TheSamba.com :: View topic - Subaru Conversion with late model Subaru engine +2012 FB25B

Sat Jul 07, 2018 12:59 pm

Hello all,
Ive been considering a Subaru Conversion using a 2012 Forester XT Donor for engine and tranny. Specifically the FB25B T engine instead of the EJ engine with the Small Car Kit. All the conversions I see seem to be 2006 or earlier EJ engines. I cant find anything on whether this is a good idea or not. Anyone have experience with a conversion using FB engine? Still in the research stage of conversion. All input welcome.

89 Canadian Westfalia.

Thanks!
Bob

Sat Jul 07, 2018 3:09 pm

If you're gonna register it in California, you'll need all the smog related parts, body control module, etc.
The F series engine will fit on the older transmissions, so using a reverse ring and pinion set is doable.
iWire can make you the necessary harness.

Sat Jul 07, 2018 4:43 pm

The EJ swap is a well sorted and documented conversion. There are several variations of the EJ and I would encourage you to research all of these before making an engine decision. The 2006-2008 2.5 SOHC drive-by-wire is a nice swap with 173HP.

The FB does have its advantages. It should have more torque with the longer stroke and is a newer engine. The downside is that you'd be blazing new ground.

There are more EJ swap kits than Small Car. Look at RJES, Rocky Mountain Westy, and Vanaru to name a few.

You also need to read up on the California laws regarding engine swaps. Most go with the pre-approved Subaru 2.2 with Kennedy kit. I read through the CA laws recently and they do state that you can use any engine that meets CA smog laws. You would need to source an engine from a CA car and be sure to have ALL of the related emissions parts. It will still likely be a hassle to get registered even if you do everything right.

Here is a good place to start.
https://www.bar.ca.gov/Industry/Engine_Change_Guidelines.html

Good luck.

Sat Jul 07, 2018 10:34 pm

11BC2 wrote: If you're gonna register it in California, you'll need all the smog related parts, body control module, etc.
The F series engine will fit on the older transmissions, so using a reverse ring and pinion set is doable.
iWire can make you the necessary harness.

Yes I am looking for a donor car that is complete so that I can bring over all emission control equipment. I am concerned about some of the necessary sensors eg speed sensor, torque etc that may be used for emissions management. Does Iwire do harnesses in California?

Thanks
Bob

Sat Jul 07, 2018 10:52 pm

Take a look at www.subatronics.com. They make a CAN Bus emulator that will allow the engine management system that goes along with the FB25 to be used in a conversion.

The engine mounts are in the same place as those on the EJ engines, so the established engine carrier systems should work. since the cylinder spacing is tighter on the FB, I'm guessing the existing headers won't work. Not sure about the oil pan. I know it's a deep unit like and EJ, so it should be possible to shorten it and gain clearance, but I don't know if it shares the shape and bolt pattern with the EJ. I doubt it does.

It would be a lot of work to do a conversion using an FB25, but it would be nice to see someone do it. It's getting harder to find EJ25s with reasonable mileage on them given their age.

Sat Jul 07, 2018 11:36 pm

The FB is a newer engine, and some of the early ones displayed a problem with excessive oil consumption. Subaru has fixed the design, but the 2012's, like my Forester, were susceptible. (I did get a new short block out of it.) If your engine is coming from a running donor, be sure to do the Subaru devised oil consumption test.

Also remember that the turbo engine you're considering demands that the drive train needs to be in top condition.

Sun Jul 08, 2018 7:57 am

D Clymer wrote: Take a look at www.subatronics.com. They make a CAN Bus emulator that will allow the engine management system that goes along with the FB25 to be used in a conversion.

The engine mounts are in the same place as those on the EJ engines, so the established engine carrier systems should work. since the cylinder spacing is tighter on the FB, I'm guessing the existing headers won't work. Not sure about the oil pan. I know it's a deep unit like and EJ, so it should be possible to shorten it and gain clearance, but I don't know if it shares the shape and bolt pattern with the EJ. I doubt it does.

It would be a lot of work to do a conversion using an FB25, but it would be nice to see someone do it. It's getting harder to find EJ25s with reasonable mileage on them given their age.

Thanks for the tip. I looked at the Subatronics Canbus emmulator because im also considering Subgears tranny conversion. I also am considering using an Arduino with Canbus shield and hacking the codes.

As far as the oil pan fit, illl give Small Car a call tomorrow to find out about the bolt pattern and fitment on FB engines

Sun Jul 08, 2018 8:03 am

WLD*WSTY wrote: The FB is a newer engine, and some of the early ones displayed a problem with excessive oil consumption. Subaru has fixed the design, but the 2012's, like my Forester, were susceptible. (I did get a new short block out of it.) If your engine is coming from a running donor, be sure to do the Subaru devised oil consumption test.

Also remember that the turbo engine you're considering demands that the drive train needs to be in top condition.

Interesting. What was the cause of the oil consumption?was there a recall? what was the fix?

As far as drive train condition, I plan to use a reversed 5 speed Subaru tranny.

Sun Jul 08, 2018 8:30 am

I'd like to see more folks putting in the 3.6R with a subaru 5 speed. Not sure if these suffer the same oil consumption issues. It seems CANbus and changes to how the ECU interacts with the transmission, etc make this swap more complicated from the electrical end of things.

I'm unsure of the oil consumption root cause but I know my friend had a forester which got a replaced shortblock under warranty due to oil consumption and it didn't have high miles either. I want to say ~30k or less.

