Gents,

I read through all the AFR Table threads here I could find. I also looked at a bunch of AFR tables via google search. My tune is posted in https://www.miataturbo.net/megasquir...-thread-91932/

Here's a question.

At Virginia International Raceway, I can get two hard 30 minute sessions out of a full tank of gas. If I fill up in South Boston, about 22 miles away, on the way to the track, I'm only comfortable doing one 30 minute session before filling her up again. I'm consistently in the 2:20s with the Rotrex, if that makes any difference. I go through a lot of gas at the track, and get about 24 mpg on the highway.

Is that normal? Not complaining. Just wondering.

Thanks,

 

Running forced induction at the track burns a lot of gas, yes. I manage about 6-8 mpg on track, depending on my boost level. Since the car has decided it's unhappy feeding fuel below about 6 or 7 gallons, this means I get 2 20 minute sessions before I have to go fill it up again.

--Ian

 

I get 30+mpg on the freeway fwiw.

 

My Miata gets infinite mpg on the freeway on the way to the track. The tow vehicle, OTOH...

--Ian

 

Turbo > SC for mpg.

Your usage sounds about right to me. If it makes you feel any better, on my normally aspirated track car, 3x30 minute sessions and I'm heading for the pumps.

 

That's how I remember her, pre-Rotrex.

​​​​I'd really like to get just a little more time on track out of a tank. I'd hate the humiliation of running out of gas trying to complete that second session...

 

Just bring a gas canister with 4-5 gallons in it so you can get 2 sessions in before you have to go to the pump.