[STINick19]

View attachment 63857

Nick,

I think those numbers are great for a mechanically stock STI. I would say perfect for a street car. I'm glad your posting this data because I have a hard time relating how changes to a stock platform relates to a real world driving experience. For example, "My STI put down 330 WHP and 350lbs of TQ", I can't relate that to anything but other peoples dyno numbers, but I can relate changes to 0-60 times.

I'd love to see one of these big box automotive media outlets or even a vendor (like Cobb) take a stock STI and run it against a modified STI at the different "stages" and capture the type of data your capturing.

Thanks! It just goes to show how capable the STI still is with light modifications. Granted, I spent countless hours on this tune

My 5-60 mph has also improved quite a bit:

Stock: 6.01
COBB Stage 1: 5.73
My tune: 5.16

Having a downpipe (stage 2) would help improve this metric as the main enemy here is turbo lag.

 

[magnetite2020sti]

The Cobb SF or Redline intake makes a difference too. I ran stage 1 ots for 1500 miles before switching to their larger velocity stack maf with the stage 1 + ots tune. It definitely spools faster and pulls better up top. fyi

 

[JFAZ]

Thanks! It just goes to show how capable the STI still is with light modifications. Granted, I spent countless hours on this tune

My 5-60 mph has also improved quite a bit:

Stock: 6.01
COBB Stage 1: 5.73
My tune: 5.16

Having a downpipe (stage 2) would help improve this metric as the main enemy here is turbo lag.

That's a great improvement in 5-60, did you. think a DP would get it under 5s?

Do you tune for living or is this just a hobby?

 

[STINick19]

That's a great improvement in 5-60, did you. think a DP would get it under 5s?

Do you tune for living or is this just a hobby?

Just a hobby. I've always loved modifying and tuning cars.. and understanding all of the engineering behind it. I have my COBB tuning certification and went through all of HPA's courses. I had planned to start my own Subaru tuning business, but all of the recent EPA crackdowns, fines and now CARB testing for any non-CARB approved tune during smog just made it not worth it. The EPA & CARB are really trying to put an end to aftermarket performance tuning for ICE engines. There's a lot of risk being a tuner now and I'm not sure how much longer it will be a lucrative endeavor, especially given the cost of COBB's protuner license. EVs are sadly the future.

I think a downpipe could definitely get it under 5 seconds.

 

[JFAZ]

Just a hobby. I've always loved modifying and tuning cars.. and understanding all of the engineering behind it. I have my COBB tuning certification and went through all of HPA's courses. I had planned to start my own Subaru tuning business, but all of the recent EPA crackdowns, fines and now CARB testing for any non-CARB approved tune during smog just made it not worth it. The EPA & CARB are really trying to put an end to aftermarket performance tuning for ICE engines. There's a lot of risk being a tuner now and I'm not sure how much longer it will be a lucrative endeavor, especially given the cost of COBB's protuner license. EVs are sadly the future.

I think a downpipe could definitely get it under 5 seconds.

Very cool that you got certified and took all the courses! I do fear for the future of our hobby, although I've come to terms with our EV future and hopefully in the future, classic ICE vehicles will be something that "enthusiasts" can still enjoy on the streets.

All of this has made me rethink modifications and it seems the safe bet to avoid any CARB issues is just doing a Cobb Stage 1, as it is 50 state CARB legal. I'm content with my stock performance and per your numbers, stage 1 is more than enough for my street car. I also have 93, so I wonder how that would effect your results.

 

[STINick19]

Very cool that you got certified and took all the courses! I do fear for the future of our hobby, although I've come to terms with our EV future and hopefully in the future, classic ICE vehicles will be something that "enthusiasts" can still enjoy on the streets.

All of this has made me rethink modifications and it seems the safe bet to avoid any CARB issues is just doing a Cobb Stage 1, as it is 50 state CARB legal. I'm content with my stock performance and per your numbers, stage 1 is more than enough for my street car. I also have 93, so I wonder how that would effect your results.

On 93 you should be very close to my numbers or slightly better in some areas. I spent a lot of time balancing the AFR, boost & ignition timing in the areas where I was knock limited trying to make as much power as I could safely. If I had access to 93, I could probably squeeze a bit more power out over COBB's map, but it's honestly really good for essentially being free with the AP. Any honest protuner will tell you this. There's very little power to be gained from a stage 1 "pro" tune. However, there are gains to be had in other areas as it's tailored to your car and your fuel, climate, altitude, etc.

