6mt 3.0r swap project.

Save me the preaching. I know this that or the other thing is more cost effective, or easier, whatever. I know.

 

This is what I want to do, and I'm doing it

 

I put a post up awhile back about doing a little bit different swap and said **** it, if I'm going to do this I'm going to overdo it.

 

I've secured a new DD, and the building begins.

 

Ez30r or ez30d mk II as some like to call it, and an sti 6mt going into an 05 legacy NA limited chassis.

 

Not all parts are secured yet, but there is a reason for that. I'm trying to figure out what I need and what I don't need.

 

So far what I think I need:

04-09 sti 6mt and crossmember(s?)

Dccdpro

R180 diff

AT trans driveshaft

New hub assemblies so that new hub bearings can accommodate cv's between diffs and hubs because of different splines ( would appreciate confirmation of this) and also a big brake kit.

Megasquirt ms3 and expansion

New clutch kit

Ez30r engine and crossmember

Ez30 radiator because apparently it has 2 inlet locations

A bunch of wires and pins to add everything for avcs

Lots of wiring diagrams

Better connecting rods

Misc updated sensors for aftermarket ecu

Probably a coilpack conversion

Misc general maintenance parts.

Turbo stuff ( I'll work that out later. Can't turbo if you don't have an engine)

Upgraded fuel pump, injectors

Probably 5x114.3 rims

 

Am I missing anything here? Am I missing a lot?

 

Also fun stuff that isn't crucial to the build:

Window tint

Lgt seats

New carpet

Sound insulation

 

If anyone has wired up a megasquirt to an ez30r, I'd love to hear from you.

 

Thank you all in advance for your help!

Have you watched Mighty Car Mods's Super Gramps series? Pretty much the same thing you were doing here (plus turbo).

 

Info I can provide:

- 5 speed & 6 speed transmission cross-members are the same. You will need a different transmission mount however.

- You don't need new hub assemblies, STI hubs won't work anyways. You need 07-09 Spec. B rear axle shafts to convert from R180 to legacy hubs.

- Because above, you'll keep 5x100 wheels.

Is the 05 NA limited manual (not sure on what lower spec US vehicles came as)?

If auto remember the trans tunnel is a different shape so a custom trans subframe is needed. If manual them the chassis is all the same.

 

Can Megasquirt do any CAN communication? Haven't previously heard of anyone trying but you'll be in for a whole heap of work getting basic car functions to work unless you piggyback it with the stock ECU. A more costly option would be an EMTron (MY06+) or Haltech (pre-MY06) ECU which has been proven to work on JDM Legacy’s with very few changes needed to wiring, besides adding extra wiring for additional cylinders of course. The CANBUS has been decoded for JDM and AUD vehicles so only minor work will be needed to carry that over to US vehicles.

Have you watched Mighty Car Mods's Super Gramps series? Pretty much the same thing you were doing here (plus turbo).

 

Info I can provide:

- 5 speed & 6 speed transmission cross-members are the same. You will need a different transmission mount however.

- You don't need new hub assemblies, STI hubs won't work anyways. You need 07-09 Spec. B rear axle shafts to convert from R180 to legacy hubs.

- Because above, you'll keep 5x100 wheels.

 

That's some super awesome info, thank you. I have watched supergramps but perhaps it's worth a rewatch.

Is the 05 NA limited manual (not sure on what lower spec US vehicles came as)?

If auto remember the trans tunnel is a different shape so a custom trans subframe is needed. If manual them the chassis is all the same.

 

Can Megasquirt do any CAN communication? Haven't previously heard of anyone trying but you'll be in for a whole heap of work getting basic car functions to work unless you piggyback it with the stock ECU. A more costly option would be an EMTron (MY06+) or Haltech (pre-MY06) ECU which has been proven to work on JDM Legacy’s with very few changes needed to wiring, besides adding extra wiring for additional cylinders of course. The CANBUS has been decoded for JDM and AUD vehicles so only minor work will be needed to carry that over to US vehicles.

