Originally Posted by Modified Dave

DaveB, all dyno runs were done on the U2Ndyno.com Dynapack hub dyno, which is one of the most consistent and reliable dynos on the market today. For both the baseline and with the intake install, we did enough pulls such that we stopped seeing gains and in fact started to see power loss due to heat soak. We used the best run before and after as our point of comparison, though if you averaged out all the before and after runs net gains are basically identical to the gains seen on the best before/after runs.

Obviously a dyno is not the real world. We do not have the same airflow characteristics when a car's on a dyno compared to when it's rolling down the road, and this can both help or hurt power gains depending on the kind of modification being tested. With intakes it tends to hurt them more than it helps them.

Nevetheless, IMO a dyno is a far better way of consistently and fairly measuring performance gain than a drag strip. With any kind of scientific testing the objective is to limit as many of the confounding variables as possible. At the dyno the main confounder is the lack of airflow over the car and to the engine. With a drag strip, you have real world airflow, but you have many other confounding variables that render the results less scientifically valid. The driver is a huge variable, as are track conditions, tire conditions, transmission and clutch conditions, ambient air temp (which dyno software corrects for), etc., etc. A dyno elminates all of these confounders, and is therefore a far better tool for measure performance gain IMO.

Of course the best scenario is to triangulate or cross-reference your data by using multiple test methods, whereby you create a more complete and accurate picture of peformance gain. To "triangulate" your testing, you'd need to have 3 points of data or three testing methods, say the dyno, the drag strip, and a road course where lap times are generated. Believe me, if I could do this kind of testing on a magazine budget, I would! But that's not the reality of my situation, so we opt to use the dyno since it gives us consistent and repeatable power numbers and limits confounders more than a drag strip or road course.

Originally Posted by Modified Dave

After installing and testing a Stillen exhaust on my '06 6MT coupe, we installed a Stillen intake. Here's the results, as tested on U2Ndyno.com's Dynapack.

This graph shows the baseline achieved with the Stillen exhaust vs the intake and exhaust combo.

Attachment 230396

As you can see, we saw consistent power gains from 3250rpm all the way to redline. We also saw quite a large jump in torque at just 2650rpm, where there was a 10wtq gain compared to the best run with just the exhaust installed (although this may have been the result of the way the Dynapack loads up at the start of a run). The biggest horsepower gain was seen at 5650rpm, right in the sweet spot of the powerband, with a 6.5whp jump over the exhaust-only graph. As for peak gains, maximum wheel horsepower jumped to 235.3whp at 6250rpm compared to 230.14whp at 6300rpm with just the exhaust, while maximum torque increased from 219.76 @ 4650rpm with the exhaust to 223.1 @ 4635rpm with the hi-flow intake added to the equation. Given that this kit really only replaces the stock intake box and filter, these gains were impressive and inexpensive not to mention very easy to install. Literally about a 15-minute job to install it.

Here's a few pics of the intake on the car. I particularly liked the way the velocity stack bolts between the filter housing and the MAF housing. Clever piece of engineering.

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Originally Posted by The G.C.

question, does the stillen power duct allow for a turbo installation? I have 1 also on my 06 g35S, but from what I'm seeing in pics (from others that have nice turbo kits), I'm seeing the turbos going right where the power duct attaches to the grill assembly. Doing a 550 whp build and I'm afraid I might have to swap out the stillen for a different style cold air kit to fit the turbo's spacious needs.......reply with any knowledge on the mentioned issue.

Originally Posted by herrschaft

It would be useless to try and use. N/A designs try to benefit from a ram-air setup. A basic turbo setup does not need this.