Compared to COBB's OTS, I spent a lot of time in the following areas:

• Leaning out the AFRs at WOT and especially in the cruise areas to improve fuel economy. COBB's maps are conservative and run quite rich.
• Fine tuning the target boost to minimize boost error, integral & proportional gains to prevent boost spikes/overboost as you reach peak boost between 3-4k rpm.
• Smoothing out the ignition curve to improve driveability and reduce knock.
• Changing the throttle mapping. I retained more of a stock-like throttle mapping with the drive modes (I, S, S#) as I wasn't a fan of the single linear response in all of the drive modes. Of course, the drive modes still control the amount of boost that is available.

Carrying power to 7k rpm on ACN91 was quite difficult due to knock and the turbo running out of steam at that point. The VF48 physically couldn't make any more boost up top (with stock hardware), so it was all about balancing timing & AFRs without encountering knock due to the crappy fuel that we have in California.

It was a really great learning experience and quite satisfying. You understand what the "pro" tuners are doing and can go above and beyond since it's your personal car and you have the time and passion. I really can't recommend HPA's courses enough for the price. They really establish a great foundational knowledge. They also have worked examples for tuning the EJ & FA and spend a lot of time on understanding Subaru's knock control system.

 

[JFAZ]

On 93 you should be very close to my numbers or slightly better in some areas. I spent a lot of time balancing the AFR, boost & ignition timing in the areas where I was knock limited trying to make as much power as I could safely. If I had access to 93, I could probably squeeze a bit more power out over COBB's map, but it's honestly really good for essentially being free with the AP. Any honest protuner will tell you this. There's very little power to be gained from a stage 1 "pro" tune. However, there are gains to be had in other areas as it's tailored to your car and your fuel, climate, altitude, etc.

Compared to COBB's OTS, I spent a lot of time in the following areas:

• Leaning out the AFRs at WOT and especially in the cruise areas to improve fuel economy. COBB's maps are conservative and run quite rich.
• Fine tuning the target boost to minimize boost error, integral & proportional gains to prevent boost spikes/overboost as you reach peak boost between 3-4k rpm.
• Smoothing out the ignition curve to improve driveability and reduce knock.
• Changing the throttle mapping. I retained more of a stock-like throttle mapping with the drive modes (I, S, S#) as I wasn't a fan of the single linear response in all of the drive modes. Of course, the drive modes still control the amount of boost that is available.

Carrying power to 7k rpm on ACN91 was quite difficult due to knock and the turbo running out of steam at that point. The VF48 physically couldn't make any more boost up top (with stock hardware), so it was all about balancing timing & AFRs without encountering knock due to the crappy fuel that we have in California.

It was a really great learning experience and quite satisfying. You understand what the "pro" tuners are doing and can go above and beyond since it's your personal car and you have the time and passion. I really can't recommend HPA's courses enough for the price. They really establish a great foundational knowledge. They also have worked examples for tuning the EJ & FA and spend a lot of time on understanding Subaru's knock control system.

Sounds like you really got your tune dialed in and it's very cool that your able to tune your own car as an enthusiast. I liked that your retained the stock-like throttle mapping as that's one area that I'm hesitant with the Cobb OTS, as I'm not sure I'll like the targeted boost and linear throttle vs the stock configuration. Does the stock (I, S, and S#) modes alter boost or any other settings in anyway or is it purely just a change in Throttle response?

 

[STINick19]

Yes, the throttle mapping is controlled via "requested torque" which essentially translates to throttle position and boost.

Each drive mode has its own Requested Torque table which is Accelerator Position (%) vs RPM. Below is the stock S# table:

The requested torque value is then used for the boost targets & wgdc:

It sounds complicated and isn't completely intuitive at first, but once you spend a little time exploring the various tables it starts to make more sense.

 

[JFAZ]

Great information and thanks! I've read many times that the different modes only effect throttle response, so thanks for clarifying. I'm going to study the tables you posted and try to figure them out.

