Hondata

This Problem you have on every Dyno-sheet
wthout hondata
http://www.fnhatch.de/forum/download/fi ... &mode=view
and with hondata
http://www.fnhatch.de/forum/download/fi ... &mode=view
and partly you have more difference
but it can't be that with hondata where i pay for 900€ i have less power than with the original ecu...

I suspect that the MAF is reading significantly different from stock, and the AFs are a long way off optimum, both on the stock ECU and Hondata ECU. Also, because the power loss is mainly at the top end, it could be that a restrictive exhaust does not like the extra advance.

What has changed on the car from stock? Do you have a AF ratio on the dyno graph?