mitsuman

iTrader: (1)

So i've been researching a bit on the topic, although am trying to get some additional info. How many of you guys use, have used, or plan to use water injection, more specifically pre turbo?

How do you like it? Any data sheets(i.e. IAT before and after, etc)? how does it affect the spool? long term effects?

thanks

Boostage

http://www.alcoholinjectionsystems.c...icle_info.html

TheShodan

iTrader: (14)

Good link. Very informative for a variety of reasons . Answers many,many questions and easily resolves a lot of myths and truths associated with it

mitsuman

iTrader: (1)

Great link. thanks.

what the article doesnt cover though, is what size nozzles work best and what not.

Any of you guys want to share your set ups?

TheShodan

iTrader: (14)

Unfortunately, few Honda people here utilize meth/water injection except for a few regions, because of the whole phenomenon of "E85 is better than p**sy, man!" So, what happens is you have those that use mainly a 550cc-615cc injector into the throttle body, and about 200-315cc for the inlet into the turbocharger.

Californiadad actually did a 4 X315cc direct-port style meth/water injection in his intake manifold. check his thread for specifics.

mitsuman

iTrader: (1)

thanks for the info. what are your thoughts about pre turbo injection? do you have any experience with it first hand? there are many different opinions on water/meth vs wiper fluid vs pure water etc etc etc, and size nozzles. i know each different application will require different pressure/flow. but i have literally not seen any info on pre turbo injection on a honda

tepid1

It's been done and the results were not publicly available. What I know is that it didn't work well on an all out drag car. It caused turbo rpm to drop to the point where it hindered perfromance. What happens is the large surface area on the blades caused the water to recombine into larger droplets. When you loose the atomization you lose the heat removal potential and can induce premature wear on the compressor wheel. This is even more of a problem on the billet wheels with grooves in the compressor wheel.

mitsuman

iTrader: (1)

^ thanks for the info. i am not planning on pushing more then 300-350whp max with an evo 8 turbo. So that puts me in a much lower bracket. I guess i will have to just test things out.

heres a link i found with some results for those interested:

http://www.dsmtuners.com/forums/nitr...t-results.html

TheShodan

iTrader: (14)

Oh. that's it? on an evolution? Ah, you should have said that from the beginning. I was thinking Honda related (due to the forum and all, who'd have guessed? )

A simple pre-throttle body 500cc injection nozzle is all you need. About 3-5" really, enough time for it to atomize. The other Evolution 8 we got is using a TR3030R with a single nozzle of 95% methanol 5% distilled water (simple yellow bottle HEET) for over 470AWHP so far on the stock 2.0 with GSC S2 camshafts and zeitronix wideband with a Cobb Access port. Very nice, easy, and stable. been done for years. Simple AEM kit.

When we tried the Pre-turbo option, similar results occurred with what Tepid1 described. Mainly because the turbocharger compressor just didn't see enough heat in the inlet itself to enable a good atomization process to occur, and it was almost like compressing water.

I say keep it simple, by single nozzle, or you can get a bit crazy with the direct port version if you must. But the pre-turbo wasn't worth it.

mitsuman

iTrader: (1)

haha well, i should have explained. i will be running a d16z6 with a evo 8 turbo. No evo here!

so my curiosity stands, still no info on pre turbo on a civic haha. I am not looking at pushing 450 on pump gas, i am simply trying to maximize the efficiency of all of my components. from what i read(only read, no experience here on this topic) water/meth injection pre turbo helps the turbo act more efficiently, now if i inject post turbo, yes i will see lower temps, but would it be more beneficial to have the turbo acting more efficient? or simply having lower iat's?

tepid1

Just focus on lower IAT's. Why would you want to take energy out of the turbo? As it is it takes energy to spin it so it's a double negative. You'll get better results post turbo. Like TheShodan said, keep it simple and keep it reliable.

Most of what I have seen has been theories and noting has ever come to being effective. I think the key is to keep the preturbo nozzle small and the pressure high (100psi+) so that it's a super fine mist. Also, forget about anything with water in it.... yes even 5% is too much. Straight alcohol/meth or even acetone would work great. For anyone who knows high grade race fuel knows acetone works like a dream!

TheShodan

iTrader: (14)

Nooo. That's only if there is enough heat generated by the compressor side to create a flashpoint for the methanol to atomize properly. If not, there's no point in doing it, and in actuality, you could damage the turbo itself with the wrong mixture, as you you're now trying to compress water, not just methanol.

It's even stated in the article as a caveat.

"To do this properly requires proper sizing of the nozzles in relation to the compressor size and output. Additionally, the type fluid being used also effects the size of the water injection nozzle selected. When done properly, very little of the water methanol mist injected into the inlet of the compressor survives the process."

The author continues:

"When injecting water, we can quickly over saturate the air charge and have an excess of fluid discharging the compressor. Water has a much higher latent heat of vaporization, nearly double that of methanol, and does not flash (instantly evaporate) like that of methanol or other alcohols when injected into a hot air stream. Therefore, a smaller nozzle must be used when spraying pure water. "


Lastly:

"One major concern associated with pre-compressor injection is [physical] erosion of the impeller. This is only likely to occur when injecting solid stream of water at the impeller of a turbocharger or using an excessively large nozzle". This is from the higher speeds seen on turbocharger impellers than centrifugal or Rotrex superchargers.

