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Discussion Starter #1
This is my first turbo'd car ever...
I'm being told that to do anything I need a tune. That even changing out the air intake for a CAI would cause me to run lean unless I run a tune at the same time.

So... how much can I do to the motor to get more power before I have to get a tune for it?

Adjusting the waste gate to build boost sooner / higher?
CAI?
Catback exhaust?
Hiflow Cat?
 

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This is my first turbo'd car ever...
I'm being told that to do anything I need a tune. That even changing out the air intake for a CAI would cause me to run lean unless I run a tune at the same time.

So... how much can I do to the motor to get more power before I have to get a tune for it?

Adjusting the waste gate to build boost sooner / higher?
CAI?
Catback exhaust?
Hiflow Cat?
I don't know about adjusting the wastegate, personally would leave that one alone. For the other listed mods, any/all can be done prior to a tune but you won't see any gains until you have a tune that adjusts the ECM to allow for an increase in Torque & HP. Best approach would be to decide on the mods, and then add them just prior to tuning. That way your tune can be tested and optimized for these mods. If you are looking at something like the Trifecta budget tune, it will provide a base tune that will safely increase the parameters and allow for the Torque & HP benefits of the mods. Your biggest gains will be from the HF Cat, and then maybe some from the exhaust.
 

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Do NOT touch the wastegate adjustment. There is no field repair for that setting. They are set at the manufacturer using a flow bench. Each unit. Individually. If you change the adjustment you are as likely to have a bad outcome as a good one and its not something you can go find a procedure to make it right again.

The factory tune is well documented on the forum. See Flashs owner discussion. He was one of the power train engineers for the car.

The factory tune is torque based. It manipulates the settings of the engine to product the target 260 ft pounds. If you change the components without changing the tune, it will always make changes necessary to achieve 260 ft pounds. We used to call this learn down. Its an artifact of the tune.

In order to achieve any improvement in power, you need to have a tune.

The GMPP tune changes the baseline to 330 ft pounds of torque but it also greatly changes the allowable power produced. You can get well into 300 hp and above with the GMPP tune and the appropriate mods.

There are other after market tunes that are available. See the trifecta vrs GMPP tune threads. They do a good job of explaining the differences. Many love both tunes.

The GMPP tune is supported and warranted. It is expensive.

The other tunes are as far as I can tell not well supported anymore and in at least some cases people have had difficulty getting the developer to even talk with them.

As a practical matter, my experience was that I got 305 HP at the wheels and close to 400 ft pounds with the GMPP tune modified slightly by DDM works, after market intercooler, charge tubes, cold air intake, high flow cat and cat back.

If you want to know more, research the appropriate threads and then talk with DDM Works and Werks about their experience with tuned cars.
 

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My results were almost identical to Rob. No power adders will be noticed for more than a day unless you change the tune. GMPP also has a no lift feature that's fun, but if you want even more power, HP or Trifacta tune will get you there.keep in mind that fuel quality will become an issue as performance increases.
 

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The point is on these cars, parts changing and a tune kind of go hand-in-hand. One is limited or worthless without the other.
 

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Why a CAI? The only thing it does is enhance the sound of the turbo. The factory intake does a very good job of breathing. If you want to add a CAI, stay away from anything other then the GM if you are not tuning it. I have a Fujita, which is the hardest to tune for.

"Cosmetic" items (items that add looks or add very little power <20hp) don't really need to have a tune. Power adders do unless you have the original OE factory tune. If you do IC piping, IC, exhaust or the GM CAI, you really don't need to be retuned....but if you are changing the turbo, fuel injectors, anything that will REALLY add power, then you should really get a retune.... Leave the wastegate alone!!! If you add major power adders, you must have a custom tune or dyno tune, a canned tune like Trifecta's won't work!! But, Trifecta does have a custom tune option that cost more and requires data logging.
 

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Discussion Starter #7
GMPP tune...
You say that's expensive. How expensive are we talking?

A muffler change to help the sound will only be cosmetic from what I'm understanding... so I can do that without worrying about a tune.

Interesting that it tunes to get the 260 torque... Different way of doing it I guess.
I've mainly had old school vehicles. My last daily driver was a 1970 Chevelle (****er slammed on the brakes in front of me... so now she's in the garage waiting for a whole new front end), so all this fancy ECM stuff is new to me. Literally...
 

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You've had very good advice (meaning I agree with them....) :D
I'd add that the GMPP tune was important while warranties were still in force, but there are better, more productive tunes for less money out there. Ghost is right - some after market intakes (sound change only, no power) can screw things up.

No intake or muffler change will make a difference, but if you want to change to an exhaust system that will sound much better and offer more power when you do tune, the build quality of the Solo products is impressive, as is the service they offer, and they have a high flow CAT that mates to their systems and is one of the biggest power contributors to a tuned engine.
 

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Solo Performance makes AWESOME exhaust! I have the Solo Street Race, which has no mufflers. The turbo muffles the exhaust sound enough. It's not loud until about 1/2 throttle, but even then it's bearable.
 

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So here is my input based on years of living here . .. but ignore that.

1. Get a tune that you know will be supported. l agree that there are marginally better tunes than the GMPP but for the last couple of years I have seen reports that the non GM tunes are not well supported by their creators.

2. The only change that is agreed by all to add horsepower is a high flow cat. I have had great luck with the Solo unit but there are several others.

3. After market charge tubes, in my opinion, do not add power. But what they do add is they reduce internal turbulence which with the factory tubes results in roll off of power beginning somewhere above 5000 RPM. So they reduce or eliminate the loss of power at higher RPMs which is kind of like adding power.

4. The cold air intake does not add any power. But they do sound pretty cool. And when showing off your motor at any event they can wow the crowd a bit.

5. My car when it was a 2.0 sounded like crap because while the factory exhaust is good with respect to power production it just sounds bad in my opinion.
 

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I don't necessarily agree with all of the advice above.

Computer controlled engines do not benefit much from bolt on horsepower without a tune.

The ECU adjusts the various parameters back as close as it can to factory specs. By making changes, you are actually pulling the car off the spec line and the ECU works hard to get it back. It's the same as driving to a different altitude or having a misfiring plug. The ECU compensates for the differences and tries to optimize the engine's performance as much as it can.

Mandrel bent intake tubing, a larger intercooler, a flow thru cat and cat-back, even a CAI are all going to be tuned out by the ECU in an attempt to keep the car running on spec. RTE makes a good point that the smoother intake pipes will improve breathing, but for the engine to really make use of your bolt-ons, you'll need a tune.

A tune without the mods will get more out of the engine but only to the limit of the hardware. Improve the goodies first, then custom design the tune for what you did.

Speaking of unsupported tunes Rob, whatever happened to PCM4Less?
 

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Oh, never mind.
PCMforLess is still going strong. I just found their website.
So is Wester's Garage which offered the most favored tune among Kappa owners. They can get you all the way up to race mode with 23 pounds boost and still not blow anything up.

It's the damn Dejon pipes that I can't buy anymore.
 
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