Donorless builds

[RobC76]

Might have just invented a word lol. Does anyone have any knowledge of someone building a goblin without using a complete donor. I have a complete drivetrain and stand-alone harness. Plan on using DF’s new subframe and rear suspension. Using coil overs. Buying seats from Goblin, boost reference fuel system. What do I seem to be missing here. Steering and pedal boxes? Please help as I’ve never built one.
Thank you

 

[k.rollin]

@Tinkles is doing a donorless build, IIRC.

 

[RobC76]

I have a donor but…

 

[Gtstorey]

Most of the other parts needed can be purchased separately from places like rock auto. You have or have mentioned most of them. You will need a lot of odds and ends.

What do you mean by complete drivetrain? Axles? Knuckles?

Parking Brake parts? Horn? Headlight/turn signal mutli-switch? What are you doing for tach/speedo? Etc, etc, etc

 

[Rauq]

Shifter, but you can also get that from DF. Cruise control and automatic headlights come from the stock Cobalt computers. Turn signal switch also has the light controls. You mentioned steering, but that includes both the rack and tie rod ends, the steering shaft, and electric power steering if you choose to run it. Pedal boxes also includes the Cobalt brake booster, again, if you choose to run it. Fuel hat and pump assembly, a few of the parking brake components (handle and guide tubes). Axles and wheel bearings, not sure if the DF subframe and suspension kit will include knuckles (I think so). Coolant reservoir, and radiator hoses, off the top of my head.

The other thing you'll run into is that a lot of the hardware used for construction comes from the donor. You'll get nickel'd and dime'd buying Grade 8 and Grade 10.9 hardware where it's needed (although probably not more than the cost of a donor).

 

[Brian74]

The toughest part of a donorless build is obtaining a body wiring harness and transmission (for the SS cars.) Many of the other stuff can be obtained at the local pull your-own. ECM/BCM can be had through LKQ, but its good to ensure they both come from the same car.

 

[RobC76]

Good Info here
I planned on running a painless wiring harness or just building one for blinkers, headlights, running lights.
Dash I was thinking of running a digital dash solution. Probably biggest question is pedal assemblies and steering solution with column ect.

 

[RobC76]

Shifter, but you can also get that from DF. Cruise control and automatic headlights come from the stock Cobalt computers. Turn signal switch also has the light controls. You mentioned steering, but that includes both the rack and tie rod ends, the steering shaft, and electric power steering if you choose to run it. Pedal boxes also includes the Cobalt brake booster, again, if you choose to run it. Fuel hat and pump assembly, a few of the parking brake components (handle and guide tubes). Axles and wheel bearings, not sure if the DF subframe and suspension kit will include knuckles (I think so). Coolant reservoir, and radiator hoses, off the top of my head.

The other thing you'll run into is that a lot of the hardware used for construction comes from the donor. You'll get nickel'd and dime'd buying Grade 8 and Grade 10.9 hardware where it's needed (although probably not more than the cost of a donor).

Yes I have complete set of knuckles, axles, Brakes but nothing in regards to parking brake parts.

 

[Brian74]

Good Info here
I planned on running a painless wiring harness or just building one for blinkers, headlights, running lights.
Dash I was thinking of running a digital dash solution. Probably biggest question is pedal assemblies and steering solution with column ect.

You’re not going to find anything for the body harness from painless. The engine harness can be purchased new for around $300. The body harness connects the ECM and BCM to the rest of the car as well as the CAN bus and VATS handshake (which cannot be bypassed on the LNF.)

I actually modified an existing LSJ harness to work with an LNF. I also have over a decade of automotive electrical experience. It was a huge ass pain and I do not recommend attempting it. The parts and tooling are expensive. The right angle exit Bosch E69 ECM to body harness connector is a unicorn these days.

You will need to source a body harness. There is really no getting around that unless you build a stand alone ECM setup for the LSJ. Even then you will have to design your own auxiliary harness to replace the BCM circuitry and run everything else.

Your best bet on a non donor harness is to find someone parting out and go there yourself to rip out the entire interior and pull the harness.

 

[RobC76]

Copy that, I was hoping to simplify and Eliminate the BCM. I have one LSJ harness I thinned to be stand-alone from a stock harness. I also purchased a stand-alone from RDM Ecotecs, he builds new ecotec harnesses for sand rail customers. It’s a really professional job. I used HP Tuners to handle the VATS. However this is an LSJ not an LNF. With that info if you still think it’s a mistake please say so. I respect advice

 

[RobC76]

What all is ran by BCM on a Goblin?
Lights
Ignition
Gauges
Steering?
Sorry just not sure

 

[Brian74]

What all is ran by BCM on a Goblin?
Lights
Ignition
Gauges
Steering?
Sorry just not sure

These are all of the combined BCM pinouts for every year and model Cobalt (That could apply to a Goblin build). Should give you a good idea.

 

[RobC76]

Thank you
Great Info

 

[Tinkles]

Don't go down that road. Just buy a base model with the trans of your choice, it will make everything soo much easier. It sucks having to make junkyard trips for stupid little bolts/connectors/trinkets that you didn't think you needed. Or saving up for racecar parts to adapt into the chassis because you don't have the stock parts. I went donorless because I am using a non Cobalt engine/trans and a standalone PCM. I have spent a ton more money that I needed to and my Goblin would be ALOT closer to being finished now if I bought a donor. Still build your Goblin the way you want, nothing you have done yet is wasted effort. But to make your build 1000x easier, pick up a cheap donor. That way when you need the bolts to bolt down the seat belts or the thermostat housing or a special clip, you should already have it.

 

[Rttoys]

As others have said, you “can” do it, but it’ll nickel and dime you to death with all the little things, then it will also be a huge headache on the big stuff. Don’t forget, the cobalt has been discontinued for a while now, so normal parts are getting hard to find and those odds and ends parts are now made of unobtainium.

 

[RobC76]

Just reread through this. Man was I out to lunch thinking an LNF could be stand-alone like the older stuff lol. Learned a lot about LNF and the PK3 security since then. Anyway you guys are all spot on. I recently picked up the Goblin Michael ( The guy that was going to build Goblin the new harness) was building. It has a new LNF and F35 LSD in it. I’m trying to get it running just to test everything out and he must have misplaced the VATS module. After some research it appears you cannot program a VATS module on different key module / BCM than it was originally programmed with. Im assuming it must etch the code in the module. I’m also somewhat assuming that as long as key / key resistor ring and BCM all match then when you install the new VATS module it basically handshakes the first ignition cycle and basically ties itself to that key and BCM. Does anyone have any insight on whether my assumptions and google education is accurate. Thanks

 

[Markm]

What year is your donor and I’ll get you the description and operation for it. Pk3 is nothing like the old VATS chip key

 

[RobC76]

2009 Cobalt SS /TC
LNF, MU3
Thank you

 

[Gtstorey]

I’ve read the service manual and it’s hard to decipher exactly what does what and what actually needs programming. For example, when I replaced my ECM the service manual the immobilizer has to be programmed to match and that isn’t true. I just had to do a key relearn.

The most sure bet is to have the ability to SPS program the modules to work together. But it’s hard to say exactly how much has to be done.

It’s supposed to be possible to rewire the ECM to run without any of the other modules, according to a few post on HPT forums. But there was never any details given. I think RPM Performance can do it by reprogramming the ECM, but I don’t remember the details.

A few of the aftermarket ECMs can handle direct injection so that might be another option.

 

[RobC76]

https://www.cardone.com/content/Products/PT77-0011.pdf

This is one of the best articles I’ve found explaining the security systems. The issue is it doesn’t tell you how to install a new module between key and BCM lol.