Mild Modifications

Luke Rado

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Joined
Oct 6, 2017
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44
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Gold Coast QLD Australia
Hey Guys,
As my Warranty period starts to wind down, I’m starting to think about mods and seeing as bulk power is out of the question with the CVT Limits, I was hoping anyone with the following mods could provide input and their own experiences. A few more noises to get that race car feels is what I am hoping for, TIA!
 

Luke Rado

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Oct 6, 2017
Messages
44
Location
Gold Coast QLD Australia
BOV - (Blow off Valve)
I asked on a seperate thread, but might as well ask here for completeness. Any fit a vent to Arno style? I’m thinking a GFB Deceptor Pro style one so I can turn it off and on haha but I guess my question is, does it affect the CVT/Stall with getting off the throttle? Don’t know anyone with a CVT and BOV (vent to atmo)
 

Luke Rado

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Oct 6, 2017
Messages
44
Location
Gold Coast QLD Australia
Varex/Rear Muffler only,
I’m thinking a Varex so again can turn race car up or down, but what’s the Levorg like with a straight pipe/non baffled Exhaust with the factory exhaust. MRTs video says there is little gain from a brand new exhaust, so I’m thinking rear only for controllable baffle/rumble/FA non rumble
 

Luke Rado

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Oct 6, 2017
Messages
44
Location
Gold Coast QLD Australia
Other mods I’m unsure of:

semi unequal length headers for that boxer rumble but still the bi-vane turbo response? Any technical gurus on here to suggest this is a bad idea?

Intercooler upgrade - eg Perrin, Cobb, PWR etc.
I’m thinking this would be more of an aesthetic/engine bay dress up with the amount of techno-wizardry in the computer, to provide any real world gains. Pretty sure the Computer limits boost and controls Air/Fuel?! Could be wrong, but the boost gauge readings bounce around like the computer is making ‘00s of fractional changes every second.

other than that I have sound system and Suspension upgrades planned. But I think I’m sorted on that.
 

Guvna

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May 18, 2017
Messages
316
Location
Victoria, Australia
Vehicle(s)
MY17 Subaru Levorg 2.0LTR GTS
CAI - (Cold Air Intake)
Do you actually hear any further intake noises.
Our Levorgs seem pretty soundproofed.
Gday Luke, Definitely more intake noise with a CAI, but you HAVE to get a Dynotune as well. For a slight increase you can tape off the top of the baffle bottle inside the stock air box, it's just there to quiet things down a bit. Not heaps more noise, but a little, especially driving in manual mode with the paddle shifters.
 

Guvna

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May 18, 2017
Messages
316
Location
Victoria, Australia
Vehicle(s)
MY17 Subaru Levorg 2.0LTR GTS
BOV - (Blow off Valve)
I asked on a seperate thread, but might as well ask here for completeness. Any fit a vent to Arno style? I’m thinking a GFB Deceptor Pro style one so I can turn it off and on haha but I guess my question is, does it affect the CVT/Stall with getting off the throttle? Don’t know anyone with a CVT and BOV (vent to atmo)
BOV not needed unless making big horses, they sound good, but because it happens after the MAF sensor and the air is vented to the atmosphere the ECU will inject too much fuel into the cylinder making it run very rich, this can eventually foul the spark plugs and clog the Catalytic Convertor, in extreme cases can melt it as unbuned fuel on the Cat burns very hot. The standard BPV on our cars works perfectly fine up to 20 odd psi.
 

Guvna

Active Member
Joined
May 18, 2017
Messages
316
Location
Victoria, Australia
Vehicle(s)
MY17 Subaru Levorg 2.0LTR GTS
Varex/Rear Muffler only,
I’m thinking a Varex so again can turn race car up or down, but what’s the Levorg like with a straight pipe/non baffled Exhaust with the factory exhaust. MRTs video says there is little gain from a brand new exhaust, so I’m thinking rear only for controllable baffle/rumble/FA non rumble
Without a Dyno exhaust gives a little extra not alot. You can do Catback or axleback without needing a dyno. Main difference is noise, cool noise ;) Also I found after I installed by catback the revs didn't drop off as much at the top end as stock did, but extra power...not really. But it's much more fun to drive hearing it respond to your inputs. I looked into the Varex myself for the open and close baffles but I installed Invidia Q300 Catback for around the same price as the 2 Varex mufflers would have cost, and also because the input tube of the Varex is larger diameter than the stock it would need to be fill-welded on, I wanted to avoid additional installation costs and fit it myself which the Invidia excelled at. It actually mounts up to all the standard exhaust points with zero mods needed and actually sits a little higher improving ground clearance, even though it is a larger diameter. It comes with the midpipe resinator so no drone, which would be the same for you if you just install mufflers and leave the stock resinator.
 

