My Diaries

A Lurid Tale of Obsession, Depravity, Wits and Attempted Wit

Tue Mar 23, 1999

A Personal Comparison of the Prize Viper versus a Built-Up Viper

I had previously found the white prize Viper GTS-R frustrating to drive.

So I "put together" a red one by race-modifying a purchased Viper GTS. The red one is 578bhp, 2169lb versus 680bhp, 2753lb for the white one--almost 600lb lighter. But the default racing suspension adjustment is the same for both, hmm...

Anyway, I have become a less worse driver, and won first USvsUK, almost sweeping it. I got 1st in all races, and pole except at SSR5 where I qualified third. I don't remember why. I was a fairly long way from my Cerbera LM records in all cases. This won me another RX7 Aspec LM, but blue instead of green. Well, I think it's blue, I wouldn't call it purple.

After that I won USvsJP, sweeping the series, with all five poles and winning all five races. I haven't raced that series since becoming a less worse driver, so I broke most of my records too. The red Viper won another white Viper.

Alright, so a day later, I try with the white prize Viper.

UKvsUS, I won, with more difficulty, 4 races, coming 3rd at SSR11 after messing up my first lap. I took pole only at GVEii and HSR(!--by .005) I won another blue RX7 Aspec LM which is probably still sitting on the Mazda used car lot.

USvsJP, I won with a little more difficulty, although I did seem to be eeking a little more speed out of the car. Peak power is significantly below red line for that car, and my qualifying seemed a little worse. I won the first four races again, but SSR11 was a disaster; all five AI cars seemed determine to race for a change, and I lost, but, of course, still won the series, winning another white Viper.

So, it *seemed* that, even with extra power, the prize car was not as good as the red one, although at least now I know how to stay out front with it, except on one course .

So I tried a test of truth. I went to trusty old GVEii time trial, and first took the white prize Viper for a spin. Eventually, with a struggle, it beat its ghost down to 1:59.xx

So then I took the red one out. It easily left the (best) white ghost way behind, finishing about 2 seconds faster. (It must have been close on the first lap, because I recall easily outdragging the ghost from the last hairpin). And a couple of tries later, I broke 1:00 on the first lap, posting a 1:55.xxx; not only that, the car was comfortably to drive. Rather than struggling to keep control I could ponder where to gain more time. I had previously noticed an excessive tendency for the GTS-R to "get stuck", e.g. on inside rumble strips of turns, but noticed that less this time.

So, in short, a race-modified Viper GTS seems superior to a GTS-R, and could give some drivers the edge they need to win the USvs series with an American car.

Some of it might be tuning. Should a car 25% heavier have spring rates pretty close to 25% higher, or is it not directly linear? I did crank the white Viper's spring rates up .2 at both ends, and that did seem to help and certainly not hurt (I run with full rear aero and backed of slightly on the front on both cars). But the biggest problem seemed to be the weight penalty. Both cars have 8litre V10 engines, so I don't think the GTS-R engine is heavier. So they should weigh the same. So it makes me wonder if the spec'd the racing modification for an empty gas tank, and the GTS-R for a full one. Or else they were over-enthusiastic in spec'ing a "racing modification" for a production car which is designed "race-modified". Actually, the Cerbera LM versus a fully-modified Cerbera has the same weight anomaly even though it has the same size engine, but in that case the extra power (and handling?) of the LM makes up for the weight.

Fuel consumption would be really neat in Gran Turismo. Try to get too much of a weight advantage, and you might not finish. During longer races, you might notice handling change as fuel is consumed. And in the GV300 you'd need to pit for fuel as well as tires. The computer would need to keep track of fuel consumption and weight changes for the other five cars as well, though...

Of course, while white is a pretty good colour for making a car go fast, red is way superior. Jet Jaguar really should have a "colour selection guide" section to his Tuning Guide.

Gees, I run on...

I finally found out how to see power curves for non-turbo engines, e.g. GTS-R

In "the pits", you must go to "Change Parts" and select "Turbocharger". It then, I believe, shows you (although faintly) the hp and torque curves. For the GTS-R it appeared to correspond to the numbers in the Spec sheet. It looked like a very spiked power curve, and a wide torque curve, with peak bhp much later than peak torque.