View Full Version : Water Injection
Jon@VAGWORX
29-10-2003, 10:50
Can someone explain the theory behind water injection and wether it's a good idea for our 20vt's?
I think you'll find some old threads on this;)
Jon@VAGWORX
29-10-2003, 11:25
I have done a search and found scraps of info, but it just confused me:(
Water Injection is where they inject atomised water pre-fuel injection to stop pre-ignition (pinking), i had a word with vince @ stealth about it as to whether it would help the 20vt engine and its notorious heat problem,he reckoned it would but i never got any further than that
try www.aquamist.co.uk
:cheers:
christos
29-10-2003, 11:39
Here's a good article
http://www.autospeed.com.sg/A_0090/cms/article.html
christos, that article is good, but its to do with Intercooling, not water injection.
As Saul said, water injection is where a very fine mist of water is injected into the inlet manifold and it help keep the temps down. The higher the temps get the more chance there is of the fuel igniting prematurely during the compression phase (ie. before the spark.), this is known as pinking/preignition/detonation (Actually they are not quite the same thing, but the terms are often (mis)used interchangably), and the cooling effect of water injection helps prevent this.
I spoke to Jabbasport (Not sure who, but it wasn't Mike) and they said that Aquamist (The most popular water injection system) would help on a high boost 1.8T and that they had successfully used it a couple of times in the past. I was going to get a system for my car but Jabbasport said that they wouldn't have time to set it up. :(
Also note that some people think Aquamist is an intercooler water spray... its not! An intercooler waterspray is something completely different, ie. it sprays a fine mist onto the outside of the intercooler, which then eveporates taking some of the heat out of the intercooler and thereby cooling the charge temps.
With an intercooler waterspray no water actually goes through the engine, whereas with water injection it does! I've got an intercooler water spray which I plan on fitting once I have the IHI fitted (Bought from Autospeed (See link above)),
Cheers
Ben
christos
29-10-2003, 12:26
Sorry, my mistake
Jon@VAGWORX
29-10-2003, 12:37
Thanks folks, good link Saul.
Now i know how it works, just need to know what gains you can expect from it. Also how will the kit get it's info from, eg when to spray etc:confused:
Thanks for clearing that up Ben.
J-R,
Water injection doesn't directly give you any more power.... however if you don't use water injection then the car is likely to pink and this will be picked up by the knock sensor, which in turn will result in the ECU retarding the ignition and the car will loose slower (This happens a lot on rolling roads and is why our cars often give poor dyno plots). Water injection stops (Or at least reduces) this effect and so the car will in reality end up with more power.
How much power? Depends on how much the ignition was being retarded before fitting the water injection. Some cars have seen 20+bhp lost on a rolling road, which may be returned if using water injection.
Really you shouldn't think of water injection as a way of increasing power, it should be thought of as a way of preventing the loss of power. Also, its main function is to prevent detonation which ultimately allows you to run more boost (And more power) without the engine blowing up!
There are various systems, using various triggers of when and how much water to inject. The simplist systems use a pressure switch so that they inject a preset flow when boost pressure crosses a preset threshold... steer clear of these.
The best systems use either a pressure sensor (Not switch) or an injector duty cycle sensor and allow you to program a map of water flow against boost pressure/duty cycle. Typically you would set this system up to start injecting a small amount of water at maybe 70% of max boost and then increase the water flow as the boost increases. These systems are expensive and for best results they should be setup (mapped) by a good tuning company.
Also, to get the best results you should have your car remapped at the same time.
Aquamist is on my plan, but not just yet.
Cheers
Ben
Originally posted by BenS1
this is known as pinking/preignition/detonation (Actually they are not quite the same thing, but the terms are often (mis)used interchangably)
from memory pinking is related to heat and detonation to compression?
Originally posted by Saul
from memory pinking is related to heat and detonation to compression?
Not to forget that heat and compression are strongly related and so, you can solve both by using water injection or lowering the compression ratio (Or both). I think.
I'm (Probably) going for the lower compression ratio AND water injection in the long term, and so loads more boost! :D
Ben
Jon@VAGWORX
29-10-2003, 13:43
Let me know how you get on Ben;)
ibizacupra
29-10-2003, 14:27
I believe I have water injection currently on the MKIV... :( but for the wrong reasons..
CC is loosing water at the rate of one washer bottle's worth per 200 miles! Hmmm. It aint dripping out either.
FMIC here I come. Sooner rather than later.
