The H6 Impreza Resource Thread

[S2 13BT]

Thanks mate.

Yeah, not worried about it seizing or anything like that. Just want to be sure I'll get nice cool air in summer if I go ahead.

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[Patrick Olsen]

A couple posts on what I've done for A/C in my '97 Legacy:
https://forums.nasioc.com/forums/sho...postcount=1773
https://forums.nasioc.com/forums/sho...postcount=2710

The first post points out that my old EJ25 compressor would not fit in the EZ30D compressor bracket. I would guess that your '06 Forester has a smaller A/C compressor than my '97 did, so you may be able to make the Forester compressor work.

However, that doesn't address the issue addressed in the 2nd post I've linked above. Because of the shape of the EZ30's intake manifold, the A/C line has to come forward to clear; your stock Forester line probably doesn't do that. So even if you're able to fit your original compressor, you're most likely going to have to do something custom to fit the lines.

Note that my car has still never been completed, so I have no idea if the A/C works, but I don't see any reason why it won't when that time comes.

[S2 13BT]

Thanks Patrick.

From some cursory GIS's it seems the belt between the two cars is completely different too. The EZ belt being wider with more ribs, so unless the clutch can be swapped over that seems an unlikely solution.

The H6 compressor appears to have an additional sensor on the compressor that I think is an rpm sensor (like a borg warner turbo!), to detect if the compressor isn't turning. Then there is the connector for the clutch, which I assume would work exactly like the EJ comporessor clutch, but maybe a different shape connecter, which would be a simple enough fix.

So, with my extreme lack of knowledge and undestanding of how A/C works perhaps it's just a case of some custom pressure hoses, a connector change for the clutch wiring and Bobs your Aunty it's good to go. Assuming the pressure in the system isn't completely different from the EJ setup and the EJ sensor doesn't disable the system waiting for the pressure to reach "normal".

[carnz-pj-410]

I know it seems this thread is more EZ swap based, but I have successfully gotten my EG33 swap to start over the weekend on my 2005 Forester using a Link G4+ plug in ECU (WRX104+).

I wanted to post the trigger information in here as I had some difficulty finding it, so maybe it'll help someone else in the future.

Wiring definitely varies depending on engine year and car used (obviously lol), but I have the timing information to get people in the right direction as far as the triggers go...

Using the Link you can run the EG33 using the 12 tooth front crank sprocket (the rear is unused), and the 1 tooth cam sprocket.

The OEM 3 wire IACV is compatible and can easily be configured in PCLink

Configure the ECU as follows:





If this duplicate info from somewhere in the thread I apologize! I am willing to offer some help (wherever possible) to others trying to run an EG33/Link ECU, figure the more helping hands in a swap, the better!

[vicious_fishes]

The a/c is easy to swap mechanically - a combination of your recipient and donor car lines are easy to get it plumbed in. The connection from the condenser is the same so all you have to do is cut the line off the top of the a/c compressor and mate it to the line coming from the recipient chassis which can be done with a simple AN-10 straight fitting.

The hard part is the electric side of things as they have very different circuits. Just connecting the positive wires isn't enough as there's a pressure switch and some other BS to deal with.

[S2 13BT]

Originally Posted by vicious_fishes

The hard part is the electric side of things as they have very different circuits. Just connecting the positive wires isn't enough as there's a pressure switch and some other BS to deal with.

Yeah, seems like a headache. Looking at specs and wiring diagrams (remembering I don't know what I'm talking about), it looks like there are similarities, but it's certainly different. The operating pressures are different, but maybe swapping the 3 way pressure switch would take care of that. Or maybe changing the auto A/C out for manual A/C would be a way to get past some of the differences.

And obviously going to a standalone and removing the factory ECU removes part of the system too. I guess the standalone can easily send an A/C request and idle up, but will the rest of the smarts play along?

I just don't know!

[RubyLGT]

Awesome thread, I bet an h6 imp is a blast!

[vicious_fishes]

Yeah it's like driving a v8 around. But awd, with handling.

[jvangelder]

Making headway on my swap, hope be able to start it by months end ( only 1 month later than i planned) I finished my first set of fuel rails last night, took a bit longer than planned as i ran out of matl to make the standoff mounts and am going to run off a few extra's if anyones in need. They are 11/16 id and take -8orb fittings and use factory style top feed injectors. Pictured mounts have alot of hard edges, i didnt bother making them pretty as I expected to have to make adjustments which turned out to not be the case.






