2005 Legacy GT V8 Build (LS2/LQ4)

[DanHalenBro]

This will be an amazing build... Talk about a sleeper!

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[wtyree]

Subscribed.

[GregsblueRex]

THIS = Awesome. RWD Legacy is exactly what the world needs.

[eg33GC]

Originally Posted by climberd

There is plenty of room. The problem is going to be getting the GM ECU to talk to the Subaru ECU. It's possible, sure. Yet that solution posted above is by far the hardest thing I can think of to make for a Subaru, or for any modified car project. Back to reality, the only "good" solution I have found to this problem (and I have put very serious research into this) is to do the simple old cam trigger and crank trigger wheel/sensor faking. Feed the Subaru ECU just enough so it will a) crank the starter, and b) not throw a CEL code. The cam trigger is the key. You can clear away any other code, but you're not going anywhere without a cam signal unless you completely bypass every Subaru ECU function. Let's say you do that, no Subaru ECU outputs except CAN, no inputs except GM ECU's tach output (which has a different logic of trigger wheel shape)... you would have to find a way to get the cluster to come alive. Any way you cut it, short of hiring a software/hardware engineer, you may be best off just adding a crank trigger and cam trigger wheel in the Subaru format. If anyone has a plan that would work better, I would love to hear it.

you grossly know little about how the wirign harnesses are structured in subarus.

the wiring is cake. the starter will engage without the ecu with a simple wiring change.

[paulharmo]

Oh man. This may be worth keeping an eye out for.

[myk]

Subscribed for awesomeness.

[lgt2000]

Originally Posted by climberd

Subscribed, mostly interested in your wiring choices to get the LGT ECU to play nice and not freak out with cam sensor missing.

The LGT ECU is being removed. I am using the GM ECU and most of its harness. We are still working on the cluster but it may end up being the guts of a GTO cluster behind the Legacy faces

[lgt2000]

Originally Posted by Skrane

Why iron block?

I bought a whole Express van for $1600 dollars and I am going to part it out to basically be at $0 for all the parts I am using out of it (Engine, ECU, Harness, Sensors, Starter, Alternator, etc.) plus once I decide to mod the engine (bore out, or add boost) I have a bigger safety margin

[lgt2000]

Originally Posted by RallySport Direct

And so it begins...


This is awesome, I will keep checking back for updates, and can't wait to see this thing up and running! Good luck with the build!!

Thanks,
Rick

Thanks, we like to use most of our time to actually make progress on this but will post updates when we can. We are also working on a V8 Miata at the same time using an aluminum 5.3L and a CTS-V T56

[lgt2000]

Originally Posted by Patrick Olsen

I was wondering the same thing. I understand the iron block would be cheaper, but it shouldn't be that hard to find an aluminum engine, and the weight savings on the nose is more than worth it IMO. The aluminum 5.3L engines (LM4) can be had for $500-800 complete, for instance, and will make tons of power just like the other LS motors.

I see where you are going with this Patrick and I agree complete. There is an LM4 sitting right beside this LQ4 but it is going into a Miata. The goal of the initial project was to keep costs low and as you can see above the engine should be at $0 in the end. Once it is built, its not going to be hard to swap to an aluminum block if that is what I want to do

[lgt2000]

Originally Posted by Turn in Concepts

At this point I really don't care if he does aluminum, iron or purple monkey dung. I just want to see it happen.

:-DDD

[lgt2000]

To keep things simple we are going to most likely make a GM/Subaru hybrid cluster

Originally Posted by climberd

There is plenty of room. The problem is going to be getting the GM ECU to talk to the Subaru ECU. It's possible, sure. Yet that solution posted above is by far the hardest thing I can think of to make for a Subaru, or for any modified car project. Back to reality, the only "good" solution I have found to this problem (and I have put very serious research into this) is to do the simple old cam trigger and crank trigger wheel/sensor faking. Feed the Subaru ECU just enough so it will a) crank the starter, and b) not throw a CEL code. The cam trigger is the key. You can clear away any other code, but you're not going anywhere without a cam signal unless you completely bypass every Subaru ECU function. Let's say you do that, no Subaru ECU outputs except CAN, no inputs except GM ECU's tach output (which has a different logic of trigger wheel shape)... you would have to find a way to get the cluster to come alive. Any way you cut it, short of hiring a software/hardware engineer, you may be best off just adding a crank trigger and cam trigger wheel in the Subaru format. If anyone has a plan that would work better, I would love to hear it.

[lgt2000]

Some pics of the van that gave its life and a few of the motor being broken down:

[lgt2000]

Picked up some L92/LS3 heads

[lgt2000]

Cleaned up the block a bit

[lgt2000]

We notched the subframe further so the engine would move back toward the firewall and test a 3/4 in. shim in between the subframe and body to drop it lower

[bugeyetex]

clicked to see a v.8 build, found a v8 build. Can't wait to see it in motion.

You one of those people who answers the question 'why?' with 'why not?', aren't you?

[Psychoreo]

Fits better than a turbo subaru motor

[lgt2000]

It fits pretty well. We are still doing some work on the subframe for good clearance while keeping it sturdy

[GT35RHybrid]

I apoligize if I missed it but will this retain AC and other creature comforts?

[Homemade WRX]

Originally Posted by Turn in Concepts

At this point I really don't care if he does aluminum, iron or purple monkey dung. I just want to see it happen.

purple monkey dung

I know a group of guys that are kicking around the idea of building a $50 93 Impreza chassis for Chump car with a 6.0L (L96) engine. It's either that or the freebie EG33 sitting around. The Marine V8 will be easier was easier on electrical.


....so I'm taking notes

[lgt2000]

Originally Posted by GT35RHybrid

I apoligize if I missed it but will this retain AC and other creature comforts?

It will have AC, power steering and cruise control

[lgt2000]

If it is the GEN IV L96 6.0L the you have basically the same motor I do as it comes factory with the heads I bought as an upgrade. You can mill the heads a bit, throw a cam in there and upgrade the springs and be around 450 hp. If you decide to go that route, let me know as I am sure I will have some leftover parts to share

Originally Posted by Homemade WRX

purple monkey dung

I know a group of guys that are kicking around the idea of building a $50 93 Impreza chassis for Chump car with a 6.0L (L96) engine. It's either that or the freebie EG33 sitting around. The Marine V8 will be easier was easier on electrical.


....so I'm taking notes

[RallySport Direct]

Originally Posted by Homemade WRX

purple monkey dung

I know a group of guys that are kicking around the idea of building a $50 93 Impreza chassis for Chump car with a 6.0L (L96) engine. It's either that or the freebie EG33 sitting around. The Marine V8 will be easier was easier on electrical.


....so I'm taking notes

This would be awesome. I love stuff like this, so cool!! And thank you LGT2000 for keeping the updates rolling in!

Rick

[lgt2000]

Sure thing. Here is where the parts collection stands now:

LQ4 6.0L Block
L92 Rectangle Port Heads (will be milled down to get compression around 10.5:1)
Billet Timing Chain Kit
GTO Front Sump Oil Pan and Pickup
Comp XR273HR Camshaft (220/224 .530/.534 112LSA)
L76 Intake Manifold
LS7 Fuel Rail
LS3 Corvette Water Pump

The front sump oil pan is required for the way our subframe is set up and I am going to run LS3 accessories as they are approximately 3/4in. closer to the block than their F-Body counterparts

Next parts on the list to pickup are:
LS3 Injectors
Springs and Retainers