Aquamist might be tried on mine at some point with mike. It has been discussed on a few occasions.
Uprated rods and fasteners will be done before hand tho to keep it all buttoned together.
One note tho.
All this talk of this and that power and IHI's etc... Remember your transmission & drivetrain. It has to cope with this load.
CV has worn out on mine. NSF. Driveshaft is showing severe signs of 'ghoulling' (sp) on the splines. :eek: Drivetrain backlash is higher than last inspection...
321 lb/ft torque is taking its toll.
Be prepared to visit other components in your quest for more and more gee gees
bill
Originally posted by ibizacupra
One note tho.
All this talk of this and that power and IHI's etc... Remember your transmission & drivetrain. It has to cope with this load.
CV has worn out on mine. NSF. Driveshaft is showing severe signs of 'ghoulling' (sp) on the splines. :eek: Drivetrain backlash is higher than last inspection...
321 lb/ft torque is taking its toll.
Be prepared to visit other components in your quest for more and more gee gees
bill
im thinking cadwell + bill + lsd x 300+lb/ft = :eek:
munch munch munch
Originally posted by ibizacupra
I believe I have water injection currently on the MKIV... :( but for the wrong reasons..
CC is loosing water at the rate of one washer bottle's worth per 200 miles! Hmmm. It aint dripping out either.
FMIC here I come. Sooner rather than later.
Aquamist might be tried on mine at some point with mike. It has been discussed on a few occasions.
Uprated rods and fasteners will be done before hand tho to keep it all buttoned together.
One note tho.
All this talk of this and that power and IHI's etc... Remember your transmission & drivetrain. It has to cope with this load.
CV has worn out on mine. NSF. Driveshaft is showing severe signs of 'ghoulling' (sp) on the splines. :eek: Drivetrain backlash is higher than last inspection...
321 lb/ft torque is taking its toll.
Be prepared to visit other components in your quest for more and more gee gees
bill
How come Jabba will fit Aquamist to yours but they don't have time for mine? :(
As for all the extra power and its effect on the other parts of the car, I was using you as a benchmark! :D As I hadn't heard of any problems with the gearbox, driveshafts etc on yours I figured that mine should be Ok.... however now you have listed a loads of problems developing with yours and so I'm gonna have to have a think about what I'm gonna do. :(
Can the problems you have listed be prevented? (Uprated driveshafts etc) Expensive I'd guess? :(
Ben
Jon@VAGWORX
29-10-2003, 15:17
Doesn't your Beeza just get permanant abuse though Bill?
With all the track days etc;)
salamanzer
29-10-2003, 22:31
yeah water injection allows you to run a more advanced ignition allowing for increased torque and reduces knock by reducing in-cylinder temperatures.
But the gains will not be all that good because the water injected takes up space in the cylinder which reduces the amount of air and fuel in the cylinder thus reducing power.
Water injection is a good idea for high boost applications and for cars which can only use low octane fuel.
Otherwise a proper engine map should reduce the onset of knock and pinking and costs less than a water injection setup ;)
J
ibizacupra
30-10-2003, 08:01
Originally posted by BenS1
How come Jabba will fit Aquamist to yours but they don't have time for mine? :(
As for all the extra power and its effect on the other parts of the car, I was using you as a benchmark! :D As I hadn't heard of any problems with the gearbox, driveshafts etc on yours I figured that mine should be Ok.... however now you have listed a loads of problems developing with yours and so I'm gonna have to have a think about what I'm gonna do. :(
Can the problems you have listed be prevented? (Uprated driveshafts etc) Expensive I'd guess? :(
Ben
re Aquamist...Discussed it Ben... thats all.
Bare in mind that my car is being used as a development tool for Jabba, so what works (or not) for me, gets rolled into the production spec or options list. (remember CC, fuel pump, larger injectors etc.... all evolved into the customer spec now, or discarded in favour of something else)
Wear and tear Ben is what the drivetrain is taking. I doubt many people drive as hard or as frequently on tracks as I do. This is a good reason why Mike & I are carefully watching over mine, ensuring things are Ok etc...
People will be nieve to think you can drive any car this hard with this much power without allowing from some consummables and increased wear and tear on transmission components. It is'nt broken, it is simply wearing.
don't panic... but do be realistic about what you're getting into.
Track use is what wears mine out... not road use.
bill
max_torque
30-10-2003, 09:47
Bill right about wear and tear, anyone who drives there car hard will be increasing wear rates dramatically.
