Many many thanks to you Richard and JohnA.
I won't run additional injector(s) (assuming you recommend me fitting it pre TB), cause Im a bit paranoid with back-firing when the throttle is shut. I do wonder what is the effect of actually fitting the additional injector(s) along side the water injection pre TB?
Apart from that, I can't run additional injectors post TB as the factory intake manifold is made out of plastic. I doubt superglue could hold up
so unless I fabricate an aluminium intake manifold and runners(where power gets to serious levels), then I'll go for this. Furthermore, things get complex with the extra injectors on each runners(extra fuel rail, fuel lines) as there's more things to fail.
There's a big likelyhood that Im gonna run a piggback Greddy E-manage and run bigger primary injectors, cause I don't want the hassle of tuning the cold start, injector priming etc like what you do in a stand alone ECU. I may have to make a return fuel line and fit a FPR.
Back to the topic, Im gonna go a bit radical here so
let's say..I want to run more boost, I fill in my tank with straight Avgas and 40%W/60%M injection, I do reckon it is possible(but not necessarily safe, due to engine's components strength limitation..etc) to run up to 12 psi due to the slower burning mixtures right?
Now, I'd like to hear most of you forummers here's experience of getting away with pinging and lean mixtures with water injection (assuming its 50%W/50%M mixture).
Besides hearing knock ,how do guys know you're at the outer limits of the water injection system? What sort of A/F ratio and EGT we're looking at?
I found this article from SDS efi,
http://www.sdsefi.com/techegt.htm
Here's a few words which kinda confuses me,
Quote:
It should be mentioned that the target EGT is valid only on the same engine configuration as was used on the dyno. If you change the ignition timing, cams, pistons, headers etc., the optimum EGT may also change. Raising the compression ratio with no other changes will drop the EGT at the same AFR. Retarding the ignition timing will generally raise the EGT at the same AFR. One engine might make best power at 1350 degrees while a very similar engine might be happier at 1500. You can't guess at this or you are simply wasting your money on the instrumentation. Wankel engines have higher EGTs than comparable piston engines due to their lower thermal efficiencies. 1800F is not uncommon here.
Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop. It is VERY important to know which side of peak EGT you are on before making adjustments. It is safe to say that peak power will occur at an EGT somewhat colder than peak EGT.
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Any words on this?
Again, many thanks for the reply. Really appreciate it.