I have autocrossed and I can look at things mid run and since this an event that pretty much kills your result. Eat a cone and gather some information.
But, you answered your own question
My solution plus a passenger. You say another guy drives your car. Do runs with both of you in the car. When it falls flat, Have him gather the data.
Other solution is to stop complaining and deal with it.
People are trying to help you, and I am sorry to say, you are being kind of an @$$ in your responses.
First, challenging responses is not being an ass. Maybe it would be helpful to throw E85 in the tank, get a tune, race the car, and see how losing 800 rpm feels. Next, "dealing with it" sounds like NOT looking for a solution. Further, I have not been able to replicate the problem on the street. To do so would require driving in a fashion that would land one in jail!! The problem is not predictable, so WHEN to have a passenger is impossible to predict. As for "eating a cone", intentionally compromising a run puts the load on course workers, and that is not fair.
The issue with E85 is not uncommon. I am simply questioning some of the conjecture. It's called bench racing. If some facts are revealed, all will benefit.
Here is what I DO know;
1) The tank in the Kappa has a floor that is flat as a billiard table. NOT good for controlling slosh.
2) The tank pump sets in a "bucket" that has ONE inlet besides the open top. The inlet is about the size of a dime and is controlled by a rubber diaphragm, so the flow is modest. [attach=1]
3) The problem occurs with E85 because the tune extends the dwell of the injectors to allow enough fuel to actually operate the engine under load and to not do so could destroy it. Gasoline seems not to have this problem (with stock turbos), not matter what octane or tune.
4) The E85 issue is well known, and so far the solutions center on tuning back the engine if it is having problems, and not all LNFs react the same. People have actually found problems with the factory fuel lines at the swedges. And building lines that can manage the pressure and volume is not a shade tree proposition.
5) The discussion about after market tank pumps flowing more/less than stock seems to be a Cobalt thing. ZZP states that the Walbro flows less than stock, but they say that is in reference to Cobalts. They have NOT answered my questions about the flow rate of Cobalt pump and the pump they sell. DDM insists that the Walbro flows more than the Kappa pump. (And I, or others, have found NO reason to doubt what Dave says about anything Kappa.)
6) I am still waiting for some answers to these sort of questions in another thread, but nothing so far.
7) The varied opinions are welcome, and some may lead to new ideas. Maybe if some who have tried E85 and tunes in race conditions can share what their experiences have been.