I took a brand new Focus RS (7 miles on the clock) to the italian alps 2 years ago, 6000 miles and 3 weeks later it was completely knackered, nothing had actually broken (well except for a couple of rims i broke "ditch hooking"!) but just about everything in the drivetrain was seriously worn. CV's all clicked/knocked like crazy, there was so much play/lash in the gearbox that you had to lift the clutch when traffic lights went amber if you wanted to be moving on the green, all the suspension was knackered and i had even got the front damper top mounts to put dents in the bonnet!
While thats was a serious beating for any car thats basically what will happen to any car if used to it's full performance:p
If you want a properly bullet proof car, take a look under a WRC car sometime, i was surprised to see rose joints of 1" diameter in suspension links, having last seen these on a large farm tractor that weighed 6 tonnes and could pull a 24 blade plough!
Originally posted by ibizacupra
re Aquamist...Discussed it Ben... thats all.
Bare in mind that my car is being used as a development tool for Jabba, so what works (or not) for me, gets rolled into the production spec or options list. (remember CC, fuel pump, larger injectors etc.... all evolved into the customer spec now, or discarded in favour of something else)
Wear and tear Ben is what the drivetrain is taking. I doubt many people drive as hard or as frequently on tracks as I do. This is a good reason why Mike & I are carefully watching over mine, ensuring things are Ok etc...
People will be nieve to think you can drive any car this hard with this much power without allowing from some consummables and increased wear and tear on transmission components. It is'nt broken, it is simply wearing.
don't panic... but do be realistic about what you're getting into.
Track use is what wears mine out... not road use.
bill
Chill Bill, I was only joking about the Aquamist and you getting things first! ;) It does make good sense to develop and monitor the kit on one or two cars.
As for the wearing, I understand and agree with what you are saying. My question is though, what happens when they get too worn? Can you simply buy new driveshafts and it will be as good an new again, or will it of damaged the gearbox, or what?
I just want to get an idea of costs... are we talking a new set of driveshafts every year if driven seriously hard regularly on track, or could we be talking driveshafts and new gearbox every year!?!?! (How much are driveshafts?)
You could go 4wd, then the torque per driveshaft is halved. :)
MaxT, you are a nutter! :D Who's car was that? Did it get sold onto a customer?
Salamanzer, I agree with what you are saying about water injection, and it taking up some space in the cylinders.
Cheers
Ben
ibizacupra
30-10-2003, 12:54
Originally posted by BenS1
As for the wearing, I understand and agree with what you are saying. My question is though, what happens when they get too worn? Can you simply buy new driveshafts and it will be as good an new again, or will it of damaged the gearbox, or what?
Ben
When they get too worn (splines) then it will slip. CV's are replaceable... just done my NSF one. £40 Total running gear consummables are front CV and rear NS wheel bearing so far, in 37K miles use. New driveshafts are available... not sure if ghoulling was what bit.. AutoT told me. did'nt see it first hand.
Originally posted by BenS1
I just want to get an idea of costs... are we talking a new set of driveshafts every year if driven seriously hard regularly on track, or could we be talking driveshafts and new gearbox every year!?!?! (How much are driveshafts?)
not driveshafts per year... unless you drive like a loon and dumop the clutch off the line. I am positive there are peeps on here who coudl break this car in minutes! ;) no names..... (poor old Focus :p ;) :D )
Originally posted by BenS1
You could go 4wd, then the torque per driveshaft is halved. :)
Yep... and its called an Audio A3 quattro
Tempting.
Bill
Yep... and its called an Audio A3 quattro
Tempting.
Bill
And to think that I've been calling them Audi's all this time. :p
I'd jump at getting an A3 Quatro if they weighed the same as the Ibiza, but they are just way too heavy in my opinion. :(
I wonder if you could easily get an A3Q's weight down to 1100Kg by stripping it out? Doubt it.
Cheers
Ben
ibizacupra
30-10-2003, 14:22
Originally posted by BenS1
And to think that I've been calling them Audi's all this time. :p
I'd jump at getting an A3 Quatro if they weighed the same as the Ibiza, but they are just way too heavy in my opinion. :(
I wonder if you could easily get an A3Q's weight down to 1100Kg by stripping it out? Doubt it.
Cheers
Ben
Owdee.... Now thats it is'nt it?
A3 Quattro sounds like a nice package.
Can't wait for a rip in Mikes baby.... although I may well regret it..
