Air Fuel Ratios

[RINRIN 1]

Hi Everybody,

 

I did a search but could not find my answer about AFR values.

 

I bought an AEM AFR and started playing with my standart 1.9 phase 2.

 

First of all I realized that my fuel pump was not good at high revs then I changed it. It really made a difference.

After, I start to tweak the AFM' s temp value to effect the injection timing and at last I get 12.5 AFR at full throttle for a whole engine revs.

But one of my friend who has a tuning garage told me to set the AFR value to 12.8.

We tried on dyno both 12.5 and 12.8 AFR values and 12.8 resulted a little better engine power.

So I also would like to ask you, if you do, what is best AFR value for full thorttle for an normal aspirated 205 XU engine?

 

Thanks

[Jon_Bmw 13]

I would go with 13.5 for full power, but after around 4500rpm 13:1 is probably preferable for longevity of the engine whilst still making nearly as much power. I am geuinenly suprised you can do anything 'controllable' with the AFM temp value, without fecking up part of the accel map.

[sideways danny 0]

12.5-13:1 is as accurate as you'll need to be. dont go leaner on WOT as you'll start to get too hot. 12.9:1 is perfect on WOT so if you've got a steady 12.8:1 that's superb.

 

If you want to get more from the engine, mapping the ignition timing is the key

Edited December 31, 2009 by sideways danny

[RINRIN 1]

with jetronic is not possible as u know, I need to change the management system, but with a 8v engine I dont see any reason.