PP6 finally fixes my NA blues.

[douglas vincent]

My daily driver is just a rebuilt 2.2 na. All stock. And all slow. I only had power up to 4500-5000 rpm, then there was serious bog. I installed the PP6 awhile ago, but after trying to just get better milage (and failing) I gave up and stuck the bridge in for the past few months.

Well yesterday I spent some time on the phone with "Adam West" trying to get his PP6 and ecu to work together (long story), I went back to work trying to tune my own wagon.

And I got it to finally make some "power" up top! I had to add a bunch of fuel up top, WOW, what a difference!

I have also concluded that if you have a malfuntioning O2 sensor, no matter how much fuel you pull at cruise, the ecu is going to depend on the O2 sensor for tuning and give you crap milage. Time for an OEM sensor!

Anyway, long story short, the DD is now a blast to drive, other than the fact it isnt really that fast.....

[93forestpearl]

To get better mileage by pulling fuel you really need to be able to advance the timing. When you go leaner than stoich, the flame front slows down and takes longer to go across the bore. At 15.5:1 I run up to 48 degrees. Keeping it from surging can be a bit trickey, but upwards of 29mpg talks, even if the EPA doesn't like it.




Good to see you got the dogginess out of it though. What AFR was it happiest at?

[Legacy777]

I just got a new OEM O2 sensor for the impreza.....the mileage in it never has been overly stellar....but at 141k miles on the original O2 sensor, I probably can't be too hard on it.