For those of you who have gone with a standalone, did you use the factory oil and coolant temp sensors or go with whatever the ems brand pushed, gm, or something else. Also safe to assume the oem map sensor is no good for boosted applications? I havent bothered measuring the output with positive pressure but im guessings its built strictly for n/a applications.

Also, does anyone have the scaling or a factory rom so i can pull it for the factory sensors if they are in fact good enough to use

Thanks

[vicious_fishes]

what's the purpose of those rails?

[jvangelder]

Originally Posted by vicious_fishes

what's the purpose of those rails?

I wanted return style rails and didn't want to weld or try to tap the existing rails

-Jacob

[Kito818]

Originally Posted by jvangelder

I wanted return style rails and didn't want to weld or try to tap the existing rails

-Jacob

How much are you selling those extras you made for? PM me the details I'd like to know.

I went with a Haltech, I'm not boosted yet, so I can't talk about MAP too much(pretty sure it won't work I THINK the stock sensor only does 1.5 bar[21lbs?] not sure I'm remembering correctly) but while the coolant temp sensor works just fine, oil temp is a no go, BUT that could be a bad sensor, I haven't even bothered replacing it as I'll take care of it when I turbo the car, but I plan on getting an aftermarket sensor so I won't have an answer for you on that. The rest of the sensors seem to function just fine with the haltech elite 2500, though I will tell you only use beck/arnley factory replacement sensors for crank and cam position. I tried to use some cheap ones because my swap car is my daily and I was trying to be both quick and take care of a number of issues from the swap at the same time, the cheap ones did NOT provide a very good signal and the haltech reported a lot of miss reads or no reads which just made the engine run like crap and burn extra fuel. While I hear people complain about project/daily cars, daily driving your project helps you flush out a lot of problems so while there have been some periods of time that sucked to drive the car during the process, I was able to get a lot of things worked out faster because of the constant driving.

Overall though, man does the car bring a smile to my face when I get on it, and I'm still running a base model 5spd, the JDM Spec.b 6spd(gears 1-4 match JDM STI 6spd while 5 and 6 are much better for fuel than the STI) should be in by the end of February, and I know that will be even better.

[Kito818]

Unrelated to active topics, but I don't think the EZ30 likes 5spd transmissions. I've been fighting an issue with the clutch on mine since the swap. I thought it was a bad bleed on the clutch system for awhile, I had never bled a clutch system before, never needed to on my previous cars. So I went through that process a few times, then I found the plate that holds the shift strut to the transmission had ripped one bolt out, destroyed the threads and I had to drill and helicoil that hole, the rest of the plate sheared off above the bottom two bolts, one of which also had previously met a similar fate because it already had a helicoil installed. I hammer fabricated a new plate out of stainless steal, it wasn't pretty, but it worked, didn't flex a lot and I was proud of it because I made it with just a scrap piece of stainless at work, a micro sledge, chop saw, bench grinder, and a vice. It worked long enough for me to order a replacement online. Still having issues so I bench bled the clutch system, still having issues, still having issues, still having issues, finally the master cylinder blew out(it wasn't even a year old), so I replaced the master cylinder, the hard line, a braided stainless replacing the soft line, and while it's 'better' now, the syncros are trashed, it grinds going into every gear but 5th now. I'm waiting on a reply for the spec.b rear differential that matches with the transmission I already have, hoping to order it tomorrow, so I'll be swapping over here soon, but thought I leave this in here for people who may be attempting in the future. Yes everything bolts up with the 5spd, but I think the pressure plate doesn't quite completely release the clutch from the flywheel which makes shifting difficult and idling annoying. Maybe if the whole clutch system, master cylinder, slave cylinder, clutch line are swapped at the start with a good bleed things might work out better, I don't know.

It was always in the plan to get the 6spd in for my car so it wasn't/isn't a huge deal for me, but if you're reading this because you're planning a build, spend the extra money to buy a full drive train swap. If I had bought my engine just a month later there was another deal that came with an uncut wire harness drive shaft, rear diff, all four C/Vs, and front and rear suspension for the same price that I paid to get just my spec.b engine and trans with a cut harness. Otherwise I'd recommend buying just an engine then getting a matching full 6spd conversion package. My approach may have been the bad idea, I started with a base model impreza with the idea of building up from there, rather than buying a WRX or STI, but I thought, and still feel this way so far, that starting with the base model is better since they're both cheaper and easier to find. Often they're also not as abused(biggest reason for me) as much as the WRX or STI models.

[Kito818]

Originally Posted by RubyLGT

Awesome thread, I bet an h6 imp is a blast!

