Spark Plug / MPG Issues / Gap Size

*for reference only – Checked new turbo wastegate settings – it was set to 8 mm. Per  @starscream5000 ‘s suggestion, I backed the wastegate down to 6.5 mm. The new turbo, even without the tune, was pushing close to 27 psi on WOT( I had my alarm set at 26 lbs, and I would hit it frequently) Pulled all four Brisk racing plugs out – notes on my receipt, as well as speaking to the rep @ Eurocompulsion, the plugs should have been gapped to 0.20″ – but instead I found they they wouldn’t even fit onto my gap tester – putting them at about 0.18″

I should have never listened to what was recorded and checked them myself – but I didn’t. I’ve now gapped the (same) plugs to 0.22″, as I still haven’t heard anything from  @Greg@EC . Took it on a drive for 30 miles last night. I didn’t see a huge difference in instantaneous mileage, but that is hard to compare. My mostly highway drive, and some usual city driving was 30.5 MPG average. This was higher than I got on the 350 mile commute home on the interstate from Ohio to Chicago – which was only about 27-28 MPG.

This morning, on the 9.65 city commute in rush hour traffic, I was able to feather the throttle and get 27 MPG. Before the new turbo, my best record on this commute was 33 MPG, but only hit that once. I also did not note any “chugging” this morning between 1400-1800 RPM, as (  @Exitus04 &) I had previously encountered, but it has only been one trip. Only pushed up to 26 psi once since, but that was unloading in 3rd gear up a hill, and overall, the boost looks about 3 psi lower.

This is not enough data to formulate any conclusions, I’m just data logging to see how things progress. As noted in the HPSI video, my wastegate started moving slightly @ 6 psi, but moved significantly closer to 7 or 8 psi. This also corresponds to why my boost was so high.

 

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