Fuel Starvation

#1

Hello Spec E30’ers.

I have always had fuel starvation problems with my E30’s…from my M3, to Cars 54 and 325 - it has always been an issue - especially longer distances events (i.e. enduros)

I’ve replaced all the major players including the fuel pump(s) etc…but still experience the starvation, usually after long right handers, one the tank is less than half full. In my experience, a new pump will solve the problem short term, but it would be nice to be able to run the tank down lower.

I’m curious as to other people’s fuel starvation experiences, especially during enduros.

If enough people have these problems, it might be worth looking into allowing fuel starvation kits (like Ireland sells) which are bascially small reservoirs that sit inline with the fuel feed, but are also fed from the fuel rail return, so that if the pump starves for a second or two, the system still gets fuel from the reservoir.

-Vic
So #325

#2

I am having the exact same problem. It occurs badly after I have consumed roughly 6 gallons of fuel (from a full tank). If I continue to push, it will completely un-port, and I’ll wind up coasting into the pit lane (if I’m lucky) as happened to me at Pocono North this year.

My plan was to replace the fuel system with a spare tire well fuel cell, as the rules allow. Not cheap, not pretty, but I figured it was the best and safest solution.

Other thoughts?

#3

victorhall wrote:

[quote]
If enough people have these problems, it might be worth looking into allowing fuel starvation kits (like Ireland sells) which are bascially small reservoirs that sit inline with the fuel feed, but are also fed from the fuel rail return, so that if the pump starves for a second or two, the system still gets fuel from the reservoir.

-Vic
So #325[/quote]

Interesting idea. I’ve basically just learned to drive around the problem by keeping the throttle at 3/4th instead of flat on the floor around long right-handers once I get down to 1/2 tank or so. Costs me a couple miles an hour, but so does the engine cutting out on corner exit. I’d love a better solution!

#4

Matt,
I’m really not a fan of the fuel cell idea for a couple reasons. The stock tank is really low and tucked away. This is great from a safety perspective. It also has a nice weight-distribution advantage. Putting a fuel cell in the spare-well just moves it closer to a potential crash zone.

I think the seasoned BMWCCA guys stick with the stock tank.

Not to mention the cost and trouble of this modification…

#5

Hmmm thanks for the food for thought B)

#6

victorhall wrote:

[quote]Hello Spec E30’ers.

I have always had fuel starvation problems with my E30’s…from my M3, to Cars 54 and 325 - it has always been an issue - especially longer distances events (i.e. enduros)

If enough people have these problems, it might be worth looking into allowing fuel starvation kits (like Ireland sells) which are bascially small reservoirs that sit inline with the fuel feed, but are also fed from the fuel rail return, so that if the pump starves for a second or two, the system still gets fuel from the reservoir.

-Vic
So #325[/quote]

Spec E30 is designed as a sprint series so this has never been an issue during the season. I start the races with about 9 gal (for weight) in the tank and get down to about 6 by the end, and have never had a fuel problem.

Our 3.5-hour enduro at VIR isn’t a points race…but I agree that it would be nice to avoid a problem, if even for that one event each year.

Can anyone else shed some light on the subject, taking into account the fact that we are very reluctant to change the Spec E30 Rules?

Carter

#7

victorhall wrote:

[quote]Hello Spec E30’ers.

If enough people have these problems, it might be worth looking into allowing fuel starvation kits (like Ireland sells) which are bascially small reservoirs that sit inline with the fuel feed, but are also fed from the fuel rail return, so that if the pump starves for a second or two, the system still gets fuel from the reservoir.

-Vic
So #325[/quote]

Somebody has one of these on there cars now. I don’t remember which car, but I distinctly remember someone talking about it at one of the races.

Anyone want to fess up and let us know if it actually works?

Ric

#8

Carter,
I appreciate your desire for rules stability, and agree that for our sprint races, fuel starvation is not an issue in most cars (mine included).