Originally Posted by vicious_fishes

Yeah it's like driving a v8 around. But awd, with handling.

I really wish there was some kind of thumbs up for this post. It very much is a blast and I'm not even close to done yet.

[jvangelder]

Originally Posted by Kito818

How much are you selling those extras you made for? PM me the details I'd like to know.

Sent,

By chance, do you have the factory map sensor pinout?

[vicious_fishes]

Originally Posted by Kito818

Unrelated to active topics, but I don't think the EZ30 likes 5spd transmissions. I've been fighting an issue with the clutch on mine since the swap. I thought it was a bad bleed on the clutch system for awhile, I had never bled a clutch system before, never needed to on my previous cars. So I went through that process a few times, then I found the plate that holds the shift strut to the transmission had ripped one bolt out, destroyed the threads and I had to drill and helicoil that hole, the rest of the plate sheared off above the bottom two bolts, one of which also had previously met a similar fate because it already had a helicoil installed. I hammer fabricated a new plate out of stainless steal, it wasn't pretty, but it worked, didn't flex a lot and I was proud of it because I made it with just a scrap piece of stainless at work, a micro sledge, chop saw, bench grinder, and a vice. It worked long enough for me to order a replacement online. Still having issues so I bench bled the clutch system, still having issues, still having issues, still having issues, finally the master cylinder blew out(it wasn't even a year old), so I replaced the master cylinder, the hard line, a braided stainless replacing the soft line, and while it's 'better' now, the syncros are trashed, it grinds going into every gear but 5th now. I'm waiting on a reply for the spec.b rear differential that matches with the transmission I already have, hoping to order it tomorrow, so I'll be swapping over here soon, but thought I leave this in here for people who may be attempting in the future. Yes everything bolts up with the 5spd, but I think the pressure plate doesn't quite completely release the clutch from the flywheel which makes shifting difficult and idling annoying. Maybe if the whole clutch system, master cylinder, slave cylinder, clutch line are swapped at the start with a good bleed things might work out better, I don't know.

It was always in the plan to get the 6spd in for my car so it wasn't/isn't a huge deal for me, but if you're reading this because you're planning a build, spend the extra money to buy a full drive train swap. If I had bought my engine just a month later there was another deal that came with an uncut wire harness drive shaft, rear diff, all four C/Vs, and front and rear suspension for the same price that I paid to get just my spec.b engine and trans with a cut harness. Otherwise I'd recommend buying just an engine then getting a matching full 6spd conversion package. My approach may have been the bad idea, I started with a base model impreza with the idea of building up from there, rather than buying a WRX or STI, but I thought, and still feel this way so far, that starting with the base model is better since they're both cheaper and easier to find. Often they're also not as abused(biggest reason for me) as much as the WRX or STI models.

none of the 5 speeds are even close to tall enough. not even the factory h6 legacy tall ratio 6 speed is tall enough.

i very seriously considered swapping a transmission from a diesel forester.

[Kito818]

Originally Posted by vicious_fishes

none of the 5 speeds are even close to tall enough. not even the factory h6 legacy tall ratio 6 speed is tall enough.

i very seriously considered swapping a transmission from a diesel forester.

Tall in what way? If you mean the gears aren't tall enough, I'd agree the 07 5spd that was installed in my car before I bought it definitely isn't tall enough. The transmission is THE paired transmission for this block, not arguing that another transmission wouldn't be better suited for the engine, but the transmission is the one the factory paired with this engine before it was installed in the JDM Spec.b the combo came out of (I think it's the tall ratio 6speed you mentioned).

One of my weaknesses in the automotive arena is gear ratios so, forgive me if what I'm about to say sounds stupid or just completely wrong, and please do correct me I want to learn. I noticed that the 5spd 5th gear ratio is 0.780, JDM spec.b 6th gear is 0.756, and JDM WRX/STI 6spd is 0.707. If 1st gear is the least fuel efficient/fastest accelerating gear and 5th/6th is the most fuel efficient/slowest accelerating gear, doesn't that mean that I would want a 0.707 6th gear if I was more interested in fuel efficiency, or do I have that backwards?

[jacky4566]

Gear ratios are not directly related to fuel efficiency. You can drive around at 60km/h in 3rd gear and it will be just as efficient as 80km/h in 4th. You need to look at the demanded torque, the BSFC of that particular engine and the RPM/ Transmission ratio/ tire size. Chart to help illustrate.

