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In my inbox today....

2021 Subaru Ascent Tuning - COBB Tuning


2021 SUBARU ASCENT SUPPORT NOW AVAILABLE


Subaru’s newest SUV, the 2021 Ascent, features a 2.4L direct-injected and turbocharged power plant that is ripe for turning up the wick. We initially released support for the 2019 and 2020 MY Ascents a little over a year ago and are now excited to make tuning support available for the current model year. Below, we’ll take a quick look at the Accessport, included Off The Shelf Maps, and power gains to expect.


OFF THE SHELF MAPS:
Every Accessport will come with our Off The Shelf (OTS) Maps pre-installed and available to flash to your Ascent. At this point, hundreds, if not thousands, of hours have been poured into understanding Subaru’s factory logic and ensuring manipulated calibration data does not negatively impact the car’s drivability. We even put our development Ascent through it’s paces at Circuit Of The America’s in a good old fashioned torture test.




6766
 

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Will the next ots map change anything on the 2020 maps? Any updated on older tunes?
We haven't had any requests for changes, or complaints on the Ascent tunes, so we have no plans to alter them as long as everyone is happy.
We understand some will decide to get custom tunes which are more aggressive, but we've seen what additional torque does to the transmission and we are not comfortable removing the margin of safety we've intentionally put in our tunes.



And in terms of the hard part we were developing, we tried, but are not bringing the product we tested to market at this time.

A stock vehicle with a tune can easily make more power than the transmission can handle, so where did that lead us?
The stock intake has a carbon trap and it flows better than it needs to already.
The exhaust system also flows well and houses critical emissions components, plus we don't get the feeling Ascent owners want their car to be loud for no performance gain.
The wastegate system works awesome, and the bypass valve doesn't leak at any reasonable pressure.
The intercooler works really well at reasonable boost levels, but maybe we can make it better?

We 3d scanned, CAD modeled, fabricated, got castings made, created ducting, flow benched, dyno and road tested etc.
It turns out after a great deal of effort, at a power level the stock CVT can handle, there just isn't much room for improvement, and there isn't a need to replace the intercooler.
If as the cars age we find people report the stock intercooler is failing at the seams, or something of that nature, then we'll be happy to fill the need.


I don't suspect there's a 6 speed manual option coming soon, so are there any non power related products you're hoping for from COBB?
 

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^^ Thanks for the great update!
Exactly what I expected given the CVT and how efficient the stock intakes can be on these cars.

What do you feel about a sway bar set? Or even just a rear bar? I swapped an STI rear bar into my old ’14 Forester XT (only a mm or two thicker than stock) and it transformed the FXT. Totally improved the driving dynamics without creating any weird oversteer or imbalance or ride quality issues.
I bet the same results could be had in the Ascent?

Loving my AP BTW. Absolutely zero problems with it after almost 2 years now.
 

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I don't suspect there's a 6 speed manual option coming soon, so are there any non power related products you're hoping for from COBB?
Imagine if there was a 6-speed swap… that would eliminate cvt torque limits, right? Makes me curious how much power we could get out of it then, hypothetically, with the 6-speed swap that doesn’t exist.
 

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We haven't had any requests for changes, or complaints on the Ascent tunes, so we have no plans to alter them as long as everyone is happy.
We understand some will decide to get custom tunes which are more aggressive, but we've seen what additional torque does to the transmission and we are not comfortable removing the margin of safety we've intentionally put in our tunes.



And in terms of the hard part we were developing, we tried, but are not bringing the product we tested to market at this time.

A stock vehicle with a tune can easily make more power than the transmission can handle, so where did that lead us?
The stock intake has a carbon trap and it flows better than it needs to already.
The exhaust system also flows well and houses critical emissions components, plus we don't get the feeling Ascent owners want their car to be loud for no performance gain.
The wastegate system works awesome, and the bypass valve doesn't leak at any reasonable pressure.
The intercooler works really well at reasonable boost levels, but maybe we can make it better?

We 3d scanned, CAD modeled, fabricated, got castings made, created ducting, flow benched, dyno and road tested etc.
It turns out after a great deal of effort, at a power level the stock CVT can handle, there just isn't much room for improvement, and there isn't a need to replace the intercooler.
If as the cars age we find people report the stock intercooler is failing at the seams, or something of that nature, then we'll be happy to fill the need.


