First day to check out the WAI. On the way to work I noticed that the ignition started to retard after the IAT reached 120. The temp maxed out at 155. The MPG for the trip were ok but not what I expected with a tail wind. Same on the return leg, good but not what I thought it should be for the conditions. So I did a quick test loop on rolling terrian of 10.5 mile with the cruise control set on 35 no stops.

Wind 050@15G20
Temp 80

WAI 135-155 WT 200-213 MPG 37.3
Modified WAI 125-140 WT 200-213 MPG 38.0
No WAI 105-125 WT 200-213 MPG 37.9
WAI 130-155 WT 200-213 MPG 37.4

I know that this is not enough data points to confirm that the WAI decreases FE but the trend seem to indicate that on my car (OBDII) that the best IAT range would be 100-120. Has anybody else noticed this? And What kind of temps are you seeing on the IAT?

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I h8 that ignition retard stuff,

It's unfortunate that this mod only works for some of us and not for others.

the only cars I've seen this work is with small displacement. Prius, Insight and etc. The problem I think with bigger engines is they suck more air in and since the WAI allows for more air the bigger engine takes advantage of this.

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The whole point of it is that it lets in less air!!!

What is the compression ratio and what octane fuel do you run? Maybe its at its limit running with the fuel you are giving it, and therefore if it gets any hotter, it pings and retards?

wai and cai let more air in. The only thing restrictive is the stock airbox. Unless of course you get your air straight from the exaust manifold or the cat. It will kill your power but give you some mpg.

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[quote]What is the compression ratio and what octane fuel do you run? Maybe its at its limit running with the fuel you are giving it, and therefore if it gets any hotter, it pings and retards?

I think you're probably right. between the heated fuel lines and the warm air it reached the fuel/car limits. I'm almost due for a fillup I try the expense stuff and see if that makes a difference in FE with the WAI. It wouldn't need to be to big a gain to make up the difference in cost.
One of these days I figure out how to quote the text right.:?

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Goodness gracious, the whole ****ing point is too let less air in, that's the reason it's ****ing hot, if more air is getting in you're doing something wrong.

zpiloto, to quote just highlight what you want to quote in the post while you're posting and hit the quote button, or cut and paste and surround the quote with the ["quote"]["/quote"] tags, but take the parens out.

thanks.
I agree with SVOboy. The hotter the air is the thinner(less dense)it is. Thats why the go to the desert to set speed records and why airplane burn less fuel at altitude there is not as much air.

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[quote=zpiloto]I hadn't noticed the heated fuel lines. How hot is the fuel? DiamondLarry had heated fuel and was having problems, I think he said because the fuel was getting TOO hot, and so he removed it. IIRC, someone said to heat it 30f would be good. Did you happen to test before and after the heated fuel, and maybe notice whether it was retarding spark more after? If the motor is higher compression, it will be more prone to ping on low octane fuel. You might try running a tank of 89 just to see if that solves it, then you'd know.

Don't know the temp of the fuel but have not had any problems with the spark until the WAI mod. Had the same problem when I tried the IAT mod but did not think of trying higher octane. I filled up with 93 today and will see if that helps. If not I'll just run the IAT around 100-115 and make adjustments for the different seasonal temps.

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You might want to see if you need to reset the computer, since it may have detuned itself to allow it to run on what gas you'd been feeding it. On some cars you'd need to do that or it would take a bunch of engine temp cycles for it to adjust. GM's newest designs sense when more than 1/2 tank goes in and reset for octane at that point, but I don't know how Mazda's work there.

Can I ask if you tested fuel economy before and after the heated fuel mod and what was the result?

I got a little over 3% increase but it was only 3 data point A-B-A. I think there is a thread on it call Heated fuel line revisited. So take the results with a grain of salt. It was not that hard to do and it was not a negitive like the IAT mod or the WAI so I left it on. Here's a picture of the setup.

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