I believe that Han experienced fuel starvation issues during his first race this season - he didn’t start the race with a full tank. In his case, his car weighs enough that he doesn’t need a full tank to finish over weight.

I’m not trying to argue for a rules change - in fact, I’d agree with you that a rules change is not necessary.

Having said that, I’m still curious as to people’s experience with fuel starvation, and would love to hear if this reservoir helps. It would be an easy enough install that I could remove it for the season, but run it for non-Spec E30 events, such as the enduro.

Thanks!

-Vic
SO #325

#9

In the piston-engine airplane world, we call those things "header tanks" and they generally hold between 1 - 8 gallons, depending on the specific purpose. They ensure the engine gets a steady supply, even when the pilot is manually switching tanks and pumps in-flight, and in some cases they provide fuel when the entire aircraft is upside-down. I suppose for E30 use ours would be much, much smaller than 1 gallon. It would need to be somewhat guarded against impacts and debris. I’d love to find out if there are already items like this on the market for race cars.

#10

[quote][b]Carter wrote:

Our 3.5-hour enduro at VIR isn’t a points race…but I agree that it would be nice to avoid a problem, if even for that one event each year.

Carter[/quote][/b]

One other point - for those of us running KP as well it would be nice to be able to run the tank down lower than 1/4 to take advantage of the lower min weight when running with BMW CR. (IE - a car at min spec weight at 5/8 of a tank would be darn close to min KP weight at 1/4 of a tank.)

Of course the primary goal of spec e30 rules is not to help the cars run with other classes.

Post edited by: sdais, at: 2005/12/01 12:57

#11

A Spec E30 legal solution (as per my rules interpretation) would be adding a second pump on the driver’s side. This is a modification that some E36 racecars have to combat fuel starvation.
I’ve got a spare gas tank that I’m looking at to see how difficult this modification would be.

I did some internet research on header tanks - cool stuff :slight_smile:

#12

I can offer a little more insight here:

I have tried the such tank that Ireland Engineering has, I tried it last year when I was having problems with my car starving in the corners. IE calls it an Accumulator, all it is doing it storing extra fuel for when your supply lines starts pushing air. It only holds about 6 ounces total.

Now, unless I hooked it up wrong, which I am pretty sure I didn’t because I had a schematic faxed to me from Ireland, and I was on the phone with them as well–But, It did not seem to help at all. (I really like these ireland guys, but this is just my experience with this one item…) I still got to less than half a tank and it would sputter on me. So, I asked them if the orientation of the reservoir mattered, could it be on its side, need it be upright, and so on…so I tried it in different orientations (even though Ireland said it should not matter) and to no avail. So, I just took it off–of course I was just doing this testing at driving schools…no races.

James Clay then told me about the newer E30 tanks, how they are configured differently with their crossover from side to side, I think he said these worked on a Venturi effect? Well, so I considered getting another tank. But didn’t. Instead I just replaced my in tank pump and that fixed the problem. I can run it down really low now, without a problem. So, after replacing the pumps, I am not sure what your problem is…maybe the crossover tube it plugged? I am not sure. Let me know if you figure it out, but I do Not think that Accumulator will help you. Now unless for some reason it would not work because my intank pump was not working and maybe not filling the accumulator up in advance properly preparing it for when I needed it…Now that is a thought i had not thought of until now…

~Forrest

#13

my 89 starved just like I think they all do on the right handers.

#14

On my '89, I had stavation and replaced the in-tank pump. This solved the problem. And come to think about it…I have driven my car at speed with a low fuel level. A couple of times this past season I didn’t want to fill the tank early in the morning and went out in the morning warmup. 'Never had a problem.

Also, we can (and will) check min. weight after qualifying. If a car is underweight, that car starts the race at the back of the field.

And my car is available to anyone at anytime, to check anything, including weight. If someone slips an anonymous note to me, I’ll leave the keys in the car and will go get a sandwich.

Carter