I don't suspect there's a 6 speed manual option coming soon, so are there any non power related products you're hoping for from COBB?

91 Octane Map for the Accessport... Unless the 87+ map can take advantage of 91 Octane effectively.
 

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I don't suspect there's a 6 speed manual option coming soon, so are there any non power related products you're hoping for from COBB?
Yes. Is it possible to remove the "fake shifting" the CVT does and make the CVT act like a CVT?

Case in point, my 2013 Outback with a CVT was smooth as butter, no fake shifting. The Ascent? Not so much.

Say "yes", and you've got yourself a customer right now that's willing to wait for that development to happen later this year!
 

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^^ Thanks for the great update!
Exactly what I expected given the CVT and how efficient the stock intakes can be on these cars.

What do you feel about a sway bar set? Or even just a rear bar? I swapped an STI rear bar into my old ’14 Forester XT (only a mm or two thicker than stock) and it transformed the FXT. Totally improved the driving dynamics without creating any weird oversteer or imbalance or ride quality issues.
I bet the same results could be had in the Ascent?

Loving my AP BTW. Absolutely zero problems with it after almost 2 years now.
Awesome I'm so glad you hear you're enjoying it.
Sway bars could certainly help the handling during aggressive cornering. The Ascent had a significant amount of body roll when I drove it around Circuit of the Americas, but I still thought it did great for the type of vehicle it is.
Springs could be interesting as well. I wonder how many people would want to stiffen up the ride of their Ascent and sacrifice some comfort for handling performance...


Imagine if there was a 6-speed swap… that would eliminate cvt torque limits, right? Makes me curious how much power we could get out of it then, hypothetically, with the 6-speed swap that doesn’t exist.
Sure if someone put a 6 speed manual in the car the torque limitation would be raised, but I don't know what issues they might run into with vehicle integration. New vehicles don't always react favorably when components are missing. Perhaps some day someone will give it a shot. Getting a manual shifter situated where you could shift it would sure be interesting in that chassis.

91 Octane Map for the Accessport... Unless the 87+ map can take advantage of 91 Octane effectively.
Yup the 87+ map will add power on 91.

Yes. Is it possible to remove the "fake shifting" the CVT does and make the CVT act like a CVT?

Case in point, my 2013 Outback with a CVT was smooth as butter, no fake shifting. The Ascent? Not so much.

Say "yes", and you've got yourself a customer right now that's willing to wait for that development to happen later this year!
CVT behavior is indirectly impacted by the engine tune so I did tweak it a bit, but what you're describing would involve a totally separate development effort to tune the transmission control computer. It's something we have investigated, but do not have a solution for.
 

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Yup the 87+ map will add power on 91.
Any chance y'all have some sort of chart/graphic showing performance with 91? I'll be moving to CO (hopefully) in ~August, and it'd be great to not lose out on all the fun I've been having with the 93 tune since getting it.
 

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Yes. Is it possible to remove the "fake shifting" the CVT does and make the CVT act like a CVT?

Case in point, my 2013 Outback with a CVT was smooth as butter, no fake shifting. The Ascent? Not so much.

Say "yes", and you've got yourself a customer right now that's willing to wait for that development to happen later this year!
THIS!... Fake shifting is terrible. like you said my 11 outback had the smoothest CVT aside from the valvebody/tq convertor issue.

FXT is not as bad as the ascent, but its still not as smooth as the outback.
 

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CVT behavior is indirectly impacted by the engine tune so I did tweak it a bit, but what you're describing would involve a totally separate development effort to tune the transmission control computer. It's something we have investigated, but do not have a solution for.
On the topic of removing the fake shifts of the CVT, is the expected result higher MPG as well because the transmission is more frequently using best gearing possible instead of being forced to 'shift'...or am I misunderstanding how a CVT works with fake shifting?

Our current minivan has a CVT (plug-in hybrid, so a bit different), but it has no fake shifting. Just has a power meter between 0 and 100 and it's super smooth as a result. If there was an MPG gain/benefit for removing fake shift as well I'd be really interesting in a solution for that.