Guvna

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Messages
316
Location
Victoria, Australia
Vehicle(s)
MY17 Subaru Levorg 2.0LTR GTS
Other mods I’m unsure of:

semi unequal length headers for that boxer rumble but still the bi-vane turbo response? Any technical gurus on here to suggest this is a bad idea?

Intercooler upgrade - eg Perrin, Cobb, PWR etc.
I’m thinking this would be more of an aesthetic/engine bay dress up with the amount of techno-wizardry in the computer, to provide any real world gains. Pretty sure the Computer limits boost and controls Air/Fuel?! Could be wrong, but the boost gauge readings bounce around like the computer is making ‘00s of fractional changes every second.

other than that I have sound system and Suspension upgrades planned. But I think I’m sorted on that.
Unfortunately the twin spool turbos require equal length headers and nothing but equal length. If you install unequal length you have to ditch the twin spool for a single spinner and then BANG, boxer rumble be back, of course this will also require a dyno as well. Though the twin spool doesn't push you back in the seat as much as a single, it's pretty much always on boost so performs better into and out of corners. I watched a youtube video where they ran the 2015 twin spool wrx against an older single turbo, the single was quicker in a drag but slower around a track thanks to the twin spool staying on boost better, thought it was interesting.
As to intercooler upgrade, I think you're right that its more dress up than anything else, as the stock one is fine for the power it's making. Don't quote me on this one...but I THINK you can install a VTMIC without a Dyno. Of course you're also not taking advantage of the part then either. To take advantage of the bigger intercooler you'll need to upgrade the Intake and exhaust as well, a Bigger cooler will get more air in but then you need to get that extra air out as well, that means full turbo back and up-pipe, and of course a retune, the amount of power that would unleash in the engine would blow the CVT to bits in no time. There are some parts you can install without a retune (catback, axleback, Drop in high flow air filter = yes, Turbo back, CAI = no), but a retune will allow you to take full advantage of the new parts and give the available gains they have to offer.
As always these are my opinions and are provided just to give you my perspective, I err on the side of caution, there are people that will tell you installing a CAI doesn't require a retune too :confused:?
Hope all this helps, it would be good to see others ideas on these topics you've raised too.
 
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Luke Rado

Member
Joined
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Messages
44
Location
Gold Coast QLD Australia
BOV not needed unless making big horses, they sound good, but because it happens after the MAF sensor and the air is vented to the atmosphere the ECU will inject too much fuel into the cylinder making it run very rich, this can eventually foul the spark plugs and clog the Catalytic Convertor, in extreme cases can melt it as unbuned fuel on the Cat burns very hot. The standard BPV on our cars works perfectly fine up to 20 odd psi.
Thanks Guvna!
Yeah I am not super fussed on Power, I’ve come to terms that the CVT limits any real gains, but I’m just thinking of making more Subie noises haha rumbles whistles etc
I was a little concerned about the MAF and BOV issue, fouled sparks doesn’t sound healthy.
 

Guvna

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Messages
316
Location
Victoria, Australia
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MY17 Subaru Levorg 2.0LTR GTS
Same here. Was looking at a drop in K&N filter in the OEM Air box as I know that release more induction sounds, but researching further found that the reason it flows more freely and allows the sounds out is because it sacrifices MOST of it's filtering capabilities :(
Would rather do without the sounds than send debris into the turbo and trash it. There are some very good youtube video tests on air filters. The most induction noises will come from a CAI, gonna look into their filtering capabilities a bit more and hope they do both jobs, Filtering and High Flow (if that's possible). Hopefully its not a matter of 'you have to sacrifice one for the other'.
Running no blow off valve at all (BOV Delete) gives that cool flutter, but not sure how that goes with a non-manual?
The search for sounds continues lol
 

BigShorts

New Member
Joined
Jan 6, 2021
Messages
1
Vehicle(s)
MY16 Levorg 2.0
Hey Guys,
As my Warranty period starts to wind down, I’m starting to think about mods and seeing as bulk power is out of the question with the CVT Limits, I was hoping anyone with the following mods could provide input and their own experiences. A few more noises to get that race car feels is what I am hoping for, TIA!
I fitted an Invidia Q300 (rear only) and it certainly improves the sound, no (zero) drone not even from a cold start, can't tell if it improved the performance as I had it fitted when I got the MRT ECU-Tek tune done, and that really perked the old girl up!!
 

robo498

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Sep 19, 2020
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Melbourne Australia
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My17
I fitted an Invidia Q300 (rear only) and it certainly improves the sound, no (zero) drone not even from a cold start, can't tell if it improved the performance as I had it fitted when I got the MRT ECU-Tek tune done, and that really perked the old girl up!!
Nice, more details please. Such as costs?
 

