Steve Fort

Anyone tried it, or had it fitted to a scoob? If so, what were the results etc.......
Just an idea i was toying with, but can't remember anyone ever mentioning it on here.

Cheers,

Steve

Nezz10

Try on {url=http:/www.22b.com] and do a search for water injection. There is a thread that is HUGE with posts from a lot of very technically minded people.

Nezz.

(hope the link works)

Nezz10

Ok try this instead...

22b webstie

Nezz10

It early ok. Last time..

If this doesn't work I give up

http://www.22b.com

dowser

Why do you want water injection has to be the first question - it's generally used to control charge temperatures when you're already running too close to the edge.

Richard

5 Type R

I have a dual pump water injection system fitted to my scoob.

Not as a performance mod , purely as an added preventative measure when running more boost.

It is mapped in and controlled by the Unichip

Steve Fort

Cheers Nezz

Dowser, I want a way to drop the charge temps more, as i think that the TMIC does a crap job of it, sitting on top of the engine.
On my old MY00 i got over it by fitting a HKS FMIC, but theres no way i'm going to cut my P1 about like that. I just see water injection as a good(?) alternative, not sure what it'd do to my warranty though.

Adam M

water injection is properly used for lowering egt not intake temps.

if it is dropping inlet temps it is wasting its effectiveness as it is only doing so by introducing non combustable vapour at a lower temp, which gets partially heated by the charge.

water inj by dropping egts increased the amount of ignition you can run before the onset of det.

Water spray should be used for dropping intake charge temp along with a chargecooler or more efficient air to air intercooler such as a front mounted item.

dowser

Charge temp = temp of charge in bore before ignition spark
EGT = temp post spark, after it's been 'exhausted'

One is *quite* closely related to the other....I can't think of any way to get water into the bore unless it's sucked in with the air/fuel mix - so lowering one lowers the other. I have, of course, been wrong before

Richard

Adam M

rich, temp before is not htta closely related to temp afterwards. The combustion is very complex and the energy it yields can affect a lot of things in many different ways. I dont know enough to go into it, but in essence if there is water in the chamber, it will be boiled instantly, meaning the intermolecualr (in this case hydrogen bonds) will be broken, leading to water turning into steam, this happens at one temperature (dont knwo what that is as it is pressure dependent) and the calorfic value associated with this is very high compared with that for heating a mole of water by a specific amount.

As a result a small amount of water can make a massive difference to temp after combustion, so over a period, the average temp stays lower. hence less det.

you can have a v low intake temp but run so much advance that you achieve enormous egts, you can also run massively lean and so the fuel iself has a lower cooling effect.


You are right you can only inject before, but if you leave the injection until just before the cylinder otr as close as possible, there is less exposure time for the water injected to be heated up by the charge.

john banks

All I understand from the theory agrees Adam, in the chamber is the primary effect, cooling the charge is of secondary importance. Intercooler efficiency is also higher if you spray after the intercooler - there is a larger temperature difference intercooler and environment = greater heat transfer.

Advancing the ignition resulting in HIGHER EGTs? Is this a special extreme situation? Without WI I have found that the EGT is raised by retarding and leaning and lowered by advancing and richening, but of course I have not tested all situations as some are ludicrous for good engine operation/sanity. Are you saying there is a point you cross with advance where the EGTs then climb?

NINJA

bite the bullet chop the bumper fmic is only way to go tmic is pony

Bob Rawle

Try leaning and advancing ... my egt's are highest under fast cruise at just under zero boost ... as soon as I apply boost with the correspondingly richer mixture then my egt's drop from that.

if you run an engine with too much retard then, of course, egt's will climb but .... there should be no case when that occurs. (unless you run with anti-lag)

As a general point a good sensitive EGT guage can tell you a shed load about your maps.

Trout...

I must admit - my EGTs are highest at 145 on track at 1.4bar

EGTs are excellent for telling you how your fueling is performing and I also use WI to control onset of det and the amount of advance I can run.

It has been a boon for on track performance.

Trout

john banks

145 Trout?

At lambda voltage of 0.87V I think mine was too lean - as I could add 3 degrees from going to lambda voltage of 0.89V. Charge temps are certainly not silly. I only saw about 10 degrees difference in EGT. 20 C drop from going from 1.5 to 1.4 bar though. All quite small changes perhaps? Wish I could quantify these as AFRs as the amount of fuel added to the map seemed a lot and 440s struggle. WB awaited. I am running again about 10 degrees midrange going to about 18 at the top - not as advanced as some Maybe I need some water, or a bigger turbo where does it end!