As for MPG gains in general, are there any COBB maps that have seen even slight gains without adding power or requiring different octane? I'd love to find a way to keep the power (so not add any additional stress on the overall vehicle/engine/trans/etc) while gaining even a small amount of MPG. It'd be easily worth the COBB purchase if there was a solution here.

We are very seriously considering getting a 2022 Ascent Limited later this year.

Thanks!
 

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On the topic of removing the fake shifts of the CVT, is the expected result higher MPG as well because the transmission is more frequently using best gearing possible instead of being forced to 'shift'...or am I misunderstanding how a CVT works with fake shifting?

Our current minivan has a CVT (plug-in hybrid, so a bit different), but it has no fake shifting. Just has a power meter between 0 and 100 and it's super smooth as a result. If there was an MPG gain/benefit for removing fake shift as well I'd be really interesting in a solution for that.

As for MPG gains in general, are there any COBB maps that have seen even slight gains without adding power or requiring different octane? I'd love to find a way to keep the power (so not add any additional stress on the overall vehicle/engine/trans/etc) while gaining even a small amount of MPG. It'd be easily worth the COBB purchase if there was a solution here.

We are very seriously considering getting a 2022 Ascent Limited later this year.

Thanks!
All the above. The fake shifts are a pure marketing gimmick to mimic a traditional slush-box auto.
Energy is lost, mpgs are lost and the occasional jerking/delay/lurching from the fake shifts is infuriating. I’ve had a turbo CVT Subaru that didn’t have the fake shifts and it was glorious. Pure, efficient power delivery, smooth etc.
They removed some of the best parts of a CVT with the Ascent.
 

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It only does a fake shift when you use a fair amount of accelerator. Even after fake shifting, it still varies the ratio continuoulys to optimize engine rpm for the conditions. It is not stuck in the fake gear it fake shifting into. It's still stupid, but not quite that stupid.
 

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It only does a fake shift when you use a fair amount of accelerator. Even after fake shifting, it still varies the ratio continuoulys to optimize engine rpm for the conditions. It is not stuck in the fake gear it fake shifting into. It's still stupid, but not quite that stupid.
Interestingly, this video from Redline Reviews (skip to 13:15) a couple weeks ago shows them testing 0 to 60 and noticed it doesn't do any shifting when flooring it.


Must be some scenarios where the Ascent chooses to just give it all it's got without the fake shifting.
 

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^^ It’s true. Except it’s not completely predictable. I think engine or tranny temp, chassis pitch and perhaps other variables can come into play besides just throttle position. It might be the unpredictability that’s most annoying..
..and I’ve definitely had it fake shift during light throttle..
 

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I think someone had posted here before about a YouTube video that showed someone brake-torqueing an Outback and that apparently removed the simulated shifts for that acceleration run. I guess the same works in the Ascent. Brake-torque it and enjoy a full second reduced from the 0-60 time. Wow. That's impressive.

(To be clear, if you just mat the pedal without brake-torqueing the car, it will simulate shifts.)
 

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All the above. The fake shifts are a pure marketing gimmick to mimic a traditional slush-box auto.
Energy is lost, mpgs are lost and the occasional jerking/delay/lurching from the fake shifts is infuriating. I’ve had a turbo CVT Subaru that didn’t have the fake shifts and it was glorious. Pure, efficient power delivery, smooth etc.
They removed some of the best parts of a CVT with the Ascent.
I own a 2020 Ascent Touring and a 2021 Crosstrek Premium. The Crosstrek is smoother than the Ascent by light years even though it cost 20K less. The programming on the ECU needs some help on the Ascent for sure.
 

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It weighs 1,500 pounds less, has no turbo, not nearly as much power, different engine and different transmission. It's a very apples to oranges comparison.
 

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It weighs 1,500 pounds less, has no turbo, not nearly as much power, different engine and different transmission. It's a very apples to oranges comparison.
trust me....TOTALLY understand...you would just figure that the more expensive vehicle would drive better but the Ascent just does odd stuff every now and then. Mostly under very light throttle conditions...stop and go traffic, etc. It seems like it wants to lock the converter ASAP for fuel economy, but ends up lugging the engine, then unlocks, etc. It "behaves" better under more throttle!
 
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