Its a common issue. I get it in my BS 2004 and have to run a full tank at every event. If it gets below 3/4 full, it'll starve everytime in that situation. The more grip you have the more likely you are to experience it.

 

Yeah, search the forums and you will find a lot of relevant info on it.

 

Here's a video I stubbled upon on YouTube of Earl Guessford showing Lee Ann how to autocross of the first time at CDC.

http://www.youtube.com/watch?v=B1-Z6xL6LeE

The video really captures the enthusiasm of autocrossing for the first time. It looks like Lee Ann liked it, especially since she attended again this past week!

So if any of you want to tell people what it's like to autocross, show them this video, enjoy!

Ed

-PS, it also highlights Franklin Dam's camera mounts.

 

I guess I find it somewhat difficult to believe its a fuel tank design issue alone. I have driven 5 difference S2000's at Auto X events, all modified to varying degrees, and only this one has had this issue (though this one is the most highly modified). 4 of those have consistently been auto crossed with 1/4 tank or less, and 2 of them have been auto crossed with the gas light on, with literally no issues in the long sweeping left handers.

My best guess is the fact that this particular S2000 is running a full I/H/E system with the stock fuel pump and ECU. We're hitting the design tolerance limitations with the additional air flow through the system and thus the high fuel demands to keep the A/F mixture consistent. It's being exacerbated with long left hand cornering and and the volumetric capacity of the fuel lines / pump. We're simply running out of fuel in the system volume with the higher fuel consumption demands.

How modified is your S Apeatwo?

 

Also to note, all cars are/were using extreme performance summer tires, StarSpecs, RS3, RE070, etc.

 

I have driven my 2004 S2000 with maybe 2 bars left and never had fuel starvation issues, but I know that a lot of S2000s have that issue.

Apeatwo car is in BS trim so he has suspension/ FSB and maybe cat-back, the real issue will be the tires that he uses in BS, those Hoosier will generate some crazy G-forces on corners.

I don’t know what class you run, but at least for BS and STR you cannot modify the fuel system or fuel tank, so the only solution is to run with more gas.

 

If you were correct I would have no issues. I'm stock, mostly. I have Motons, Gendron FSB and 245/275 hoosiers. Intake, header and exhaust are all stock. I've experienced it in Jadrice's CR and even a stock s2k on star specs. One event in the CR I was getting fuel starve at one point on course and Jadrice was not, so driving style can lead to it as well. However, the primary issue is the fuel slosh. I would guess that the car that you experienced it in has the most grip of any you've tried, that, or you were just able to drive it harder.

For the record, the first time I experienced the strave was at the Black Lakes Shootout when the car was pulling 1.4x Gs in the sweeper. Stock suspension.

 

Yeah unfortunately it looks like there's just too many variables to consider. Prior to StarSpecs, my friend was running HTRZ II's (which as you know are tire's that don't understand the concept of grip), and the issue was still there... I fear we may be chasing a ghost in diagnosing the issue. It's just so odd that some S's have the issue where others do not. I have literally run my S on fumes, and never had the problem even on courses with lots of hard left handers.

I guess we'll need to take his car out to an opening parking lot and do some experimenting with gas tank levels and how it affects sustained and hard left hand cornering.

 

You just have to trust us. I never have the problem at Fedex Field, but at places like the Meadowlands in NJ (super big site) and those with long and fast sweepers it is definitely a problem. No issues at 95% of the sites I attend -- even at 1/3 tank -- but I have had fuel starve several times in NJ at even 5/8 tank. I started carrying a 1.5 gallon tank with me as I got comfortable with each site after I first had fuel starve because it will ruin that run (and probably all subsequent runs if you don't have gas). The car basically shuts off for 1.5 seconds. So believe us or not, but it is a real problem and one that you will experience if you go to enough different locations with varied enough courses. It is arguable that I have been to more locations, and probably autocrosses than most people on this subforum, so just take my word for it... and it's not STR or BS... its all S2000s that have enough grip to cause loss of fuel pickup. There is a fix for it if you research the forums, but the fix is not STR or BS legal since it involves modifying the fuel pickup inside the tank.

 

Oh no, I trust that this is an issue with the design. I acknowledge that there is a reason F1 teams baffle and chamber their fuel tanks.

We'll do the full tank test on his car, and report back. I'm just trying to save him from blowing a ton of money with ECU's and tuning when it could simply be a "design flaw". I definitely appreciate all the feed back! Thanks!