Tripple Webber Setup Questions

[CharlesJ]

Finalizing my setup and have a few questions after searching around. For background, I have a Daddywad Alpina intake setup combined with Korman triple DCOE40 setup, installed by Korman. I currently have a low pressure fuel pump feeding it directly, no return line, no regulator. It does start and run, but just for testing purposes.

With that, here are the questions:

• Do I need a fuel pressure regulator? I assume yes, but this setup is new to me.
• If so, I have seen debate on the need for a return line or bypass. If I do not do a return line, does this hurt the pump?
• Do I need a relay for the pump for when the ignition is on, but the engine is not running to avoid the pump from constantly going?
• Do I need to do anything with the wiring that would have going into the Zenith carbs, or just terminate and cover those? Similarly, there is a set of relays that sit right behind the brake booster connected to these wires - can those just be removed? Guessing these are cold start actuators or emissions control.
• Somewhat related, I assume I do not need all the various emissions control vacuum switches, bosch speed control unit, etc, and can just leave all that off, only hooking up the standard vacuum lines to the distributor and brake booster

Thanks!

 

[Ohmess]

HI Charles - good to hear your project is getting much closer to completion.

You don't need a fuel pressure regulator, provided your fuel pump is properly sized. I'm running a pierburg pump which is properly sized and removed my fuel pressure regulator about eight years ago. Here is some detail on my setup: https://e9coupe.com/forum/threads/adding-a-electric-fuel-pump-suggestions.42221/post-369474

A return line is not needed for this setup. That is only for a high pressure system. You don't need a relay, but it is recommended as it is far safer.

All the wiring for the old systems can be removed. Webers are completely mechanical.

 

[Stevehose]

• Do I need a fuel pressure regulator? I assume yes, but this setup is new to me.

Yes, preferably <3lbs psi unless you have a guaranteed low pressure pump.

• If so, I have seen debate on the need for a return line or bypass. If I do not do a return line, does this hurt the pump?

What kind of pump? Most don’t need a return line.

• Do I need a relay for the pump for when the ignition is on, but the engine is not running to avoid the pump from constantly going?

Yes it’s best to do this. A few of us have the Revolution Electronics device.

• Do I need to do anything with the wiring that would have going into the Zenith carbs, or just terminate and cover those? Similarly, there is a set of relays that sit right behind the brake booster connected to these wires - can those just be removed? Guessing these are cold start actuators or emissions control.

These can be removed/hidden.

• Somewhat related, I assume I do not need all the various emissions control vacuum switches, bosch speed control unit, etc, and can just leave all that off, only hooking up the standard vacuum lines to the distributor and brake booster

Correct, which model Webers do you have that have vacuum ports? No vacuum retard for the distributor.

 

[CharlesJ]

Amazing, thank you both. I am using a Carter 4070 pump, which is rated at 4-8psi, maybe just a touch on the high side. Also that Revolution Electronics fuel pump control is exactly what I was looking for, just ordered

 

[Ohmess]

Stevehose should address this one: https://e9coupe.com/forum/threads/diy-triple-weber-install.11517/post-75279

 

[Stevehose]

Amazing, thank you both. I am using a Carter 4070 pump, which is rated at 4-8psi, maybe just a touch on the high side. Also that Revolution Electronics fuel pump control is exactly what I was looking for, just ordered

I have the 4070 and use a regulator to just under 3 psi. I've run it temporarilly without it with no problems, but I didn't want to take a chance of it inconveniently blowing past the needle valves and flooding.

 

[Stevehose]

Stevehose should address this one: https://e9coupe.com/forum/threads/diy-triple-weber-install.11517/post-75279

I no longer have the Holley regulator in the trunk, it’s now up front where I can attach the gauge occasionally. I think it’s a Malpassi or something like that, made in Italy. Not the one with the filter built in, just the regulator. The 4070 mounting location on the diff has worked well, quiet and no chance of vapor lock.

