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Hi all , I've been reading up on water/water methanol injection of late because no matter what I do I can't get acceptable consumption out of E70 in a daily driven GTS25T . I'm not the worlds best road tuner but I can get my car to start cold and drive quite well around the burbs . Most of my driving is in traffic and the AC isn't used much .

I think standard V8s do better than I do , topped off last night and got around 110 km out of 18L of E70 .

There's something wrong with your car or your driving if you seriously can't get better than 16L /1ookm. I can get 12L/100 out of my 1800kg Stagea around town if I don't floor it away from every traffic light (and it was much the same when I had the RB25DET in it).

There's something wrong with your car or your driving if you seriously can't get better than 16L /1ookm. I can get 12L/100 out of my 1800kg Stagea around town if I don't floor it away from every traffic light (and it was much the same when I had the RB25DET in it).

On ethanol?

There's something wrong with your car or your driving if you seriously can't get better than 16L /1ookm. I can get 12L/100 out of my 1800kg Stagea around town if I don't floor it away from every traffic light (and it was much the same when I had the RB25DET in it).

Pretty sure your consumption will be on petrol - you need around 50% more fuel to achieve the same lambda on E85 than petrol, which might put that into perspective?

Disco - I forget, don't you have a Link or something... now? If so, why not go flexfuel? 30-40% ethanol gives you a GOOD gain over petrol - like a reasonable percentage of the the different between petrol and E85, but you only end up using a comparatively negligable amount more fuel. Do most of your fill ups on petrol and occasional pour some eFlex in there if you don't want max thirstiness.

Well the thing is Lith I reckon once the user found their sweet spot the E70/E85 becomes redundant and the only reason to be flex tuned is because you can't buy E30-40 at the pump . If we could I reckon more people would have a play with ethanol because the agro is directly proportional to the percentage of ethanol vs straight ULP .

Back later cheers A .

  • 2 weeks later...

Heya guys,

In a rush, so skimmed the last page.

I was talking to a very experienced backyarder about WMI vs E85 last weekend.

He mentioned they were on par performance wise. He's currently using E85, but will move back to WMI on his next setup for costs sake.

I have always wanted to try pre-turbo WMI but haven't bit the bullet just yet.

My mate has run pre-turbo and noticed the compressor wheel had 'chips' on the leading edge after prolonged use. He then moved it to post TB with similar performance results, then to multipoint where he found no further gain in performance but mentioned a lower tolerance to pushing the quantity of WMI he could throw in.

He runs a 200psi pump which may be too low to effectively atomise the WM enough for pre-turbo application (hence the compressor wheel 'chipping' when nozzle was mounted pre-turbo)

My first suggestion was to mount the nozzle just past the turbo on a bend facing downstream, which he'll try in the next incarnation.

I did some research a few years back and couldn't find anything much beyond 200psi (anything rated more than that was a 200psi pump with the regulator wound up which reduced flow)

For the cost associated with E85 (pump, injectors, regulator, tune and possibly an ECU) and the cons of sourcing E85, cost, cold start issues etc; I'd suggest giving WMI serious consideration for a small boost in power on a budget. E85 is great for big applications, but 'as good' results can be had on a smaller 'DIY' budget in my opinion.

I hope some of this helped.

Mark :)

PS: Ethanol smells nice, you should include that in your decision making process ;)

I see two imperatives with WI:

Reasonable distribution across all cylinders

Being confident that the system will deliver on demand every time. Clogged nozzle/s and sufficient water supply tank come to mind.

A tune optimised for WI should lead to a quick engine failure if the water system fails to deliver, due to leaner fuel mixtures and the ignition advance. And there lies the biggest advantage of an E85 setup: only one liquid delivery system to worry about. The stories/pics of carbon sludge in E85 do ring some servicing alarm bells though... :domokun:

I don't see that much cost difference between the two systems if starting from scratch and chasing 250-350kW. Different injector sizes and maybe a replacement fuel rail for E85 sized injectors but that's about it. Each will need an ECU, tuning etc. The WI system certainly requires some creative thinking to package tank/pump/lines and nozzle/s placement.

End of the day, product availability probably wins the argument. In Queensland there are not many locations where you can get E85 from a bowser, but water comes out of all the fuel station taps.

The aquamist system has a fail safe trigger to send a signal to the ecu, it incorporates a tank level sensor and a water flow sensor. Once set up the flow sensor will trigger fail safe if the flow is higher or lower than normal due to either a leak (flow would be high) or blocked nozzle (flow be low).

That sounds pretty good tbh, a flow meter really is fool proof as basically every problem possible will result in no flow eventually.

There are some problems with preturbo. You need to inject a bucket load, if your using a 200psi surflow pump you will probably need another one even if you have boost pressure going to your tank. You need to inject atleast double, since your compressor is soaking compressor heat and to get in cylinder benefits.

I ran the smallest nozzles 0.5mm, I couldn't get a 0.3mm bit in so size might be before it was plated. Even so at over 350psi the comp wheel looks sand blasted on the outside 2/3. You really need to run it right at the nut for it to avoid damage- not possible on twins.

I have been using water injection for a long time. If you start with a very well cleaned system and use only distilled water you generally wont clog a nozzle. If you run multi point small nozzles the chance of blockage increases. I also trigger a bit earlier then normal, you can feel a clogged nozzle and can back off before you get into full boost or high rpm

I ran an Aquamist 1S system on my old RB25 twin turbo converted engine. Engine was running OEM 26 turbos at 1 bar (360 rwhp - so not highly tuned) with a GReddy Emanage to control the single pulsed water solenoid and jet. The reservoir was the S13 washer bottle re-located to the boot.

The water injection was mapped from around 3800 upwards depending on load etc using the E-manages additional injector map. The E-manage was already handling the fuel/ignition control for the 'blow-through' MAF and larger injectors. The mix was mainly distilled water (out of a de-humidifier) but with the addition of some methanol based screenwash to stop it freezing in the bottle in the winter and to retain some cleaning ability as it was still being used for windscreen cleaning duties ! The bottle lasted two or three tanks of fuel.

You could run more ignition advance with it on and I ran it for around 25,000 miles without any issues with the jet clogging. When the engine was stripped the combustion chamber/valves/tops of the pistons were still remarkably clean.

We don't get the E70/E85 fuel blends in the UK so I'll be using the kit again on my RB30/26DETT when its done. Fuels hideously expensive over here so the plan is to try running it daily on nomal unleaded (95) rather then the 'Super' unleaded (98/99) normally used.

Cheers

Stu

Edited by mambastu

I reckon a reasonable compromise could be the lowest cost/octane ULP plus water meth injection - and use it in any situation where the engine may try to detonate ie even when not boosting . It is known that higher octane ULP doesn't make any extra power at all where there is no detonation . If you can supress the detonation with a cheaper anti detonant than oil company additives it's all good .

A .

If the power target and type of use ie. occasional/track or daily/road is factored in, I would agree that lower octane fuel could be a reasonable choice when total running costs are part of the equation. Couldn't see the sense for track use if it means saving $5-$10 over the course of a day for the sake of saying you are running low octane fuel if there is a remote possibility that you might strike detonation problems.

I don't know of anybody that has reported detonation problems at low load/cruise conditions with a turbocharged engine. It's when full torque is demanded from the engine that it comes unravelled. Quantity of water to be injected under low load on-road (ie more often than not) would mean a pretty big water tank is needed. It would be interesting to find out if water or water/meth made any difference to how the engine runs at light loads, as per E85.

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