Coyote PCM/ECU placement? Urgent help needed!

[mkassab]

I can't figure out where to place/mount the Coyote PCM/ECU and I'm seeking advice from those who have built a '33 hot rod or '35 truck with the Coyote engine.

Here's my two key issues....
1. the engine wire harness that connects to the PCM is located on the front right of the engine right head and is too short to get to the cab
2. the engine bay with the '33 Hot Rod and the '35 truck are the same and is too small to mount the PCM there that I can see.

My question is to those that have built a 33 or 35 and installed the Coyote.... where did you mount the PCM, and if it's the cab inside the firewall, how did you lengthen the wire harness on the engine to reach/connect to the PCM?

thx, Mark

My build link is in my signature below

Pic of PCM/ECU with the vehicle side wire harness.

[edwardb]

My truck build was an LS3 and the harness let me put the PCM behind the dash without much effort. But I have done two Coyote builds (Roadster and Coupe) and you're right, the harness off the engine without modification pretty much requires the PCM to be at the RH side of the engine. Same place as on the Mustang. What I can tell you though is a number of Coyote builds have been completed moving the PCM to the firewall or further. Maybe even behind the dash on the truck? From what I've observed, the harness isn't lengthened, but rather unwrapped, loosened, then rewrapped. Enough that it can be moved back. Don't know how much this helps. But there are enough other builders out there who have put Coyotes in the hot rod or truck that hopefully you can get more feedback than that. Good luck.

Note: I see you posted this several times in different sections. FYI, "cross posting" is discouraged. Maybe even in the forum guidelines.

[mkassab]

Thanks Paul.... I was aware of the ideas you mentioned. Hopefully, someone else that built a 33 or truck with a Coyote will provide their solution. I also know Erik on his Voo Doo truck repined his engine harness to rotate it 180*... but that's not something I want to do if at all possible.

Mark

[Alan_C]

Here is an idea, not sure it would apply to your build. I am building a 70 Mustang restomod with a 2nd Gen Coyote. The length of the engine harness definitely limits where you can place the PCM without extending the engine harness. What I did is make bracketry to mount my PCM in the outer fender area opposite where the OEM battery location is. I found out that the Gen 2 harness connectors will just pass through a hole made for the access to the rear shock mounts.
https://www.npdlink.com/product/plug...1970&year=1970
I made a similar hole in the inner fender apron so I could pass the engine harness connector through it. I then cut and modified one of the grommets to accommodate the diameter of the cable. I then ran the PDB cable through the outer fender area and into the interior. I mounted the PDB in the interior in the upper right corner of the passenger footwell. This approach has hidden much of the wiring one would normally see under the hood. I will made a cover to go over the PCM and wrap the cables to keep out the dirt and moisture that the front tires will through around.



Just another approach that might provide ideas you may or may not be able to apply.
The PDB harness is more than long enough, in fact I expect I will have to reduce the length when wiring the car.

[mkassab]

Thx Alan... I recognize all the pics as I also did a 70 mustang restomod with a Boss 429 (bored and stroked to 529 cu in).

Mark

[Alan_C]

Wow, Jon Kaase B9, that must have been a beast when done. Good to see another Mustang enthusiast here. My MK4 was a gateway drug to my Mustang. Like taking an overdose of Fentanyl, my Mustang will be one and done. I never realized just how easy it was to build the MK4 until I got into restoring/restomoding a 50 plus year old car. Even though I sold my MK4 back in 2018, I still participate here as this forum has more Coyote swap info than anywhere else I have been.
Got any pics of the B9 Mustang? I know it is off topic but I love looking at the work of others as it usually gives me new, and usually expensive, ideas.

[progmgr1]

You could go old school if you don't want to disassemble the harnesses. The FFR Coyote Fitment Instructions from back in 2015 - 2017 (Gen 1 HR, Gen 1 or 2 Coyote) showed mounting the ECU under the oil pan in the front of the engine. The pdf image is a page from that document with a decent line drawing and murky photograph showing the FFR provided ECU mounting bracket. The attached photo shows my interpretation of that design. Yes, it's tight, but the connectors do fit inside the frame crossmembers and all the harnesses tuck in tight to the block.

HTH Keith HR #894

Coyote ECU mounting.pdf ECU mounting.jpg

[Alan_C]

Very interesting, I had not seen that suggested placement before.

[progmgr1]

IIRC, there was a similar photo showing the same ECU mounting position in the documentation that came with my Coyote crate motor. I bought it as a "power pack" (motor & transmission), if that makes any difference.

