OT: Experimenting with your car

Mr Benevolent

I've been doing a bit of research and have hit upon a few interesting engine mods. One involves a small amount of water injection through a syringe needle before the throttle body by suction. Water injection isn't new - in fact it's well known, but not on modern cars. I know it's unlikely, but has anyone ever tried this. It wouldn't give massive performance gains but it would be interesting to find out if it can make a practical difference. I'm tempted to try it on something like a '93 Micra out of curiosity.

Another is removing or disabling the EGR valve, as it seems that engine may well be more efficient without it. It'd fail the NCT without it though. Still, another thing to try. Any opinions or mods that you've done you of the spirit of experimentation? On your car, not the cat

Robbo

Confab wrote: »

Another is removing or disabling the EGR valve, as it seems that engine may well be more efficient without it. It'd fail the NCT without it though. Still, another thing to try. Any opinions or mods that you've done you of the spirit of experimentation? On your car, not the cat

There's a few lads on BMWLand.co.uk who've blanked off their EGR valves in the 4/6 cylinder diesel engines and haven't suffered for it.

voxpop

Disabling the EGR (on a VAG diesel anyway) causes no problems - its easy to do aswell, just disconnect the vacuum hose and plug it with a golf tee or something similar. You could also get a blanking kit from forge or use vag-com to stop it opening.

I dont think it gives any performance boost - well not any you would notice - it just stops the inlet manifold getting gunked up.

itarumaa

I have heard many times that people have used water to clean up the engine, usually in carburator engines tough.

And no problems but you have to find a balance between the water flow and engine revs.

JHMEG

Older mechanical EGR valves can be removed and the aperture blanked off without any issues. Newer valves have a sensor and the ECU will illuminate the CEL if the valve isn't present or working.

voxpop

JHMEG wrote: »

Older mechanical EGR valves can be removed and the aperture blanked off without any issues. Newer valves have a sensor and the ECU will illuminate the CEL if the valve isn't present or working.

Yeah some cars will give an error - I know there is no errors thrown on late mk4 golfs. Newer than that (04+), I cant comment - pretty easy to test though

YbFocus

Water injection is used in high performance modified cars or time attack cars etc.
It cools the charge temperature of the air heading into the block to cause the air to get denser, denser air has more oxygen within it and for that reason has more combustion = more BHP! It only really works on a high powered turbocharged car as the high temperatures of the turbo heating the air can be offset by water injection. It only adds about 15-20bhp on a 500-600bhp car.

Another reason for it is to stop the dreaded engine detonation, which is a real bubble burster on high powered cars! Which is when the air/fuel mix ignites on it's own at the wrong time (other than the ignition stage).
This causes huge imbalances in an engine and ends up with a big bang very quickly!!!

On a naturally aspirated engine, like your micra, it won't make any difference as the air is coming straight in with no chance to heat at all!
You could use the old trick of pinching the fuel return from the rail though, not completely but just enough to add a little back pressure! But again the result would be so small on the micra engine you wouldn't notice it!

Hope this helps!

Matt Simis

I installed an Aquamist Meth Water injection system on my old Audi S4 (2.7T V6 K04 Biturbos). It allowed me to reduce detonation but run 95octane (no Maxol 99.2 back then).
Car was putting down 24PSI of boost on smallish side intercoolers with minimal heatsoak. Around 440BHP.

Not sure if its worth doing these days, just use E5 fuel instead or tune for E85 (big power!).