 

It is a NA legacy limited manual. I am unsure of megasquirt's CAN abilities. I've done everything before with the exception of using an aftermarket ECU, so this is new territory for me. I was hoping to go with Megasquirt because I didn't really want to spend 1500+ on an ECU and I heard good things, but if I do need to fork over the cash I can, I'm just cheap.

 

Either way I'm not going to tune it myself. I'd probably break something.

Yea megasquirt are good for simple setups but don't think it will be able to control the dash or any other CAN based modules which is quite important for these vehicles.

 

Have a chat with this guy. He's going to be using a Hydra EMS which apparently is plug and play including dash stuff and includes additional wiring you'll need for the extra cylinders.

https://legacygt.com/forums/showthread.php/new-year-new-build-v-3-0-ri-277229.html

That's some super awesome info, thank you. I have watched supergramps but perhaps it's worth a rewatch.

 

They use Haltech I believe for the reasons stated above. They're also local, which probably helps.

Too bad you are starting with a N/A H4 05 Legacy vs a H6 05 Legacy. It would be easier to swap a MT into that than to swap a H6 and 6MT into the 2.5i.

 

Have you considered a EG33 over the EZ30D?

Too bad you are starting with a N/A H4 05 Legacy vs a H6 05 Legacy. It would be easier to swap a MT into that than to swap a H6 and 6MT into the 2.5i.

 

Have you considered a EG33 over the EZ30D?

 

I have considered the eg33. I ended up choosing the ez30 for 3 reasons.

 

1. The ez30 was designed to fit into that engine bay, and because of the way it was designed, the engine only ends up being about an inch longer than the 2.5, whereas the eg33 is much longer. Also, parts such as mounts and crossmembers are readily available.

2. Info from a few others I've spoken to on the subject are assuring me that 05-07 6mt sti trans will bolt straight up to a ez30.

3. Apparently with some upgraded connecting rods and perhaps a well done head gasket job, the ez30 tends to be quite resilient. Aftermarket parts are becoming more and more available for it, and I also want the avcs.

 

Since mine is already a manual stock, the trans tunnel should be suitable. Honestly I've worked extensively on Subarus and many other cars. There is almost nothing outside of a CVT trans that you can throw at me that would scare me mechanically. Wiring, canbus integration, and programming/tuning is what scares the living **** out of me.

Good call on EZ vs EG. I put an EG33 into a 2.5RS (GC8 chassis), it was fun, but the extra length was a major pain.

 

cheers

If anyone has wired up a megasquirt to an ez30r, I'd love to hear from you.

 

Thank you all in advance for your help!

 

 

Or get the wiring harness and ECU from an European 3.0R Spec B with 6MT (Yes, they do exist)

Update time finally!

 

Alright. So.

 

Bunch of weird stuff happened. Long story. Ended up having to source parts elsewhere... A few compromises were made but I think in the end I've found the best balance for me.

 

First order of business-

 

Transmission. I have acquired a JDM Subaru legacy 6mt off of a 3.0r model.

 

Model number is ty856wvdba. So here's my question (s)... My car is a 05 legacy 2.5i limited.

 

I'm pretty sure the transmission tunnel is the correct size for the 6spd. Confirmation would be nice ...

 

I'm having a super hard time confirming if the front CVS from my USDM 5mt will fit the JDM 6mt.

 

A chart I've found shows me that this trans originally came with a r160 3.9FD diff in the rear. So if I get that, rear shafts should still work, right? Or am I just getting myself in trouble with fitting a driveshaft? (4eat shaft)

 

Other items I have secured include:

 

Group N trans mount

Perrin short shift linkage and adapter set for a legacy specifically.

Exedy dual plate clutch and flywheel, all supporting stuff for pull style clutch

6mt shifter and reverse lockout

 

And a Hydra 2.7. I'll worry about this later.

 

For now, I'm looking at solving any issues with fitting this trans in the car, namely space for the trans, and diff/shafts combos.

 

Suggestions from experienced people as to what kind of diff I should choose and why would definitely be appreciated. I understand the differences on paper but I've never tried different diffs. (Vlsd, torsen, open...) Goal is a powerful yet comfortable cruiser. No track tramp by any means.

