Planet 9

So I finally did my dyno day
No before/after mods pulls, nothing but MY OWN baseline before I play around with other mods in the near future!
Edit: Even more important, result not to be used to proof that the IPD plenum does deliver performance! Thanks.

After searching for quite some time now and talking to many people in my area, I finally decided which dyno facility to use.
The criteria for me was simple, I wanted a new(er) and accurate dyno, preferably a Dyno Jet.
During the last 2 weeks I heard of a few results from other dyno facilities which made me wait, I mean, I don’t want to see a
300 rwhp result (on a bone stock Cayman S), but also not a 240 (or less!). I want a real good and true result, and a facility I
can go back to anytime due to the fact that I can trust the operator who understands what they are doing and not wasting
my time. I had a hard time finding one! So I called the guys and RSS to check where they have their cars and mods tested.
They spoke very highly about GT PRO in Fullerton CA (Well, I was hoping for a facility closer to where I live, but I guess can’t
have it all). Called em up, spoke to Brian (extremely nice guy) and scheduled a session for Saturday for me and another CS owner.

Here the result (the blue graphs only!) of my ’06 Cayman S

STD correction factor (what most shops use) and *smoothing* to level 5 which lowers the HP number but
in my opinion is a better way to read the graph.
(Edit: The red graphs is a bone stock Cayman S they ran as well... Please, don't use as a
comparission against my modified car in any way! We all know that results differ from car to car!)

We did 4 pulls total, all came in very close. The best results were the last two ones with 286 rwhp (about
337 at the crank) and 244 torque. I didn’t see reason to post a graph with all runs since you almost can’t
tell anymore which one is which. I am pretty happy with the results, considering all my mods so far didn’t
really cost me an arm and a leg altogether.

Mods:
V-Flow & de-Snork
B&B exhaust
IPD plenum & throttle body
Softronic
(No aftermarket headers/cats)

Btw, my friends Cayman S with a Porsche sports exhaust and the IPD plenum came in at 276 rwhp (His car
also has the stock air filter and is not de-snorked). Great result, he was very happy with it.


Again, thanks to Brian at GT PRO, the owner who also operated the dyno! Nice work.

Cheers!


My car resting between pulls…

gforce,

Where did the stock CS number originate?

According to PCA cars from the factory can vary as much as 5% in HP output (~15 HP).

While it looks like your car is generating significant HP (congratulations!), it is still necessary to see this comparison on a like car basis, if for no other reason than to remove the speculation.

Cheers,

The stock CS was dynoed at GT PRO

Just to make this clear, I did this for me, to have MY baseline, as stated and I am sharing in here. Nothing more ;-)

What do I see when I look at these charts....? A couple of things.

The first is the fact that the 'stock' torque fell off like a brick after about 6,200 RPMs, versus your cars nice extension past 7,000 RPMs. This looks dramatic and makes you wonder if they kept the stock Cayman pegged. But it does make sense. The exhaust and intake mods that you've done will provide the most benefit in the high RPM neighborhood, so I'd say that's an incredible improvement and consistent with your mods.

The next thing that I notice is a dramatic drop in the torque of your modified car from 4,700 RPM to about 5,600 RPM. What could be causing that? My guess, the elimination of the distribution flap on the 2 stage resonant intake system. It just so happens that the resonant flap is programmed to open at exactly 4,700 RPM. My guess is that since the first circuit of the 2 stage intake has been removed, the 2nd circuit is all messed up.

__________________
Gator Bite
PCA Cayman Register Advocate

Nice work g-force, it is great to see the testing imfo you posted on three Caymans.

The gains of 31HP and 26lbs torque with your Cayman S are some real nice increase.

The Cayman S with the only performance mod being the IPD plenum reporting 277 RWHP is a 21 RWHP ( 24 FWHP ) gain over the stock Cayman you tested.

I quess this stacks up just like you have been telling us all for months that the IPD plenum really is an outstanding modification for the Cayman.

Looks good to me. I plan on making the plenum my next mod at some point in time. Thanks for sharing!

__________________
'07 Black/Black Cayman S
'07 White/Black Lexus IS 250
'08 White/Gray Jeep Compass

Did I miss something? Is there a dyno run on a car that has the IPD plenum, a before and after?

