F.A.S.T. A/F RATIO METER

**bill Dedman** · 02-23-2009, 03:52 AM

I just bought a new F.A.S.T. Air/Fuel ratio wideband meter and am wondering if there is any affect to the readings from the use of a water/alcohol injector during the testing.

I have a Snowperformance BoostCooler and run windshield wiper fluid in it (blue.) It sprays 4 oz. in 10 seconds, and come on at 3.5 psi.

I was hoping that somebody on this forum (Spedytang?) might have run a setup like this and could tell me what effect, if any, the spray would have on the meter readings at full throttle.

Would there be any difference in the readings if I ran pure methanol in the sprayer?

I'm going to take the car to a chassis dyno shop soon, and want to know what I should do with the BoostCooler during the runs; I don't want to skew the exhaust A/F readings they get with water, or alcohol.

Anybody ever done this? Is there any difference?

Thanks for any information!!!

***speedytang*** · 02-23-2009, 07:49 AM

Yes the numbers will verify when the Meth is used. On Snows web site a couple of years back he had a conversion chart or maybe even Andersons Ford web site still has one listed. I always had to convert the numbers for using E85. I just don't remember the conversion for using Meth I always used straight Water back in the day. I will search and find the answer today unless you beat me to it. lol

***speedytang*** · 02-23-2009, 03:01 PM

Found this on my backup drive 1992.

11.5 with no alcohol
10.5 with alcohol.. then fine tune to see what your combo likes

these are safe A/F numbers to start with

**bill Dedman** · 02-23-2009, 03:17 PM

I just talked with Derrick at Snow and he said that the number reflected in the F.A.S.T. meter will be accurate (what the engine is REALLY seeing) with or without the water/alky mix being injected. He also said to take two small cans of "HEET" gas-line anti-freeze and add to each batch of injection fluid to make a 50/50 mix out of minus 20-degree washer fluid.

Thanks for your advice! 10.5 sounds AWFULLY rich, but maybe that's why I'm not hearing any detonation any more...

But running almost 120 in the quarter (106 at the eighth) it can't be too far off..... can it??? :)

I think I'll call "F.A.S.T." and ask them about this spraying as to the effect on the meter reading, too...

I'll let you know what they say.

Have a good week!

Bill

**bill Dedman** · 02-23-2009, 03:34 PM

I just talked to the tech at F.A.S.T. and he said that unless I was spraying pretty heavy (like in a high boost application, and I'm not) I should see very little change with the spray on.

He also said basically, I was wasting my time checking both collectors, that I would very likely see no change, or minimal change (.1. or .2) from one side to the other. I only bought the single pickup unit; the dual is about a hundred dollars more, and I figured I can spend that hundred dollars on some sub-frame connectors... so my doors will continue to close... LOL!

Thanks again for your good advice and info, Speedytang.... I REALLY appreciate the info!

***speedytang*** · 02-23-2009, 05:01 PM

The Meth should make the meter show richer than it is so a 10.5 showing on the meter should be more like a 11.1 real number. I have a conversion chart for when I ran E85 but my Wideband let me program the scale so what I was seeing on the meter is the true scale. Sub-Frame connectors are really important unless you can stand driving around with a 6 point cage in the way.

**bill Dedman** · 02-23-2009, 08:36 PM

What was your feeling about the E-85, in the final analysis? I have thought about it. but the closest E-85 station for me is 25 miles away...

Since I can't see putting a cage in a 4-door sedan, I guess I'll go with the subframe connectors! lol!

Thanks for the advice on the A/F ratio meter readings. I'll remember that.

***speedytang*** · 02-24-2009, 07:55 AM

E85 was excellent. The power gains was a Meth Injection and a Intercooler all in one. I run full timing (42 degrees at WOT) and 14lb of boost with the Twins I have now and still could go another 6lb of boost if my motor could take it with full timing or another 15lbs if I held the timing at 24degrees at WOT. Today E85 was $1.71 and Unleaded at $1.61, Prem. $1.81. E85 is still .30-.40 higher in my area than most but 106 octane that does not use chemicals to slow the burn like race gas. I only use E85 now and then because I don't really need 500whp on the street. I have settings in my PMS unit for 87 octane, 91 octane and E85.

**bill Dedman** · 02-24-2009, 02:58 PM

Yes, that sounds like a dream come true. My blow-thru setup has to run one or the other, which means a $259.900 modification to the carb by the Carb Shop if and when I decided to go E85, but IF it becomes available in my area, that's probably what I'll do.

Thank you, Speedytang, for the good info; that was just the information I was looking for (as usual, from you!)

Supercharger hellp is lucky to have you as a moderator; you obviously know your stuff.

One more question:

Down the road, after I get a better (forged) shortblock and some Cometic head gaskets, I want to put this other Vortech blower I have on the engine so I can run more boost.

(I call it "the bad idea that won't go away").... lol!

I can either modify the "Extreme Performance" carb hat, shaping the intake pipe into a "Y" that will accept discharge pipes from BOTH superchargers, OR, I can blow the second supercharger's discharge directly ito the inlet of the original unit (compound supercharging.)

I realize this is going to generate more heat, either way, so something must be done about that, either a second BoostCooler, or some sort of intercooler, maybe before the pressurized air from blower #1 gets to blower #2, if I go that route.

Which do you think might be the better setup, compound supercharging, or blowing into a "Y"-configured carburetor "HAT"?

I probably shouldn't even THINK about doing this without an intercooler.... right?

Thanks for any advice....

Bill

***speedytang*** · 02-24-2009, 03:37 PM

Keep the units separate. Buy a 'Y' Hat and also put the Meth spray bar in the center of the hat. You will just use a bigger Meth jet and your set. The bonus to this is that you can run a bigger pulley on each unit to get the speed down and the temperature will go down also and still make your target psi.

**bill Dedman** · 02-24-2009, 03:59 PM

That's what I needed to know.

I appreciate the info a lot; gotta get some forged pistons and rods into this bad boy, first...

In due time.... In the meantime, I'm having a ball with a high-11 street car!!! :teeth:

**sleeper88** · 02-27-2009, 02:54 AM

I have a snow stage 2 kit, i see about a .5 enrichment at full meth injection on my aem wideband. That is running a mix of 1 gal -20 washer fluid mixed with 2 cans of heat. I think that the water meth is the most underated best bang for your buck there is on a boosted car imo.

**bill Dedman** · 02-27-2009, 03:54 AM

Thanks for the advice! I'm definitely going to buy a CASE of that stuff ("HEET") for my Boost Cooler. I appreciate the advice!:)

***speedytang*** · 02-27-2009, 07:35 AM

Off Topic for Me but it is not under rated it is the same problem as when used in aircraft. What happens when your tune is based on it being injected and it runs out or a part fails. I use a tuning device that sees that the temperature is rising/lowering in the engine and picks the timing tune for what ever the temperature range is. This device uses only one sensor and a few wires to adjust the timing based on that information. It also has a fail safe circuit. Think about it, you can use any fuel and the car auto adjust for that burn rate.(Meth,E85,Unleaded,Leaded).