread)

engineb.jpg

Hose 1: Draws air from manifold?

Hose 2: ?

Hose 3: Manifold pressure hose for fuel rail (does this blow manifold air through or is it a vacuum?)

Hose 4: Coolant?

Hose 5: ?

Do any of these hoses flow air from the intake manifold? As the air will be mixed with water/methanol I want to know if this air goes straight to the engine or do they bypass through any of those hoses?

Thanks :D

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1 is the pcv, flows towards the manifold under vacuum and doesnt flow at all under boost (pcv valve closes)

pretty sure 2 is coolant, not air

3 is vac line for fuel reg as u said, doesnt flow just pressures/vacuums. however i dont think methanol would be too good for it.

pretty sure 4 and 5 are coolant

1 is the pcv, flows towards the manifold under vacuum and doesnt flow at all under boost (pcv valve closes)

pretty sure 2 is coolant, not air

3 is vac line for fuel reg as u said, doesnt flow just pressures/vacuums. however i dont think methanol would be too good for it.

pretty sure 4 and 5 are coolant

1. PCV vacuum

2. Coolant to throttle body

3. Fuel Pressure Regulator vacuum

4. Coolant from plenum to coolant galley above injectors

5. Coolant feed to plenum

Sweet thanks for that guys. Hose #1 and #3 are explained as vacuums. Although would any manifold air pass through these pipes?

As I will be hooking up a catchcan to the piping, would I end up with a puddle of water/meth? What about the fuel pressure regulator?

Tap the methanol into the cross-over pipe that fits directly to the TB. Any other means of supplying methanol to the A/F mixture isn't going to work.
The "J" pipe about 4" before the throttle body is the best place although someone did mention that the water gets back into the compressor when the bov operates and may cause some erosion of the wheel over time

yeah the plan was to mount the nozzle on the cross over pipe but as mentioned by smell, this water/meth will then be recirculated through the turbo and intercooler due to the factory bov. I have found some nasty pictures of pre-turbo water/meth sprays which have chewed through the fins.

I was thinking of mounting the nozzle after the TB, that way nothing will flow through the turbo. However, im not sure if I would get an even spray to each cylinder as the manifold is quite large..

So yeah, any chance of methanol causing damage to the PCV and fpr?

Thanks

#1 won't supply the mixture when you are on boost - and that is when you want the mixture most.

And #3 is simply a pressure source for the FPR - no air actually flows through the hose.

If you feed directly into the manifold, after the TB, you risk uneven distribution of the mixture to the cylinders.

Tap it into the cross-over "J" pipe. Any methanol flowing back through the BOV will probably drop out because it will be a low velocity air flow.

#1 won't supply the mixture when you are on boost - and that is when you want the mixture most.

And #3 is simply a pressure source for the FPR - no air actually flows through the hose.

If you feed directly into the manifold, after the TB, you risk uneven distribution of the mixture to the cylinders.

Tap it into the cross-over "J" pipe. Any methanol flowing back through the BOV will probably drop out because it will be a low velocity air flow.

Thanks for that. Feel more comfortable going ahead with the water/meth.

Just need to find a solution for any water/methanol flowing back to the turbo. Perhaps a type of filter/catchcan to remove any water/methanol from the air, or reroute the bov piping so it feeds the air after the turbo instead of before..

cheers

Thanks for that. Feel more comfortable going ahead with the water/meth.

Just need to find a solution for any water/methanol flowing back to the turbo. Perhaps a type of filter/catchcan to remove any water/methanol from the air, or reroute the bov piping so it feeds the air after the turbo instead of before..

cheers

You can't feed it back to "after turbo", because that area is at the same pressure as at the BOV. It has to go back to "before turbo" ie low pressure area.

A lot of installations actually inject before the turbo because you can do it with a low pressure pump. If there was a risk to the impeller blades, I doubt they would consider it.

So what mods do you have?

Looks pretty stock to me

WMI needs a tunable ECU, and mods to make it worthwhile.

thats the idea, to look as standard as possible :D

Ive got nistune ecu, hks2530 and all the bells and whistles to support it.

Main reason i want the water/meth is for cooling as im getting detonation in heat, and the methanol is an added bonus :P

You can't feed it back to "after turbo", because that area is at the same pressure as at the BOV. It has to go back to "before turbo" ie low pressure area.

A lot of installations actually inject before the turbo because you can do it with a low pressure pump. If there was a risk to the impeller blades, I doubt they would consider it.

Ah bummer scratch that idea then.