Adam M

John,

why dont you have a word with mark or pat and ask them what happened when they compared the output from the narrow band to the output from the wideband sensor once the exhaust had heated up to proper running temp!


I believe pat was almost upset at how far out it went.

I will not allow my car to be mapped on a non wide band sensor again, but then I suppose thats easy to say if your ecu can cope with a wideband, not so easy if it cant .

Trout...

John,

145mph...


Trout

john banks

It will be interesting indeed. I quite like the sound of the self map on the Autronic ECUs. Sit and watch it map itself whilst drinking your coffee I'll be getting the WB input into the datalogger somehow.

Trout, oh 145 mph, didn't think of that

john banks

Then I was going to say is that all?

john banks

or...

john banks

was that going around a corner?

R19KET

John,

I suspect, that if you think the Autronic can just "self map" itself, and give you a good map, you're going to be VERY disapointed.

The Pectel has this "feature", and whilst it works well for "cruise", anything else, is a waste of time, unless you're mapping on an engine dyno, or perhaps a RR.

You need to hold the engine at a steady rpm, at a steady boost pressure, for about 2~3 sec's, for the ECU to latch on, and adjust the fuelling.

I gave up trying this, on anything over 4000rpm, and .2bar vacuum. I just found that if you hold the RPM, the boost drops, and if you hold the boost, the RPM climbs too quickly.

Anyway, back to WI. I started using the ERL system about 3 years ago. Correctly set up, it can make a dramatic difference to how a car performs.

Even just set up for "safety", you will find that on those rare occassions we have hot weather, or you're on the track, the car will give far more consistant power delivery.

And if it's used as a tool to extract more power, you can balance power v "extra safety", depending on your goals.

I always find it interesting, that people say you don't need WI, if you have a FMIC. Well it really depends on just how much you want to get from your engine. Even with a FMIC, there are still massive beifits to be gained with WI.

Now, I need to point out, that I have recently been appointed as an ERL Aquamist distributor. However, my opinions are based on several years of using the products, on both my own, and many friends cars.

Mark.

R19KET

I'm using true wide band with the Pectel, but once you get on boost, you transit the zones so quickly, the ECU just doesn't have a chance.

The Link has also got an "auto tune" feature, but it only took a few attempts to realise it was a waste of time. I had hoped the Pectel would be better, and if it was used on an engine dyno/RR, it would be very good. I would assume the Autronic to be similar.

As for WI, it will be going back on my car, regardless of the FMIC.

Mark.

Mantamac

The ERL system was fitted on my Courtenay Turbo Manta way back in 1987. The system still performs perfectly today.Unfortunately the system I have is no longer availible. It has an intergrated boost controller so that when the system is armed more boost is run. The car run's 26psi and if run without the water injection it det's very badly. I tend to find the car run's better with a 50/50 mix of water and methanol.( also stop's it freezing in winter )
Don't think of water injection as a means to more BHP, think of it as an insurance policy!

PS. My car also has a front mounted intercooler.

Mac

SMG

Alcohol baste screen wash 50/50 can be good, mixes with water well
alcohol aids combustion and it can help prevent corrosion to manifolds and alloy internals plus sufrace rust that can occour
in the bore which acts as a deglaze!!! if the car is left for a period of time after use, only a real issue on cars that have not
had the w/i set up correctly. If your going the cheap diy rout although the ERL stuff is great!.... i learnt the hard way remember
correct jet size a must, measure flow into container, use a anti-run back valve and filter not saying this is the way to go but a
high power headlight washer motor can work wonders, run a LED for
power on, and also run a LED to show power to the motor also good
for setting up, try and use a bottle with level indicator and mount in a cool place. Remember all this process takes time so your presure switch mounted after the comp housing may need to be set
before you want it to activate by 2 or so psi you will have to suck it and see. Mount the jet after the intercooler and dont blame me if it goes **** up..

Steve.

Nezz10

Mark - Do you run the pressure switched WI or the link mappable?

MorayMackenzie

Mark has a system will all the bells and whistles.

David_Wallis

marks car has that many sensors and **** in the downpipe he needed a custom one

David

R19KET

This is my original set up, using two pumps, one for WI, and the other for water spray. The gauges just make adjusting the water pressure easy, the "tubes" are "dampers" to smooth out the pulses from the pumps, the WI is mapped using the ERL MF2 controller/pressure switch, and the water spray uses a pressure, and temp input.

There were also a few other bits used, such as the ERL high speed valves, and a gizmo to spray the IC, a few sec's, on, then a few sec's off.

It's a "bit" overkill for most, but enabled me to test different options, and see what worked best with my set up.



Mark.

R19KET

OOps, sorry it's a bit big. Must learn how to get the best size to post !!

Mark.