Performance question from a first Porsche owner

[tac27]

After several years of planning I have recently had the honor and fortune of purchasing a 2003 Cabriolet with a six speed transmission; I use the car primarily as a daily commuter.

Being unfamiliar with what is 'typical' for Porsche behavior I am hoping someone can provide a bit of guidance.

I have noticed that there is a sudden surge in power as the car moves through the 3,200 RPM range; it is most noticable while moving through the first and second gear. The dealer from which I purchased the car and an independent 'Porsche only' garage has opined that this is just the car, "moving into the Porsche power band."

Is this true?

Thank you.

[bsg03Cab]

Variocam. Normal but does take some getting used to. My 03 is much more pronounced than my 00.

Have fun and congratulations on the car!

Bruce

[Orient Express]

Normal transition for Variocam.

Easiest fix is just to make sure that you drive at a fast enough speed so the engine is always above 3200 rpm :D

[tac27]

Thanks, I appreciate the answers.

And yes, driving at speeds above 3.2k is a good idea; and really, really fun!

My only complaint about owning a Porsche is all the other cars that are in my way.

[ADias]

It is the famous Variocam II transition - a glitch really in 02 and 03 models, apparently fixed in 04 models. I wonder if the fix is software ,and if so, if there is an update for 02/03 models.

[Tazzgolfer]

It is the famous Variocam II transition - a glitch really in 02 and 03 models, apparently fixed in 04 models. I wonder if the fix is software ,and if so, if there is an update for 02/03 models.

I purchased a used 2003 996 cab w/ 6spd at 62K miles and had the 60K maint performed. At 73K it started misfiring and the shop had to replace all 6 coil packs and plugs. It ran like a dream for about a week and then it started surging around 3400 RPMs in every gear. It only does this when I'm going thru the RPMs slow to normal. At brisk acceleration, it doesn't happen. If this is the Variocam or Variocam II transition, why did it just start? Could it be that changing the coil packs caused it to start? Is there a fix? I often drive the car in traffic which makes brisk driving dangerous and the surge is annoying. Thanks for any help.

[Modavi]

Regarding the VarioCam "surge" at 3200 RPM - I have a MY 2004 C2 manual trans and it exhibits this symptom. So maybe it was not fixed for 04? Or do I have a different problem?

[4runner]

I had the same issue with my 03 C2. After switching to Phaff modified mufflers (PSE hack) car accelerates smoother, and with much less effort right from idle.

[THoward77]

I have a 2003 996 C2 with a rebuilt 2005 3.6 in it. It also comes into the power band at 3200 rpms. I can feel the car start to pull harder and accelerate as it passes 3000 rpms. My Miata is the same way, the power band starts just pass 3000 rpms.

[george996]

As everyone mentioned, the surge is the Variocam Plus switching over from small to large intake valve lift. The surge is more noticeable with non-stock exhaust. I tried the Daren Fister mod and loved the sound but didn’t like the small loss in low end power and more noticeable surge at 3,200rpm.

[frisbee91]

... I tried the Daren Fister mod and loved the sound but didn’t like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

[george996]

... I tried the Daren Fister mod and loved the sound but didn't like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

The Fister mod produces great sound, especially above 2800 rpm. However, I did notice a slight loss in power when letting out the clutch. You needed to pay a little more attention and give it a little more gas. Also, my 2004 has Variocam Plus and when the intake valves switch from small to large lift you could really feel the surge much more than with the stock mufflers. I went back to the stock mufflers and could easily notice the difference. From what I read, some back pressure is a good thing and helps low end power. Although I loved the sound made with the Fister mod I was willing to give that up for easier starts and minimal surging.

I also tried 997S headers with stock mufflers and had similar observations. I ended up going back to the stock headers.

Currently I am running mufflers that are completely gutted, everything inside removed. The mod was done by Hergesheimer. They produce a Ferrari-ish type sound and surprisingly are just a little louder than stock. It sings at 3,500rpms.

[Nehmaiz]

... I tried the Daren Fister mod and loved the sound but didn't like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

The Fister mod produces great sound, especially above 2800 rpm. However, I did notice a slight loss in power when letting out the clutch. You needed to pay a little more attention and give it a little more gas. Also, my 2004 has Variocam Plus and when the intake valves switch from small to large lift you could really feel the surge much more than with the stock mufflers. I went back to the stock mufflers and could easily notice the difference. From what I read, some back pressure is a good thing and helps low end power. Although I loved the sound made with the Fister mod I was willing to give that up for easier starts and minimal surging.

I also tried 997S headers with stock mufflers and had similar observations. I ended up going back to the stock headers.

Currently I am running mufflers that are completely gutted, everything inside removed. The mod was done by Hergesheimer. They produce a Ferrari-ish type sound and surprisingly are just a little louder than stock. It sings at 3,500rpms.

I was Seriously considering the Fister mod... now i'm having second thoughts... but in all honesty my stock exhaust doesn't fulfill the sounds i need from my car!

