methanol based windscreen washer fluid for water injection.

[Mad]

Jennychem deliver and sell methanol. I run meth for water injection in my P1

These old posts are great

8)

 

[PobodY]

Yeah? Where are you injecting?

I was looking at the Aquamist forums, and the consensus seems to be the best spot is before the turbo to maximise charge cooling and improve the compressor efficiency. However, the Aquamist jet isn't really set-up for injection there... and I'm worried I'll fux0r the turbo, but if I inject in the right spot in the induction pipework I can probably get the air to mix/distribute the mixture so that there's no droplets hitting the compressor wheel.
...and it's a 20-year old turbo; it's probably due to fail any day soon even without methanol going through it.

 

[Mad]

Right before the top mount. Benefits are reducing Heat allowing to run more boost and timing. Very effective on a top mount. I run 50/50 distilled water/ methanol but you can run more meth with better piping. I've heard gains of upto 30bhp with the right mapping

 

[Makaveli_se7en]

Yeah? Where are you injecting?

I was looking at the Aquamist forums, and the consensus seems to be the best spot is before the turbo to maximise charge cooling and improve the compressor efficiency. However, the Aquamist jet isn't really set-up for injection there... and I'm worried I'll fux0r the turbo, but if I inject in the right spot in the induction pipework I can probably get the air to mix/distribute the mixture so that there's no droplets hitting the compressor wheel.
...and it's a 20-year old turbo; it's probabvly due to fail any day soon even without methanol going through it.

Perfect if you can maintain perfect atomisation over the complete range of operating conditions (near impossible) or like to replace erroded impeelers every few 1000 miles.

Right before the top mount. Benefits are reducing Heat allowing to run more boost and timing. Very effective on a top mount. I run 50/50 distilled water/ methanol but you can run more meth with better piping. I've heard gains of upto 30bhp with the right mapping

Better to inject post the intercooler in my opinion as you are more likely to keep the water/meth suspend in charge. Putting high charge with a high moisture content through an intercooler is likely to result in condensation in the inlet.

 

[PobodY]

Ed, that's what I've read too. - Before the intercooler just means they cancel each other out; it's not just that the water/methanol mix may condense inside the core of the intercooler, it's also that the greatest effect is to let the air/water/methanol charge enter the inlet manifold like that.

What really appeals to me about injecting pre-turbo is that you can make it adiabatic! I don't need to explain to you why that seems so awesome to me.
If the compressor is adiabatic it will behave like a much bigger turbo... so I thought I might try to bleed a little in between 0.5 and 1.0 bar; that way there's no injection off-boost, but if you really mean it the power gain should be mental!

There seem to be people who run like this without any significant turbo damage for years... but they're not running an old aquamist. - That's really why I haven't tried it yet. I'm just hoping that if I'm sensible and don't inject too much, I can get a moderate increase with minimal turbo damage.

 

[Mad]

It is fitted between the top mount and inlet in the inlet pipe, after the intercooler.

I was referring to looking at it visually.

 

[Makaveli_se7en]

George, I know that theoretically its a very nice idea but I don't entirely buy into everything you read about. Mainly because its taking a purely thermodynamic view of what is an aerodynamic system. I'm not going to explain this well, but my take on it is that the water/meth solution isn't going to change the aerodynamic characteristic of the impeller, there will always be the same loss mechanisms (e.g. separation, recirculation) and most importantly there will always be shocks generated which will lead to the onset of choke. As I'm sure you've read injecting water/meth theorectically absorbs the energy generated through these loss mechanisms through phase change making the compressor more efficient (or more adiabatic if you want to sound clever :lol. However in normal operation (near the middle of the map) order to be truely adiabtic the amount of water/meth will need to perfect for the level of losses, which lets face it isn't going to happen. Then if we look at the idea of acting like a bigger compressor, yes the efficiency island in the centre of teh map will be bigger and hence cover higher flows, but the onset of choke is predomenantly caused by the shocks generated by transition to supersonic flows and injecting water isn't going to change this. This also doesn't take into account the effect of changing the air density into the compressor inlet will have on the surge line (I love how this gets over looked by the pre-compressor fan boys), basically your surge line is going to move to the right making it more likely that you will run into surge.

So in summary the best you can hope for is to make the compressor a bit more efficient and have a lower inlet temperatures. This can just as easily be achieved by post intercooler injection to further increase the charge cooling efficiency and by running a decent amount can have further anti-knock characteristics by under going phase change within the combustion chamber. With the added benefit of not risking damage to the compressor impeller.

 

[red reading]

I like it when clever people can give a good explanation, nice to see you back ed.

 

[PobodY]

Thanks Ed. You've settled the decision for me; after the intercooler it is.

You've correctly identified how I was looking at it; as an inorganic chemist I look at it as a thermodymanic system. As an engineer, and someone with a lot more practical experience, you see it as an aerodynamic system. - Adiabatic compression is like a holy grail in physical chemistry, that's why it was (is) such an exciting idea to me... but something kept telling me it was a "free lunch".

It sounds like the only way you could really make this work is to map the methanol injection to be proportional to the turbo flow; that's far too complex for me (and I'd guess most people).

I'm just looking to give myself a bit more safety margin so I don't destroy the engine. - My wife is on about selling one car, and if I don't want it to be this one I've got to keep it reliable.

 

[skiddusmarkus]

I have the fia2 controller which injects proportional to fuel injector pulse. Wouldn't that be in line with what you're saying George?

I have mine post intercooler, although did like the idea of pre turbo but put off by the prospect of impeller damage and wanting to run blowthrough.

 

[PobodY]

I don't understand the complexities of a turbocharger like Ed does, but I read what he said to mean that you'd need to inject the correct the ideal amount for all compressor speeds to achieve near-adiabatic performance without choking it (and negating any increase you may have gained). - To my mind that means you'd need some kind of feedback between the injector and the turbo; maybe the injector pulse is good enough, but I suspect Ed would say it needs to be more sensitive to the compressor behaviour.

 

[Makaveli_se7en]

I like it when clever people can give a good explanation, nice to see you back ed.

Cheers Danny, been busy with the new job so just have time for a little lurking these days

I have the fia2 controller which injects proportional to fuel injector pulse. Wouldn't that be in line with what you're saying George?

I have mine post intercooler, although did like the idea of pre turbo but put off by the prospect of impeller damage and wanting to run blowthrough.

That helps with matching the injection to where the engine is running which is not the same as where the compressor is running. Which is not an issue for post compressor injection. In fact that is the same set up I intend to run on my car.