air fuel ratio?

Belvedere II · 11-07-2013, 05:48 PM

My narrow band sensor setup was pretty useless for actual numbers but did indicate I was running out of gas on the top end when it happened and got me to pull the tank and fix the pickup. That problem was pretty easy to diagnose though without the meter. More recently I installed a wideband Innovate setup and found my carb leaning out at a certain point. I thought the problem was being on the edge of a timing advance limit when street driving, but with the sensor watched the A/F run from 11's and 12's to 15 then 16 then 17:1 as the car started bucking during that part of pedal travel. Searched online to find this was a common problem with Demon carbs and that replacing the HSAB's fixed it. I stripped a couple of helicoils from the Demon this year and put my old Thermoquad on to finish the year, really slick to see how a street oriented carb runs compared to a race design. I think it'll be a more useful tool with the capability to record and review exactly what the A/F is doing during a race, but haven't gotten those pieces yet.

11-07-2013, 05:48 PM	#5
Belvedere II Junior Member Join Date: Dec 2010 Posts: 6 Likes: 0 Liked 0 Times in 0 Posts	Re: air fuel ratio? My narrow band sensor setup was pretty useless for actual numbers but did indicate I was running out of gas on the top end when it happened and got me to pull the tank and fix the pickup. That problem was pretty easy to diagnose though without the meter. More recently I installed a wideband Innovate setup and found my carb leaning out at a certain point. I thought the problem was being on the edge of a timing advance limit when street driving, but with the sensor watched the A/F run from 11's and 12's to 15 then 16 then 17:1 as the car started bucking during that part of pedal travel. Searched online to find this was a common problem with Demon carbs and that replacing the HSAB's fixed it. I stripped a couple of helicoils from the Demon this year and put my old Thermoquad on to finish the year, really slick to see how a street oriented carb runs compared to a race design. I think it'll be a more useful tool with the capability to record and review exactly what the A/F is doing during a race, but haven't gotten those pieces yet.