Planet 9

Test Vehicle: 2007 Cayman S, 6 Speed Manual with 5,962 miles. Test completed by Farnbacher Loles on Dyno Dynamics Dynamomoter.

Stock Cayman S (RWHP):




Cayman S w/Borla 12653 Race Exhaust Installed (RWHP):




Stock Cayman S (BHP):




Cayman S w/Borla 12653 Race Exhaust Installed (BHP):




Overlay Comparison, Stock Vs. Borla (BHP):

For more inforation on the Borla 12653 Race Exhaust, please see the following threads:

http://www.planet-9.com/cayman-mod...py-photos.html

http://www.planet-9.com/cayman-ven...-released.html

http://www.planet-9.com/cayman-mod...n-12653-a.html

Porsche Factory Exhaust Removal Article

Borla Race Exhaust System for Porsche Cayman (p/n 12653 & 12654)

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Gator Bite
PCA Cayman Register Advocate

Hey nice graphs!

One thing I'd like to point out to people.

Look at the variance between runs on the stock system. Probably +- about 10 or 15 hp over 5 runs. If you kept doing runs you would see that it would continue to happen like that. The accuracy is only around 3%, this is normal for a dyno.

With the Borla exhaust, only 1 run is shown. We can assume that across 5 runs, it would vary as well, within about 3% either up or down or both.

So if you are thinking "20hp from this product", I would say that with this data, you shouldn't draw that conclusion. Rather, with a 3% variance you would guess that subsequent runs would yeild 5 to 35 hp over stock. For former would be true if this run is at the "high" end of the variance range, and the later true if this single run is at the "low" end of the variance range.

For marketing purposes, if a company supplies a dyno comparison versus stock, they often take the "low" stock run and the "high" product run, exaggerating the average difference by at least 3% of total HP. However, these results were done by a forum member so really it may be more fair than that, but its hard to say from 1 run.

Tests have shown that most people can only notice changes in hp above 10%, if sound and other factors do not also change. So arguably, that would mean that your car won't feel faster unless you gain 30whp. Practically speaking though, with any exhaust you will "know" your car is faster and it probably sounds louder or has more vibration, and so you'll think you can feel a performance difference too.

He did nine runs and threw out the first which came in at 318. Most of the other runs came in right at or very near 315 as Gator Bite posted elsewhere.

Kor,

I applaud your skepticism. I'd be wondering the same thing. As Sapentia mentioned, here is my post from another thread elaborating on the different nuns.

I too would like to see all 9 runs on one graph. Next time I visit F/L I'll have Kip pull my file and print it up.

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Gator Bite
PCA Cayman Register Advocate

One more thing. I totally agree with you on this. Before I had that 'after' dyno test done, I had driven the heck out the car and tried to determine if I could feel a difference in power. My butt dyno kept saying there was a slightly noticable difference, but nothing dramatic.

I think this is very subjective. Guys like you and me (skeptics, realists, pessemists, what ever you want to call us) won't feel much difference. Optimists on the other hand will.

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Gator Bite
PCA Cayman Register Advocate

I don't think it shows up as much in feel (apart from sound) but in noticing a difference at the end of a straight on the track or on a favorite strip of hwy. After 10 seconds of acceleration you realize you are going faster than you used to in that particular situation, that kind of thing. Same as with suspension upgrades realizing you can take a turn 10 mph faster than previously.

The stock vs borla chart shows the stock hp and torque starting lower in the rpm range. Is this correct or just an artifact of the testing? In other words are we sacrificing low end for top end?

Great curves.
One has some confidence when the measured result is very close to the spec of the Cayman S.
Unlike reported cases where measured stock power is way over the spec, which only indicates to me that such a reading is just plain inaccurate.

Your first chart shows stock RWHP of 243, and in the 3rd chart it translates into 294 at crank. This implies a loss ratio of 17%. How do you justify that?

Looks like a typo. The first 2 graphs should be of base Cayman. The second two graphs are of Cayman S.

It's actually a little spooky that you wrote that because just yesterday I was talking with my neighbor and he asked me if I can feel a difference. I told him maybe a little, but the one thing I notice is that if I jump on the highway and nail it like I used to, I am going way faster than I used to.

No, the increase is constant across the board. What you are seeing is part of the Dyno Dynamics Shoot Out procedure. They recommend several runs, all starting at different RPMs. So the operator is starting each run at a different point. This procedure more closely simulates actual street driving conditions and it blends out many variables that would otherwise compromise the results.

There is no sacrifice of power with the Borla at any RPM. Take another look at the graphs and you will see what I mean.

