devellis
Been here awhile...
- Joined
- Nov 20, 2017
- Messages
- 511
- Reaction score
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- Location
- North Carolina
- Genesis Model Type
- No Genesis Yet!
It's a hot topic, to be sure. I've heard automotive engineers in videos also say that simply changing intakes and exhaust doesn't buy you anything. Altering back pressure with a free-flow exhaust, they said, essentially causes changes in the system that would offset any gains. Back before cars had computers monitoring and regulating how a car operates, you could do things like increase air flow, dial in a slightly richer mixture to take advantage of the increased air, and squeeze a bit more power out. Now, the car expects certain parameters to be within factory spec and as they depart from that, the ECU essentially tries to compensate to bring them back to spec.
Is that description 100% correct? I have no idea. I'm not an engineer. The people who've made the argument were generally engineers for the cars they were discussing. On one hand, that may motivate them to discourage any changes. On the other hand, they know their engines really well. I can't recall where I saw the videos that are relevant. If I get a chance, I'll se if I can find them.
I think everyone has to make their own calls. Speed shops, of course, will tell you that every little change will be beneficial. And they may be right if you couple that change with other alterations (like changing the programming) that won't essentially counteract the first change. There are lots of engine additives out there that also claim to increase power. The key phrase in all of these claims is "up to" preceding the listed power increase. And any measurement system will have variation. Power measurements will vary randomly as a function of imperfections in how measurements are made and systematically as a function of the testing conditions. What we often see reported is the peak performance obtained after some mod. But you can be pretty certain that the peak performance is uninformative, as it represents the circumstance where both random and systematic errors in measurement have combined to yield the highest number. regression to the mean is virtually guaranteed to yield lower power in actual use.
For me, none of these mods hold any interest. The more I think about them, the less appeal they have. If dealers offered an alternative exhaust with a more aggressive note, I might go for it. But that would be my limit. But that's just me. Each person can do as they please and should do whatever they like to maximize their enjoyment of the car.
