So does that mean an engine dyno is of little use? I mean hey, I've never seen just an engine drive around the block all by itself with no car, so any results from an engine dyno lab must be worthless, right?

The dyno itself is just a fancy comparison tool. Hood up, hood down, hood off or stuck to the ceiling. Doesn't matter for comparative purposes. As long as you are testing the part back-to-back in the same conditions you'll know right away if there are any gains...or losses. Is it 100% perfectly able to replicate how you drive it one the street? No. But it gives you a snapshot on whether the part has any benefit. I'm quite certain if I would have posted that DSport found the K&N intake to lose significant horsepower, nobody here would be questioning the validity of DSports testing and everyone would be nodding their heads and saying "See? The K&N is crap!".

The product tests I've seen on other cars they've tested (WRX, EVOs, 350Z etc) have been in line when I've seen the actual products being tested on a dyno when I've been present.

Don't believe it? No worries. No one says you have to. I just don't automatically assume every magazine is taking money under the table for a dyno test. As an automotive engineer, I'm skeptical by nature. Heck..I've tested some products myself (on my Supra and other cars) and have presented the actual dyno sheets and people have said "BS" because the results were so good. Other times I myself have said "No way!" to something I have tested. Either way, you can't win. Show a "legitimate" dyno sheet and it's BS. A magazine does it and it's BS.

Some people just won't believe it unless they are sitting there and watching it for themselves...and that's fine.

 

Yeah, I get what a dyno is and there are many flavors of dynos. Putting an engine on a stand and connecting it to a water brake isn't foreign to me, but I also know not to assume what I see in the dyno room will translate into better performance in the car. It CAN, but it MIGHT not.

So putting a car on a chassis dyno with the hood up and proclaiming victory only means you can brag about your dyno number. It doesn't translate into real world performance, BUT THAT'S WHAT K&N AND THE MAGAZINE ARE IMPLYING. They don't say - we got this improvement on our dyno under conditions impossible to replicate in actual service. If you can't replicate it in service, why bother?

I'd be a lot more impressed if they did acceleration tests before and after. They're not hard to do, and they're meaningful - the car is actually in service and it's delivering exactly what they're claiming. It's also not rocket science to convert acceleration tests to horsepower - your iPhone does this today...

 

^^I agree. But again, just because it's a magazine doing the test, doesn't mean it's worthless. And for plenty of magazines, getting to a strip isn't always practical, nor are you always able to quantify any gain/loss because there is so much difference run to run at a track. Tire temp, traction, headwind, etc, etc.

In addition, not all gains would be clearly evident during a drag run. For example, I've seen mods that give little (or no) gains in peak horsepower. However, there may be great gains UNDER the peak curve....say 20-30TQ. These wouldn't necessarily show up on a drag run, but would be present on a dyno sheet and more evident in normal street driving. An example of this would be Sound Performance's Quick Spool valve. On the dyno, massive gains are shown because of the quickspool valve. 80+ TQ under the curve in some instances. VERY, very noticeable on the street and on a dyno sheet. But at the track, since you're leaving the line hard and under boost (or under anti-lag) the valve does little to nothing in improving the 1/4 mile time.

And as you know, some mods (high stall TQ converter) will show significant losses on the dyno (unless you lock it), but massive improvements at the track.

Perhaps we'll just have to agree to disagree on our feelings on DSPorts testing. I can say that nearly every part they've tested on the WRX (and a recent Genesis 2.0T test) was duplicated almost exactly in dyno runs that I've been present.

 

When magazines are not funded by advertising the products they're testing, I'll be less skeptical. In the 40 years I've been reading magazines I've seen far too many articles claiming to be tests when the reality is they're just making extended copy for the advertiser.

I've bought a LOT of stuff over those 40 years based on test results and found most of those items to not deliver on their claims - K&N is one of them (and in fact, the first K&N filter I bought introduced severe driveability issues because its design was so completely wrong for the application). So just call me very unconvinced K&N was able to do something no one else seems to have duplicated.

 

^^Understood....But as I mentioned, I've seen K&N work very well indeed on some applications. It really woke up some Ford 4.6s