Water injection - first test

[sdminus]

There\'s an interesting thread on injecting pure alcohol on rx7club.com

The problem is alcohol doesn\'t have the latent (sp?) heat capacity of water but adds fuel to the mixture. I\'m unsure of what to do with the information lol  :xconfused

[ScuttleRX]

Me neither, alcohol has the 50% oxygen content which is something to with the extra fuel I think? more oxygen to burn, all getting a bit fuzzy to be honest, been reading too many threads too late at night

50/50 Methanol/water and an extra injector, I will leave it at that for now



although.......i may try some acetone in there too

[bnaellis]

I find that if say my air temps 35
if I plant my foot down throught 2nd and through 3rd then look at my controller straight after it\'s reading like 29.
If I staright away blast through say 3rd gear and look at the controller it\'s ready 23. Seems as though it\'s quite affective at killing intak charge which is not the reason I installed it so pretty pleased.
I have mine about 2 inch before throttle body 140 psi pump, 375ml@60psi jet
mine comes on at 6psi 50% duty cycle and opens linear to 17 psi where it\'s at 100% duty cycle.

[ScuttleRX]

Sounds like you have a good set-up Brian Do you get the same sort of results when full throttle in 4th and 5th as you do in 2nd and 3rd? I\'ve noticed a slight drop off, still works just not as well.

Just crusing along dual carraigeway last night, few 5th gear half boosts got my temp down to 17C dont think ive ever seen it that low! Handy say after a traffic jam or something if the car has got heatsoaked

Im planning on stickng my second injector where you have your one, reckon having it there will really help kill the charge.

What are you using to control your injector cycle, is it an aquamist system?

[ScuttleRX]

What I am after, dont know if such a thing exists, is an rpm switch. Something that will be normally closed till a pre-set rpm then open...

[sdminus]

Try this one

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7987235627&category=33740&sspagename=WD2V

Hope it helps

Scott

I seem to remember there is a prob with some alchs in which they seperate in the intake tract....not 100 percent sure tho

[ScuttleRX]

nice one cheers for link scott, something like that does exist then I can put my plan into action (if needed)

Having my second injector set-up for high boost is not gonna stop it coming on at say 4k rpm when inj duty is still low so may need the rpm switch to keep it say 6k and above. Thats if it starts bogging down in low rpm, if it doesnt then happy days

[sdminus]

I really dont think you will need it mate.
Mine does not bog at all which really surprised me !

Scott

[ScuttleRX]

That\'ll be handy then.

I changed the injector last night, took out the angled bit and just had it spraying across pipe. I though the same as you having that big bit in the middle of the pipe might disrupt the air flow, nice and flush now.

Had a quick test last night on way home, hard to make direct comparison as conditions were different, but when replicating conditions where temp use to rise, it seemed to control this better. Car did feel like it pulled a bit harder too, not sure if the angled bit was disrupting the flow, boost got to a slighty higher pressure than it has last couple of days.

One thing I did notice, old set up a couple of half boosts which got the pump to run 3 or 4 cycles, would make the temps drop, didnt do this every-time with this set-up (does do it sometimes), think maybe now as its not sprayin against flow its not getting enough time to cool before temp sensor, so second injector might be best placed just after intercooler to give it whole tract to cool in, and current one best for det control and stopping temps rising.

Ways it runs now and then kind of matches what it says here.
On lower pressures the old position injector might have had water reach somewhere near point C, or at least not go straight into thottle body, making it the best one for intercooling, and like-wise how it is now is making it like point A.

Might be talking out of my a-rse but it all kind of makes sense

[ScuttleRX]

2nd injector is now installed, need to set up the boost switch properly (bit too wet today + running out of time fast), at the moment it is just 1/4 of a turn more than first one.

Initial results look good, like I say its wet today so hard to give a proper test, temps are seem to be dropping quicker again, so all good. Real test will be at the weekend, will see if the consistently low temps will give a better 1/4 mile time/speed.

2nd injector is 2.3g/ph

[dandan]

I\'ve been following this link as I tend to do with everything that is aimed towards a better run, longer life engine, and to be honest the technical side of it was making me think it was a really complicated affair, but that image you just posted makes it all seem so simple, I assume the blue pipes have the injectors on the end, the pump is at the other end of the pipes, and the electronic gubbins that controls the system is all connected to the pump in the cockpit somewhere?
simplicity!
You may have unwittingly created quite an effective how-to thread!

[ScuttleRX]

Yes its a very simple set up, best way to start I think. Pump and tank in the back seat recess,  then there is an inline water filter. The pipes then go to the solenoid which is wired to a boost activated switch, when the preset boost is hit solenoid opens, pump pumps and water goes in There is a bit of wiring to a relay which is not very tricky, especially if your good with car electrics, hardest bit for me was routing pipe/wires cos I didnt know where to start

Just got a 12.96 today so must be doing something right they timed 0-60 as 4.36
Spilled methanol mix all over back seat recess, hope I got all of it cleared out cos the warning label on methanol looked pretty nasty :eek

[sdminus]

Good work Andy !
Shame i couldnt make it.
How much meth did you run and how does it differ from running water only.

Scott

[ScuttleRX]

It was quite a weak mix in the end, was 60% water to start with, and there was still 1/4 of a tank of water in there when I added it. Would have made it stronger but I want to check out the whole fumes in the cabin thing first! Warning label said serious irreversible damage from inhalation, scared me a bit! As its diluted with water presume not a prob, have sorted out my little leak to so hopefully im safe!

Seemed to work more efficiently, reckon a 50/50 mix will give a more noticeable increase. First 2 runs were just on water, they were 13.08 and 13.09, last run on meth was the 12.96, whether that was just better run or whether the meth helped i dont know...imagine it must have done a bit

ran the tyre pressures down a bit this time, on about 20-21, may go a bit lower tomorrow Saw carlos there he says hes going round the slamom tomorrow so gonna keep an eye out for him

[ScuttleRX]

Right just run a stronger methanol mixture today, close on 50/50, and I can see a definate improvement

Sustained 4th and 5th gear runs on that handy private road resulted in no increase in air temps when on boost (compared to temps slowly rising when on just water), and the usual temp drop off when off the throttle.

Adding the methanol seems to make the whole thing work more effectively, definately worth experimenting with.

At some point in the future will have to see how it affects the afr\'s, and maybe have it mapped to exploit some of the extra octane points.

Scott, calling on your sparky knowledge, any chance of a wiring diagram so I can have a blast on idle from a switch rather than fiddling about under the bonnet just before the start line

I did find if I did it too early, temps would have risen again before ive got on the line (happen a couple of times, mainly due to hold ups on the people before me!).