Here are some pictures floating around of pre-turbo injections. A lot of suppliers also do not recommend it as they dont want to be liable for any damage. The benefits of doing pre-turbo sways people to try it out as it significantly cools the air before it enters the turbo.

But as you can see from the pictures, if the nozzles doesnt atomize properly, water droplets can do some damage.

compressor_tips_erroded2_sm.jpg

This amount of damage was caused by a poor setup whereby the nozzle was dribbling water onto the fins.

DSCF2376.jpg

Ok lets clear some things up.

I've been running a high pressure system for YEARS. The nozzle is plumbed in about 5 cm after the BOV.

There is absolutely nothing to worry about, it does not go back through, because if you buy a proper system, when you back off, the BOV will open, and the WMI system will stop pumping.

The only reason you'd put a before turbo system on is if you want to run the turbo above its standard efficiency range. This effectively movesd the entire compressor map top the right. BUT you will get decreased turbo life if you do not use a proper kit that atomises the mixture properly, and shuts off properly. There are systems out there that work like a fuel injector.

Anyway, do what I did, and there will be not problems. How to I know? I currently have my engine out of the car. The pistons are perfect. The turbo impeller is perfect. The inlet tracts are clean as a whistle. There is no carbon buildup.

4.JPG

6.JPG

7.JPG

As you can see, I used that lug to have more meat to tap into.

awesome thanks very much for the photos and your experience! Good to see other skyline owners having gone down the water/meth path!

Seeing as water/meth wont go into any of the hoses and cause no issues to the turbo I will now pick up the water/meth injection kit :D

Thanks all

Or if u want to be absolutely sure that u wont have any comp wheel damage u can install a nice shiny atmo bov and use the ecu to tune out the over fueling..... i know this can be done with the pfc , not sure about nistune though

I'm sorry but this is bad advice.

The BOV will not drag any WMI vapor through because when the BOV is open, the Intake manifold is under vacuum, and the WMI kit will not be pumping.

If you don't believe me, I can take a photo of my turbo right now and show you that it is in perfect condition.

I'm sorry but this is bad advice.

The BOV will not drag any WMI vapor through because when the BOV is open, the Intake manifold is under vacuum, and the WMI kit will not be pumping.

If you don't believe me, I can take a photo of my turbo right now and show you that it is in perfect condition.

I understand that part but when you're at wot and water is being injected and u snap the throttle closed u remain with some mist between where the nozzle is and the tb.... i know its not much but this little bit still gets sent back to the comp

In another scenario say you set the injection to start at 5psi and you're running 20psi at wot and u ease off the throttle but not totally, u might still be above 5psi so the injection keeps going but ur bov did open a little to get rid of the extra pressure so there will be some sent back to the comp as well

But hell....you've tried it and had no probs thus far and my wmi kit is still in my closet :thumbsup:

  • 3 weeks later...

alrighty

I'm sorry but this is bad advice.

I agree more with

In another scenario say you set the injection to start at 5psi and you're running 20psi at wot and u ease off the throttle but not totally, u might still be above 5psi so the injection keeps going but ur bov did open a little to get rid of the extra pressure so there will be some sent back to the comp as well

that's the doo doo doo/chopping sound that everyone loves...depends on the stiffness/adjustment of your bov spring but it often happens for a split second before the bov opens (or when the thing above that 'smell' said happens), and that's when there is potential for water/methanoled air hitting the compressor blades...and backwards too, omg......BUUUT (as stated in the pics above of the comp. blade damage) it only causes damage if there is un-atomized water meth droplets......plus think about the fact that only that tiny portion of air between the meth nozzle and throttle plate has been sprayed, so for it to even get to the compressor wheel it has to go through all the piping and the cooler, and be in droplet form. I imagine it would get caught in the cooler then evaporate pretty much instantly the next time you come on boost. If there was even enough actual liquid to form a droplet.

Maaybe if you pumped the throttle (full boost, full vacuum, etc etc) many times in quick succession that tiny bit of meth could build up and form enough for a droplet....but I reckon the hot air coming directly from the turbo would evaporate it anyway.

So assuming that's all correct, as long as you have a good high pressure kit (at least 150psi) that atomizes properly and dont spray too much (you will loose power anyway if you do) you wont have any compressor wheel problems.

Ive got a 32 GTS4 with 2530 too and am halfway through installing a snow performance kit at the moment, so im not talking from experience yet but I have read a whole crapload of info and talked to everyone I can think of, so am pretty confident with what ive learned. So if anyone knows better please let me know as I will be using the same 5cm from the bov setup as 'The Mafia' described.

Hope that helps!

Dave

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