Last time I drove a Jabba car, I HAD TO HAVE ONE... and ended up getting the Ibiza done.. Ching Ching $$$$
Classier chassis than the Ibiza and is going to be the more user friendly motor.
When you get yours done Ben.... start with their basic kit IMHO.. and live with it for a while and see if and how you like it day to day. More sounds great, 350bhp, 360bhp etc are all numbers.... and living with it is something else.
Step by step... go as far as you want... but progressively is the way to do it.
You can only scare yourself so much... :D
bill
Yeah cheers Bill.
I will be taking it one step at a time. I will start with just the basic Stage 3 package. However, I may go for the uprated Rods/Pistons for the lower compression ratio and extra strength.... both giving more peace of mind as it'll be stronger and less prone to detonation.
I have a feeling that after I get the stage 3 I wont be making any more significant power mods for a while as theres a few expensive projects around the house I need to do, plus the girlfriend wants to get married and after being together for 8 year I don't think I can put it off any more. :(
Cheers
Ben
max_torque
30-10-2003, 18:34
Originally posted by BenS1
MaxT, you are a nutter! :D Who's car was that? Did it get sold onto a customer?
Cheers
Ben
the car belonged to Henry, Henry ford that is! and after i had "tested" it it was left in the Dunton car park for about 6months, then put into the crusher!
The problem with 4wd is of course that athough you now have 4 driveshafts to take the torque you tend to just move the damage "upstream" as it it were, usually the clutch is the limiting factor then!
And of course you now have twice as many components to change when they wear! Nope you really want either rwd (rear mid engine, or front mid engine) or if you going to stick with driving the front wheels then you need the engine lent right back / down in the car.
what seems to wear gearboxes is constant on / off power with heavy applications of throttle, ie exactly what you do cornering on track days, what wears CV's is large torque at angles, ie steering / lowered car. Of course kerb hooking / wheel spin etc combine all these things and really cream crackers you drive train!:p
ibizacupra
30-10-2003, 20:51
Originally posted by max_torque
what seems to wear gearboxes is constant on / off power with heavy applications of throttle, ie exactly what you do cornering on track days, what wears CV's is large torque at angles, ie steering / lowered car. Of course kerb hooking / wheel spin etc combine all these things and really cream crackers you drive train!:p
LOL I do most of that apart from 'kerb hooking'. Me no Rally Driver me circuit/road driver.... I'm a chicken you see. :p
Rally Drivers are nutts. :D
320+lb/ft of torque has something to do with it.. :D
Slide into a corner, drifting in, slight lift for rear slide and power power power to drive thru the slide... eh RobT? a la 'Ring' ride.
Deffo taking its toll on the motor.
Cage is essential to hold the shell together.
Bill
Yeah, I'm now looking at a custom cage as the one i have doesn't really meet my requirements.
Anyone know the number for Custom Cages? Seriously, I've been trying to get it for months and can't get it from anywhere!!!
Ben
max_torque
31-10-2003, 07:48
I can't remember it from off the top of my head, but Custom cages advertise most weeks in the back of Motorsport news, just take a biro to you local newsagents and get the number!
(seem to remember there ad is printed upside down on the page!:p )
I'm toooo good to you BenS1
R & D Motorsport
(01327) 872855
Baird Close
Drayton Fields Industrial Estate
Daventry
NN11 5RY
round the corner from Revo
Mark
Cheers Guys,
Is "R & D Motorsport" the same company as Custom Cages?
Cheers
Ben
no, i just like making people phone the wrong people......
R&D Motorsport aka R&D 'Custom Cages' Motorsport
:D
I just thought it may of been another places that makes cages to your custom designs.
I didn't realise they had another name.... thats probably why I couldn't find them on the net, in yell or even directory enquiries!!!
Cheers
Ben
:cheers:
30 seconds of google & bt.com
i posted the address of them a few months back.... i guess the world is too technical to write :)
Originally posted by m0rk
30 seconds of google & bt.com
i posted the address of them a few months back.... i guess the world is too technical to write :)
You found them on Google/BT.com under the name Custom Cages? I couldn't.
If I had known that they were called R&D motorsport then I would of done. :D
Anyway, getting VERY off topic, but I just phoned them and they quoted £900 + VAT Fitted for a cage made to my custom requirements. Oh well, there goes another grand. :(
Ben
fairly direct search to confirm the company name :)
custom cage daventry drayton roll i think was the search string i used. :)
then onto BT.com