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BMS JB4 'Piggyback' Tune for the 2.4T Outback(s)

29007 Views 515 Replies 36 Participants Last post by  teamdrop
After searching for available performance parts for the 2.4T, I learned that Burger Motorsports had the JB4 available for the ‘22+ WRX. I reached out and they replied that it would work with the 2.4T Outback as well. It is still in Beta format but I still went for it and placed my order. I received it on Monday and spent 1hr last night installing it. I opted for the Bluetooth module and purchased the app (personally, I think that they should include a one-time use code if you opt for the BT module add-on because it feels like they’re nickel & diming the customer to keep purchasing extras).
The install was straight forward and the online PDF/directions were pretty thorough (if you have some sort of mechanical competency). Identifying the plugs that are sandwiched was pretty easy. Pulling the HPFP plug was a pain and removing the front belly pan was the most labor intensive to get at the EWG plug at the Turbo. I rigged the OBDll plug and went out the door jamb because I couldn’t access firewall port last night (I will reroute it this weekend when I have time to pull more stuff apart..). After everything was installed and zip tied, I started it and connected the BT app and took it for a drive.
Now, on to the good stuff, and it is good. The JB4 is pretty simple in function; uses general operating parameters with data collected from motor via the module plugs & OBDll plug to override the factory mapping and controls the Electronic Waste Gate to hold boost longer rather than bleeding it (simplest explanation without getting too technical). I certainly feel the added power without a doubt. The drivability is absolutely normal and feels like stock in terms of the cars mannerisms while driving. The power comes on smooth and pulls harder all the way to redline. The CVT is totally unaffected by the additional power and drives and ‘shifts’ very similar to normal. In the end, it really is about a 40-50hp gain and is very suitable for the Outback considering the weight of the car, gearing and the fact that it IS NOT a WRX. I have only run Map2 which is for 93oct. I have ample access to E85 so I could run the E30/40 map too if I wanted and probably will just to test it out. My goal was to add a bit more power, which to me adds some confidence passing, entering a highway etc and for me, goal met. I have driven a true tuned cars for the past 15yrs (with the exception of my Gen5 3.6R) so I do feel that I have a very realistic expectation and understanding of tunes. In this case, I am onboard with the plug & play module vs a remapped ECU tune so that I can remove if/when needed and there’s also going to be a market to sell it down the road to the anyone driving the 2.4T if I decide I do not want it any longer. This option gives me what I think the car needs and I have zero concerns for the CVT handling the power, especially considering others will tow thousands of pounds regularly which will have much more strain on the CVT than adding 40ish more hp. On another note, it is still hot & humid here in the Tri-state area and the car will perform much better when the IAT’s drop with the change of the weather.
I will add some install pics this weekend when I have more time and continue to report progress with more usage. Feel free to ask questions and I will answer as best as I can. I also have ZERO affiliation with BMS and am just sharing information with the community for those that may be interested .

Cheers

Link to product page:
JB4 Tuner for 2022+ Subaru WRX BETA
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I got a long 3”ID 45 degree silicone coupler off of Amazon. After wrestling with it for 1 hour and testing different angles, this is the best I could do. At least I got the ram air duct to fit. I hope someone will go to Burger Motorsports so they can make an Outback XT intake. You’ll most likely get a free intake for your troubles :)
 

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I got a long 3”ID 45 degree silicone coupler off of Amazon. After wrestling with it for 1 hour and testing different angles, this is the best I could do. At least I got the ram air duct to fit. I hope someone will go to Burger Motorsports so they can make an Outback XT intake. You’ll most likely get a free intake for your troubles :)
May I ask - Is your Filter “crinkled” because it sticks up too high and the hood is mushing it down on itself? I appreciate you testing the waters and sharing your results with us.
 

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It’s me strong arming it in multiple configurations before. Expression of my frustration lol
I will admit, I am highly interested in following your path and getting the LaMarche DP, Perrin CP, and BMS intake… I am worried though - without E30 (or ethanol for that matter) being accessible nearby (nearest station with e85 is 30 miles in the wrong direction) that this would be worth it. I have 93 available but question it’s volatility in addition to the reliability of the BMS tune. I know you have had great results, what are your thoughts?
 

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You can run Map2 for good gains without any E30. The E30 adds a layer of knock protection to maps 3,4, and 5 so you can run more boost. Higher ethanol contents like E60 and E85 drastically alter the tune whereas lower ethanol content is more protective to supplement 93 octane. JB4 OTS tunes are fairly conservative when you see Cobb protunes shatter the 400whp barrier with just stage 2.

