Fuel System Upgrades for Blow Thru carb with Turbo's

[TheSilverBuick]

Belt driven fuel pump?

[Scott Liggett]

Belt driven fuel pump?

No. Race pumps are mechanical and use the stock mounting location. They require one tenth the pressure on the rod to operate and move ten times.the fuel.

[TheSilverBuick]

Hmm, as long as it can be boost referenced. Remember, with a hat or box once boost exceeds fuel pump pressure fuel won't flow, and flow will drop off before that happens too. Not an issue in applications like Squirrel's with the supercharger/turbo under the carbs, but a different ballgame when the boost comes in above the carb.

A guy on the inline and V8Buick forum just lunched a 250 inline six with a turbo from running 10psi boost with a turbo with a non-boost referenced mechanical fuel pump. Leaned right out.

[Scott Liggett]

Can be regulated from 5-60 lbs.

[Scott Liggett]

http://www.racepumps.com/FuelPumps-RoadRacing.html

http://www.racepumps.com/Regulators-RoadRacing.html

[JeffMcKC]

I hope they have those fixed, I was going to run one on Drag Week till I checked into them and then say all the "Rebuilt" ones on Ebay

[Beagle]

Can be regulated from 5-60 lbs.

do the junkyard thing... two electrics, switch the second one on at any positive manifold pressure? Hobbs switch.

Boost reference, I thought you could tap the atmospheric vent on the pump and put some fish tank air line sized tubing on it from a manifold port? I've read it before, never done it. Seems like you would need some sort of check valve to keep it from putting a vacuum on it?

[CDMBill]

The diagram Scott linked to on his first Racepumps post showed the boost reference line in green. The pump list indicates those that have the #4 idle bleed line to prevent vapor lock. Thi net as I read is that this is essentially a dead head system with the #4 bleed to abate heat soak by the carb. The Racepumps appear to be incredibly elegant engineering solutions. I have no direct experience with them nor have I seen one in use so I can't comment on they work in the real world of street driving and racing we all do.

[CDMBill]

The Aeromotive controller takes an RPM input that you share off the Tach wire. Then you set it to come on above a selectable RPM. We hooked it up on Bill's car and had it running the first time I was out there. I didn't know until recently that he hasn't been running it a while. I was mostly interested in its' compatibility with the Tach Output on the EMS-pro Bill uses, and it worked like a champ, driving a tachometer, a fuel pump controller - and something else I am forgetting (I know it was 3 devices).

The tach output of the EMS-pro allowed me to drive the Stewart Warner digital shift light tach, the Aeromotive controller and an MSD tach drive adaptor for the factory dash tach. It all worked great. I also pulled the MSD tach adapter when we were chasing RFI noise in the input signal to the EMS. That was the single biggest issue we faced with the EFI conversion. The MSD tach adaptor makes a whine/buzz you can actually hear with the car running, which is to say its loud.

[ecorl]

Guys. It took quite a while to go through this post in its entirety. Quite a bit of info and opinions. I almost hesitate to open it up again but as I am somewhat of an agnostic, I do request assistance. I take all opinions, consider each, weed out what I think is not useful, and implement with discretion.

Set up: Roots blown v6, prostreet, (404 HP at 6psi boost for the street, 600 HP at 22 psi boost at the track), EFI, megasquirt, E85, 43 psi fuel pressure, external fuelab pump and return regulator. Tank is 10 gallon, sump-type, in trunk. Feed and return are AN8, vent is AN10.


I queried this string because around town my engine will sometimes die during braking/deceleration. Im thinking it might be a cavatation issue. During deceleration the O2 sensor shows lean and it simply starves out. If it does cut out, it starts right back up without any issues.

question1: Is there something in the megasquirt settings that I can adjust that might help?
question2: I am currently having a 10 gallon stainless steel tank (Rick's) made with an in-tank fuelab pump. I thought that maybe going with an internal pump might help with the heat/cavitation issue. I have my own opinions on fuel temp but think its best to keep them to myself at this point. Anyway, Fuelab's pump can also be controlled but instead of a tach signal, they use a transducer coming from the regulator to control pump speed. Should I spend the $380 on the regulator or maybe look into cooling the fuel? Since Im still having the tank built, I was even playing with the notion of cooling the tank itself. Thoughts?

ed