For some unknown reason, I have lowered it. I think it could be because the unit can be used on the mappable system as well.

Eight clicks is about 3.5V. So there must be a window area of 0.3V depending on the RPM /load/gear vs boost (10psi). I think we are on the correct working area.

Richard

So at the moment the box is only taking readings from the car. I take it it is not changing any signals yet ? It looks really good by the way :wink: . The big problem with the zlet is the AMM, there always braking down ! Would the box be affected by an AMM break down ?

Correct, it is not making any changes yet - this will be setup on a rolling road.

Any time soon ? :D I really hope it works well. Can you just explan how and why it will give more power ? I kind of got an idea but, might be wrong.

I think it is all in this thread Basically, turbo engines run rich underload as a safety measure. This keep the engine cooler as the excess fuel helps with cooling and I think with detonation too. The problem with this extra fuel is that it causes inefficient combustion, so you loose power. By removing the extra fuel under load, you get more power. The water injection then takes the place of the fuel and cools the engine and helps with detonation.

An engine is being over-fueled for the purpose of keep the incylinder temperature down to suppress detonation. This safety measure is often adpoted by the manufacturer as well as the aftermarket tuning industry.

Engine produces best fuel economy at afr 14.5:1 upwards, but also produced high combustion temperatures. Flames colours are often blue rather yellowish similar to setting up a bunsen burner.

Best power is generally obtained around 12.5:1 afr.
Best torque around 11.9 afr. Richer afr (cooler burn) enables the ignition timing be more advanced and hence more torque.

Due to warranty issues and reputations, tuners often tune the afr well below 12.5:1. the afr ranging between 10:1 top 11.5. almost as much as 20% extra fuel is being used to keep the engine running cooler.

For those who doesn't care about economy but just want to keep the engine safe should read on... Excess fuel burns with a yellowish and sooty flame. Over rich afr produces a great deal of carbon monoxide. Carbon monoxide only yields 30% power of carbon dioxide so your precious oxygen is being carry away as well as neat fuel out of your exhaust pipe.

The little unit basically tries to shift the rich afr towards something approaching 12.5:1 in presence of WI. Since onlyone part of water is being used to do the same job as injecting six times amount of fuel.

See the chart below: (only 3% w/f ratio is enough to reduce your fuel consumption at WOT by 20%)
http://www.aquamist.co.uk/forum/gallery/afmr/100w.gif



The proposed unit has a certain amount of failsafe mechanism inbuilt. It constantly monitors the lambda value, if it drop below a preset point, it disables the MAF converter. Converter automatically switches on when WI is enabled. It can also trim the MAF voltage in relationship with the amount of water flow if a water flow sensor is used.

Who knows, if a car is equipped with a Wide band lambda sensor, you can preset your desired afr with this unit.

Cannot comment on the MAF sensor failure - it will depend on what output it gives after failure.

Richard

Mike,

I cannot make the dyno next week - just over booked my time table.

What about the mid-week following?

Richard

No problem, whenever is good for you.

Cheers for the explation. Its alot clearer now. good luck with the dyno, hope all go's well.

Richard, let me know when you have a date availalbe so that I can book the afternoon off. Cheers. :)

Mike,

I am afraid this week is not possible - I am sorry. I will update the possibility for the week after.

Richard

Hi Richard - any update on a date?

Mike, I have just spoken to Gary at GTART, he can put me in on Wedneday, thursday, Friday or Saturday week, He is fully booked for this week. Let me know if you can make any of those days.

Richard

How about noon on Wednesday next week?

I will arrange it .

Is everything still working?

Yes - it all seems great. :D

Mike,

I have asked for Wednesday week (15th) is set for 2pm. We should have some fun.
Would you like to meet me earlier at ERL and may be get a bite of sandwich before setting off.

Richard

Sounds good to me. I'll be leaving work at 12:00.

If there is any change from the present arrangement I will post here in good time. I will confirm with Gary (GTART) tomorrow by the latest.

Good luck with the R/R setup. Finally got the car mapped the other day. It hit 267bhp, theres some kind of restriction in the exhaust ! :sad:

With or without WI?

By thursday next week, I should learn a great deal more on the Astra. Hope I can gain some new power. The only tool I have a trimming the MAF. We shall see.

So far so good.

Without.

The WI is not fully installed yet. Had to hold my horses cause the cash spent on the R/R. But its ok now. will phone next week to order the rest of the parts needed and hopefully install it all next weekend.

Well ....... ?

Sorry, im a little inpatient to find out the result !

Not good power wise, although Richard has some before and afters to work on.

Take a wild stab at which sensor caused me to loose 30bhp (this is nothing to do with the WI btw).

AMM ! or the o2 sensor. Think one of my o2 sensors is out.

Yep -AFM.

Here is today's dyno run. Didn't have a chance to try the MAF converter since the afr is quite lean already at certain places.

The first run -base:
http://www.aquamist.co.uk/forum/gall...o/baseline.jpg

Second run -with 50M/50W 0.5mm jet:
http://www.aquamist.co.uk/forum/gall...o/first-WI.jpg

Third run - abandoned midway due to leaning after replacing another MAF sensor:
http://www.aquamist.co.uk/forum/gall.../dyno/lean.jpg

Thats a shame. The AFR line look quite erattic ! Was bhp figure at the wheels or flywheel ?