I see it as making the turbo less efficient as you would essentially be slowing down the airflow/pressurization process on the compressor side of the turbo. Especially if only using this for "daily duty", I see more detriment than benefit based upon my experience and the article's interpretation. 1) You're not generating enough consistent heat in the compressor cover to create a constant flash point for the methanol, 2) more than likely you aren't using 100% methanol in the first place to where that flash point comes quickly enough. 3), you're not going for that kind of use and power, and the erosive effects will more than likely take over faster than a purpose-made car anyway.

Again, whether its a civic or an Evolution whatever, Keep it simple at the TB neck. And make sure you have the right distance so that it can atomize properly. Focus on lower IAT's and lower cylinder pressure temps in the combustion chamber. Leave the compressor wheel out of the equation

wantboost

iTrader: (2)

The key is that the nozzle must be centered on the wheel or you'll have wheel erosion

The issue is you only inject enough to vaporize as it compresses which is what takes the heat away. You don't want it leaving the turbo in liquid form

When done properly you'll see a turbo outlet temp that's at ambient temp or below. Users have reported everything from condensation on the hot side piping and intercooler to having ice form on the intercooler

Aquamist makes a pre turbo injection nozzle holder that is ingeniously made, they've done extensive testing on this subject and have shown that with the nozzle centered in the inlet (aimed at the shaft center) and the proper fluid volume that no wheel erosion occurs and theres no liquid methanol/water leaving the turbo. It simply vaporizes when compressed


I'll be utilizing pre turbo meth injection on my build as well

mitsuman

iTrader: (1)

thanks guys for the info. Can you look at this response by a member of another forum on the subject. He gets into some pretty technical terms, which i feel most of us are unaware of. can you pick it apart? theres also a pretty technical post after his...

http://www.aquamist.co.uk/vbulletin/...78&postcount=6

http://www.aquamist.co.uk/vbulletin/...read.php?t=251

tepid1

Here's the fact.... if you're gonna inject preturbo.... you're gonna have erosion. Period. Whether it's water, meth or sand, it's gonna affect the compressor wheel. Compressor RPM is directly related to compressor output. Compressor inlet temps affect density, however the adverse affect of rpm outweighs the affect of density. Understand?

Next, all that BS about making the turbo more efficient is just that. BS. Believe what you want, but a car in the 1/4 mile that goes 180mph on pre injection then goes 184 without and no other changes and same boost target is making more power. Period.

wantboost

iTrader: (2)

Potential erosion is why I'm have the comp wheel hard anodized, same with the comp housing and like I've stated in other threads this is simply an experiment. I'll be monitoring a lot of factors and decide from there if it has a benefit

I still however am running "direct port meth/water injection" in every runner of my itbs. It's a good way to monitor how much or how little is needed. This also gives me equal distribution and the abilities to fine tune each jet in each cylinder, as well as overall system pressure

Like I said. Still experimental

TheShodan

iTrader: (14)

The anodized material will not only erode as well, but tends to "chip" off. Just like an older tattoo, especially when utilizing alcohol. Keep the direct port if you'd like, but direct inlet, Nope..

TheShodan

iTrader: (14)

He's basically saying the same thing as the other article with more chemical analysis in his argument.

But again, he, like the other author, warns the user

"By injecting water/alcohol ahead of the compressor two things happen. You cool the inlet air substantially, this in effect moves your true operating point to the left on the compressor map. (in most cases for max performance this is a good thing, although on some turbocharger conditions it can cause compressor surge.)"

wantboost

iTrader: (2)

Here's a randkm idea that I just had

What about injecting into the compressor volute right as it starts after the wheel. It would still compress/vaporize slightly but at the same time lower compressor outlet temps without pontential wheel damage

TheShodan

iTrader: (14)

Dude, that would be worse it would compress the water, not the mist from the flashpoint, which wouldn't be reached. That's like injecting DIRECTLY into a TB to "cool things down".

wantboost

iTrader: (2)

Well I wouldn't be using any water. Pure methanol pre turbo and water/meth at the intake runners

TheShodan

iTrader: (14)

Try it if you want, my friend.. That's just too much for one purpose. It makes no sense at that point. that's like adding up 4 different bolt-on modifications that have an advertised HP ability and adding them all together. There's a net effect, but not in the way you think.

wantboost

iTrader: (2)

True but I have seen a lot of successful pre turbo setups. The flow volume has to be precise as does atomization and line pressure, like 300psi minimum

I know a lot of compound diesel and large single diesel guys use pre turbo with no issues but they've somehow figured out how to generate 1000psi for their injection system

TheShodan

iTrader: (14)

Diesel is not gasoline is not car and have slightly differing heat properties with differing purposes. For 99.9% of the people on this forum planning to use methanol, you know that it will be abused and you'll have more failures than working prospects. So to say that it is fine "if YOU do it", may be.. but not everyone is YOU.. So I'm careful as to making sure that people know the risks and that in this case, they far outweigh the benefits stated.

Never said it doesn't work, only that you must be precise in that inlet location. Let's just agree to disagree at this point, as its getting redundant.

wantboost

iTrader: (2)

True

I know it will take trial and error getting it right

This type of injection is not as simple as bolt on and go