ohkun

ok.. so far, it happened twice already.
during sharp corner, it feels like my car is experiencing some sort of throttle cut.


it does not lag, it's not a hesitation, throttle cuts out as if I was to let off gas.
not very cool as there would be bit of oversteer from it..


I've searched s2ki and did not find anything.

it happened during left turn, and both time I've noticed rpm was at around 5k rpm
happened as I was exiting corner...

bit puzzled..

ss04

That's a known problem with AP1's. In hard left turns, if you are at half a tank of gas or less, you may experience the throttle cutting out .

Solution: fill your gas take up regularly!

kenny_son

This happens to a lot of AP1's. And most of the track guys are complaining about it.

There are a few ppl that are trying to find a solution to it with no luck so far (extra baffles in fuel tank).

Even with a full tank of gas it is do-able but a lot harder than if you had a half tank or less.

I was talking to Duaine (S2S) about it. We were wondering if we swap in an AP2 fuel tank will it solve it? But were not quite if there is a difference between the two.

Lhung

i believes that is called "fuel starve". A lot of autoX guys experience this when cornering with R-comp tires.... It shouldn't be a huge problem with street tires though. But like kenny and cam said just keep the gas tanks above 50%.

ohkun

good to know there's nothing wrong with my car..

it was hella scary.. totally unexpected.



I'm running on Dunlop Direzza Z1.. pretty decent tire..

SumAznGuy

It is because of where the fuel pick up is. The pickup is on the left side of the tank, and under left cornering, the fuel sloshes to the right side and there is no fuel being picked up.

mavm86

Here is a good read on the subject:

https://www.s2ki.com/forums/index.php?showt...&#entry17774344

I've also read somewhere that replacing the fuel filter (in the tank, on the pump) can help. Realistically you shouldn't be getting fuel starve on the street unless there is also a fuel delivery problem of some sort.

SeekeR1

I've experienced exactly as you described it ohkun! For me, I've experienced it just as I am exiting a tight / medium hard left-hander. Additionally, I've tried feathering the throttle on/off during the cutout and it stays "cutout"; I've also tried shifting during the cutout, also with no effect of eliminating the cutout.

I had tried to figure out if it it has anything to do with VSA, but it happens with VSA on and off. Fuel starvation does makes sense - I only recall this happening when I am on about half-tank or less, and only for left-handers.

I just filled up tonight and went for a drive and it did not occur. I shall try it again soon (probably this coming Tuesday night), with a focus of trying to recreate the throttle cutout.

Thanks to All who contributed here, and mavm86 for the link.

kenny_son

damn, that angers me to know that you have it in a new CR as well.

mavm86

Just one more data point to add to this:

I usually autoX my AP2 with just over half a tank of fuel to prevent starvation (on R-compound tires).

Last season I ran an event with just under half a tank of fuel. I had a friend driving my car too, and we noticed that his steering inputs were a lot less smooth than mine in a particular section of the course which included a left hand sweeper. Exiting the left hand sweeper he was consistently getting fuel starvation. I was not. In the afternoon we put more gas in the car and the starvation disappeared. Guess who was faster both times?