Dynorun with GIAC and EVO

Here is the dynorun and of my Cayman S. Stock 275rwhp after 282rwhp. Look as the gains in the lower rpm range. Work was done by Imangine Auto at Croctoberfest. Cayman W

Don't forget that you picked up another HP after the de-snork (post GIAC and EVO tuning) Can you feel the additional power down low?

I made a difference down low. It almost feels like it is in Sport mode with it in normal mode. Sorry forgot to mention the 1 extra pony for the de-snork.

Only 1hp for the de-snork? What happened to the 13hp gain I've heard about? That said, I did notice a difference with the retrictor off on mine.

7rwhp for $1300+ seems a little steep to me...

Croctoberfest attendees got it at a discount and of course opening up the intake side of the engine is only 1/2 the battle. CaymanW is also getting an exhaust which will help him net 35-40hp at the rear wheels after the intake side has been done but his exhaust did not arrive in time for an install. BTW Porsche mods are never cheap...

I guess I still need someone to explain how you can gain 35-40hp and maintain the same mpg as before the change. Horsepower requires fuel so does that mean the driver is not using the new hp that much or the hp isn't as the dyno suggests or am I just thinking wrong?

Nice AF's W. Lets not forget that mustang dyno's read lower than dynojets. Of course doing baseline and modded runs on the same dyno is a good idea, but your probably making a few more whp on both runs. Do porsche ecu's have a closed loop-open loop operation? Sorry, I am a newb to Deutschland cars.

Santa Fe, If my fuel injectors are not shooting more fuel into the engine, you can see that from my air/fuel mixture ratios on both dynos where they remain right near the constant 13 mark that you want, then gas mileage would not be affected. I could have them lean out the engine a little more but it isn't worth it because of potential long term negative effects. So if my fuel injectors are shooting in the same amount of fuel my gas mileage will be the same or better if I am unleashing additional horsepower. What is happening is that horsepower that would be wasted as heat is being transferred to the rear wheels instead by making the breathing of the engine more efficient. If the factory exhaust manifolds that are restrictive (restriction causes heat build up) are made efficient then backpressure on the engine changes, horsepower goes up, wasted energy goes down in the form of heat. So how can gas mileage go down? Well if you open up the intake side of the engine and more air gets in (which some seem to argue isn't the case even with baffle plate removal and different airfilter or EVO air intake) then if more air comes in you have to put more fuel into that air to keep a constant air/fuel mixture ratio going through the engine. This WILL decrease your gas mileage. So what happens if you open up both sides of the engine? The result is that you may burn more air/fuel but will do so in a more efficient fashion making more horsepower. Depending upon how you drive you could see better or worse gas mileage. If you are flooring it from the stoplight testing out your new power, your mileage will go down. If you are crusing on the highway with cruise control on it will take less gas to achieve the horsepower needed to hold you at that speed because you will be more efficient, thus your gas mileage will go up. This has been proven out in my car where if I just cruise I easily get over 26mpg highway and sometimes over 28 on particularly cruise friendly stretches. Conversely if I am taching it up around town listening to the exhaust I'll get around 18.5 mpg. Does that help explain it for you? Porsche could not make the factory offering as efficient as possible because it has to: 1) protect 911 from Cayman having too much horsepower and 2) meet emission and noise standards across the world. Given they had to meet at least those 2 goals the factory gas mileage is quite respectable for an engine not operating at peak efficiency.

I know normally this is the case, but the Dynojet dyno run of my car in its current configuration produced 285-286 HP max, whereas the Mustang dyno showed 304-305 (see AWE exhaust article and the attached dyno charts). Personally I think something is wrong with the dynojet dyno in our town, but no matter, both dynos showed about the same incremental increases from exhaust tuning.

Thanks Ken. I'm getting the idea.

DaveW makes an excellent point regarding the huge HP gain down low. I recently did this modification to my car (GIAC flash plus EVO intake). I was inclined to do it after a PCA driving school at NHIS last month. There was another Cayman S at the school who had already done a chip upgrade to his car. I think it was a REVO. As I chased him around the track I was quite impressed by how easily he pulled away from me as we exited the corners. He was running Hoosiers to my Toyos, and he had a full suspension upgrade, so that might account for some difference in exit speed, but it was very clear to me that there was a HP difference as well. I was at another DE yesterday where two of my students shared a Cayman S. Even from the passenger seat I felt that my own car pulled harder down low than theirs. Peak HP numbers alone do not tell the whole story! That's my .02.

Hey Doc, I was wondering if you could help me better understand the GIAC ECU tuning process. On Cayman W's dyno run, I was impressed with the changes in the mid-range increase in HP and torque. As others have mentioned, this is really where people spend the majority of their driving time and the large increases that resulted surely must create a much enhanced driving experience both on the street and the track. My question to you is: Was Cayman W's GIAC ECU tuning a "custom" tune or is it an "off-the-shelf" configuration? I'm located on the left coast and it certainly would not be feasible to visit your shop to get the GIAC tuning done so I'm wondering if I visit my local GIAC tuner can I expect to get similar results as Cayman W's dyno run? The fattening of the mid-range has to produce quite a different driving experience versus stock. I feel that there is "flat spot" in the 2800 - 3200 rpm range which the stock dyno run shows and your post GIAC tune has dramatically changed that situation. Can you shed some light on the GIAC ECU tuning process? I'm not familiar with the specifics on how these upgrades are performed. Are they custom per vehicle or is there a fix number of parameters that can be adjusted for certain variables like air intake, headers, cat back, etc. or are we talking about a fully customizable scenario? Thanks in advance for any clarification you can provide on this.

Hi Tracy, His GIAC flash is a standard file from GIAC, so you would be getting the same by visiting your local GIAC dealer. It is a flash and go system. Obviously GIAC has spent hundreds of hours in the original tuning procedures, and they put it into a simple flash program which makes the work easy for the dealers who are installing the flashes. All done through the OBDII port with a laptop. The ecu program will adapt to any additional flow characteristics provided by a filter or exhaust.