Water injection
Discussion
Dear all,
I have an EliseS with 2ZR-FE and after the first obvious changes were some chassis improvements I am now thinking about safe ways to make more power. New airbox is already installed and was worth every penny. New headers and catalytic converter are next on the list.
Very obviously the cooling system is one of the key factors to influence a boosted engine. Since the 2ZR-FE has an intercooler from the factory and space is limited I don't know how big the effect of a larger intercooler would be considering the costs. In contrast water injection sounds like an safe way to drop the temperatures and maybe add some hp or two at the same time.
Does anyone of you have some experience with a water injection? Where did you place it? That is the water usage?
Best
Jay
I have an EliseS with 2ZR-FE and after the first obvious changes were some chassis improvements I am now thinking about safe ways to make more power. New airbox is already installed and was worth every penny. New headers and catalytic converter are next on the list.
Very obviously the cooling system is one of the key factors to influence a boosted engine. Since the 2ZR-FE has an intercooler from the factory and space is limited I don't know how big the effect of a larger intercooler would be considering the costs. In contrast water injection sounds like an safe way to drop the temperatures and maybe add some hp or two at the same time.
Does anyone of you have some experience with a water injection? Where did you place it? That is the water usage?
Best
Jay
The above is correct.
WI only adds power if:
you increase boost and remap
your engine is knock limited as is and you remap
Water reduces the flame speed. in order to compensate you need to advance ignition timing (and/or increase boost). Otherwise you lose power. Adding 50% Methanol partly compensates this effect, but you still need to add ignition advance or increase boost. Otherwise power drops.
This effect of flame speed reduction gets even worse when you engine runs richer than a total AFR 11.8:1. From there on running richer drops flame speed and with it power dramatically. This is why you typically adapt the fueling.
No two engines are the same, but in general running super rich AFRs typical for OEM forced induction engines and then adding WI without a remap drops power.
if you add so little WI that you don't need a remap, WI won't do much anyhow.
Given you can remap and add boost or you are heavily knock limited as is, the gains are significant.
PS I run WI for many years now and map myself. I have tried out the effects myself on my car. Little water, lot of water, no charge cooling, charge cooling, pure water, water methanol, direct port, pre-compressor, pre-plenum.....
currently direct port with a small 0.3mm nozzle pre-compressor (Rotrex C30-94). Going any bigger gives me condensation in the charge cooler as indicated by fluctuating readings of the intake air temperature sensor mounted after the charge cooler. On hot days, I can go bigger before this effect occurs.
WI only adds power if:
you increase boost and remap
your engine is knock limited as is and you remap
Water reduces the flame speed. in order to compensate you need to advance ignition timing (and/or increase boost). Otherwise you lose power. Adding 50% Methanol partly compensates this effect, but you still need to add ignition advance or increase boost. Otherwise power drops.
This effect of flame speed reduction gets even worse when you engine runs richer than a total AFR 11.8:1. From there on running richer drops flame speed and with it power dramatically. This is why you typically adapt the fueling.
No two engines are the same, but in general running super rich AFRs typical for OEM forced induction engines and then adding WI without a remap drops power.
if you add so little WI that you don't need a remap, WI won't do much anyhow.
Given you can remap and add boost or you are heavily knock limited as is, the gains are significant.
PS I run WI for many years now and map myself. I have tried out the effects myself on my car. Little water, lot of water, no charge cooling, charge cooling, pure water, water methanol, direct port, pre-compressor, pre-plenum.....
currently direct port with a small 0.3mm nozzle pre-compressor (Rotrex C30-94). Going any bigger gives me condensation in the charge cooler as indicated by fluctuating readings of the intake air temperature sensor mounted after the charge cooler. On hot days, I can go bigger before this effect occurs.
Edited by Ive on Saturday 19th December 10:54
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