My gas mileage, with a flash tune from dtm on stock ecu, went through the roof. It took me about a full tank to get up there and like 1/2 - 3/4 to get back. It was indeed a considerable amount and yes i run open loop 100% of the time.

 

sounds about right. I figured Nick had everyone running open loop.

 

only with 280 cams as i understand

 

why only in open loop with 280's? You can change the open loop crossover and alter the cruising fueling, to get your mileage.

280's don't affect cruising as opposed to any other camset.

 

Probably for idle quality is my guess. Honestly I don't see the point in doing permanant open loop on an ECU that has perfectly capable O2 feedback. If everything is set correctly the O2 feedback should get your mileage damn near as good as it's gonna get. There are other ways to fix idle quality on big cams.

 

I am running 280's and have no idle issues (except when the AC is on). Even before it got tuned during the break in I had no issues.

 

you can alter the idle lookup and duty tables for both ac on/ac off, drive/neutral.


I've used them to make 280's idle smooth as butt, and then allowed it to be really lopy, depending on the desire of the owner.

Also the o2 feedback shoots for of course a 14.7, however the cars will do fine in the low-mid 15's, allowing for better mileage. I've run as high as 16's on my car on the interstate (AEM), and had it do ok, but it doesen't work very well around town.

All that needs to be done is to find the feedback tables and alter those values. Some on the forums are in search of them, and some have claimed to find them. However at last time I looked, no one had successfully used them for benefit.