1AS

Continued...
Your signature says you ownargraphic 997tt, so it is reasonable to conclude that is what you track. You don't say how often, how long, or at what level. I track a bunch of cars, and have had the opportunity to follow a well-driven Viper on a 1.8 mile road course (gingerman), which would certainly qualify as "twisty". The car I was driving was my 996ttX50, then a ZO6 on race rubber. It would not be easy or certain to pass and stay ahead.
I have driven a 997tt Sport Chrono, and find it about as fast as my X50, but a bit more tail-happy.
I have raced and won in vintage Can Am (lola T163) nad three other vintage calsses, after stopping current sports car racing subsequent to winning my class. Maybe you are a much better driver than I, or maybe you aren't used to high horsepower RWD cars (I race two, both of which have more power than the Viper or the 997ttSC-don't know what Cargraphic did to and for yours). I did not run away from a Viper in my X50, and I'm certain I would not have in the 997tt. I read the magazines, have thousands of track miles, and reach a conclusion differing from yours. So, I guess we do agree to disagree. You do have to be willing to keep an RWD car sliding, and clearly you need to have the skid controls turned off in the Porsche. So, out of curiousity, do you track with ASC on or off? If on, you give up a couple of seconds a lap. Just curious. AS

AAHTT

first of all it is not ASC, it is PSM and yes I have it off all the time on the track otherwise the TT understeers like an old civic. btw that's how I won second class in my class a few months ago at the annual parade PCA AX where my class P13 (not stock) included a bunch of 997 GT3s and GT3 RSs, all of us running on track tires, I got beat by a PCA instructor in his own prepped 996 gt3. I am not a track junkie and far from professional driving, so it must be the car.
second, I don't know why you keep saying that the power decreases after the overboost (4000 rpm) when in reality if you grab a manual and look at the graph, you will see a hp curve that continues to go up way beyond 4000 rpm, there is no decrease at all and the manufacturer is not saying that, you are.
You must be referring to the extra torque of 505 pounds which goes down to 456 after 5000 rpm, the hp numbers keep going up.
one more thing, like you said it is not fair to compare my protomotive TT to a stock viper because mine is tuned and the difference between the 2 is huge as I found out during the TX mile a few weeks ago, but a stock tt even with the bad reputation it is getting, has to be safer and easier to push further than a viper, but I can be wrong, I've never tracked a viper. maybe someone who has tracked both cars can shed more light on this.
Take care.

1AS

Let me post my response as questions.
Sports Chrono extra power: What is it that goes away after 10 seconds, and when it goes away, is the car slower?
PSM ( I stand corrected): Is an expert driver faster or slower with it on, and does the interruption ofpower and application of brakes increase or decrease acceleration?

My high horsepower RWD cars (and for that matter my lower powered track Lotuses) need a drift angle in most slow and mid-speed corners. I haven't tracked a 997tt, but my X50 is definitely slower with PSM on. With it on , trail braking tightens the line, but you can definitely feel power interruption, which is an uncomfortable momentary stumble.
In the wet, my tt is not enjoyable on the track with the PSM on, as it needs throttle-induced oversteer to actually turn. With the 997tt's tail-happiness, I can see where that might be a problem over either an unexplored section of road, or dicy conditions.
Aside from hoping for an answer to my two questions, there probably isn't much more on this subject. AS

AAHTT

No problem,
answer to first question: it is all about boost, with SC ON the car is boosting 0.9-1.0 bars then goes up to 1.2 bars between 2000 rpm and 4000 rpm, after that or after 10 seconds whichever comes first, the boost goes down again to 1.0 bars. this causes torque (and obviously hp too) to increase temporarily compared to no overboost, but peak hp remains the same. you do not feel any decrease in power or slowing of acceleration after 4000 rpm, it is still very smooth.

answer to second question: yes, professional drivers are quicker with PSM OFF, walter rohrl had it OFF on the ring when he got the 7:40 time and let me tell you, it really needs some getting used to...
regards,

TT_man

well my neighbor just had the heads + cam , plus a few more bolt ons added to his 97 Viper GTS. This is what the car now dynoes.
619RWHP! 619 TQ!


Ported Striker aftermarket head castings Shaved to get 11.1 to 1 Comp
Jesel 1.7 rockers
Striker street cam
Smoth tubes
S&P "Green" filters (pulled on this run)
Balenger Headers
Corsa Exhaust

I dont think I will race him anytime soon.

whyb2nd

race him in the twisties, with that rwhp you will never beat him in the straights stock. FYI keep the rpm above 4k...

1AS

So a guy who tries to drag race from a 2000 rpm roll is going to beat a Viper when the raod gets twisty? First, it is beyond stupid to truely race on winding open roads. Second, the car that starts in front stays in front. And third (and last), the better driver is faster, in either car. AS

whyb2nd

Lighten up, it was a spoof.

1AS

Don't mean to be defensive, but my first response to this thread said, "sorry if I read it wrong, but". If it was a spoof, it went right by me, and possibly by the thread-starter (see above).
It probably is my reflex to criticize street racing (reasons obvious), but if I missed a joke, I first admit embarassment, then submit apologies. AS

whyb2nd

I should have been more clear and not leave the notion of street racing in anyones mind. I had another business I sold recently, a performance shop where we installed F/I and custom dyno tuning. I knew a few that lost their license and a couple lost their lives exploiting the laws of physics.