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Discussion Starter · #1 ·
We've heard a lot about ecus adjusting to different variables. Including some talk of un-learning gains from some mods.

So without a tune, what can be done that won't get neutralized by the ecu?

I've been kicking around a few mods for a while but I really don't plan on tuning and if I'm not going to make gains in the long run I'll just hold off.
 

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What mods are you looking at doing? If your thinking of doing a intake and exhaust the ecu will learn it but in a good way. It does adapt to changes pretty good. When I was running on stock tune with my upgrades I for sure felt a bigger difference than stock.
 

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pretty much with any modern car, airflow mods will be able to compensated a little by the computer... get air in and out as quickly and efficiently as possible
 

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Discussion Starter · #4 ·
Yeah just exhaust, intake, hot pipe.
I thought I read Tork and others say that the gains could be unlearned by the computer. I may have been misunderstanding them though.
 

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Discussion Starter · #5 ·
I'm not sure exactly what that would mean. I know some cars have a target power output. When that's reached boost gets throttled a bit to keep everything within the manufacturers desired specs.
 

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I'm not sure exactly what that would mean. I know some cars have a target power output. When that's reached boost gets throttled a bit to keep everything within the manufacturers desired specs.
We have similar limiting factors

With 60mm throttle body, SRI and FMIC I was at 188 whp and under hard throttle it would feel as though it was being held back. Even the logs showed the timing being cut back along with boost dropping to 12 lb. Then I did the DP and full 3" exhaust I hit 209 whp consistently on a stock ecu and I can still tell when the ecu pulls timing and boost. This is a big difference when compared to the stock 166 whp with the A/T.

So my answer would be both yes and no, if you don't have the supporting mods on both sides intake and exhaust the ecu will learn to limit output. High cylinder temps from exhaust gases not flowing freely or being restricted will cause detonation which in turn causes the ecu to pull timing. Some of the other limitations you will actually feel is from the stock DP, if the exhaust passes through the turbo and then gets stopped with restrictions wouldn't you think it will affect the output from the turbo and why we see boost drop at higher rpms. 95% of the stock exhaust actually not that restrictive, the DP with the cat 3" from the turbo, ehh actually not the worst but below that where the mid pipe bolts up is a flange with the inside diameter of a Prius exhaust pipe. Exhaust is only as good as its smallest point and that cast flange is 1.637" inside right at the base of the DP = not good. Even just doing the DP from Tork or 845 is ok but until that flange is gone from the mid-pipe the restriction is still there. Near the rear axle is another flange that is not as bad but takes the nice mandrel bent factory 2.35" piping and reduces it to 2". Like honhon said ^^ but in different words 'if you let it in it will need to come out' and that works the other way around also.
 

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Discussion Starter · #7 ·
Ok. That makes sense.
So the limiting factor is the exhaust not the ecu. The ecu just pulls back because the exhaust is flowing poorly.
Kia must be pushing the limits of the stock system further than I would have expected then.
 

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Ok. That makes sense.
So the limiting factor is the exhaust not the ecu. The ecu just pulls back because the exhaust is flowing poorly.
Kia must be pushing the limits of the stock system further than I would have expected then.
ECU does have limitations but you won't really see that until you have everything opened up. It still doesn't stop the possible output of going higher, I would say it just reaches its maximum adjustable range of the factory tune. After running a dry 30 hp nos kit for a few passes it never once pulled back or went to limp mode like I expected it to, instead it just pulled harder. Eventually the full wet kit will be installed but the sneaky pete was good enough for testing to see what it would do.
 

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Untuned dry shot. Living life on the edge. Lol
Not really on the edge, on the dyno I am dropping the afrs into the mid 9s so the dry kit is just helping use that unused fuel lol
 

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Discussion Starter · #11 ·
So the major points of restriction in the exhaust are that flange, the cats, the resonator, and muffler?
When I got under my car the other day I was shocked at the size of the stock piping. The resonator looks like a full blown muffler though. Although I only saw it from the front of the car looking back.
The last flange being 2" shouldn't be a huge issue with our power output I wouldn't think.
 

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Discussion Starter · #12 ·
Not really on the edge, on the dyno I am dropping the afrs into the mid 9s so the dry kit is just helping use that unused fuel lol
Lol. In a way you're saving the environment by not letting that fuel go to waste. The epa should make everyone run a small shot of nitrous.
 

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So the major points of restriction in the exhaust are that flange, the cats, the resonator, and muffler?
When I got under my car the other day I was shocked at the size of the stock piping. The resonator looks like a full blown muffler though. Although I only saw it from the front of the car looking back.
The last flange being 2" shouldn't be a huge issue with our power output I wouldn't think.
In order I would say,
Most restrictive to least, flanges, 2nd cat, 1st cat, muffler, resonator, dp housing then exhaust piping.
 

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I would think that's about right. When I took off the stupid muffler I noticed a really nice increase in the pull the car had. The resonator is freaking heavy and when you see inside it the size looks actually small. The pipe going into it is roughly 2.25" but the inside looks smaller.

I have a muffler coming today that I will post up when I get it and post a video of the sound difference. Had to get a muffler because a cop warned me about it lol. Stupid cali
 
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