cakezxc

New Member
Joined
Nov 8, 2021
Messages
10
Vehicle(s)
Levorg 2.0 GTS, about 10 BP Legacys
Hey Guys,
As my Warranty period starts to wind down, I’m starting to think about mods and seeing as bulk power is out of the question with the CVT Limits, I was hoping anyone with the following mods could provide input and their own experiences. A few more noises to get that race car feels is what I am hoping for, TIA!
FWIW, the TR690 (assuming you have a 2.0 here) can take up to around 420-460nm of torque at the very limit (source: Kido and XRT both quoted within that range). There are a couple SJ FXTs here in Taiwan thats running Steamspeed 67R turbos pushing around 410nm/300whp with the TR690 for around 2 years now without issues (no CVT coolers fitted on one of them). So no. Any mild mods you do wont kill the 690 provided your tuner is good and sensible. I myself am running with full stage 2.5 mods (decat straight through, 3 port BCS, full custom intake+IC) and havent had much issues after 30000kms.

TR580s found in the 1.6 though, thats a different story. But again, with the 1.6, the mods youve been thinking about doing (CAI, muffler, BOV etc) wont be adding much. Maybe like 15bhp on a good day. Its not gonna be an issue.

As for the Semi UEL setup, AVO offers only that for a FA20DIT, so take that as you will. If they think its fine its probably fine lol. Then again id probably do a 150-200 cel sports cat first. Thats gonna unleash way more on any turbo engine.
 

Luke Rado

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Messages
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Location
Gold Coast QLD Australia
FWIW, the TR690 (assuming you have a 2.0 here) can take up to around 420-460nm of torque at the very limit (source: Kido and XRT both quoted within that range). There are a couple SJ FXTs here in Taiwan thats running Steamspeed 67R turbos pushing around 410nm/300whp with the TR690 for around 2 years now without issues (no CVT coolers fitted on one of them). So no. Any mild mods you do wont kill the 690 provided your tuner is good and sensible. I myself am running with full stage 2.5 mods (decat straight through, 3 port BCS, full custom intake+IC) and havent had much issues after 30000kms.

TR580s found in the 1.6 though, thats a different story. But again, with the 1.6, the mods youve been thinking about doing (CAI, muffler, BOV etc) wont be adding much. Maybe like 15bhp on a good day. Its not gonna be an issue.

As for the Semi UEL setup, AVO offers only that for a FA20DIT, so take that as you will. If they think its fine its probably fine lol. Then again id probably do a 150-200 cel sports cat first. Thats gonna unleash way more on any turbo engine.
Thanks Cake, very good to know!
Yeah I assume Semi UeL may give a slight rumble I’ll have to look into.
Edit: yes I have the 2.0L
 

Guvna

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May 18, 2017
Messages
316
Location
Victoria, Australia
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MY17 Subaru Levorg 2.0LTR GTS
Thanks Cake, very good to know!
Yeah I assume Semi UeL may give a slight rumble I’ll have to look into.
Edit: yes I have the 2.0L
G'day Luke, Tomei have released an UEL Header for the FA20. Subie Rumble pretty much back, sounds awesome! Installing it does negate all the benefits of the twin scroll turbo mind you, being quicker boost response, better fuel efficiency and low end torque to start with (and IMO the CVT cuts out alot of the low end torque already, bugger losing more ey!). Plus you need a Dynotune after install.
So to me it's a VERY expensive way to do two things - 1. Get the awesome rumble back and 2. Downgrade your performance significantly (boost arrives 500rpm later than EL and drops off much more up top, and it loses about 27whp as opposed to the stock ELH). Add to this that one of the MAJOR benefits of the ELH is Cylinder temperatures are kept even and lower which improves engine longevity drastically, there is a reason the EJ series engines had failures in cylinders 2 and 4, because that is the side that had the longer header length, which took longer to clear the exhaust gases and runs way hotter than the short side on cylinders 1 and 3, and that extra heat transfers to those two cylinders making that side of the engine run way hotter than the other side.
I'd love to have that rumble back, but losing that power, adding heat to one side of the engine and losing all those twin scroll benefits on a car we can't really work much performance wise?? Damn tradeoffs! Personally I want a lil more performance, not less. But for those who don't mind losing a chunk of performance, at least it seems like there is an option out there now other than changing to a single spinner as well as UEL Headers. Personally I'm not sold on how healthy it would be for the turbo either, being that the twin scroll has two separate channels to feed the turbine symmetrically (from both sides of the engine equally) UEL means the exhaust pulses will no longer be arriving at the turbo in the same manner, can't imagine that would be good for it long term, but hey I'm no mechanic either. EL=Performance, UEL=COOL Sound and heat. But if you want to hear the FA20 with a rumble, look on youtube for Subiespeed Tomei Headers.
 
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Guvna

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Messages
316
Location
Victoria, Australia
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MY17 Subaru Levorg 2.0LTR GTS
Ok I'll do it for yas! lol
Here's the links:-
Subiespeeed Tomei UEL Header Introduction
Subiespeed Tomei UEL Header being Dyno'd
You're welcome ;)
 
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