Because the H6 is a bit more grunty and probably has a better BSFC in the lower RPM you can use a taller transmission and get better economy. Engineers spend many hours trying to get JUST the right ratios for the best fuel efficiency and sporty feel. Plus having a lower reving engine on the highway is just quieter.

[Kito818]

Originally Posted by jacky4566

Gear ratios are not directly related to fuel efficiency. You can drive around at 60km/h in 3rd gear and it will be just as efficient as 80km/h in 4th. You need to look at the demanded torque, the BSFC of that particular engine and the RPM/ Transmission ratio/ tire size. Chart to help illustrate.

Because the H6 is a bit more grunty and probably has a better BSFC in the lower RPM you can use a taller transmission and get better economy. Engineers spend many hours trying to get JUST the right ratios for the best fuel efficiency and sporty feel. Plus having a lower reving engine on the highway is just quieter.

The quiet part is something I want a lot. Most of the time I feel like the lone tuner who wants an almost silent performance car lol, while every other car just gets louder and louder. My stylization point is towards stealth builds though, and loud engine noise takes away from that. Back to your point about efficiency not being directly tied to gear ratios, the link you shared was very useful and I'm going to be making some adjustments and testing based on the post, specifically using a vaccum gauge to somewhat display fuel economy. It also helps simplify my question, or answers it really. Thanks for the post.

[vicious_fishes]

Originally Posted by Kito818

Tall in what way? If you mean the gears aren't tall enough, I'd agree the 07 5spd that was installed in my car before I bought it definitely isn't tall enough. The transmission is THE paired transmission for this block, not arguing that another transmission wouldn't be better suited for the engine, but the transmission is the one the factory paired with this engine before it was installed in the JDM Spec.b the combo came out of (I think it's the tall ratio 6speed you mentioned).

One of my weaknesses in the automotive arena is gear ratios so, forgive me if what I'm about to say sounds stupid or just completely wrong, and please do correct me I want to learn. I noticed that the 5spd 5th gear ratio is 0.780, JDM spec.b 6th gear is 0.756, and JDM WRX/STI 6spd is 0.707. If 1st gear is the least fuel efficient/fastest accelerating gear and 5th/6th is the most fuel efficient/slowest accelerating gear, doesn't that mean that I would want a 0.707 6th gear if I was more interested in fuel efficiency, or do I have that backwards?

yes as in taller gears.

707 for fuel efficiency, but even that isn't tall enough, it's just the best you'll be able to get other than a diesel 'box.

you'll need to get a speed sensor machined into the bell housing though. it cost me about $100.

[Kito818]

Originally Posted by vicious_fishes

yes as in taller gears.

707 for fuel efficiency, but even that isn't tall enough, it's just the best you'll be able to get other than a diesel 'box.

you'll need to get a speed sensor machined into the bell housing though. it cost me about $100.

I have wheel speed sensors so I'm not sure that will be necessary, at least I hope not. My current transmission, which is from an 07, has a speed sensor, but it's blocked off(wires cut at the base), and there isn't even a harness connector that goes to the trans for it either, yet speedometer works fine, as does ABS.

[DSR-3]

FWIW I have had no issues in 2k+ miles with an EZ30R + 5MT in my 818. The clutch works well, shifts normally, and the gearing is fine for street driving. I have not had it on track yet, but that's usually a compromise with any street car on track. I am using a WRX clutch and ACT flywheel.

[Zabnorg]

Okay, I have successfully pounded thru this entire thread and feel I should make myself known.

I have a bugeye slugbutt 2003 Impreza that desperately needs more torque, and thanks to maniacs like Eazy E(van) and Bruceyy on the Outback forum providing ideas and goading on I have pulled the trigger on a donor car (2002 LLBean) and am currently collecting parts from the local pick and pulls, of which there are 5 or 6 within 50 miles of my house. (Gotta love the Bay Area!).

iWire will be dealing with the harness merge and I'm 50/50 on trying to switch out to the auto AC setup or retaining the manual AC somehow, auto seems easier but that means I need more junkyard parts (the friend who was babysitting the Bean and let me tear out the motor/trans at her place - twice so far - has bonded with the donor car on a trip to LA and has offered to cover both replacement parts - including a pick and pull motor/trans I plan on grabbing this weekend with a purchased 12 month warranty for what was going to be $600 but fortuitously they have a 40% of sale this weekend - and the purchase price of the car. Plus, she's just an awesome human and deserves a quality ride.

