Hi All,

Great site - I've gotten a lot of excellent info here.

As an insurance policy for hot days, track days and the occasional dyno run, I'm adding an alky system to my Vortech-blown (T-trim), intercooled 383 with the Holley 950 Commander Pro (with FJO Racing Wideband controller). I chose the FJO Racing Alky/Water Injection controller, pump and solenoid nozzle. I also got the cable that interfaces the alky to the wideband controller.

I do plan to run a 33% distilled water/67% alky mix, to keep the boiling point of the alky a little higher than straight alky so I don't have to worry about it disappearing from underhood temps.

My question is how to change my current 950 tune to accomodate the alky. Since I can pick the RPM, TPS and MAP points where the alky will start, and how much to inject, I'll be starting at the 6# of boost level. The alky will inject right at the 'hat' sitting on the 4bbl throttle body, and my injection is multipoint. The alky will inject pointing directly upstream at the incoming air.

I figure maybe I should just use my current setup as is, run a small amount of alky and datalog a couple runs, then trim fuel out until I get AFR's in the 11:1 range at WOT and above 6#. I max out at close to 11# with this setup.

Any feedback on this approach?

Also, once I get the fuel part of the tune stabilized, I was planning on going back and adding back in some timing. Anyone have experience on how much timing to use with alky at 11# of boost? My non-alky current tune is set to a conservative 17 degrees advance at 11# boost, and around 24 degrees at 6#.

The Grey Ghost put down 501rwhp through a 4L80E with a Vortech SQ S-trim, now it's upgraded with a SQ T-trim and better belt drive and pulley wrap, and it's hitting 10.85# at 6200rpm. Dyno runs scheduled for next Tuesday on the same Apex Motorsports dyno as before.

All suggestions and ideas welcome.

Thanks,

Jim

My Site: http://home.mindspring.com/~jim_fisk/id1.html

 

I dropped .2 tenths and gained about 1-2 mph on average when I added it.

 

And how did you change your tune when you added it, like ignition advance, AFR's etc?

Jim

 

Back in my V6 days, i did just as you described. Though i was cutting back fuel, i ended up having to add a 2nd nozzle i was spraying so much alky. switched to a walbro 255 pump in the alky tank, and i ended up adding to the point of about 40% of my fuel. as i did this, i still maxxed out the injectors, but just kept ramping up pump speed to compensate. Starting with a 17#, 19 degree tune from 93oct gas, i ended up with 32# and 26 degrees of advance at the high point at a 10.85:1 ratio. Had to keep it that rich, thats what the calculator said i wanted with that much alky. But usually stayed around 28psi and 26-27 degrees advance. What you may find is that you will have equally as good of luck adding timing as boost. You should be just fine with 11-11.2:1, and should be able to take it up to about 24 degrees. Just remember, if it knocks, turn the pump up, then add another degree dont take away timing
Gary

 

Thanks, good detail.

Jim

 

Like Grr was saying it allowed me to not have to bump my injectors up close to their max percentage. I was also able to add up to 4* of timing at WOT and a few more at various other spots in the rpm band. My IAT's went down by 40 degrees F too! Since my car is mainly a street car with regular track use I have used it as a safety measure more than anything.

 

When using methanol as a means to regulate A/F ratio, make sure the tank is always full. It only takes one oops forgot to fill it to make big problems.

Keith