Delete relay board

930cabman · 02:42 PM

Our 914 rustout project is far from a concours example, more like a rat rod if a Porsche can be such a thing. No heat, no fuel injection, no roll up windows, nothing extraneous. I am just diving into this now but on first observation it appears this relay board can be problematic and perhaps not necessary.

Forgot to mention, I cut into the harness today with a cutting wheel

thanks

Dave at Pelican Parts · Dave at Pelican Parts's Garage

There's a good chance you'll regret cutting the harness...

The relay board serves a few functions. Figure out what you don't need and if you can find other ways to deal with the functions that you do need, and you can get rid of it.

First, it serves as a connection point for the main wiring harness, the engine wiring harness, the fuel injection wiring harness, and the alternator wiring harness. It lets you unplug those connections so you can do stuff like drop the motor without having to unplug sixty individual wires.

Second, it serves to hold the voltage regulator, and to tie it into the charging system. Note that the stock system very much needs to run the alternator light in order to actually charge.

Third, it serves to hold one fuse that is used for the fuel pump and the EFI power.

Fourth, it serves to hold four relays. One for the FI power supply, one for the auxiliary heater blower motor power supply, one for the fuel pump power supply, and one for the rear window defogger.

Sounds like you don't need a lot of that, but you still will want to tie the various wiring harnesses together and deal with the voltage regulator at the least.

The relay board can be problematic, but it usually isn't unless it has been damaged. I feel that people are often a lot quicker to blame it than it deserves, much like the FI itself.

--DD

Charles Freeborn · Charles Freeborn's Garage

Quote:

Originally Posted by 930cabman

Our 914 rustout project is far from a concours example, more like a rat rod if a Porsche can be such a thing. No heat, no fuel injection, no roll up windows, nothing extraneous. I am just diving into this now but on first observation it appears this relay board can be problematic and perhaps not necessary.

Forgot to mention, I cut into the harness today with a cutting wheel

thanks

I removed mine, but my car is far far from stock. Has none of the original gauges, alternator set up or any of the like. I built my own with a simple blade type fuse block and a couple of modern type relays for the high draw items such as ignition and cooling fan. Pretty much the only thing remaining in the rear of the car that's original are the brake lights (doesn't even have tail lights). I'll snap some pics when I have a chance.

930cabman · 01-20-2021, 02:50 PM

At least several items tied to the relay board will not be used for this build. I am eliminating "unnecessary" things as I go. Might remove the window winder mechanisms.

GregAmy · 01-21-2021, 04:52 AM

I'm not sure what the question is?

I removed the relay plate on my race car. But I don't need it for:

- EFI (I'm using carbs)
- Fuel pump (rewired the car for a tank-mounted cell and driver switch/circuit breaker as well as rollover valve)
- Alternator or VR (I run "total loss", so no alternator)
- Heater blower
- Rear window defroster
- Backup lights
- Tailights

...and run wires to hard-wire the brake lights and I have Deutsch hard-connects for everything else to drop the engine. If you're willing to re-wire all of that - or do without it - then you're golden.

But I'd never do that to my street car. Too much hacking to get the necessary functions.

So what's the question again?

930cabman · 01-23-2021, 02:11 PM

Quote:

Originally Posted by GregAmy

I'm not sure what the question is?

I removed the relay plate on my race car. But I don't need it for:

- EFI (I'm using carbs)
- Fuel pump (rewired the car for a tank-mounted cell and driver switch/circuit breaker as well as rollover valve)
- Alternator or VR (I run "total loss", so no alternator)
- Heater blower
- Rear window defroster
- Backup lights
- Tailights

...and run wires to hard-wire the brake lights and I have Deutsch hard-connects for everything else to drop the engine. If you're willing to re-wire all of that - or do without it - then you're golden.

But I'd never do that to my street car. Too much hacking to get the necessary functions.

So what's the question again?

Yes, I am in a similar boat. I will be running rear lights and an alternator but all the relays/connections are unnecessary.

Mark Henry · 01-31-2021, 05:03 AM

I deleted my relay board when I did my /6 conversion, but not a single factory wire has been cut on my car.

930cabman · 02-01-2021, 04:23 AM

Quote:

Originally Posted by Mark Henry

I deleted my relay board when I did my /6 conversion, but not a single factory wire has been cut on my car.

Did you go with Webers? are you happy with your choice which ever

Mark Henry · 06:20 AM

Very happy, the Webers are a bit thirsty, but I don't care and part of this issue is my heavy right foot.

Here's my engine build and 914/6 conversion, somewhere in the thread it shows what I did with the relay board.
914World.com - The largest online 914 community!

930cabman · 02-02-2021, 08:40 AM

Quote:

Originally Posted by Mark Henry

Very happy, the Webers are a bit thirsty, but I don't care and part of this issue is my heavy right foot.

Here's my engine build and 914/6 conversion, somewhere in the thread it shows what I did with the relay board.
914World.com - The largest online 914 community!

Thanks, if you had to do it again, would you stick with Webers? I have also found Webers can be thirsty on an Alfa spider, but who wants to drive around with "soft touch" on the gas pedal?

Mark Henry · 02-02-2021, 12:02 PM

My carbs work good and seeing an aftermarket FI system will cost likely 3X what I have into my carbs I likely won't change.

Carbs are a challenge to set up, different mindset than tuning aftermarket FI, but when sorted correctly they work great. I followed Paul Abbott's Performance Oriented tech articles religiously, and he answered a couple questions here and I got everything sorted. Things you will never get around is a bit of gas smell and high performance rich exhaust smell.

BTW I run aftermarket EFI on my 2.6 914 based T4 engine I have in my bug.

930cabman · 02-03-2021, 09:42 AM

I am on the fence with Webers (for simplicity) or CIS for this /6 conversion. I have two CIS systems, could probably make one good one. Wife hates the fuel odor with my carb'd cars. I hate that *#$%@ car!!

When the CIS is running well, life is good, otherwise it's a pita. I have several books, a pressure gauge and have trouble getting the system dialed in 100%.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Note that you will either have to modify the rear wall of the engine bay to fit the CIS parts, or you will have to re-locate some of those parts. IIRC, it's the airbox that is in the way. I believe that has been sorted by turning the airbox 180 degrees and making up new lines to fit, plus re-locating the engine lid latch.

I like the CIS for engines that were originally delivered with CIS.

--DD

930cabman · 05:01 AM

Quote:

Originally Posted by Dave at Pelican Parts

Note that you will either have to modify the rear wall of the engine bay to fit the CIS parts, or you will have to re-locate some of those parts. IIRC, it's the airbox that is in the way. I believe that has been sorted by turning the airbox 180 degrees and making up new lines to fit, plus re-locating the engine lid latch.

I like the CIS for engines that were originally delivered with CIS.

--DD

Yes, I understand some modifications are necessary to fit the CIS air box an other items. The 2.7 we are building came with CIS

Jack Stands · Jack Stands's Garage

Perhaps use the parts off the CIS system and get a more modern Bitz EFI conversion. While I like the Weber’s, they’re not entirely happy with today’s fuels if the car isn’t routinely driven.