Yes. 17% loss sounds insane now doesn't it? Everyone here would tell you the loss should be closer to 12%. But does anyone really know what loss is all about and can anyone really accurately measure it?

It's a combination of friction and rotational inertia. So a car with 19" wheels will have more loss than one with 17"s. A car with a Tiptronic will have more loss than one with a 6 speed. A car with a 6 speed will have more than a car with a 5 speed. A car with steel brakes will have more than one with PCCBs. A car with low mileage will have more loss than one with higher mileage. Etc....

Farnbacher Loles uses the Dyno Dynamics AWD 450DR QS Chassis Dynamometer. This model is known as one of the most accurate dynamometers for testing high performance cars. In the industry it's been nick named the 'Heart Breaker' because of it's tendency to spit out low RWHP numbers, and I have to say, it definitely broke mine when they told me my car was producing 242hp. Kipp told me that RWHP numbers are all over the place from dyno to dyno, even when comparing the same brands. So the most accurate way to dyno a car is to have each dyno calibrated to deliver the most accurate BHP numbers possible. He told me that they calibrated theirs and that it is 'dialed in'. (Knowing how much time they spent developing the GTR, I have to imagine that the car spent a lot of time on that dyno and that they compared the results between their engine dynamometer and their chassis dynamometer.) The fact that their dyno is estimating my bone stock Cayman S BHP at 294 is further evidence that they have that thing dialed in very close.

So, to more directly answer your question, do I believe that my car has 17% loss between the engine and rear wheels? No, I don't. In fact I don't believe my car (or any manual shift Cayman) has more than 5% loss between the engine and rear wheels. I believe that the Dyno Dynamics AWD 450DS QS that is installed at F/L reads 17% low at the rear wheels when uncalibrated.

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Gator Bite
PCA Cayman Register Advocate

See my last post. All charts are from my Cayman S. The first two are the uncorrected Rear Wheel Horsepower, the rest are Corrected Flywheel Horsepower.

You can see the file number is '83691'. Those are the last 5 digits of my VIN and they identify my car. '83691.05' denotes run number 5 (also file number 5, each run saves a new file).

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Gator Bite
PCA Cayman Register Advocate

Interesting, your graphs are very consistent w what Kor said. 3% variablility translates to +/-8.85 horsepower (for stock). I would say that those graphs are consistent w that. 315 +/- 9hp = 306-324 where the range for stock would be 286-304.

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Gator Bite, your rwhp uncorrected dynos are almost identical to my Maxflow Fabspeed catback. I did have an EVO intake as well.

241.6 / 261.6

Ooops! Sorry Gator. The numbers look just like the horsepower/torque graphs in the cayman brochure.

Matt

Speaking of drive train loss...Last time I spoke to the Dyno operator he said the drive train loss was NOT a constant %. The loss varies depending on the BHP. Suffice to say the loss was less as power goes up. At the end of the day only a calibrated system can give you some reasonable accuracy.

I may go back later and ask for my BHP printout rather than just RWHP printout.
If I use the same loss figures as GB the my BHP is 366. My run was done on the same brand machine also in shootout mode.

RWHP:

I don't mean to bring you down, but even among the same brand numbers will vary from dyno to dyno. You'd be better off asking your shop for the corrected numbers off of theirs, assuming they have calibrated it.

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Gator Bite
PCA Cayman Register Advocate

Err I think I said that. And yes it is calibrated. The D.D. guys go to all the shoot-out accreditated shops and cal the machine as reqd, which btw I thought they did not do outside of Australia. I just gotta make the trip and hassel them for it. I got the RWHP printout because that seems to be more common.

Understood. I didn't mean to question you, I just wanted to make sure that the other spectators reading this understood that. I knew you already did.

I was kind of annoyed when they handed me a print out showing corrected BHP, because everyone here goes by RWHP. I had to ask for the RWHP print outs, just because I knew I would catch flack for bucking the CC system. That's when I got the lecture about how RWHP numbers are all over the place and less accurate. Then, he handed me a dyno chart showing 242hp. Like the human I am, I instantly started comparing my car to all of the other 260+ RWHP threads I remembered. That led me to do a little research, and that research taught me that the Dyno Dynamics dynos were the most unforgiving, but also the most accurate.

Here's and interesting description on the difference between 'Fixed Acceleration' (Dynojet) and 'Sustained Load' (Dyno Dynamics) dynos.

If you'd like to read more, you can do so here.

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Gator Bite
PCA Cayman Register Advocate