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Cobb tunning

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Hey guys I got a Q.

I have a 04 rx8 that I did a half bridge ported on the renessis. I have a Cobb ap. And am wondering what formula to use with calculated load and rpm. I do the hole logs thing but can't tune it properly I have just been using the + and- on the values. It's running pretty good at moment but still got to tune at high rims and under wot. It's got upgrade coils,a email clone intake (lol),stage 2clutch,cat delete and aftermarket mufflers.

Thanks in advance

What was Cobbs response to this?

Nothing yet.

Just saw your message.

I have tuned over 200 RX8's so far (with Cobb, Hymee, MazdaEdit etc).

Did you finally tune it, or do you need some help?

Yes please. Need to know what formula I would need to calculate for the fuel adjustment. To add fuel or take away fuel.I got it to the point now that I can cruise with it ,but under wot it will go 11 afr.

You can adjust the fuel by leaning it out in the corresponding fuel table, or by adjusting the VE table.

A simple but effective way to calculate is the following.

Use a wideband to see the actual AFR. The stock RX8 wideband can not read lower than 11.1 or 11.06 (some models). So if your actual AFR is lower, you will not know.

Now let's take a small example. Say you measured AFR at 4000 RPM and 100% load at 11, whereas you would like it to be around 13.

Just divide 13 by 11 ( gives you 1.18) and multiply this in the cell that corresponds.

If you like, you can send me a copy of your fuel map (just copy paste into excel) and a log and I can send you one back.



Yeah that would be good. I have to put it a pause on tunning it due to winter and snow in the northeast of the US. But inbox me at my email pitoracing24@gmail.com

We usually reply within 12hrs (often sooner)

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