My primary track is Ozarks International Raceway. One of the features of this course is a long section of constant left turns, from a 180 degree hairpin then into a long sweeping lefthand turn down the front "straight" (which isn't). With my Dark Horse's stock fuel system, by the end of the pit wall when the fuel was around 50% the car would start sputtering. This is annoying for a lot of reasons, so I bought a KRM fuel pump which claims that their pickup will not have this issue, and will make all of the fuel in the tank available.
I've done two track days at Ozarks since the install plus two days at Heartland Park and I can say that it works completely as advertised. HOWEVER I have found one issue, which has nothing to do with the KRM unit itself but has to do with the fuel level indication damping in the Mustang. The fuel pump will absolutely use 100% of the fuel in the tank. But, the fuel level sender is damped pretty heavily, and so what will also happen is that, when you get towards the bottom of the range, the fuel level indicated will not accurately keep up with what is in the tank.
At Heartland Park I ran into this issue where, coming onto the front straight, the engine gave a hiccup with the fuel indicating 11% in track mode. I got off immediately and got back to my RV. When I went to go start the car up to drive to the gas station, it wouldn't start. I put in roughly 1.5-2 gallons, drove to the gas station, and put in 14.6 gallons on a supposed 16 gallon tank.
Last night at Ozarks this caused me issues again. I decided I needed to come in for fuel as I knew I was getting low. In turn 15 (roughly 3/4 of the way through the course) with 13% indicated, it ran out of fuel and was dead. If any of you were there, my sincerest apologies for black flagging the session while they hauled my dumb self off the track. As I was sitting with the car powered on while I threw a couple gallons in so I could load the car back up on the trailer, I saw the fuel level continue to drop, further providing evidence to the heavy damping.
So, lesson learned: 20% = get off the track. Normally this wouldn't have been an issue, but this was a 90 minute session. I'd been going for a bit over an hour total when it happened.
But, as to the issue that the KRM pump sets out to solve of no longer having fuel starvation at half a tank, it does absolutely do that.
Hope this helps someone both to solve the fuel starvation issue, and not get embarrassed on track like I did. Your car (and driving), of course, may have a different number where it says it runs out. My guess is that the 13% at Ozarks vs. 11% at Heartland Park had to do with the fact that Ozarks is much more intensive and constant on having some form of lateral Gs. Or, maybe it's just variability. Either way, 20% is my "get off the track" number.
I've done two track days at Ozarks since the install plus two days at Heartland Park and I can say that it works completely as advertised. HOWEVER I have found one issue, which has nothing to do with the KRM unit itself but has to do with the fuel level indication damping in the Mustang. The fuel pump will absolutely use 100% of the fuel in the tank. But, the fuel level sender is damped pretty heavily, and so what will also happen is that, when you get towards the bottom of the range, the fuel level indicated will not accurately keep up with what is in the tank.
At Heartland Park I ran into this issue where, coming onto the front straight, the engine gave a hiccup with the fuel indicating 11% in track mode. I got off immediately and got back to my RV. When I went to go start the car up to drive to the gas station, it wouldn't start. I put in roughly 1.5-2 gallons, drove to the gas station, and put in 14.6 gallons on a supposed 16 gallon tank.
Last night at Ozarks this caused me issues again. I decided I needed to come in for fuel as I knew I was getting low. In turn 15 (roughly 3/4 of the way through the course) with 13% indicated, it ran out of fuel and was dead. If any of you were there, my sincerest apologies for black flagging the session while they hauled my dumb self off the track. As I was sitting with the car powered on while I threw a couple gallons in so I could load the car back up on the trailer, I saw the fuel level continue to drop, further providing evidence to the heavy damping.
So, lesson learned: 20% = get off the track. Normally this wouldn't have been an issue, but this was a 90 minute session. I'd been going for a bit over an hour total when it happened.
But, as to the issue that the KRM pump sets out to solve of no longer having fuel starvation at half a tank, it does absolutely do that.
Hope this helps someone both to solve the fuel starvation issue, and not get embarrassed on track like I did. Your car (and driving), of course, may have a different number where it says it runs out. My guess is that the 13% at Ozarks vs. 11% at Heartland Park had to do with the fact that Ozarks is much more intensive and constant on having some form of lateral Gs. Or, maybe it's just variability. Either way, 20% is my "get off the track" number.