 

[NorthernRage]

On 93 you should be very close to my numbers or slightly better in some areas. I spent a lot of time balancing the AFR, boost & ignition timing in the areas where I was knock limited trying to make as much power as I could safely. If I had access to 93, I could probably squeeze a bit more power out over COBB's map, but it's honestly really good for essentially being free with the AP. Any honest protuner will tell you this. There's very little power to be gained from a stage 1 "pro" tune. However, there are gains to be had in other areas as it's tailored to your car and your fuel, climate, altitude, etc.

A bit of a tangent, but I'm curious on your opinion. I live within an hour of Lachute Performance and they offer their "stage packages" using Ecutek and their own in house made hardware. As additional information, according to them they do annual revisions to the tune where necessary for each model year - so a customer with a 2019 model would get the 2019, etc. What the actual incremental changes are that are being made is unknown to me

Naturally without knowing the specifics, and assuming the tune itself is "region" favorable and factors in local temp, fuel availability, altitude - and I live in the region, would you think that there are any tuning advantages to be had in getting them to protune my specific car over their canned stage tune? Is there enough mechanical difference between two STIs of the same MY to warrant the extra costs of a protune? Curious.

 

[STINick19]

A bit of a tangent, but I'm curious on your opinion. I live within an hour of Lachute Performance and they offer their "stage packages" using Ecutek and their own in house made hardware. As additional information, according to them they do annual revisions to the tune where necessary for each model year - so a customer with a 2019 model would get the 2019, etc. What the actual incremental changes are that are being made is unknown to me.

Naturally without knowing the specifics, and assuming the tune itself is "region" favorable and factors in local temp, fuel availability, altitude - and I live in the region, would you think that there are any tuning advantages to be had in getting them to protune my specific car over their canned stage tune? Is there enough mechanical difference between two STIs of the same MY to warrant the extra costs of a protune? Curious.

COBB does the same thing in regards to years. They have to have an update the tune/software for each MY to make it compatible with the actual ECU. For example, even though the 2019 & 2020 tunes are exactly the same in regards to the data in the tables, you can't apply a 2019 tune to a 2020 due to compatibility between the ECUs. It's very likely that nothing changes within the tune itself unless Subaru has made a mechanical change (eg when they upgraded the intake in 2019). Not much ever changes in the EJ world.

As for the canned vs protune, it really depends on the cost and if you're willing to pay for it. There isn't going to be significant variance between two STIs of the same MY. Most canned tunes are going to be a bit more conservative and likely run richer for safety since Lachute won't be checking the data logs to see if you're encountering any knock. They may be willing to push their protunes a bit further since they're monitoring the AFR and knock.

 

[STINick19]

I can't seem to break the 4.3x sec 0-60 mph time on the street. My best 60-ft is 1.78. My 1/8-mile time is consistently around 8.23 @ 83.9 mph.

Out of curiosity, I took the best 10mph deltas for all of my runs.. if you combine my best launch, shifting and acceleration across all runs, my theoretical best "perfect driving" 0-60 mph time is:

0-60 (no rollout): 4.23 sec
0-60 (1ft rollout): 4.03 sec
60-ft: 1.78 sec

I just can't seem to get everything perfect in a single run. The benefit of driving a manual transmission.. human error 😂. I'll never be able to launch as consistently or shift as fast as a computer. Or in Tesla's case, there is no shifting involved, just floor the floor the accelerator pedal.

I'm done abusing the car at this point just to improve my times by a tenth or so. I'm very happy with the car's performance at stage 1. The only problem is that it requires a perfect, near redline, clutch dump for the launch.. and perfect shifting.

 

[JFAZ]

The only problem is that it requires a perfect, near redline, clutch dump for the launch...

Ouch! But Great results! More than quick enough for a street car and still fun, engaging to drive, and requires some level of skill. Telsa's and all these recent quick, but non-engaging cars that require little driver interaction are of little interest to me.

 

[JFAZ]

Nick,

Did you use the AP's launch control and/or flat foot shifting features when recording these times?

 

[STINick19]

Nick,

Did you use the AP's launch control and/or flat foot shifting features when recording these times?

Yes, I tried using both.

Launch control was set to 5,000 RPM. 4,500 RPM didn't seem to be quite enough and it would slightly bog on some runs. A harder launch at 5,500 RPM seemed to be too much as I started getting some occasional wheel hop. Feathering the clutch more helped smooth it out, but resulted in slower acceleration times.