[george996]

... I tried the Daren Fister mod and loved the sound but didn't like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

The Fister mod produces great sound, especially above 2800 rpm. However, I did notice a slight loss in power when letting out the clutch. You needed to pay a little more attention and give it a little more gas. Also, my 2004 has Variocam Plus and when the intake valves switch from small to large lift you could really feel the surge much more than with the stock mufflers. I went back to the stock mufflers and could easily notice the difference. From what I read, some back pressure is a good thing and helps low end power. Although I loved the sound made with the Fister mod I was willing to give that up for easier starts and minimal surging.

I also tried 997S headers with stock mufflers and had similar observations. I ended up going back to the stock headers.

Currently I am running mufflers that are completely gutted, everything inside removed. The mod was done by Hergesheimer. They produce a Ferrari-ish type sound and surprisingly are just a little louder than stock. It sings at 3,500rpms.

I was Seriously considering the Fister mod... now i'm having second thoughts... but in all honesty my stock exhaust doesn't fulfill the sounds i need from my car!

The sound is great with the fister mod. The only issue is a slight decrease in low end power. I have a set for sale. PM if you are interested.

[FisterD]

... I tried the Daren Fister mod and loved the sound but didn't like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

The Fister mod produces great sound, especially above 2800 rpm. However, I did notice a slight loss in power when letting out the clutch. You needed to pay a little more attention and give it a little more gas. Also, my 2004 has Variocam Plus and when the intake valves switch from small to large lift you could really feel the surge much more than with the stock mufflers. I went back to the stock mufflers and could easily notice the difference. From what I read, some back pressure is a good thing and helps low end power. Although I loved the sound made with the Fister mod I was willing to give that up for easier starts and minimal surging.

I also tried 997S headers with stock mufflers and had similar observations. I ended up going back to the stock headers.

Currently I am running mufflers that are completely gutted, everything inside removed. The mod was done by Hergesheimer. They produce a Ferrari-ish type sound and surprisingly are just a little louder than stock. It sings at 3,500rpms.

Let me state that you will not lose power with my muffler modification. The small portion of exhaust that is allowed to bypass the muffler will not decrease the exhaust gas pressure you will see in your headers which is where hp/torque is lost/gained. Your cat creates the backpressure at the headers and changing anyhing after that (mufflers) is virtually insignificant. My modification is basically a mock version of the Porsche PSE, which also does not cause power loss.

A vast majority of people running my mufflers tell me they think their car actually feels faster, which is also a placebo effect of having a great sounding car.

As far as a gutted muffler goes, you have exhaust gases going into a big empty can, bouncing around, trying to find their way out, with no actual path to follow. Not a very efficient design IMHO.

[george996]

... I tried the Daren Fister mod and loved the sound but didn't like the small loss in low end power ...

Could you elaborate on the small loss in low end power with the Fister exhaust? How did it manifest itself? I don't have Variocam issues, but am considering the Fister exhaust for my '99 996.

The Fister mod produces great sound, especially above 2800 rpm. However, I did notice a slight loss in power when letting out the clutch. You needed to pay a little more attention and give it a little more gas. Also, my 2004 has Variocam Plus and when the intake valves switch from small to large lift you could really feel the surge much more than with the stock mufflers. I went back to the stock mufflers and could easily notice the difference. From what I read, some back pressure is a good thing and helps low end power. Although I loved the sound made with the Fister mod I was willing to give that up for easier starts and minimal surging.

I also tried 997S headers with stock mufflers and had similar observations. I ended up going back to the stock headers.

Currently I am running mufflers that are completely gutted, everything inside removed. The mod was done by Hergesheimer. They produce a Ferrari-ish type sound and surprisingly are just a little louder than stock. It sings at 3,500rpms.

Let me state that you will not lose power with my muffler modification. The small portion of exhaust that is allowed to bypass the muffler will not decrease the exhaust gas pressure you will see in your headers which is where hp/torque is lost/gained. Your cat creates the backpressure at the headers and changing anyhing after that (mufflers) is virtually insignificant. My modification is basically a mock version of the Porsche PSE, which also does not cause power loss.

A vast majority of people running my mufflers tell me they think their car actually feels faster, which is also a placebo effect of having a great sounding car.

As far as a gutted muffler goes, you have exhaust gases going into a big empty can, bouncing around, trying to find their way out, with no actual path to follow. Not a very efficient design IMHO.

First of all, your modification is well worth the price and sounds great. It's a great alternative for the Porsche Sport Exhaust.

Just a few comments 1) backpressure is not the only factor affecting scavenging and low end power. Gas wave behavior is a big factor. 2) The added bypass may not change the backpressure noticeably but it does change the path the exhaust gas takes and how the waves reflect all the way back to the exhaust valves. 3) The Porsche Sport Exhaust also has a control module which opens the bypass valves above a certain speed (it is something like 25 kph). I believe Porsche did this not to control noise at low speed but to preserve the low end power. 4) Lastly, my observation about power loss is a low rpm and at part load. It was very slight and hardly noticeable. At high rpm and WOT it is great.

Regarding the gutted cans, surprisingly they perform very well. The sound is not as aggressive as PSE or your mod.

[MiamiC70]

1. The PSE valve is there to pas EU noise regulations that came into effect. It muffles the exhaust during slower speeds becasue that would be the speed you drive through a populated area at. Coincidence? ;)

2. There is ABSOLUTELY no GAIN or LOSS of power from a FisterD mufler mod. All it does is sound "better" that is ALL it does.