The usual noob questions
 

Hey all. First time diving into water/meth and I've read as much as possible but I've got a few questions on placement and nozzle size.

So I'm working with a 2016 Golf R, fully built engine, big turbo and all supporting bolt-ons with a custom tune, haven't dynoed it but its estimated roughly around ~470HP at the crank

I'm getting the HFS-4. I would like to do direct injection but I don't really see that as too feasible at the moment so it's more of a future thought. Right now I plan on just doing two nozzles, one right after the intercooler and one in a throttle body spacer. From what I have read this seems to be the general consensus on the best locations.. Any other suggestions?

Then my other main concern is what size nozzles I should run. If I'm going off the 1:1 ratio +15% then I'd be aiming for about 500cc total? Should I run them roughly the same size and split between the two or run a bigger nozzle in one location? Any suggestions appreciated as this stuff is still pretty foreign to me.

Re: The usual noob questions
 

avoid turns, hence direct port.
otherwise you will lose a fair share of the water droplets on the way to the combustion chamber.

nozzle size guidance from RichardL is a good advice to get going:

1.5cc/Hp of a 50:50 mix
2 for 100% methanol
1 for pure water.

so for a 500HP engine, you need to inject some 750ml/min of a 50:50 mix and retune.
without ignition and fuel tuning you will lose power.

Re: The usual noob questions
 

Thanks... so I got a few different sizes but I'm going to try out a single 1mm (500cc) to start out with right after the intercooler.
I didn't mention it but I'm going to be running 50/50

I plan on adding a throttle body adapter and injecting there once one is released for this car.. or just doing direct port injection in the future.

I'm curious why you say I will lose power without tuning for W/M?
I've read in other places, that you will usually gain a LITTLE bit of power from W/M if you already have say a Stage 1/Stage 2 tune... but you wont see the FULL power benefits unless you tune specifically for it.

My concerns come mostly for safety/reliability reasons.. as this is a daily driver.
I don't want to tune for higher octane / advanced timing because I've also read that's the number one way bad things can happen, if the water/meth system fails mid-delivery the engine will run super lean and detonation can occur. I understand the HFS-4 is pretty advanced and has failsafes, as does the car's ECU adjust for lean conditions, but that's still a high concern of mine.. I want to err on the side of caution... so I was planning on NOT tuning for W/M and just leaving it with my current tune and being happy with whatever little power gains I do (or don't?) get.

Not trying to argue or anything by any means, just trying to understand the reason behind it. My car is tuned already with a conservative custom tune for my big turbo, essentially a "stage 2+" tune.. tuner told me I should see a little bit of power gain with the w/m setup but I would have to tune for it to see the full effects.

Feel free to correct me on any of that or educate me as I'm just learning all this stuff, but trying to stay on the safer side

Re: The usual noob questions
 

Water, if it makes it into the cylinder as a mist, will slow down flame development and flame front speed. Effectively, the mix burns slower. If you do not add ignition timing to compensate, you'll lose power over no water. Adding methanol reduces this effect to a degree as its flame front speed is faster than gasoline. Still, as a 50:50 mix by weight, you need to add timing.

Now if you are lucky, you might gain a tiny wheeny bit of power by cooling the intake air. But don't overestimate this. The main effects are happening in the cylinder and effectively increase knock resistance while reducing flame speed.

The more you inject, the bigger the effect. Without tuning, your AFR will drop making things even worse. You will significantly lose power without tuning for it.

Once you tune for it, especially with direct port injection, it works really well.

If your engine can be tuned for max torque without being knock limited on water meth, you have to increase boost for further gains. Once you become knock limited regarding power, just inject more mix. You can do this until to insane power levels given your engine and GB takes the beating.