Let's not forget the golden Formula 1 days when FI engines were around, and how fast those things lapped - the bottom line is, with the proper setup and no major weight disadvatnage, FI > N/A, period!

In terms of the original question and like a few already said, the Turbo may never FEEL like a GT3, but with proper investment/setup, the Turbo will handle as good as GT3, and can lap faster than GT3.

 

I don't know about FI being better than NA on the road course. Most of the F1 track records are from NA V10's from early in the decade.

I wouldn't make a statement that strong, not to mention driving open wheel cars on slicks is far different from driving showroom cars on street tires.

 

Sure, but with 10+years of techonlogy advancement! F1 Turbo era changed the racing world in its time.

Open wheel or showroom, handling is handling - we are still comparing similar fendered cars built on a same platform, one prepped and built for the track out of the box and the other not. No?

Either way, this is just my biased turbo-headed opinion, and while I fully understand the advantages of smooth, responsive N/A engine, I still think a well prepped turbo car is superior.

Thoughts welcome, this is just an opinion!

 

When I first bought my car and when to the track with it in bone stock trim I thought ''why did I buy this car'' but after adding coilovers, changing the alignment and adding better tires, it made a huge difference in the handling.

I still don't think it can be made to handle as good as a GT3, but I do think it can be faster than a GT3 on certain tracks that favor power.

 

It is important to distinguish opinion from fact. You say the statement above as though it is a fact. Then, when your statement is challenged by other members you say it's an opinion. I admire your enthusiasm though.

But how is the turbo car superior?

If you have two cars, with the same weight, the same chassis, suspension setup, the same power etc...(a hypothetical situation) and the only difference is the aspiration. I can't imagine that they would give you drastically different track times.

The only key difference, which you also mentioned, is the responsiveness and smoothness advantage of the N/A engine. So if you prefer driving on the track, you most probably prefer the N/A set up.

 

At the end of the day it boils down to the suspension, the brakes, and the power of the vehicle. I'm a huge fan of torque, and I don't care how you serve it up... But if you're doing turbos, they have to eliminate lag or you'll be bogging anytime you do dip below their sweet spot. And yes, pros can keep the car spooled all the time, but I know of zero amatures that don't get bit by turbo lag... And at mid-Apex, that can make a driver into a passenger, just along for the ride...

Here are some video clips of the car at slower and tighter courses...

This was the first time I'd driven this track and the car was setup on street tires with very street friendly suspenion, and on stock brakes...

http://www.youtube.com/watch?v=kxVFhgAWJag


Here's a clip of Summit Main, both from a chase car (Z06 with the same HP as mine) and another from inside my car during a seattime day chasing race cars...


http://www.youtube.com/watch?v=WdeANh_bcCg


http://www.youtube.com/watch?v=zVluVwKRPeY


"MY CAR" could be duplicated. Lots of folks coming here every day shopping parts. All they need to do is ASK what it takes... I'd be happy to produce a list starting from the wheels and tires and working upwards...

Is a competent driver in a GT3 going to be faster in a GT2 or Turbo? I don't know... What I do know is that guys like my buddy Jim, who were lapping stupid fast in their GT3s moved onto other platforms because the GT3 hits a wall and you can break past that wall once you've extracted all you can out of the suspension and brakes... Only hp and torque can cure it...
Mike

 

The 14 constant was derived by computing a statistical regression of about 30 cars on the Nurburgring and backing into a formula for lap times based on power to weight ratios. I then adjusted it a bit for Porsches because they tend to be faster than other cars given the same P/W. Probably Rohrl and tires.


Well, I did a LOT of math. you can predict lap times to within about 8 seconds with power to weight alone and in pretty much all cases. You can pretty much account for the remaining 8 seconds by estimating grippier tires and, secondarily, 4wd. The only car that doesn't fall within the math is the GT-R (which VERY strongly suggests it had a lot more power than advertised and was on better tires; physics is physics).



