I had a recent run-in with a very aggressive 1999 Porsche turbo heading northbound from Los Angeles on the 110 freeway approaching Pasadena. The race commenced with the Porsche approaching from the rear at about 80, approximately 2 miles from the end of the freeway in Pasadena.
As soon as I recognized it as a turbo, I knew a win on outright speed would be impossible. My M5 was running very strong that night. It was about 9 p.m. and traffic was a factor. I surmise that my car must be making an honest 400 h.p. SAE. I had my patented blend of Unocal 100 and Shell premium fuel, and a set of K&Ns. (I perforate the K&N filter on the passenger side with a very sharp needle in a concentric pattern around the intake cone in the air box. For some reason, this process yields a notable difference in mid-range power to high-end power. I know it sounds weird, but I can really notice it.)
He passes me on the right at about 80 and together we pull through light traffic. He instantly pulls at least 4 car lengths.
Since this is stretch of highway that I regularly practice on, I consider it my home course. I decide to stay in the fight because of this familiarity with the highway. All I remember is continuous full throttle acceleration from 80 to about 150 going uphill with gradual high speed turns. It seemed like quite a lot of time on the throttle, but the M5 (and some skill) kept me in the fight until the final long off-camber, sweeping turn that leads to the streets of Pasadena. There was no question that from the roll the turbo was faster, but at about 130 m.p.h. it seemed that his acceleration was no faster than the M5. He netted about 5 car lengths over the course of the prolonged uphill acceleration. At 130 m.p.h., he was no longer able to pull an inch. I was amazed. That kept me close enough to begin to set up for the last sweeper. I began turn-in and noticed that this aggressive driver was a bit tenuous in keeping his line in the #1 lane. I kept a steady throttle through the apex, selected the #2 lane to his outside and stayed with it. I made the pass and continued hard through traffic to ensure my victory. I think this guy must have been surprised to see those xenons on his tail in the final turn. This was high-danger freeway stuff that I usually try to avoid, but sometimes you just have to do it. That's life. I needed everything I had to stay with this guy. Driver skill and traffic were definitely factors here, but the M5 kept me close enough to make the pass before the highway ended.
I swear that the M5 is especially strong in acceleration over 120 or so. I was impressed. The Porsche is faster though.
I was hoping not to test maximum speed that night. I have a Kellener's speed module, so I should have been good for the 296 km./hr. top end. Not on that road though. I know the module works because I did an indicated 163 m.p.h. one time. Anyway, I wonder what the top speed is for the turbo. Is the Porsche a single or dual turbo? Excuse my ignorance.
All I really saw was the back. Afterward, I asked him what year it was and he said 1999. I don't know if that is a 996 or not. The only time I saw the front for any extended period was when he was behind me before the encounter. It had bright xenon lights as I recall and I couldn't see the details of the front end well. It had the standard "turbo" label written in cursive style below the rear wing and was black.
One of my best friends has a 2001 Porsche twin turbo. I play around with him on the streets of N.C. daily. I consider myself a decent driver and him a moderate driver at best. Regardless of the speed or situation the tt kills me every time. That car is mind boggling. I am not saying that your story is untruthful as I dont have a lot of experience at those speeds, but I know at street speeds the car will eat the M5 for lunch.
The 1999 is a 993 TT. I have driven both the 996 and the 993 TT at the track and their performance is similar. As great as the M5 is it will never catch a well driven 993/996 TT even in a straight line. If memory serves me right the M5 will hit 0-150 in about 26 to 27 seconds, the 993 TT did it in 21 seconds flat, my F355 in stock form does it in 24 to 25 seconds (22 in recently converted Challenge form) and the new 996 TT did it in one magazine test at 20.2 seconds.
Ready for this, it's claimed the 996 TT GT2 will do it in under 18 seconds, only a few seconds off the pace of a fully race prepped American LeMans spec 996 GT3RS.
The fact that we can even mention the M5 in this company is quite amazing.
Jon P. Kofod
1995 F355 Challenge #23
2000 A6 Avant
This guy kept going in the streets of Pasadena, and there was no way I was going to allow him to race me there. I know he would kill me really bad and try to avenge his prior loss. The story is absolutely truthful. The advantage the Porsche has to 150 is largely accrued at the start. At higher speeds over 130, this particular turbo had nothing for me. I certainly am not claiming the M5 is faster, but it allowed driver skill to make up the deficit.