An owner at Brands Hatch had a pronounced stutter and loss of acceleration on 8 to 10 of 50 or 60 laps. It came after a tightening left-hander taken in 3rd with the throttle floored, at about the point of changing into 4th. The engine coughed and cleared. He suspected cornering force was washing fuel away from the pickup, so supply was interrupted a couple of seconds later.
Everyone who replied said it only happens on track and only with a low tank, so the first step is to keep the tank well above half on track days. Owners differed on the level, from under a half to about 25 to 30 per cent, so treat half as the safe side.
What owners reported
- The same thing on a modified VXT at Bedford (the back straight after a left-hander) and at Silverstone, on a VXR, and at Hockenheim in the Parabolica. Also at Benwaters, after a tight left with a long fast exit, with only a few bars of fuel showing.
- One owner said it cut out for up to 3 seconds, 200 to 400 metres into the straight, with the tank below about 25 to 30 per cent.
- NA cars do it too, and one owner thought the Exige does as well. So it is not just the turbo cars, and not just the VXR.
- On the road it never happens, even with the tank almost empty.
- An owner who thought he had broken the engine found one bar left on the fuel display. A Caterham driver had the same, and his tank holds 23 litres.
- One owner warned that in extreme cases fuel starvation could damage pistons. That was a general remark, nobody reported damage.
Fixes mentioned
- Keep the tank above half. The simplest.
- A swirl pot system: a swirl pot tank that stays full whatever the speed or angle, with a second in-line pump to keep it filled. One owner recommended it, saying a couple of high-powered Novas and Corsas needed one.
- Foam in the tank. One owner wondered about a cellular-foam-filled tank, and thought that if he moved his tank forward to improve weight distribution it would definitely need foam.
- One owner asked whether the ECU backs off the spark if it sees no fuel pressure. Nobody answered.
See fitting a Pro-Alloy fuel tank and fuel pump replacement for the in-tank layout.
Help wanted
Nobody in the thread says whether an aftermarket tank, such as the Pro-Alloy or a Spitfire Engineering one, avoids this, or how much fuel is left when it starts. If you know, please tell us.