Best place for Carter fuel pump?

[Jellobmw]

So after putting in the O2 sensor and the mixture digital meter (to be subject of separate post) I found I was running to lean under high rpm/load. I figured out the jets were fine so it must be fuel delivery to the 38/38 Weber carbs feeding the 3.5 liter monster.

The fuel pump I am currently is a basic square electric that goes CLACK CLACK CLACK all the time. Probably got it from JCWhitney!

So I started researching fuel electric fuel pumps, and I found these little square electric ones are known for figh pressure, but low flow. Then I found out the Carter fuel pumps have low pressure (no pressure regulator!) and high flow. Yeah!

Now the question is where to mount the Carter pump. It's bigger, cylindrical, and the support bracket must be mounted axially to the cylinder. No practical location in the trunk.

I'm thinking on the firewall near the top in front of the fan, and near the booster. Should be enough draw.

Suggestions/recommendations?

 

[jmackro]

I'm thinking on the firewall near the top in front of the fan, and near the booster. Should be enough draw.

What do you mean by "draw"?

It is best to locate electric fuel pumps low and and to the rear. This minimizes the amount of fuel line under vacuum and thus minimizes the liklihood of vapor lock. I know the original, mechanical fuel pumps were high and forward - but you have the opportunity to make an improvement here. In short, I'm discouraging the "firewall near the top in front of the fan, and near the booster" location.

 

[Stevehose]

I got the 3 rubber bushings to isolate the noise and mounted it to a differential mounting bolt as seen in this thread:

http://www.e9coupe.com/forum/showthread.php?t=11517&highlight=carter+weber&page=2

You can also put a pad between the bracket and the diff for furthur noise reduction. I cut an old mouse pad to fit. Can only hear it when engine is off. Like Jay said, it's better to keep it low to avoid vapor lock.

I've not had any problems to date.

 

[sreams]

I'm using a rotary Facet pump, which is smaller than the Carter. Nice and quiet. I used existing holes between the fuel tank side and the spare tire side.

BTW... how do you know your lean issue isn't caused by jetting? High RPM (above 5k) is actually most affected by the air correctors. Smaller for richer.

-Scott