I had baseline dynos done at two locations on my totally stock CS. A Quaife TBD was installed, and the car was dynoed again (no change). The Softronic SRP and software flash were installed, and the car was run for a weekend on the track at a DE using 100 octane gasoline (8 gallons 104 octane race gas at the track, plus 4 gallons 93 octane pump premium).

The car was put on the dyno again at both locations, still with 100 octane fuel.

Results, first shop:





This demonstrates why I had the dyno done at two shops. This shop does fine mechanical work and has a good reputation, but they did not impress me with their dyno work. This dyno showed no change in power with the SRP, flash and 100 octane fuel. Runs 1 and 3 were totally stock, runs 4, 5, and 6 were after TBD install. Runs 7, 8, and 9 were after SRP and DE weekend.

Results, second shop, on Dyno Dynamics rig, using their typical test protocol:





Horsepower increase was 22 hp (240 vs. 218), torque increase was 7 ft-lb (200 vs. 193). All gains were above 4000 RPM, with LOSSES in lower RPM ranges.

Results, second shop, using 6-cylinder shootout mode:





Horsepower gain was 16 hp (245 vs. 229) and max torque was unchanged at 205 ft-lb. Gains were above 5000 RPM, with LOSSES in lower ranges.

Second shop is a very precise, technical speed shop. They do not do Porsche work (no axe to grind, nothing to gain or lose). They do primarily VERY high horsepower Japanese cars, typically with forced induction and nitrous injection.

Comments:
1. This is definitely a TRACK modification. Look at the substantial improvements at 7000 RPM. You can really feel the car pulling strongly all the way to redline. This translated into better lap times, and a difference you could really feel.
2. If you drive on the street, and your enjoyment comes from racing away from stoplights, according to my results you will be SLOWER. Make your decisions according to how you drive and what you enjoy.
3. Even if you dyno your car, you may not be able to tell if you are improving or harming its performance. There is a little sticker on every gas pump, indicating that it has been compared to a recognized standard. That is how you know you really get a gallon of gas. As far as I know, the only certification program for dynos is done by Dyno Dynamics, and that is only in Australia. The ability to compare dyno results is otherwise non-existent, as far as I can tell. Even if you are just trying to use a shop to judge relative improvement, you are at the mercy of their test operators, equipment calibration (or lack thereof) and equipment quality.
4. My car is still choked by the stock exhaust. Capristo is on the way, will install and run for a weekend at the track and then dyno again. Next DE is September, though, so don’t hold your breath…

__________________
....its even SAFETY YELLOW! What could be more practical???

I have the IPD plenum and the Softronic tuning with a Milltek catback. I installed the plenumn, exhaust, and the tuning in that order. Several months in between each. I didn't notice a huge difference with just the plenumn, but when I installed the Milltek the car really woke up. It seemed like you needed to improve both the incoming and exiting flows at the same time. They really seem to work well together. The tuning was just gravy on top at that point.

__________________
Nov 16, 2007 build:
'08 CS Midnight blue metallic
Black sport seats
Delete model designation
Fire extinguisher
Floor mats
Sport steering wheel

Other car of interest: '86 Guards/black 951

I wouldn't worry too much about what looks like losses below 3000 rpm, dynos are notoriously inaccurate below 3000 rpm and much of it depends on how the operator puts their foot into it or not. Is this the same plenum and throttle body for the Cayman S which comes from the GT3? If so, then I'm not surprised that on a 2.7L Cayman that it simply is capable of flowing more air than the engine can handle. I also concur that once you free up the exhaust you should see some improvements across the board. Interesting that one dyno shop shows no gain and another one shows gains, just goes to show you how you can't compare dynos between shops (which people always try to do here) or between cars, etc. Good to have a record for yourself to compare future mods against, and that's really what you should use it for.

__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.

K-Man S
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.

Very interesting, thanks for posting. Its amazing that the Dynojet can bearly measure any difference. A 10% high reading seems to tie in with other peoples charts.

Just further discourage me from relying on dyno results.

The plenum is the one Scott at Softronic is selling. It is a Porsche part, but I do not know where it comes from.

My car is the 3.4 litre S model.

__________________
....its even SAFETY YELLOW! What could be more practical???

Thanks VERY much for your post. Great data points to consider.