Keith HR #894

[mkassab]

You could go old school if you don't want to disassemble the harnesses. The FFR Coyote Fitment Instructions from back in 2015 - 2017 (Gen 1 HR, Gen 1 or 2 Coyote) showed mounting the ECU under the oil pan in the front of the engine. The pdf image is a page from that document with a decent line drawing and murky photograph showing the FFR provided ECU mounting bracket. The attached photo shows my interpretation of that design. Yes, it's tight, but the connectors do fit inside the frame crossmembers and all the harnesses tuck in tight to the block.

HTH Keith HR #894

Coyote ECU mounting.pdf ECU mounting.jpg

Thanks Keith.... very interesting... but it won't work on my Gen 3 Coyote. If I run the engine wire harness connector straight down the front of the engine, The connector is at the oil pan seam where it meets the bottom of the engine block... so no way is it long enough. But, this does give me other ideas. This is a busy area since I'm running A/C. I'll figure something out.

Mark

[mkassab]

Wow, Jon Kaase B9, that must have been a beast when done. Good to see another Mustang enthusiast here. My MK4 was a gateway drug to my Mustang. Like taking an overdose of Fentanyl, my Mustang will be one and done. I never realized just how easy it was to build the MK4 until I got into restoring/restomoding a 50 plus year old car. Even though I sold my MK4 back in 2018, I still participate here as this forum has more Coyote swap info than anywhere else I have been.
Got any pics of the B9 Mustang? I know it is off topic but I love looking at the work of others as it usually gives me new, and usually expensive, ideas.

Alan.... here's a link to Ford Muscle.... my last post there with many pictures:
https://www.fordmuscle.com/features/...d-up-for-sale/
I had a complete build thread, but I guess ford muscle doesn't carry it any longer as I can fine it. Regarding Jon Kaase, We ended up going to his shop NE of Atlanta for the final dyno, as the first two dyno shops couldn't handle the size of the engine.... in fact, we borrowed Kasse's headers and had to turn them upside down at the first two dyno shops which restricted exhaust flow.... so the trip to Kaase was in order. Jon was in the Dyno room, paid a compliment to my engine builder for this engine made 740.3 HP on pump gas using a 1050 dominator carb. Key was the torque never dropped below 600 ft lb during the entire power curve.... with peek torque at 700 ft lbs. Jon even took us to lunch and I got a Boss None Kaase T-shirt.

Dyno graph Screenshot 2023-06-23 071439.jpg

Here's the magazine article on my engine build.... note Jon's comment on the last page.











I have hundreds of pic of my build if you ever need anything.

Mark

[Alan_C]

Thanks for the details of the B9 Build. I wasn't wrong when I said that engine would be a beast.
So sorry to hear you had to sell. All that effort and someone else gets to enjoy it beyond your satisfaction from building it.
If you don't mind me asking, how did you do on the sale? You mentioned another getting $120K at auction for a similar build. With the prices you see on Bring a Trailer, I could not imagine anything less than $150K. A build like yours done by Kindigit Design would likely be in excess of $300K if not $400K just to build.

[mkassab]

Thanks for the details of the B9 Build. I wasn't wrong when I said that engine would be a beast.
So sorry to hear you had to sell. All that effort and someone else gets to enjoy it beyond your satisfaction from building it.
If you don't mind me asking, how did you do on the sale? You mentioned another getting $120K at auction for a similar build. With the prices you see on Bring a Trailer, I could not imagine anything less than $150K. A build like yours done by Kindigit Design would likely be in excess of $300K if not $400K just to build.

Thanks Alan.... I didn't really have to sale it.... I was moving to where I'm at now and didn't want to move it. It did sale for 6 figures. And I usually never make anything on my labor.... and that's OK with me, as I do this for a hobby and think of it as a self-funding hobby. If I as least cover my cost I'm good. I've done a few cars/trucks like the Boss9. I've discover on my first build it was about the design & build and not the ownership. I do plan to keep the '35 truck in my signature build link and use as my daily "retired" driver.

Mark

[Dgc333]

Another option for the harness is to get one from HotwireAuto.com. They specialize in engine swap harnesses for LS, Hemi and Coyote engines. I am putting a 5.7 Hemi in my 33 Speedstar and got the harness from them. If anything it is to long for mounting the ECU on the back side of the firewall, I had to loop it back and forth before connecting to the ECU.

The owner Chris Squire is very helpful and will customize the harness for your needs.

[mkassab]

Wow.... thanks DGC333!

I was going to contact Ford Performance today to see if they offered an extension. and I'll also check with Chris at www.hotwireauro.com.

Mark