Brian S

I just had the fortune of running against a competent driver with a viper ACR on dot-r's on a short track that tops out at 130mph, is there any way for a GT3 to beat it even on a short track? I had the track record at this track, so I'm not real slim on ability but the ACR is just a complete beast and this guy was only using 80% of the track and he is running the same lap times I am.

I was impressed that a straight starting in 3rd gear 4500rpm corner to 4th with a bend ending at about 108mph that he only pulled me by 10-15' and he was braking for the bend that I took flat out and got my 10' back under braking so that 600+hp isn't completely unbeatable.

Is the ACR just considered more like the GT3Cup than a street version car?

allegretto

if you can stay near him in your 3, he's not even close to a Cup.

Brian S

On speculation alone, the track owners and I believe that based on lap times from other tracks that a real cup car with a driver would be in the 1:19 range or less compared to my 1:25 or do you think it's more than that? Like I said this guy was leaving a lot of space on the track left while I was using the strips on almost every corner. There was a guy with a 355 challenge running 1:21's with slicks, so I think we are fairly close on the estimated cup times so we're just wondering if the ACR should be in that range.

allegretto

6-8 sec sounds about right for a +/- 2mi track

I know the ACR is potent...but as with many of the newer cars,I have never run one

TT Surgeon

Well my friend just got one and I can tell you for a fact there is not a showroom 911 (gt3/2/tt,etc) that can keep up with it on a long track, we were at the glen. I took a ride, it's a beast.

NJ-GT

The ACR is a street car. Dodge has a Viper Competition Coupe that crushes the ACR anywhere, even though the ACR has more power.

The ACR has awful gear ratios, but with a small budget the gears can be re-done and the car becomes a better monster.

I think there is nothing you can do to a GT3 to keep up with the ACR. The lap time gap is just enormous .

A GT3 Cup car can keep up with the ACR, but wait until you put an ACR on 997RSR slicks, and put the car on real brakes, real shocks, better gear ratios and get it down to 3,000 lbs (easily achievable).

NJ-GT

Typically, a 996 GT3 Cup gains about 5 seconds over a 996 GT3 street car, with the street car running DOT-R tires (street legal race tires, MPSC or R6). This is over a 60 secs lap. A 120 sec lap, would show a 10 secs difference.

The same difference has remained (based on lap times) between the 997 Cup and the 997 GT3. Porsche made both cars faster than the previous generation cars.

However, switching the street car to Cup slicks will drastically drop the lap times, think 3.5 secs slower on a 60 secs course (Lime Rock), or 7 secs slower on a 2 minutes lap (Watkins Glen) compared to the GT3 Cup.

If you're running a stock 997 GT3 on MPSC or Hoosier R6 at 1:25, a 997 Cup could be running 1:17 highs - 1:18 lows. However, if your times are posted running the stock OEM MPSC, the Cup car should hit 1:16-1:17.

If the driver in the ACR is running 1:25, he has about 4.5 seconds to improve.

Yargk

Since the GT3 and ACR both have decent setups, the gap comes down to mostly physics. He has a huge power advantage and a huge downforce advantage. You can improve your suspension to make some gains, but to have a faster car you'd have to add aero AND either add power (a lot) or drastically reduce weight.

allegretto

Not sure I agree completely. On a perfectly smooth track perhaps it is more as you say, but from what I understand, the vertical control of the Viper is also a potential problem. But they are said to be fastasssombyches!

Brian, I re-read some of your posts and I don't think you should take so much away from the fact that he wasn't trackng out all the way on exit. Many very fast cars, especially when they can use the ground effects just don't use all the track. Check out a fast wings-and-things car for an extreme example. They rarely use the whole track and instead cut off those broad exits to lower times. In my Cup I find that I don't use as much of the track as I do in other cars, entering or exiting. I cheat quite a bit sometimes. Just don't need as much. This would be very handy in a race situation, if I raced...

Anyway, differnet cars take different lines depending upon their inheirent strengths and weaknesses.

multi21

How long had this guy had the ACR? If the car is new to him, he might not be using all it's potential just yet.

From all I've read, this ACR pretty much beats everything street legal. It's hard to match the big hp, wide rubber and downforce this car has even on a short track.

C.J. Ichiban

regardless of the car, if you're shorting your exit radius, you're exiting slower than you should be...that being said I'm 100% certain that aero is a learned skill and a learned comfort- driving a few wing/downforce cars, even under full power it was hard to get to the exit kerbing unless I was absolutely full throttle...the aero won't let the car slide- speed while turning in and mid-corner speed are an entirely new skill set (and extra *****) once you add real downforce.

a properly set up (like rad said- gears, etc) ACR with equal drivers will smash any other street car with equal tires...although they're pretty brutal.

I'm probably going to drive one soon, as there is a friendly local who has one and wants to drive both my MX5 cup and my RS.


brian, what track are you at? sounds like the 1.7 at MSR.

allegretto

Then we're going to disagree.

The quickest way around any corner is going to be the quickest,which is not necessarily the fastest. The sooner you're around the corner the sooner you can be on it and the sooner you'll be accelerating down the straight.

If you watch the really fastest laps in a race or qualifying they are not always using "all the track" as you're taught in school.

I'm not directly commenting on this fellow's driving. I have no idea about that or the track he's running on. But while the best line is often the widest, this is not always the case, especially with effects. And, especially when racing...

Brian S

This was at Harris Hill in San Marcos, 1.8 miles. I have some traqmate data I could upload if any of you want to see it or if any of you could offer some advice on it.

I agree with you on the various lines for sure, I can not follow a spec miata without using my power on the straight and pass one using their lines.

I also agree that I don't use 100% of the track just to use it, there are certainly times that I use less to shorten the track or lengthen a straight like on turn 8-9 of this track, I late apex turn 8 to the inside of the track to set me up for 9 flat out instead of treating it as a turn where most people slow down which allows me to carry 104mph instead of 93mph using the commonly taught line (that the ACR was using, but this one corner alone saved me from losing time to him each lap)

This driver has had various vipers in the past, but I believe only a handful of track days with this ACR and he comes back with dramatic changes each time (mostly to the aero setup) so I'm expecting quite a bit more. I may have to look into some cup spec tires, I'm not sure if he has given up on DOT tires yet or not. You can certainly see how much more grip he has in what I consider to be off line positions in a number of corners apparently assisted by the aero.

LA964RS

Bottom line...ACR=one incredibly fast street car....gearing seems very tall, but it still beat all comers at the Ring and every place its gone....for $100k...how you gonna beat that????????

Answer: You're not!

allegretto

$100K will buy a very good used 996 Cup