Forza XDi installation question

Installing Nick Forza XDi in 1979 308GTB-

Where have installers tapped into 12V 10amp unswitched power?

Thought the BAT terminal at the starter would be close and good.

Access- yikes!!!
Suggestions?! Help.

 

I'd keep it off that circuit. I know it's a pain but for all the ones I've installed I've pulled a lead from the battery directly. you need about 25ft of wire to get to the engine bay and about 40ft to the trunk.

The ECU isn't fond of spikes and drops in voltage from cranking which occurs at the alt/starter location.

 

Jerry
Did you get my PM regarding the bracket? PM me and let me know.

 

SMG: Best avatar ever!

 

Can you pull 12V 10amp off a circuit at the fuse box?

 

The bottom center terminals of the relay panel has high amperage raw unswitched battery but difficult to tap into cleanly. That terminal feeds several points on the fuse panel. The easiest is the right fuse panel's at the top of the 3 last or rightmost fuses. Plus there is usually an unused male connector there. You can also use the left fuse panel at the top of fuses #6 or #7 as there is usually one unused male connector of the two.

However, I would go the extra 2 feet directly to the battery. If you come through the engine firewall into the center console to the front of the cabin there is a grommet into the forward area where another grommet with brake lines IIRC leading under the spare container forward to the battery. Also, I also like to place the fuse pigtail as close to the voltage source (battery) as possible rather than back at the component.

Had you chosen to use key switched power, it is at the left fuseblock, at the top of the first 3 fuses (left). This is where the existing ignition coils are fed on US carb cars. But that's a busy area usually requiring a 1/4" brass splitter for access.

_________________________
http://www.FerrariWiring.com

 

Paul,
Thanks for this. Perhaps Nick would include this information in future XDi kits. One additional note- the relay schematic references #s without a color index. Adding the relay #-color index would simplify first time installations.
Question: Any reason not to run one lead to two relays?

 

separate circuits, if you use one relay then both circuits are tied to that one relay and fuse. Also a load issue, amp draw spike may exceed wire rating and once you get insulation break down the chances of a short go way up.

what color reference is missing? I've never noticed that, the schematics I've seen always include the color and gauge of the wire.

 

How about ONE 12V 10amp wire (12-14 gage) from BAT/circuit board feeding TWO separate relays? Less wire routing?! Or, does amp-draw create an issue for single (12-14 gage) line feeding two relays/coils?

picture is XDi unit during wire-up that mounts in L rear boot.
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Electromotive schematic references numbers printed on relays and schematic. Siimple help for newbies- remind first timers WHERE numbers on relays are located.

Its a snap the second time. Relay # location was preceeded by serious wall-head banging. Minor detail the 2nd time.
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Please do not go off the fuse box, there is too much noise, if anyone has done that please correct it by getting power from the battery. I enclose wiring diagrams plus we supply 24/7 tech support during the installation process for the customer, that is part of our service when purchasing this ignition system, if there is ever an issue, please contact us directly as are here to help.

 

I bought the XDi system from Nick for my former '78 308, and Nick was extremely helpful in answering questions and making suggestions thoughout the installation. He even sent an alternate trigger wheel when I had problems lining up the one that came with the kit. Also, when I was having a problem a year after the install, Nick was very patient about troubleshooting the problems, which turned out to be a bad ground. Nick is a total gentleman, an avid Ferrari enthusiast, and one of the most reputable businessmen I've ever dealt with.

(p.s. -- Nick, send the endorsement commission check directly to my numbered Swiss bank account.)

 

I have yet to complete my XDi installation (gotta wait till I pass this first smog check with the car back in CA) However I have run the power cable. As suggested by Nick I was able pull a wire through the tube that the battery cable runs thru I pulled an extra line as well while I was down there. I used a electricians snake and they pulled right through.

 

I've installed several electromotive units. In every case, I have pickup up the power from the battery connection on the starter. A line directly from the battery would be better, but that opens up other issues. In talking with Fred (owner of Electromotive), as well as Nick, the critical issue are the grounds. Fred recommends that the engine ground, which is near the crank, and therefore, near the crank sensor, be move to the other side of the car to the bolt that connects the starter to the bell housing. The ECU is sensitive to voltage. Steve found that out the hard way.

 

Good info. Thanks Paul.

 

Nick's the best. Didn't mean to be disrespectful. Terrific service followup. Thanks for the confidence re using a snake to install the wire in the OEM wire tube.

 

Nick/Scott,

Assuming a single feed line to support the switched side of both relays, what gauge wire do you recommend be run from the battery to the trunk?

Rick

 

Better check with Nick on the HOTLINE.

 

FWIW I ran 10 gauge as per Nicks recommendation.

 

Roger that!

 

In retrospect, and reading what was said about voltage fluctuation at the starter connection, I think, were I to do it again, I would run the power source directly from the battery, all the way back to the unit.

But even if you do that, you must still be certain that you have a good ground. Merely grounding to the engine, or grounding to the chassis in the rear might not guaranty that, as I found out. You must have a good, clean ground and voltages must remain over 11.5 when cranking or the ECU will not trigger properly. Guess how I found that out.

 

Back in the old days, many cars used a ballast resistor on the coils to boost the voltage when the starter was engaged including many 308s. Even though available voltage isn't taken from the starter terminal, the voltage will suck down during starter engagement as much from the internal resistance of the battery as from the wiring resistance. If you are a truly worrier, use 4/0 welding cable and double or triple up on the battery. Course my cars start immediately on the oem ignition so I'll worry elsewhere.