Sun Jul 08, 2018 12:44 pm

rmengr1 wrote: 11BC2 wrote: If you're gonna register it in California, you'll need all the smog related parts, body control module, etc.
The F series engine will fit on the older transmissions, so using a reverse ring and pinion set is doable.
iWire can make you the necessary harness.

Yes I am looking for a donor car that is complete so that I can bring over all emission control equipment. I am concerned about some of the necessary sensors eg speed sensor, torque etc that may be used for emissions management. Does Iwire do harnesses in California?

Thanks
Bob

There are really two questions here. First is the conversion, second is getting it smog legal in California. I don't think Small Car is installing 2012 Forester engines in their shop yet, so you might ask them why that is. In regards to smog legal in California, as others have said, you will need to install all of the original donor vehicle emissions equipment. Typically, when you take it to a Bar Referee, that means the original header and exhaust up through the cats. It also means a fuel tank pressure sensor and other "emissions" equipment that will take quite a bit of work to install. The following is a good thread to read:

https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Sun Jul 08, 2018 2:01 pm

brokengun wrote:

I'm unsure of the oil consumption root cause but I know my friend had a forester which got a replaced shortblock under warranty due to oil consumption and it didn't have high miles either. I want to say ~30k or less.

Poor cylinder wall surface finish due to improper honing. This was also exasperated by using 0w20 oil and extended oil change intervals.

Sun Jul 08, 2018 9:40 pm

11BC2 wrote: brokengun wrote:

I'm unsure of the oil consumption root cause but I know my friend had a forester which got a replaced shortblock under warranty due to oil consumption and it didn't have high miles either. I want to say ~30k or less.

Poor cylinder wall surface finish due to improper honing. This was also exasperated by using 0w20 oil and extended oil change intervals.

I have an 07 forested ej2.5 that I had to re ring to fix an oil burning issue. So is this fixed with honing and rings or are cylinder walls hosed on the later engines?

Sun Jul 08, 2018 10:38 pm

Subaru has to "fix" any FB engine that exhibits excessive oil consumption. This generally means they replace the short block and extend the engine warranty. Subaru has been silent about the cause, since they don't admit to there being a problem.

There is a complete list of cars that may be affected, and many more details of the class action suit here:

http://www.oilconsumption.settlementclass.com/index.html

Mon Jul 09, 2018 9:24 pm

WLD*WSTY wrote: Subaru has to "fix" any FB engine that exhibits excessive oil consumption. This generally means they replace the short block and extend the engine warranty. Subaru has been silent about the cause, since they don't admit to there being a problem.

There is a complete list of cars that may be affected, and many more details of the class action suit here:

http://www.oilconsumption.settlementclass.com/index.html

Wow that is a tough recall for Subaru. Cant get much worse than that.

Mon Jul 09, 2018 9:33 pm

D Clymer wrote: Take a look at www.subatronics.com. They make a CAN Bus emulator that will allow the engine management system that goes along with the FB25 to be used in a conversion.

The engine mounts are in the same place as those on the EJ engines, so the established engine carrier systems should work. since the cylinder spacing is tighter on the FB, I'm guessing the existing headers won't work. Not sure about the oil pan. I know it's a deep unit like and EJ, so it should be possible to shorten it and gain clearance, but I don't know if it shares the shape and bolt pattern with the EJ. I doubt it does.

It would be a lot of work to do a conversion using an FB25, but it would be nice to see someone do it. It's getting harder to find EJ25s with reasonable mileage on them given their age.

So I did talk to Smallcar this morning and they have done an Fb series engine swap. He said they liked the way it turned out. Also they are working on an oil pan for the Fb engine series. Apparently these are more work for conversions because of the ecu/harness.

Wed Sep 19, 2018 9:43 pm

D Clymer wrote: Take a look at www.subatronics.com. They make a CAN Bus emulator that will allow the engine management system that goes along with the FB25 to be used in a conversion.

The engine mounts are in the same place as those on the EJ engines, so the established engine carrier systems should work. since the cylinder spacing is tighter on the FB, I'm guessing the existing headers won't work. Not sure about the oil pan. I know it's a deep unit like and EJ, so it should be possible to shorten it and gain clearance, but I don't know if it shares the shape and bolt pattern with the EJ. I doubt it does.

It would be a lot of work to do a conversion using an FB25, but it would be nice to see someone do it. It's getting harder to find EJ25s with reasonable mileage on them given their age.

Hi D Clymer

Maybe you can answer this question ... Does Subatronics Canbus spoof the ECU and the Body control unit with canbus codes so that you dont need to modify the harness?

Wed Sep 19, 2018 10:30 pm

rmengr1 wrote: D Clymer wrote: Take a look at www.subatronics.com. They make a CAN Bus emulator that will allow the engine management system that goes along with the FB25 to be used in a conversion.

The engine mounts are in the same place as those on the EJ engines, so the established engine carrier systems should work. since the cylinder spacing is tighter on the FB, I'm guessing the existing headers won't work. Not sure about the oil pan. I know it's a deep unit like and EJ, so it should be possible to shorten it and gain clearance, but I don't know if it shares the shape and bolt pattern with the EJ. I doubt it does.

It would be a lot of work to do a conversion using an FB25, but it would be nice to see someone do it. It's getting harder to find EJ25s with reasonable mileage on them given their age.

Hi D Clymer

Maybe you can answer this question ... Does Subatronics Canbus spoof the ECU and the Body control unit with canbus codes so that you dont need to modify the harness?

Yes, that's correct. It's a CAN-Bus emulator. It works very well from all the reports I've heard and the engine runs happily using its original ECU. You would still have to modify the engine harness, though, to separate it from the main Subaru front body harness.

D