Installation advice needed on a 1.8l 20VT VAG engine

[Leon R]

Hi guys, my first post on this very interesting forum. I live in Athens Greece and unfortunately temperatures are realy HIGH during summer (sometimes exceeding 40C). So i decided to install an aquamist 1s system to my car.
My car is a MY2003 Seat Leon 1.8l 20vt which after a turbo replacement, new larger injectors, custom ECU tuning, new exhaust turbo back, 100cell cat and a FMIC, now produces 300HP and 43Kgm of torque.
Two reasons made me decide to install WI:
- high EGT (970C) when going for top speed
-wish to run more timing.
So here are the questions:
- I talked to the quy who is going to install the system and he wants to install the injector to the entrance of the FMIC (FMIC is going to have water spray very soon). After reading your posts i understand this is not a very good idea, so where should i ask him to install the injector?
-Should i use a mix of water/methanol or just distilled water? (i also use toluene for Knock supression will the possible use of methanol has to do anything with that?)
- Car is running 1.8 bar overboost and 1.5 bar ct boost. In what pressure should i adjust the WI to kick in?
-Lamda on my car is tuned on 0.83 should i expect any increase in HP with the use of WI?
Sorry for the big post but i am confused so any help is welcome.

[Leon R]

Anyone :?: :?: :?: Tomorrow is installation day i need to know :D

[hotrod]

I would think an injection point about .6 - .3 Meters from the throttle body would be about right. Definitely not before the intercooler. Let it do its job then add the water to get the additional cooling it will give you.


Most systems I've seen trigger at about .6 - .8 bar. you want it to come on at a boost pressure that is high enough that while driving in low load cruise, the system will be off, but at high load the injection will come on before you have problems with detonation and or cylinder temps.

Larry

[Leon R]

First of all Larry thanks for the advice.
1s was succesfully installed after the i/c about 50cm from the throttle body. The system is set to inject water at 0.8 bar.
Testing followed the night of the installation showed that:
EGT went down but not enough (i am now seeing 940C at 260kmh instead of 240kmh) general impression is that it now needs more time to raise EGT.
Using a 30% methanol/water mixture i was able to raise timing enough to really understand power gain while driving (i am running custom revo software with which i wasnt able to run more than timing 5 with 100 RON unleaded now i am easilly running 7 and even 8 when its cool) A dyno will follow.
Intake temps went down 10C running W/I and another 8C running W/I and water spray.
Overall a success :D
Thanks Aquamist :wink:
PS Two questions:
1. Do you propose running a bigger injector to lower EGT more?
2. A water/methanol mixture 50% will help me turn timing into 9 (max)?

[Leon R]

Any ideas here I read a lot in similar questions but i am a little bit confused

[hotrod]

Tuning WI, is still pretty much an experimental process. The rules of thumb will get you in the ball park, but you need to try different things to find out the combination that "your engine" likes.

The Buick GN folks here in the U.S. have for many years used a very simple approach. They simply keep raising the water injection rate until the engine goes flat. The frequently discribe it as the engine sounds "soggy" and has sort of a flutting sound as the WI comes on. That is your clue that you've gone too far. Then you tune for best performance at that injection level, ie play with ignition timing, and air fuel mix. Then you go through the iteration again.

Eventually you will find that the gains get smaller and smaller with each incremental change.

The good news is, you really can't hurt much using this strategy. An internal combustion engine will swallow an impressive amount of water with no injury. During WWII they ran special tests on aircraft WI engines to see what the limits were. They would "drown" the engine -- feeding so much water that they had liquid water pouring out of the exhaust ports, and they were feeding enough water that an engine rated at 2000+ hp was down to 600 hp output. No damage to the engine!

Your only risk is if you tune so the engine absolutely "needs" the WI and you suddenly lose the injection, then you risk damage due to detonation. Only you can determine how far into that region of operation you want to go. On the other hand you can tune it so the WI provides a safety cushion but is not absolutely essential for operation. In that case if the WI fails the engine just runs uncomfortably hot but can survive the experience.

On the mixture -- for over 50 years serious users of WI have used 50/50 mix of methanol and water. That would incline me to start there.

I am currently experimenting with WI mixtures on my car. I started from 50/50 and use it as the reference point for evaluating them. Early tests indicate my car seems to like a little higher alcohol mix.

Larry