 

[jmackro]

I have the 4070 and use a regulator to just under 3 psi. I've run it temporarilly without it with no problems, but I didn't want to take a chance of it inconveniently blowing past the needle valves and flooding.

As Stevehose wrote, adding a regulator to the circuit can be a good idea, especially with a pump that is rated at 4-8psi (like CharlesJ's), since Webers want more like 3-5 psi. I have also heard that regulators can serve to damp out the pressure pulses from the pump (which can be more pronounced for some types of pumps than others). If left unregulated, these pulses can cause wear to the float valves and seats.

As CharlesJ has learned from the Revolution Electronics site, they point isn't so much adding a relay to the fuel pump circuit, but adding some logic that will kill power to the electric fuel pump if the car is involved in an accident, the engine is stalled and a fuel line is ruptured. Old-school mechanical fuel pumps were smart enough to do this by themselves.

 

[Stevehose]

The Revolution device also primes the carbs for three seconds when you turn the key, a nice feature.

 

[halboyles]

I would be remiss if I didn't suggest you upgrade to our side draft linkage system. It eliminates all the unnecessary clamps. fittings and adjustment of any other system out there-- Redline, Korman, . . . This means a lot less time trying to tune the linkage so you can spend your time where it should be focused, tuning the carbs. Here's a link for your consideration:

Weber Triple Side Draft M30 | 2002s Only

The M30 Triple Side Draft System is based on the same rock-solid, low maintenance components as the M10 system. It includes everything from the bell crank to the triple Weber throttle shafts. It is $285 plus shipping. NOTE: DOWNLOAD THE INSTALLATION TIPS SHEET HERE

www.2002sonly.com

 

[CharlesJ]

Thank you all. I ordered the Revolution Electronics controller & Holley 1-5psi regulator with an external gauge. Will post the full setup once in to my project thread, but definitely looks like the way to go. The 4070 is currently mounted right by the diff, basically factory CSI location, on the isolator mounts, seems to definitely be a good spot. Being the car is still completely bare on the inside, going to integrate the controller wiring with the main harness back to the trunk and bring the wires through with the fuel line to the pump.

That simplified linkage looks great. My current setup is the one from Korman, and it is already all set and synced, but if I have issues, I may go with that. I just made my own links back to the pedal lever as well.

Thanks again all!

 

[Stevehose]

Keep the controller unit accessible so if it ever fails a replacement can be swapped in.

 

[Ohmess]

Thank you all. I ordered the Revolution Electronics controller & Holley 1-5psi regulator with an external gauge. Will post the full setup once in to my project thread, but definitely looks like the way to go. The 4070 is currently mounted right by the diff, basically factory CSI location, on the isolator mounts, seems to definitely be a good spot. Being the car is still completely bare on the inside, going to integrate the controller wiring with the main harness back to the trunk and bring the wires through with the fuel line to the pump.

That simplified linkage looks great. My current setup is the one from Korman, and it is already all set and synced, but if I have issues, I may go with that. I just made my own links back to the pedal lever as well.

Thanks again all!

Consider that instead of running wiring through the firewall, you can run wiring under the firewall on the passenger side inside the frame rail to the opening at the front of the passenger seat. From here, you can run along the sill, under the back seat, and to the trunk.

 

[CharlesJ]

Consider that instead of running wiring through the firewall, you can run wiring under the firewall on the passenger side inside the frame rail to the opening at the front of the passenger seat. From here, you can run along the sill, under the back seat, and to the trunk.

For t the tach signal, does it need to go all the way to the coil, or is there a point to pick it up in the dash? Again advantage of my car note being assembled is I can go wherever. I am going to build a mount for the control box and any extra fuse right with the main fuse block to keep it accessible

 

[Stevehose]

You could tap into the connection at the back of the tach - this is where the coil wire connection for it goes to.

 

[Ohmess]

I went all the way to the tach. My controller is mounted under the rear seat.