For the donor, the body and interior were meh but basically the reason for selling was the guy was sick of fixing it (but he took *very* good care of it, fixed everything that came up) and the money outlay involved. Probably sick of the gas mileage and filling up on premium as well, since I talked him down on price with an offer to help him pick a replacement hauler for his musician's gear - he chose a Prius V. Engine has had head gaskets and water pump replaced and transmission was basically new - until I tweaked something bolting it to the engine after a rear main seal replacement that it probably didn't need. *Sigh* Welp, trans came home with me the next time I pulled the lump out and I'll be rebuilding it with a RatioTec shift kit and custom aluminum accumulator pistons I scored from Strider327 (also a Bay Area local, although he rides in an Evo now).

Once I get this junkyard lump over to my friend's place, I can grab the donor motor and drag it home with me for safekeeping until the harness is done. Planning on some mild porting/port matching and checking the valve lash while I wait for harness and school to finish up in May before I go for it.

Cheers and many thanks,
Dave

[Kito818]

Originally Posted by DSR-3

FWIW I have had no issues in 2k+ miles with an EZ30R + 5MT in my 818. The clutch works well, shifts normally, and the gearing is fine for street driving. I have not had it on track yet, but that's usually a compromise with any street car on track. I am using a WRX clutch and ACT flywheel.

I have around 15k on my EZ30Rx5MT, though I will absolutely give you that there could be(or could have been) something else causing problems. I do also find it ironic that you timed this post to the day I lost 3rd and 4th gear, and lost is a good term as there is NOTHING there when I shift to either gear. No resistance, no grind, no noise, no gears, nothing there at all, which scares me. I have to go to work tonight but will have the time to work on the trans swap tomorrow and have the new companion flange for the differential showing up today(just checked it's been delivered), gear oil(Subaru Extra S 75W90) showed up yesterday, so that should be it. I hope your 5MT setup works for you, and there are so many "other" factors that I honestly can't say that it's not a good pairing, but a lot of people with the swap did theirs with a 6MT, and I know for the 818s there was a block off plate made to get rid of the longer rear drive shaft neck that allowed them to fit the 6MT in the cage. But I was hoping to hear from anyone else who had the 5MT pairing. Glad it's working out for you.

[Kito818]

Originally Posted by Zabnorg

Okay, I have successfully pounded thru this entire thread and feel I should make myself known.

I have a bugeye slugbutt 2003 Impreza that desperately needs more torque, and thanks to maniacs like Eazy E(van) and Bruceyy on the Outback forum providing ideas and goading on I have pulled the trigger on a donor car (2002 LLBean) and am currently collecting parts from the local pick and pulls, of which there are 5 or 6 within 50 miles of my house. (Gotta love the Bay Area!).

iWire will be dealing with the harness merge and I'm 50/50 on trying to switch out to the auto AC setup or retaining the manual AC somehow, auto seems easier but that means I need more junkyard parts (the friend who was babysitting the Bean and let me tear out the motor/trans at her place - twice so far - has bonded with the donor car on a trip to LA and has offered to cover both replacement parts - including a pick and pull motor/trans I plan on grabbing this weekend with a purchased 12 month warranty for what was going to be $600 but fortuitously they have a 40% of sale this weekend - and the purchase price of the car. Plus, she's just an awesome human and deserves a quality ride.

For the donor, the body and interior were meh but basically the reason for selling was the guy was sick of fixing it (but he took *very* good care of it, fixed everything that came up) and the money outlay involved. Probably sick of the gas mileage and filling up on premium as well, since I talked him down on price with an offer to help him pick a replacement hauler for his musician's gear - he chose a Prius V. Engine has had head gaskets and water pump replaced and transmission was basically new - until I tweaked something bolting it to the engine after a rear main seal replacement that it probably didn't need. *Sigh* Welp, trans came home with me the next time I pulled the lump out and I'll be rebuilding it with a RatioTec shift kit and custom aluminum accumulator pistons I scored from Strider327 (also a Bay Area local, although he rides in an Evo now).

Once I get this junkyard lump over to my friend's place, I can grab the donor motor and drag it home with me for safekeeping until the harness is done. Planning on some mild porting/port matching and checking the valve lash while I wait for harness and school to finish up in May before I go for it.

Cheers and many thanks,
Dave

Go for it! Keep us up to date, if you want to save some money and do your own wiring I can share the pinout for the two connectors on the back of the engine, though I encourage you to check it against your motor, since you wont have the AVLS(or is it the AVCS?) and that may change the pin outs in the plugs. Good luck, and I look forward to some nice pictures!