I put on an O2 spacer because I was getting P0420 despite having a Catted Lachute downpipe but the stock downpipe has 2 catalytic converters. Unfortunately that code is still popping up for me. It doesn’t hinder the car’s performance and is easily cleared with the JB4. Definitive solution is to add another cat right after the turbo like the stock downpipe.

I’d honestly wait until a company comes out with an Outback XT specific intake and an appropriately Catted downpipe :)
 

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I put on an O2 spacer because I was getting P0420 despite having a Catted Lachute downpipe but the stock downpipe has 2 catalytic converters. Unfortunately that code is still popping up for me. It doesn’t hinder the car’s performance and is easily cleared with the JB4. Definitive solution is to add another cat right after the turbo like the stock downpipe.
I am sure the people affected are aware, but just in case...In states which have emission inspections, the vehicle will not pass if it has a Check Engine Light.

I’d honestly wait until a company comes out with an Outback XT specific intake and an appropriately Catted downpipe :)
Good advice. :)
 

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I wonder if just running the charge pipe would increase intake sound. I really miss my turbo noises and wouldn't mind getting an intake, but would rather wait for a a solution tailor made for the Outback and it seems like the WRX charge pipe fits perfectly.
 

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@User1029 Are you planning more dyno runs in between changes? I'm always reminded of a segment on Horsepower TV(I think) where they dyno'd after every change and it turned out that some of the combinations didn't work well with each other and ended up reducing power.
absolutely, I’m trying to get a dyno scheduled this week to see the difference the intake and charge pipe made :)
 

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I wonder if just running the charge pipe would increase intake sound. I really miss my turbo noises and wouldn't mind getting an intake, but would rather wait for a a solution tailor made for the Outback and it seems like the WRX charge pipe fits perfectly.
I think removing the charcoal filter will allow you to hear a little more of the turbo rather than starting with the charge pipe :)
 

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installed the 2022 WRX Perrin charge pipe today :)

1. Fitment is perfect for the outback XT
2. The instructions said to take off radiator fan but the Outback radiator fan configuration is different than the WRX. You can’t just take off one fan, you have to off the whole row. I decided not to take off the radiator fans and install still went smoothly.
3. Turbo sounds 15% louder with more streamlined flow and no bottlenecks in the charge pipe :) butt dyno approved :)
can you share what other angle components required for pipe? Thanks!
 

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After a basic evaluation of the one you installed and the 2 perrin options show on the site the 22' WRX version looks to be the one, would that be a correct assessment? Because your link doesnt go to the 22 WRX but the earlier version. It also appears you cant copy the link to the 22 wrx one, the dns always brings up the 2015-2021 one.
 

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Yup I ordered the 2022 WRX charge pipe. I didn’t need any extra hardware for the charge pipe :) you’ll need an 8” long, thin flat head screwdriver to pry the charge pipe clip at the turbo compressor outlet. Then you transfer the Oring and clip to the Perrin adaptor.

I used this video as a guide for taking off the OEM charge pipe
 

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Yup I ordered the 2022 WRX charge pipe. I didn’t need any extra hardware for the charge pipe :) you’ll need an 8” long, thin flat head screwdriver to pry the charge pipe clip at the turbo compressor outlet. Then you transfer the Oring and clip to the Perrin adaptor.

I used this video as a guide for taking off the OEM charge pipe
I was able to use the coupon SAVE10 and got it for $260 total, Thanks!
 

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My $0.02....

If an aftermarket product, which has the effect of changing the AFR (typically by allowing more air), a product which can monitor and report on AFR should be a requirement. Why?

I am under the impression, which may be incorrect, ECUs are limited in how much they can adjust AFR/timing in response to more air, e.g., removing the charcoal canister. More air with no more fuel results in a leaner mixture.

Perhaps someone who knows the Gen 6 Subaru engines and their ECUs can comment?
 

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My $0.02....

If an aftermarket product, which has the effect of changing the AFR (typically by allowing more air), a product which can monitor and report on AFR should be a requirement. Why?

I am under the impression, which may be incorrect, ECUs are limited in how much they can adjust AFR/timing in response to more air, e.g., removing the charcoal canister. More air with no more fuel results in a leaner mixture.

Perhaps someone who knows the Gen 6 Subaru engines and their ECUs can comment?
I hope to share that my carbonless filter butt dyno will have a positive contribution 😅
 

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I'm curious if that rubber padding on the OEM plastic charge pipe is there for sound deadening? I wonder if it can be removed? Since you took your OE charge pipe out, maybe you can investigate, @User1029

The other use for that padding could be to keep the heat within the charge pipe, but I'm not sure I can see the benefit of that. People wrap headers to keep heat inside the exhaust prior to entering the turbo, but we generally want the hot compressed air leaving the turbo to cool down, which is why we have an intercooler.
 
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