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Hi all.

Heres my Dyno Sheet what do you all think??

Just wondering on how to read the air feul ratio on this graph.

Does it start at 11.5 or at 12.5.

Also what would you consider running lean or running rich.

Neways thoughts would be helpfull.

The car is a R32 GTSt wit Bolts ons running 12psi

Cheers,

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Ummm:

3" Zorst

Pod

Splitfire coil packs

Slightly bigger turbo unsure of what kind maybe VG30?? hasnt been looked at yet 2 many pipes.

Any idea on whats rich and whats lean

For example is 11:1 Rich or lean???

Is it the higher the first number the richer?

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A:F ratio = Air:Fuel

11:1 = 11 parts air : 1 part fuel.

11.5:1 is a safe setting.

when your car runs lean, it has HIGHER parts of AIR per part of FUEL.

so if you see things like 12.5:1 or higher, then you could end up in trouble.

I wouldn't like to see anything leaner than 12:1

that's why I said 11.5:1 that you currently have is a good safe reliable setting.

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you're better off taking it that high while on the dyno so that the tuner can make sure that there is enough fuel capacity till the rev limiter.

cause if you miss shift or something while racing say, then you might hit the limiter and maybe not have the tuning there and cause some major damage..

at least on a dyno, he can see it getting there and back off if required.

so it IS worth it.

and it seems that your dyno run was done in 3rd gear right?

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Hmm theres a fair few opinions on whats a good afr. I'd like mine to be 11.8:1 or 12:1, nothing leaner than that. Just incase of a boost spike or something unnatural happening.

I thought dyno runs were best done in 4th gear due to there almost 1:1 gear ratio?

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I've said it many times. :D

Ceramic turbine wheels absolutely hate high exhaust gas temperatures.

Leaner AFR = higher exhaust gas temp.

Less ignition timing = higher exhaust gas temp.

Slightly richer = lower exhaust gas temp.

As its slightly richer you can dial in a little more ignition timing.

More ignition timing = lower exhaust gas temp.

Slightly richer, around ~11.5:1 + more ignition timing = the same power but a safer same power due to a lower exhaust gas temp.

Notice how a lot of the 300rwkw+ RB's at points in the rev range run a 11:1. Its all about reliability, bugger running it leaner when it may cost you 4k if not more for a motor rebuild.

12.5 is definitely a little lean. What happens when that fuel filter becomes a little blocked? 13:1, especially if its on stock injectors up around 200rwkw.

Edited by Cubes
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