Boost Dependent Alcohol Injection

[S13Ka24e]

I went to SMC’s web site (http://www.smcenterprises.com/injector_kit.htm) and I see that they have

‘Boost Variable Speed Controller’ which ‘Automatically varies the pump speed as boost increases! This will avoid any possible "bog" from injecting too much spray too soon. Especially important on the smaller 4 cylinder cars. ($100 option)’

and ‘MAF Variable Speed Controller’ that ‘Automatically varies pump speed as airflow varies! Taps into your existing MAF sensor output signal and uses it to vary pump speed as airflow changes. Great choice for supercharged applications where boost comes in at low RPMs. Available for any car using a 0-5 volt output MAF.($100 option)’

My question it is would like to use Alcohol Injection but I want to use it as supplementary injection. That would mean that I would need the Alcohol to start spraying at 4-5psi (when the stock injectors max out). And I would like it if I could run up the boost to 15psi using just Alcohol, so I would need a Boost Dependent injection set up. What do you think about the MAF idea? What about the boost dependent idea? I just don’t know if the injection will vary enough that I’m not running super rich at 5-10psi. Do you think that I could use just this Boost Dependent Alcohol Injection for a good fuel system?

[WDRacing]

This is basically the same system I'm working on for my own kits. Except I use a MAP sensor instead of tapping into a MAF wire, and it will work on all cars, not just MAF's that range from 0-5. To have alcohol as a secondary fuel source your going to need a huge resovoir. I have the SMC kit installed on my Skyline and need a refill every 4-5 runs. With secondary injectors your better off tapping into the main fuel line and using alcohol for the times when you want to run really high boost. My drag car will have the secondary injectors supplied with alcohol, but I won't be using it daily.

Having a pump increase with boost is fairly simple.

WD

[Mikel]

Alcohol doesn't provide a whole lot of fueling.

I mean, if you're very close to going lean, it will probably keep you safe at that level, but I wouldn't turn the boost to the moon and count on alcohol for fueling.

It did fatten up my OT readings on the GN, but nothing huge.

Check into propane injection, it provides a lot more fuel than alcohol.

[WDRacing]

Hmm...I used Alcohol as the only added fuel source with my RB20 and boosted it all the way to 28 psi with no knock. I know guys that totally run alcohol...no gasoline/methonal. But like I said, if you want to depend on alcohol alone, you'll need 4 subinjectors and a large supply tank.

WD

[Red Lightning]

WDracing, is there a DIY way to make a boost dependent alcohol injection controller? Thanks in advance.