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-   -   Water injection torque and power gains (https://www.scoobynet.com/drivetrain-11/187584-water-injection-torque-and-power-gains.html)

john banks 14 March 2003 10:22 AM

It seems I can get about 10% extra power from adding a full bottle of NF to Optimax and 4 to 5 degrees ignition timing plus running 0.5 AFR points leaner and running a smidgeon more boost. Every little helps, I am sure the contribution is quite evenly split between doing all three, but you can't really do one without taking the others back without the NF.

What sort of gains have people had from optimised maps before/after water injection? Figures, timing data and AFRs appreciated if available.

brickboy 14 March 2003 10:53 AM

Does WI cool the charge in the cylinder, help reduce det by cooling / better mixing, or a combination of the two?

LimeyDrink 14 March 2003 11:05 AM


I too would like a bit more substantial information on Water Injection with maybe before and after results.

I know that increasing the octane rating of the fuel allows you to advance the ignition/increase boost by increasing the charges auto-ignition point.

Water Injection does the same by actually reducing the temperature/pressure of the charge and while this sounds safer from a thermal stress point of view, does this reduction of temperature/pressure actually offset any gain you made by advancing the ignition and increasing the boost.

LimeyDrink 14 March 2003 11:12 AM

Actually I have just found this link that contains a FAQ on water injections, although John Probably already knows all this, it may be usefull for someone else.

http://www.turbodynamics.co.uk/water.htm

EMS 14 March 2003 11:37 AM

Lots of information also on: http://www.aquamist.co.uk/

Mark.

steve McCulloch 14 March 2003 01:49 PM

John

I will tell you when Bob has finished the 2 year WI project on my car!

I would hope for several degrees more advance, but no more boost...

I would expect to gain about 10 bhp/torque from this, given the reduction in fuelling.. we'll see though. Should be running at about 1.8 bar held, once I get the new turbo and headers decided on.. that just leaves the cams then I'll be off on my next project..

So you noted what we all knew about adding a full NF bottle to Optimax then..... expensive though!... wonder what you'd get if you ermmm added the NF to 102 ron or above! even more expensive route to power!

john banks 14 March 2003 01:57 PM

If it is as effective as NF I would hope for a damn lot more than 10 lbft?

steve McCulloch 14 March 2003 02:10 PM

John

Surely theres a limit to the amount of advance you can run before you reach the 'down' point

Much more than 10lbs.... probably in the summer but dont see how you would get that much more now, given the susstitute of water for fuel...

I would expect for about 3-4 degrees more advance, which should equate to about 10bhp on the rollers, after accounting for the loss with the water..

john banks 14 March 2003 02:23 PM

The talk was of 6-10 BHP from losses from the blurb and old threads. 3 to 4 degrees should vastly overwhelm this?

Can you reach MBT with water - I think Trout thought he had once?

steve McCulloch 14 March 2003 02:39 PM

Surely water is irrelevant.... yes there was a point..... On your car you should be able to go higher as your presumably running standard compression? and you wont be at a greater risk running a bit more advance and a bit more boost

For me I'll not be doing it for the power gains but for the increase in safety.. if I get an increase this will be excellent but I would'nt expect it.....

It has been known for cars to get much more power with WI, but IMHO.. that is because the WI has eliminated the onset of det and really means that the tuner doing the map doesnt have a clue what they are doing - again IMHO of what I've seen.......waiting to be flamed for such a silly comment..

I'll be using the water to raise the Advance rather than getting rid of any det.. which I dont have


steve McCulloch 14 March 2003 02:41 PM

3-4 degrees - I would'nt bet on it

Between rolling road runs and about a week I got 10bhp from 4/5 degrees more advance....of course not an exact science and no WI on the car

Of course the car felt much faster than this on the road..

john banks 14 March 2003 03:03 PM

Well it is easy to get mine det free by just retarding the timing, the timing is not disastrous. But you can get very impressive timing with the NF still det free, and loads more power. It is whether water will be as potent for suppressing det, calorific value of the charge would reduce though.

At c. 200 BHP/litre uprated engine or not you have to run det free or it doesn't survive. That is taken as read. I want to run a calculated offset from the point where the engine dets in the worst case. So I wouldn't fit water and not advance the timing. I wouldn't fit water to cure det, I would set the car up properly. I want to fit water to get more timing, still without det and hence more power. Same approach with the NF.

The NF gives dramatically interesting results and goes like a bomb. So does £13 a pop ;)

So if you are getting such small gains from water, either you are at/near MBT, or NF is better than water?

[Edited by john banks - 3/14/2003 3:10:21 PM]

steve McCulloch 14 March 2003 07:28 PM

John

I have not got the water running.. I am talking about the results from the increase in advance that I'm expecting........ I may know for sure if I do a couple of RR prior to fitting the WI... at the moment I'm now-where near the turning point as the advance was turned down when the higher compression Pistons were put in.. so I know that I can get about 5 degrees.. will see. I would'nt have got much more power anyway with the turbo near its limit.. around the lowly 400bhp mark... am hoping to get near the 500bhp mark in the next few months...

£13 a bottle.. you need to find a different supplier.. if you buy in bulk you should pick up for £11.. (i.e. a case)

I use the cheaper Millers Booster in my Audi Turbo and NF in the Scoob.. and am investigating 76 racing fuels (116 ron variety) in the States for my Evo 8.. yeah I know, its a hard life.. someones got to do it!

rayman_2 14 March 2003 07:34 PM

heres some useful info on the subject with some interesting data.

http://www.geocities.com/blownrenault/winj1a.html

someone make it clicky ?

:D :D :D :D

Andy.F 14 March 2003 09:07 PM

www.geocities.com/blownrenault/winj1a.html :)

john banks 15 March 2003 09:40 AM

Steve I didn't want to betray my discount for quantity ;)

Perhaps with a turbo on the limit that is where you are assurred of gains given that you know it won't be anywhere near MBT?

Andy.F 15 March 2003 10:04 AM


It seems I can get about 10% extra power from adding a full bottle of NF to Optimax and 4 to 5 degrees ignition timing plus running 0.5 AFR points leaner and running a smidgeon more boost.
Yaaa beauty :) Can't wait to get the Apexi Power FC tuned in to this :) Should put the bhp up to, er, hmm, surely not ? would it ?

Andy ;)

steve McCulloch 15 March 2003 12:31 PM

John

We'll see what I can get when I get a different turbo on

Andy

Didnt think the Scots were that much into Sarcasm :p

5 Type R 16 March 2003 08:17 AM

John

a good friend of mine that bought my tuned Rev 3 MR2 Turbo, spent a long time trying to asses the benefits of finely mapping the Water Injection.
After some reasonable time on a friends rolling road , he managed to get a further 25-30bhp from fine tuning the mapping of the WI


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