fuel starvation, with and without Verus door
 

Ran Palmer Motorsports Park (clockwise, aka "remlaP") over the weekend, won my class!

After New Hampshire event where I got fuel starvation coming out of 6-7 (>180 banked left) at 7/8 tank, I got the Verus fuel door. Installation seemed to go smooovely, door would flop around on pivots as supposed to. Surprisingly I still got same starvation issues at the track over the weekend coming out of T9 (>180 banked left-hander running clockwise), with even MORE fuel in the car! 3-4 laps from full tank. Seemed to be specific to running Nankang CR-1s, could run a lot more laps on A052s despite similar lap times.

Any chance the fuel door install made it *worse*?

Where do I go from here?

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What gas are you running? 93 or E85? If the latter, how much %?

Surge tank time.

93. Would that even make a difference? Oh yeah I guess faster draw-down rate for E85! No, doesn't apply here...

Or just keep topping off after every session. Kinda PITA and especially annoying if I'm limited to ~4-5 laps!

This one has always intrigued me.. I've had fuel starvation with other cars but never with these and I usually run them until they have maybe half a gallon of fuel left in them..

I'm guessing it's very track specific and I just don't drive on those tracks or something.

I get starvation from a longish L/H turn on E85. I have switched to 98 for this W/E to see if it starves in the same place, you never no.

It's very track/turn specific

It is 100%. For me, it only happens on track with very long left hand sweepers. Like I'm WOT in this high load left handed turn for ~10-12 seconds or so total. Lot of time for fuel to drain out of the basket.

This has to suck for Zdan - we often START our races with only half a tank!

Our T4 cars (Hoosier A7/R7s) can do 1 hour long sprint races at both Pacific Raceways (left handed) and Portland (right hand) without having to refuel and without flappy doors.

Looking at the track maps of Palmer and NHMS - I could see how those track layouts could accentuate this reality.

Maybe there's an issue with Zdan's tank on the venturi pickup portion of the system. Has anyone installed a small transfer pump in the passenger side saddle to be more effective at moving fuel over to the pump side?

That's actually precisely what a lot of folks do, and just put it on a manual switch. Cost of burning out a pump once a season by just having it run regardless is well worth the lost time you prevent.

Somewhat specific to running Nankang CR-1 tires. I've run NHMS for years (usually with 1/2-tank or more fuel) with no issue, this last visit was the first time I got any fuel starvation, at 7/8 tank! I took the same 6-7 extended banked left on Hoosier A7s last fall without any prob.

I ran both CR-1s and A052s at Palmer, ultimately was getting fuel starvation at ~4-5 laps on CR-1s, ran longer sessions on A052 without issue, though running same or faster laps.

Is there an eloquent example of this somewhere? I've been searching this site but can't find one.

This may make some sense. IIRC GRM's testing concluded that the lateral acceleration force created by the CR-1's were greater than that of the A052. However, the A052 made up it's time in the straights and braking due to it's significantly lighter construction (seriously, the A052's are really light). Unfortunately the article has been moved to GRM members only, but will be available to the public (again) in 4 days. Link: https://grassrootsmotorsports.com/ar...00tw-showdown/