my dyno run printout

[MRH-22A]

Hi guyz.
I dynoed my car for the first time today. Very happy with what i got. I was wonderin if anybody knew how to read the AFR graph?

Can anyone tell me if there's anything wrong with my AFR and is there anything important about it i should know?

[fatboyz39]

a/f looks ok. A piggyback comptuer should fix it up and net abit more power.

[pornstar]

af looks crap

[ProECU]

afr isnt really that bad, its a good place to start.
the big hump is only 0.5 a/f, the graphs' scale exagerates the impact.

In fact, the curve before the hump needs to be leaned out to match the hump's peak.

Thats about 1-2hrs work.

[CUL8R]

very rich up top????

[kyobibi]

I still don't understand how to read the AFR though..

[aaronng]

Stoichiometric ratio is 14.7. I think most A/F ratios are tuned to 13:1 to obtain power, while at the same time preventing a lean condition. Yours is at 12:1 at lowcam and 12.5:1 back down to 11.5:1 at highcam. There is more potential power to be made through tuning back up to 13:1.

[CUL8R]

^^^in theory yes.

but the key is to obtain an a/f which makes maximum power, then tune the whole rpm range to that a/f.
most n/a will be in 13...most turbo will run richer like 12 through to low 11s to avoid detonation
atleast thats how i understand it. theres a reason i dont do the tuning on my car and pay my tuner to do it

[CUL8R]

I still don't understand how to read the AFR though..

on the rhs of the graph ull see numbers which indicate an a/f ratio....this is how many units of air to one unit of fuel expressed as a ratio.

stoich is 14.7 but at WOT u tune richer (lower numbers) to keep the engine from causing damage. higher numbers are known as lean and can only be viable if at low load (low throttle positions) and at low rpm.
a lean mix will result in worst cases like melted cats where rich mixes result in ditry rear bars lol and gunked up o2 sensors.

usually stoch is used for idle and low rpm low load
13 is used for na tuning
12, 11 is used for turbo tuning to avoid detonation

thats BASIC

[aaronng]

a lean mix will result in worst cases like melted cats where rich mixes result in ditry rear bars lol and gunked up o2 sensors.

That's not the worse case. This is the worse case:
Pic from Bill Sherwood.

[CUL8R]

sorry...what i kinda meant was lean yet still safe

but yes...WORST case equals some serious issues

[silver_screen]

shes runnin rich uptop

Other then that, it looks ok you should try to get it tuned to run 12.5:1 at all rpm ranges on WOT and that'll give u a good compromise between outright power and keeping the engine nice and safe through out the rev range

126kw is a nice figure but theres more to be had with tuning

Oh and btw... running rich doesnt just mean dirty rear bars... running exessively rich also makes tiny lil pin holes in the pistons not nice

But its gotta be fairly rich for that to happen