__________________
Gator Bite
PCA Cayman Register Advocate

I take this in your opinion dramatic drop (which is actually almost parallel to the stock line!) from my almost 257 torque over 212 (diff 45!) at 4,700 rpm every night and day.
What I also see is a nice zickzack on the stock car starting at about 5,300 not even breaking the 220 line and falling even further right after, while mine already improves and moves up nicely to almost 240 before 5,600 rpm… not? Maybe I am reading it wrong.

gforce,

I can accept that you are trying to get a new baseline for your car. Unfortunately, you also draw comparisons to a "stock" car in putting an exclamation on your HP gains, including your statement of support for the plenums contribution.

With all do respect (I enjoyed our conversation at Mike's); this is not accurate and frankly misleading.

Remember, performance can vary significantly among like vehicles, so if you are going to post your "baseline" I suggest you remove the "stock" car line from the chart.

I believe the only way that a comparison is valid is if it is done on the same car with the same dyno. This should not be hard to do if the demand for the plenum is so high. I imagine that RSS and others would be more than happy to pay for these tests to prove the apparent point.

I do hope to see at you at future events where you can put this HP to a test.

Cheers,

The purpose of a dyno is to give you relative numbers in order to do tuning or compare subsequent runs.

The numbers are not meant to be accurate or on an absolute scale. The device is not built to give you a number that you can compare to someone else's dyno number.

So its pretty meaningless if you start to judge based on numbers like this.

Also, IMHO DynoJets usually read "high". This is just based on personal experience, although I have probably seen at least 30 runs in the last 6 years and on the occasions where the same car was tested on a DynoJet and then another dyno, the DynoJet results showed higher numbers. This could be the shop I was going to of course and not the actual dyno hardware. But I don't think DynoJet has a reputation for accuracy or conservative numbers.

So you are saying because I have the plenum and a stock car listed my post is misleding? I can fix that!

What I will say here is that I have seen stock Caymans dyno anywhere from 260 to 282 hp at the rear wheels. Without a "Before" dyno on this car we have NO WAY to know what impact the plenum had (good or bad). At least now you have a dyno chart which can be used to compare other items, but it doesn't tell us anything about the plenum because we don't know what your car was originally.

I hope to have the "after" dynos on the plenum on both my car and DonelonPC's within the next week. That should tell us something.

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K-Man S

gforce,

When you did the runs, did you bounce off the rev-limiter at the end or ease off?

If you did the later, at what point did you ease off on throttle?

My dyno is "as stated" MY baseline, nothing more, nothing less.

Who ever said that my dyno is proof that the IPD plenum works, who?

I know and that is good that you did so, unfortunately some members (like elmo) are reading more into it and making statements which just aren't correct or at the very least are pure speculation.

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K-Man S

Thanks. I am glad you understand.

Interesting plots gforce. Sort of wobberly!

Lets see how this compares to my dyno readings as well. I will do a before and after plot. Im off to the dyno shop in an hour or so, seeing it is just the start of the day here. Then I will hammer it and my go back at the end of the week. I guess I shall start a new thread?

Very nice, can't wait to see yours.

gforce,

Please don't misunderstand. I'm not knocking your dyno pull. It looks very healthy. I am just pointing out that the dip between those points is dramatic and not ideal. In fact, it's downright weird. Just to be clear, here is the drop I am talking about, highlighted in red:



A blip or zig zag is one thing. This is a pretty big drop and it extends for over 1,000 RPM. Lots of people have pointed out the dip that the Cayman has at 3,500. Take a look at the torque in that area. There is a dip there, but it's far smaller in both magnitude and length.

I've never seen this big drop at this RPM in any other Cayman dyno runs. You literally lost about 15 ft.lbs. from 4,850 RPM to 5,250. That's why I am saying it's strange and looking for an explanation.

I understood you correctly. It was Elmo who confused me into thinking there was something more. His post suggested that this was proof that the IPD plenum was responsible for a 21 hp gain. Not the case. I understand what you are doing. I hope everyone else understand that this doesn't mean what Elmo assumed to be correct.

__________________
Gator Bite
PCA Cayman Register Advocate

Sorry Gator Bite, just a speculation didn't mean to confuse you.

When the last words I posted started with I quess (speculate) that seems to decribe the matter.

I believe it is human nature to speculate at least I hope so.