Gernby

I'm not up to speed on K swaps, but I assumed that the OEM K series ECU was used. The first thing he said was "Well, I got done tuning my car." He did NOT say "Well, I got done REtuning my car."

I'm not dismissing the results as if the guy was lying, or saying that he was providing bad information. I'm just not going to make all the assumptions that have to be made to validate his conclusion. He did not say whether the dynos were SAE corrected, but the fact that he mentioned the difference in ambient temperature implies that they were not SAE corrected. If not, then we would REALLY, REALLY need to know humidity and barometric pressure, since that is WAY more significant than temperature. The resonant hump is also a dead givaway on the intake being different. I knew that before I even read his post.

I'll check out the thread that you linked ....

Gernby

KevoS2K, the first link you gave was an advertisement from a company that manufactures and sells aftermarket exhausts, which I'm not even going to bother reading. Frankly, nobody should consider any manufacturer testing to be "proof" of anything.

The second link about the K swap car might have been even less informative than the original. There wasn't a single bit of info about the testing. Everybody was just jumping on the bandwagon talking about how "this settles everything!", and "this should be put in the FAQ!". It was basically just a bunch of kids reinforcing their existing beliefs.

kevos2k

the testing was done privately in the thread by someone that bought the exhaust... read beyone the cover i gave a page # for a reason

i'll just let you go on beleiving what you want... i have seen a trend of not worth goign against you, you can continue to disect everything else on the internet and hold what you find to be the be all end all of data.

Gernby

Oops ... my bad. I'll check it out.

Gernby

Update....

EDIT: It turns out that this particular test with the 70mm test pipe was screwed up by me installing a gasket that was slightly too small, which caused a restriction in flow. I repeated the test later, but not soon enough to save myself from a lot of embarrassment ...

I just got back from doing the "standardized" test with the stock header, 70mm Berk test pipe, and 70mm single exhaust. I used the exact same procedures that I used earlier in the week to test the same setup with a 60mm test pipe and 70mm single exhaust, and also for the same setup with 60mm test pipe and totally stock AP2 exhaust. The weather conditions were VERY, VERY similar for all 3 tests. Ambient temps were near freezing, IAT's were all within 5 degrees of each other, ECT was within 2 degrees of each other, barometric pressure was within 6 mBar of each other, and humidity ranged from 44% to 62%, and there was practically no wind. I even drove the same route from my office at lunch to the same gas station to top off the fuel tank before each test. The resulting SAE corrections were between .932 and .948. I don't believe a more conclusive test could be performed, especially on a conventional dyno.

Red for all plots is the 70mm single exhaust with 60mm test pipe, green for all plots is the 70mm single exhaust with 70mm test pipe, and blue for all plots is the stock AP2 exhaust with 60mm test pipe.




Same ignition maps for all 3. The lines at the bottom are the knock retard. The red AFR plot (70mm exhaust with 60mm TP) ran slightly lean, so I added ~1% in some areas to bring it back down to 13. I then used that calibration for the other 2 tests.


The efficiency curve is unitless, and is basically just the torque divided by injector pulse width. I just use it to see how well my power curve follows the torque curve. If there is a dip in this curve, that tends to indicate a problem with fuel or ignition timing.


So unless I can get my hands on an HFC, or you guys think of something I missed, I think this test is done. I'm really surprised by the results, espeically that the 60mm test pipe did better than the 70. I guess the exhaust flows better when there are 2 smaller increases in diameter instead of 1 larger increase.

suzuka-blue-s2k

Wow that's nuts, very surprising results.

Neutered Sputniks

Another something we agree on in the NA forum???!

I've seen the UMS Tuning plots, I had them tune my 05 with an EMS (v2). I showed about 10hp and 5ft-lbs less than one of their local guys who had nearly the exact same build. Only difference was his T1R 70R and my Tanabe Concept G exhaust.

Now, some could say that his engine is just a superior engine and able to make more power off the bat. Some would say that. But, then some would say my engine is one of the strongest ones seen in the AZ area based on back to back dyno pulls, my stock 05 right in front of an 06 with KPro chip, J's header, TP, and Mugen exhaust. I trailed a mere 5hp, with the biggest difference coming from his tune allowing VTEC to engage at 4500.

Point being, I doubt the difference in outputs between my engine and the other car tuned by UMS is due to my engine.

In other words, the T1R 70R dual flows better than my Concept G (which is supposed to flow better than stock).


Of all the dynos posted in this forum, I trust the guys at UMS more than just about anyone else's.

rwheelz

Interesting results. I would love to see what difference a HFC makes in place of the test pipe (I have a Berk that I took off my wrecked S2000 that I have yet to install on my new car- perhaps I should ship it to you?). I also wonder whether Berk's "cone" expanding section on their new exhaust makes a significant difference over an abrupt step up in the diameter at the test pipe.

So, now what we want to see is this same testing done with all of the best headers and cat-backs. I am sure you have many thousands of dollars and endless hours at your disposal for such testing, so get on it!

You have really put a lot of effort into this testing. It is greatly appreciated.

Gernby

I doubt my wife would tolerate much more of this right now, but I would definitely add an HFC test to the mix if someone shipped me one! I'm not willing to buy an HFC, but I'd pay for return shipping! However, I would hate for someone to ship a used HFC to me, then everyone question the results because it wasn't a "new" HFC.

Neutered Sputniks - I really believe that it's impossible to derive conclusions about parts that are installed on different cars, especially if they are dyno'ed on different days and / or tuned by a different person. I'm sure you'd agree that peak numbers aren't as important as "area under the curve".

Mixed

Isn't one of vendor installed berk 3 inch and got good gain from it?