I have a somewhat modified car and I decided to try some tests in order to hopefully see if its possible to squeeze a bit more power out of my car.

Firstly the disclaimer:
Please note that the results here reflect what I found on my car, someone elses’ car may produce different results or if you have different mods the results may also work differently. Also note I have no affiliation with any company or product in relation to these results. My goal is to seek performance improvements and my independent findings are published here in order to further increase the knowledge base of the Cayman S. All work to date has been financed by myself and this has not been a cheap process. Ok, so on with the results…

The current mod list:
1. "De-snork".
2. Milltek headers & Milltek Cat Back.
3. Evo V-flow filter.
4. Snapflash.
5. IPD Plenum.
6. BBI UDP.

Firstly a new base line Dyno was done. This is because I wanted to see accurately the before and after difference and minimize the variation one can get if I compare to a run done some time ago. Also wanted to make sure the temp sensor is located in exactly the same location on each run. The max HP before was 303 WHP, this new run gave 294 WHP.

First test is to replace just the hardware. The IPD Plenum and the OEM Cayman S Throttle Body was replaced with the Softronic supplied Porsche Race Plenum with the oversize 80mm Throttle Body. The result is a small improvement of around +5 WHP mid range and +7 WHP near redline. Otherwise the difference is almost unchanged. Note that I was only really expecting a small improvement when the air flow reaches maximum which would be around the very upper RPM range.
Dyno Run 014 is the initial run with the IPD Plenum.
Dyno Run 016 is with the Porsche parts.


WHP and Torque (displayed as lbs tractive force):



Same with Fuel Air ratio plotted. Note its running richer now:



Ok so now I re-flash the car with the Plenum version software from Softronics as seen on Dyno Run 018. The previous software was the standard Snapflash from the same vendor. The result is less power . A drop of 7 to 10 WHP across the entire range. Note that with Fuel Air ratio is somewhat different.
Result:
Update - Flash apparently was for race gas, thus the reason for the loss.



Ok so after that disappointment I flashed it back to the last version (Snapflash). One thing that I can confirm at the time of testing is that the “Plenum version” Software will allow the Engine bay vent fan to operate even when the key is removed. The Snapflash version does not do this.

Previously I mentioned on other threads that I had some problems with the cable for the flashing process. Scott provided fantastic customer support from Softronics and assisted to rectify the problem very quickly.

In conclusion, although I did not expect monumental changes, I was hoping for a small bump in performance and in this case it was not to be. What we need to to be able to actually tune these engines, individually, and on the fly. I dont expect all engines to be the same.

Correct final dyno coming soon.

Perhaps there was some sort of "learning" that had to occur with the new flash before it made better power?

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'06 Cayman S -JIC Cross, Quaife, CCW C14 wheels,MPSC's, Milltek cat back, GT3 seats Schroth harnesses, TC design bar, Pagid yellows, GT3 cup brake ducts,de-snorked, vanilla air freshener

A couple of questions:
- Did you drive the car at all after installing plenum flash to allow software to "learn"?
- Did you install the version of plenum software that sets off coolant sensor warning or the newer version that does not require disconnection of coolant sensor?

Thanks for doing these dynos - very interesting results.

Most definitely. The old software had the benefit of being able to learn and adapt to your gasoline and atmospheric conditions. Do you mean that you dyno'd the car, flashed it and then dyno'd it again. That wouldn't give the software time to learn at all.

Speaking of learning, the most important learning process in this is teaching the new software how to control the throttle body. If it doesn't have a chance to properly learn the TB, it's very possible that you never achieved full throttle. Let me explain.

Everyone knows the Cayman has the e-gas drive by wire throttle control and throttle body, right? Well, that means there is a sensor on the gas pedal that reports it's position to the DME. The DME then interprets that reading and 'tries' to dial in the throttle body to match. You ask for 15% throttle, the DME opens the TB by 15%. You ask for 100%, it gives you 100% open.

How does the DME know exactly how far open the TB is? Because there are two potentiometers in there that report back. But there are likely to be differences from one throttle body to the next. Because of design variances, temperature, connection integrity, part tolerance, part alignment, and so on, one TB will read a different resistance across it's potentiometer than another. So how do we fix this? By allowing the DME to adapt to and learn from the TB.

If you turn your Cayman key on without starting your car, and leave it for 20-30 seconds, the DME will run the throttle body though a series of tests. It will over close the TB and read the potentiometer. OK, this is 0%. Then it will over open the TB and read the pot. OK, this is 100%. Have you ever heard clicking coming from the back of your car when you turn the key on without starting the engine? That's the DME learning the TB. This happens every time you turn the key on without starting. If you start the engine instantly, the DME need to abort the learning process because it has now been called on to control the TB.

I would suggest you flash your car, drive it for a few days, allow the TB test and then return for your dyno test.

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Gator Bite
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Just as a quick note the last Plenum flash was not the standard flash. This was for race gas and when it was made I thought it was 98 octane and not 98 Ron . I was not privy to the info until after it was posted. The car was flashed and then driven to the Dyno. This is also a EU car.

I just called Scott on this for some clarification. My suspisions about adaptation and TB learning are correct.

Furthermore, Scott told me that he sent you a flash that was written for race fuel. This probably happened becuase of the Octane difference between Australia and the USA. Did you tell Scott you would be using 98 octane? Well, 98 octane to you is about 92 octane in the US. Over here, 98 octane is race fuel. When running race fuel you can use a very aggressive timing map and run the engine richer. But you're not using race fuel. You're using street fuel with a race fuel map. So power will be down and your engine will run too rich.

Flash your car with a more appropriate flash (already on it's way from Scott), drive it a little so it can adapt and then try again. We're all curious to see the results.

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Gator Bite
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All, some usefull feedback here.

After the new code was flashed, it was not a case of straight to the dyno. In fact I drove it several times and even managed a quite a few redlines down the highway in various gears. Previously there has been some talk of waiting for the software to adapt so I am aware of that, however I have noticed that on dyno runs before taht the adaption happens in as little as 2 or 3 runs with no further change after that.

Yes the key turn trick was done.

This version did not need any change to the coolant sensor.

I use normal fuel, you cant even buy race fuel here, or at least not at the local pump. Its the same fuel as before, even the same tank of gas and the same supplier. In any case it should be adapting to the fuel in use. I only ever mention 98 RON, not 98 octane for this exact reason.

On the A/F measurement you can also notice its richer on some parts and leaner elsewhere.

Yes maybe the non 'race gas version" will be better. I did not even know about this and thought the concept of a special high octane map was not required due the the multimaps/adaption.

P.S There was 3 days between run 016 and 018

Nice write up and good post. It's really nice that you made the effort to dyno and post your results and data points. More objective than butt-dynoing. A few comments:

* I wouldn't expect the Softronic plenum to offer radically improved performance over the IPD plenum which allegedly is already an improvement. As you said, you're trying to squeeze a bit more out. Your car is still making a quite respectable amount of HP considering the bolt-on mods.

* My very limited experience is that the ECU does, in fact, adapt very quickly for open-loop WOT performance, so I believe your measurements are valid.

* Keep us posted when you get the right octane program loaded. The AFRs look a little strange to me. Once you get the AFR and octane sorted out, you should see more gains. Since you already had the Softronic flash, you already have some gains (the majority?) "bundled" in with your "baseline" dyno, so again this is marginal gains on existing improvements.

Good luck and thanks again for the post!