Successful fuel pressure test of 8 stack EFI

That is great news Steve!

Love the setup! I have an old set Weber's that someday I would like to show off, but don't want to cut the rear desk to do that.

Ken

This car came with deck lid already cut and it was a significant factor in deciding to keep the 8 stack EFI.  It's a little hard to see in the photo below but it is cut.

Great looking car!

@stevebuchanan posted:

This car came with deck lid already cut and it was a significant factor in deciding to keep the 8 stack EFI.  It's a little hard to see in the photo below but it is cut.

That rear spoiler is growing on me 😋

@stevebuchanan posted:

Today I bench tested the fuel system on my 8 stack TWM EFI setup.  The fuel rails, injectors, and throttle bodies held 45 PSI without issues.  A couple of stainless braided hoses that came with the project leaked badly and I temporarily replaced them with others from the collection that came with the car and thus some crazy looking looking hoses in the photo.  I also bench tested the Holley Terminator X sensors (including idle air control) and harnesses, and that went well.  This clears the way to begin final assembly of the rebuilt engine and putting it in the car.  During final assembly it will get all new fuel lines.

Looks really good.

If you ever find the time, a parts list of that setup, especially with the used sensors would be great.

I am replacing the Haltech ECU that came with the car with Holley Terminator X.  Holley's quick start guide lists all of the sensors that are required.  Here is a link: https://documents.holley.com/199r11956.pdf

Here is a summary of the sensors I tested:

Cam position (provided by Dual Synch distributor)

Crank position (provided by Dual Synch distributor)

Manifold air temp (Holley's)

Coolant temp (Holley's)

Idle air control (Holley's)

Throttle position (I reused the Haltech sensor)

Oxygen (Bosch, comes with the Terminator X)

MAP (built into the Terminator X ECU)

Injector harness (harness only - not connected to injectors.  This was enough for the ECU to start up)

All of the part numbers are in the quick start guide.  While this is a sophisticated and complex system, they really make it fairly easy.  They also have a tech support forum that is much like this one.  I have posted two topics and got good answers.

Steve, is the EFI fuel pump tunable for pressure? On some systems like TWM  it adjusts from 45-55 psi and changes the engine tune a bit. The spray pattern & volume changes with pressure. Holley's tech line might know, or a dyno run would confirm any benefits.

FWIW, the downforce effectiveness of low mount rear wings can be increased by adding a 'Boxer slat' above the decklid opening. Most of the airflow is high up over the rook & out the big opening on sugar-scoop deck designs. The slat bends some of the airflow down closer to the tail surface. Thats why Ferrari added them to the 512BBs, as they found after the car was released that the air inlets to the carbs were near the tail of the decklid. So Boxers tended to run lean at 160+ mph and burnt valves. If you plan never to get up there, the slat is just a rear window sunshade.

Hi Jack, the Bosch fuel pump itself is not tunable but the fuel pressure regulator at the return side of fuel rails allows the fuel pressure to be easily adjusted.  Just loosen the jam nut on the hex head screw and then rotate the screw to get the desired pressure.  Clockwise increases pressure while counter clockwise (I might have this reversed) lets more fuel return to the tank and reduces pressure.  My Bosch 0280155868 injectors are rated to flow 36lbs/hr at 43.5 psi.  I might reduce the pressure to get closer to the injector's ratings.  The injector rating is required data in the Terminator X software.  The regulator is the original unit that came with TWM 8 stack setup and seems to be working fine.  I think Borla still sells the same regulator.