Well, Power/Weight has by far the biggest impact on performance, but obviously tires are the next biggest contributor.

 

Here are a couple of CMP Videos. One is of one of the fastest street 996 GT3's in the NE driven by one of the faster GT3 drivers in the NE. Car weighed next to nothing and was on new michelin slicks. Car also had nearly a full cup suspension on it and motons. Had quite a bit of experience at CMP running both old and new configurations. Time was mid 1:41's

http://www.youtube.com/watch?v=0FOZ8yXe9SI


The next vid is me, my first time at CMP ever, first day was flooded so I didn't get any fast laps, this is my first day driving at speed on the track. Car is over 3550 with me in it and running crusty old Yokohama Slicks on JIC one way adjustables. Still learning the track in my second dry session of the weekend. Also managed to beat a 996 Cup by a couple hundredths of a second with the previous record holder. Only mods are JIC and rear sway bar, lwfw and K24's with tune and straight pipes. Fought a lot of understeer which kills your time here. I also didn't figure out I was running WAY too high (35 psi hot) tire pressures till I was asked by an autometrics engineer and he told me I needed to be at 28-30 psi hot.
Time was 1:39.9


http://www.youtube.com/watch?v=zlc-DDnMGc0


My times at Barber are also mid pack Cup Cars and only a couple of seconds adrift of some guys driving 997 Cups at the 24 hours of daytona right now. And that was only my second time at Barber.

 

You are losing me with all the math, I agree with the GT-R being a cheater car, but you still can't take 20% off a lap time like you can 20% off of weight/power ratio. They will not add up. That is a fact.

 

That isn't what the math says. I was just using the 2% to 20% comparison as an over-simplified example. Actually, that was a really bad example because the GT2 in fact runs the lap time that a GT3 would run if it had the same p/w ratio. That implies that the GT2 doesn't suffer at all from turbo-lag-related handling issues.

What the math does say is that there is a decreasing marginal decrease in lap times as a result of p/w increases. For example, a 3500lb car with 500hp would be 12 seconds faster than the same car with 400hp, but with 600hp it would only be 8 seconds faster than with 500. Adding power makes you faster, but it makes you incrementally less faster.

There isn't a direct % relationship between lap times and p/w (20% more power doesn't equal 20% lower time). Actually, everytime you add 20% more power, the decrease in time drops by a lower %.

 

I agree with that which is why I said diminishing returns earlier. More HP needs several things to be utilized completely.

 

more power allows you to put more downforce on a car, which increases grip. If you design the platform around the power increase, you can go faster. If you look at a race car like the porsche 956, it had lots of power and lots of downforce and it ran the ring in 6:11.

 

Dez, That's exactly why I'm of the opinion that you will get more out fo the TT... IF you want to correct the geometry issues, you can still bolt on the subframes and cupcar uprights, and other bits to get the most out of the 996TT. With the GT3, you hit a wall, and then have to decide on spending a LOT more for motor upgrades.

Mike

 

Stiggy, the reason I've qualified my statement with "opinion" is because we are mostly talking opinions in this thread. Secondly, I have not owned and tracked both cars to their limitations to be able to state facts.

Who said anything about power? The thread talks about handling, and my rationale for saying FI > N/A is exactly that. At the end of the day, the same platform N/A car will hit the power ceiling well before an FI car. You can always compensate for additional power with more/better tire, suspension, geometry, etc, but at some point, compensating for lack of power becomes difficult.

Mike hits it right on the button below, and BTW, note he is only stating an opinion as well. ;-)

 

I tried searching to find what is involved in a cup car upright swap and subframe and found a few things. But I am still missing the parts list involved with the swap for the Cup uprights. Is a GT3,GT2 and Cup car upright all different?

I couldn't find anything on a subframe swap at all though. What is gained by installing a GT2 subframe other than a bill $? Is it a weight thing or is it for GT2 suspension bits? Thanks.