Critics of the 997 turbo complain about all of the lag. The same critics applaud cars like the bmw 335 and the nissan gt-r for having barely perceptible lag. The same goes for the VW 2.0l motor. Porsche has been running turbos for over 20 years! And porsche has VTG which
claims to reduce lag! What gives?

 

What critics are you talking about?

 

Lag?...what lag?

 

Excellent question. I honestly can't remember. that Fifth Gear episode talks about it a little, rather it talks about the gt-r's lack there of. I think R&T and car & driver both mention it too. And I know that European car has mentioned it often.

 

the 997TT does have lag....

 

It's those VGT's, another over advertised under producing item by Porsche (I.E. PCCB Gen 1, PSM)

 

Depends on your definition of "lag". Full boost at 1800-2000 rpms is not "much lag" if you ask me. If you want to experience turbo lag go drive a single turbo 930 or 964. Big difference compared to the twins.

My M3 had a VATN turbo and had a little lag...15 psi at 1800 rpms. The VTG feels much more responsive than my M3 IMO.

 

Correction VTGs (Variable Turbine Geometry) not VGT's.

 

Lag....pushing the accelerator to the floor and not going anywhere.

The 997TT has lag.

I have the GIAC/Exhaust/Headers and the car still has Lag.

 

All turbos have some degree of lag - it's the nature of the mechanics. The turbos are dependent on exhaust flow while a supercharged engine has a drive belt.

 

Interesting, my M3 turbo also has a similar spool up. "Lag" doesn't refer to initial spool up. It refers to the time between pressing the accelerator and feeling the power. The VTG turbos obviously do a wonderful job of creating low end boost pressure, but that is different from general boost response all over the rpm band.

So here's another question. The veins in the turbo seem to change degree in response to boost pressure (I guess). I wonder if it would be better to electronically link it to rpms? That way the beins would always be at the exact optimal degree to maximize boost when the accelerator is pressed. That should take away some of the "lag."

 

It has a little lag. Who cares. I consider it as adding to the charisma of the car. If you don't want any get a Z06.

 

Yes, it does have a lot of lag...it's annoying, but I love the car anyway. It's relative, though...less than the old 930 turbo, more than a 335i. In fact, it also has more lag than the 3000GT VR-4 and RX-7TT that I had 15 years ago. A lot of that has to do with the sequential turbos those cars used to build up boost more smoothly, which apparently works better than the VTGs. But beyond that, the overall boost and power output of the car are to blame. You're going to feel more lag getting 500 hp out of a 3.6L engine with turbos than you are getting 300 hp out of a 3.0L, no matter what you do.

 

I was being sarcastic.

 

...We're talking about Porsche here. Why do you TT drivers put up with it? If i was spending 120k or more on a Porsche turbo I would want the most lag-free turbo engine on the planet.
Porsche needs to step it up.