I tried to use the flat foot shifting feature to an extent, but it didn't make much difference for me. FWIW, I had it set to 5,500 RPM. The main problem is that my brain is hardwired to pushing the clutch in to shift, so I rarely flat foot shifted/power shifted on any of the runs. I'm sure I could improve on it if I practiced more or frequented the drag strip. I think if you dialed in the FFS RPM a bit more and perfected the technique that you could improve the performance a bit more. The main problem is that you can only set a single FFS RPM. It should technically be gear dependent because you want it set around the RPM that you would land at when shifting into the next gear. This RPM will be different for 2nd, 3rd, 4th, etc.

 

[Tifosi]

Been following your incredible build process but noticed you appear to be parting out the car As of recently. Went back on your thread and saw your conversation about California’s new EPA reg. Is this why you are parting out? If so, it is such a shame that it has forced you to stop your build.

 

[STINick19]

Been following your incredible build process but noticed you appear to be parting out the car As of recently. Went back on your thread and saw your conversation about California’s new EPA reg. Is this why you are parting out? If so, it is such a shame that it has forced you to stop your build.

Yes, ultimately California’s ever tightening smog/emissions & CARB regulations stopped me from pursuing the build. At this time, COBB’s stage 1 OTS tune & intake are the only legal power mods for the STI.

I’m likely saving for a Porsche GTS 4.0 as my next car. My wife also likes the M2C because it has a backseat. I’ll likely be selling my STI soonwith used car values so high right now. CarMax offered $40k for my STI which is more than I paid for it new. Or maybe I’ll just save the money and get an ND2 Miata or the new BRZ and just get a cheap drivers car.

It’s a bummer that the government is pushing for EVs and trying to ban any fun with ICE engines.. yet there are still CARB legal 700-800 HP supercharger kits for Mustangs, but you can only have a COBB stage 1 tune for the STI.
Regardless of which route I go I’ll still be around the Subaru community enjoying others’ builds

 

[Tifosi]

Yes, ultimately California’s ever tightening smog/emissions & CARB regulations stopped me from pursuing the build. At this time, COBB’s stage 1 OTS tune & intake are the only legal power mods for the STI.

I’m likely saving for a Porsche GTS 4.0 as my next car. My wife also likes the M2C because it has a backseat. I’ll likely be selling my STI soonwith used car values so high right now. CarMax offered $40k for my STI which is more than I paid for it new. Or maybe I’ll just save the money and get an ND2 Miata or the new BRZ and just get a cheap drivers car.

It’s a bummer that the government is pushing for EVs and trying to ban any fun with ICE engines.. yet there are still CARB legal 700-800 HP supercharger kits for Mustangs, but you can only have a COBB stage 1 tune for the STI.
Regardless of which route I go I’ll still be around the Subaru community enjoying others’ builds

FWIW, thank you for sharing with us of your STI journey.

 

[pwh]

Yes, ultimately California’s ever tightening smog/emissions & CARB regulations stopped me from pursuing the build. At this time, COBB’s stage 1 OTS tune & intake are the only legal power mods for the STI.

I’m likely saving for a Porsche GTS 4.0 as my next car. My wife also likes the M2C because it has a backseat. I’ll likely be selling my STI soonwith used car values so high right now. CarMax offered $40k for my STI which is more than I paid for it new. Or maybe I’ll just save the money and get an ND2 Miata or the new BRZ and just get a cheap drivers car.

It’s a bummer that the government is pushing for EVs and trying to ban any fun with ICE engines.. yet there are still CARB legal 700-800 HP supercharger kits for Mustangs, but you can only have a COBB stage 1 tune for the STI.
Regardless of which route I go I’ll still be around the Subaru community enjoying others’ builds

Bummer dude. I go back and forth between (A) modifying my car and (B) selling it for a profit (as you might right now with the crazy economy) and buying something in the future like an M4 / GT4 / used 911 or another 3-pedal car with factory HP. I really enjoy AWD + 3 pedals + turbo, but I'd have to give up AWD to keep the manual transmission.

Good luck with it, whatever decision you go with.

 

[STINick19]

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