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Discussion Starter · #1 ·
I e-mailed Trifecta and they said they are already working on a tune for the 2021 Trailblazer/Encore GX. I know a lot of people were looking forward to a tune, so it looks like we may have one soon.
 

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That's good news. The only problem is that it will void your warranty, so I'm waiting until my warranty is up for any tunes. It's too bad GM decided to create a way for the computer to record any attempt to alter the factory tune.
 

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Discussion Starter · #3 ·
That's good news. The only problem is that it will void your warranty, so I'm waiting until my warranty is up for any tunes. It's too bad GM decided to create a way for the computer to record any attempt to alter the factory tune.
I can understand that. It can be expensive to repair cars these days.
 

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Trifecta also makes a tune for my ZR2 which is out of warranty next year, so I'm looking forward to getting it. I am curious to see what they'll get out of our little 3cyl engines. I'm guessing 10-15 hp. We already run up to 22 psi of boost, so I don't think they're going any higher there.
 

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Funny, I was just under the hood tonight looking at the routing of the intercooler and thinking how a bigger one might fit. Trifecta was on my mind. Their tunes on the 1.4L were impressive on paper.

Anyone pull the intake ducts yet to look for any removable baffles? If present they quiet the turbo noise but also restrict the intake airflow as well.

Similarly, who has access to monitor KR on 87? (KR isn’t a std PID on my scantool.) Wondering how much…if any…factory knock the engine has heatsoaked (eg, daily conditions) on 87 versus using 89 or 92+. I won’t be surprised to see a steady dosage of KR with 87. A tune on premium, with perhaps a thicker IC, 20-25hp/tq gain could be possible without going too extreme with timing advance. That’d be plenty for me.

I understand why it was factory tuned for 87; the vehicle & buyer demographic isn’t one where requiring 92+ would be advisable. But for some of us, well….it’s not easy to squash the mod bug - and I’ve been out of the scene for 10 years.
 

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Discussion Starter · #6 ·
Funny, I was just under the hood tonight looking at the routing of the intercooler and thinking how a bigger one might fit. Trifecta was on my mind. Their tunes on the 1.4L were impressive on paper.

Anyone pull the intake ducts yet to look for any removable baffles? If present they quiet the turbo noise but also restrict the intake airflow as well.

Similarly, who has access to monitor KR on 87? (KR isn’t a std PID on my scantool.) Wondering how much…if any…factory knock the engine has heatsoaked (eg, daily conditions) on 87 versus using 89 or 92+. I won’t be surprised to see a steady dosage of KR with 87. A tune on premium, with perhaps a thicker IC, 20-25hp/tq gain could be possible without going too extreme with timing advance. That’d be plenty for me.

I understand why it was factory tuned for 87; the vehicle & buyer demographic isn’t one where requiring 92+ would be advisable. But for some of us, well….it’s not easy to squash the mod bug - and I’ve been out of the scene for 10 years.
I looked at the ducting and there are two resonators. One is a Helmholtz resonator, so we can't mess with that or we'll lose power. The other looks like a regular resonator on the boost pipe. But I doubt you'd see any gains replacing it.

I actually feel like the stock intake setup is quite efficient and will be really hard to beat with an aftermarket intake. Drop in K&N filter will likely be overkill for air volume requirements on this engine.

See attached pics.
976
977
 

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Always Trifecta man I wish people knew how bad they really are. I'd save your money your not gonna get a lot out of the 1.3T much less the 1.2T it's not setup like the 1.4T and they can't do shit with your transmission which means your going to be rev hanging and getting mad even more when your engine prematurely begins to have issues when the gear doesn't change and the ECM demands to much. I'd wait to avoid any warranty on these until all the bugs are worked out people are beginning to have AWD system failures left and right lately not sure on their mileage though. Not saying Trifecta is the worse out there but they are the worse for locking your ECM and then when something goes wrong never speaking to you again.
 

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The intake side isn't bad and a drop in K&N will probably be more than sufficient for incoming airflow.

The real problem is the exhaust. There's a small muffler (more of a resonator) just behind the cat, then there's a huge restrictive muffler behind the rear bumper. That rear muffler has to go, lol. I'm going to try 2 setups. The first one will leave the resonator and remove the big rear muffler. In place of the rear muffler will be a y-pipe that routes exhaust to the dual outlets in the bumper. If that sounds good I might just stop there, but if it doesn't sound good I'll replace the resonator with a Borla XS Pro series muffler which is just a straight through design, perfect for a turbo engine.

I've already had the rear muffler off and it wasn't very loud until you get over 4k. As some of you know engines with turbos aren't very loud because the turbo removes alot of the exhaust noise and it provides more than enough backpressure, so you want the rest of the exhaust to flow as freely as possible. I'm just waiting on a few 90° degrees pieces of stainless tubing to get started, so I'll definitely post some pics and get a sound clip before and after.
 

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Discussion Starter · #9 ·
The intake side isn't bad and a drop in K&N will probably be more than sufficient for incoming airflow.

The real problem is the exhaust. There's a small muffler (more of a resonator) just behind the cat, then there's a huge restrictive muffler behind the rear bumper. That rear muffler has to go, lol. I'm going to try 2 setups. The first one will leave the resonator and remove the big rear muffler. In place of the rear muffler will be a y-pipe that routes exhaust to the dual outlets in the bumper. If that sounds good I might just stop there, but if it doesn't sound good I'll replace the resonator with a Borla XS Pro series muffler which is just a straight through design, perfect for a turbo engine.

I've already had the rear muffler off and it wasn't very loud until you get over 4k. As some of you know engines with turbos aren't very loud because the turbo removes alot of the exhaust noise and it provides more than enough backpressure, so you want the rest of the exhaust to flow as freely as possible. I'm just waiting on a few 90° degrees pieces of stainless tubing to get started, so I'll definitely post some pics and get a sound clip before and after.
The good news is the exhaust itself is actually pretty good aside from all the resonators and muffler. I'm pretty sure the stock size is enough for anything we'd be able to get out of this engine.
 

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The good news is the exhaust itself is actually pretty good aside from all the resonators and muffler. I'm pretty sure the stock size is enough for anything we'd be able to get out of this engine.
The 2" exhaust should be adequate. Most 4cyl engines use 2-1/4". The factory exhaust becomes restrictive after the cat which doesn't help a small turbo engine. It was designed for sound control not performance.
 
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