 

Tl:Dr 5mt CV's with a JDM ty856wvdba 6mt trans, an r160 rear diff at 3.90 FD, and a 4eat driveshaft should be a working combo, right?

 

Thank you all in advance. None of this would be possible without you legends

Transmission tunnels are identical, but you will need 6spd front cross member/transmission mount iirc.

 

I'm running the 5 speed transmission crossmember with a 6 speed mount, it works fine.

Wait, isn't the 5mt in the 2.5i and the gt the same trans? If so there's no reason the crossmember would be different

Here’s Turbo Yoda’s advice on the flat 6 line up, he has great insight and has built many H6s in the past.

 

 

 

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Hey... So I just realized the rallispec chart says my transfer ratio is 1.1, not 1.0. my final drive is 3.9. does that mean I actually need a 3.54 diff?

Correct, I believe any STi or Spec B R180 is 3.54:1 or a 02-05 WRX with a manual transmission is the R160 you’d need. Edited April 2, 2020 by Neal Cassady

Have you seen this yet? They're developing cast turbo manifolds for twins on the ez30r:

Have you seen this yet? They're developing cast turbo manifolds for twins on the ez30r:

 

I saw this on my YouTube feed actually! I'm at work so I'm waiting till I get off to watch it in T-minus 5 hours

Correct, I believe any STi or Spec B R180 is 3.54:1 or a 02-05 WRX with a manual transmission is the R160 you’d need.

 

Awesome. Glad i didn't buy anything. I gotta pay better attention...

 

The interwebs aren't being very helpful currently. Lots of diffs of the wrong type, even more that aren't marked with fear ratios or diff codes.

 

Good thing I'm in Subaru rich Montana. Looks like I'm doing some yard-hopping.

To be absolutely sure you have the right ratio, you can pull the diff cover the the ring gear will be marked 39:11

Correct, I believe any STi or Spec B R180 is 3.54:1 or a 02-05 WRX with a manual transmission is the R160 you’d need.

 

To be absolutely sure you have the right ratio, you can pull the diff cover the the ring gear will be marked 39:11

 

Thanks Neal, I'll do that.

 

Anyone know the torque split (I know this is a controversial term) for a 3.9 front 1.1 center 3.54 rear set up? Just curious.

 

Also... Being that I'm having difficulty so far finding the correct diff, could I just swap the ring and pinion gears or is that a huge pain?

Swapping the ring and pinion requires fairly involved set up in terms of lash/pre-load/pinion depth.

 

Easiest to find one with the correct ratio. If you have no luck locally, check out subierecycler.com. They will most likely have one and they ship anywhere.

This might be helpful taken from here https://legacygt.com/forums/showthread.php/difference-between-2-5i-and-gti-167291.html?p=3495909

 

The 2.5i and the 2.5T (LGT) use the same reinforced transmission housing for all 4th gen Legacys/Outbacks.

 

The gear-ratios/final drives between the 2.5i and 2.5GT Legacys are different and so the rear diffs are not the same ratios (from an LSD nor from a ratio perspective)

 

2005 2.5i Legacy 5MT

 

1st 3.454

2nd 2.062

3rd 1.448

4th 1.088

5th .780

Rear Diff (non-LSD): 3.90

 

Compared to the

 

2005 2.5GT 5MT

1st 3.166

2nd 1.882

3rd 1.296

4th .972

5th .738

Rear Diff (LSD): 4.111

 

There were some subsequent changes to the gear ratios to make better use of the VF46-huffed 2.5GT power delivery, and none of the above really addresses the drivetrain (transmissions and final drive) differences between the LGT and the 07+ LGT Spec Bs.

__________________

 

 

So... I fall under the 2005 legacy limited 5mt with the non lsd 3.90 rear.

 

My question is, does mine fall under the 3.54 category and is it just 3.90 because the center diff is 1.1 and math? Or is the center diff in the original 5mt a 1:1? Can't seem to find that info.

 

Guess I'll go pull the thing off and do a turn count. Only reason I haven't so far is that it's still snowing here and I don't have a garage. Or a paved driveway...

Updates?