Was thinking, would it be possible to moniter the AMM like the lambda sensor ?

Although the last plt was abandoned midway, it still made respectable power running at extremely lean condition (WI was switched on).

Unfortunately the bottom scale is not in RPM but scaled in seconds.

I did my best to superimpose the lean run on top of the baseline. After loosing some power during acceleration, it appeared we have picked up some power -only just. Lean plot is the fainter one.

http://www.aquamist.co.uk/forum/gall...eline+lean.jpg

The power plot was "at the wheels".

RIchard, what was the name of that diagnostic bit of kit you suggested, I've forgotten.

Here is the link:
http://www.innovatemotorsports.com/

Richard

Mike,

You have managed to try out your fuel leaning tool (extra lean MAF sensor) before I try out mine.

The results showed how lean you can run your engine and still gain some power increase.

I would never have dare to run lambda at .93 on someone's car!!

you were very brave!!! :twisted: :twisted: :twisted:

Well I think if I didn't have the water injection, the engine could be dead by now!!!! I won't be trying it again though.

What the next step now ?

I may be reading this wrong, but it appears to me that the wi has had little effect on power. I am assuming the first graph has no wi.

I have logged a large change in inlet temps (60C-38C) and would have expected some increase in power due to a cooler charge. However these graphs are showing no real change in power delivery. Sad to say, but I am beginning to think that wi on the Astra is not effective in raising power levels. I have other reasons for this thought.

Please, don't think I am being negative. I have spent considerable money intergrating a wi on my car, and I would love it to work.

There were a few clues as to why WI was not effective in this case.

Temperature reduction is very small when the ambient air was at 7 degC during the dyno and not having been able to use the MAF due to the re-mapped ECU displaying irregular afr pattern. See the black curve on the bottom of each plot.

I believe Vaxuall has done a great job making the engine very difficult to tune, It appeared the boost pressure is controlled by the ECU. This was shown by the progressive drop in boost pressure at the RPM climbed, the aim of the exercise by to achieve a flat torque curve regardless of anything else.

I have also noticed the designed of the turbo components. The intergrated inlet flange, the tiny exhaust manifold and electronic bleed valve arrangement, all seemed to indicate and confirm that Vauxhall is making this Astra difficult to tune for extra power.

After giving some though after the dyno session, I concluded that the only way to get power is to remove some of the restrictions imposed by the mechanical design. But before embarking on such an assumption, I think the next simplest thing to try is to gentlly modifying the boost curve - I have some ideas how this can be achieved.

Finally apart form abandoning the last dyno run midway, we can see the positive effect of WI when power gain was achieved midpoint during the momentary lean running.

I would like to continue the development if Mike is willing to continue - modifying the boost cuve to acieve one or more psi after it has dropped to 12psi after the initial 18psi and bear fruit. Anyway , not quite given up the fight with Vauxhall yet.

Richard

I have been running without WI since December, I have found out why my "in pipe" jet "union" failed, it was inserted back to front with the wide flange on the outside!

Now I have my new intercooler fitted I can locate the jet after the cooler, but before the map/temp sensor. I shall do this over the next couple of weeks and then see what happens on Courtenay's Dyno (if Jon's happy to do so) and also rig up a cooler spray to see if any gains can be made there too.

It's looking to me that the WI is only going to be effective when the ambient temp climbs and the charge temp gets close to the 70 deg C, after which the mapping chucks in extra fuel as a fail safe (I assumed you knew this trigger point, but never reached it?).

Not given up yet, but I don't want to trim the map to remove fuel for obvious reasons, I have rebuilt a C-LET once because of detonation and I don't fancy a Z-LET based reincarnation!

Interestingly, due to the low evaporating rate of water in cold inlets air, most of the cooling power of water is transferred to the combustion chambers. If the amount of water is not reduced to compensate, the engine will loose power. It is especially pronounced when the engine is not tuned for WI injection.

There are instances where WI will sustain good gains in winter if the engine is highly tuned for it. I am trying to designed a interface unit that will allow WI to be effective all year around - Mike's car was my attempt down this route. Processing re-processing sensor signal is a low-cost affair, if it can be incorporate into the WI setup at minimal cost. you will get the WI benifit all year around and it is not a risky add-on either.

Most engine management is equipped with active knock control and as well as boost control. It just DOESN'T know that water injection has the effect as putting in a tank of higher octane fuel instantly (as during the dyno run), if Mike car is allow to run with WI for a few weeks, the engine management should adjust itself to accomondate the "knock" suppresssion properties of water and create new maps to suit.

I think the Astra will benifit with mid-range torque increase with WI and top-end power requires more mechanical mods. Trimming the fuel can not be used unless you have a consistant MAF sensor - too risky. I was withnessing the immediate afr leaning after Mike change over the MAF element during the dyno session. If you want to further your tuning potential, I recommend you getting the Innovate wide band lambda unit. Armed with this unit, you can be very safe during any home or road tune.

There are just so many ways to tune and there is not enough time....