My Diaries

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

Fri Mar 26, 1999

A Tale of Two Settings

Based on email to jjaguar@worldnet.att.net

For the 560bhp prize Concept Car

Okay, so I put up the springs, to try and prevent bottoming out, and also raised ride height for the same reason. It makes sense to me that a light car would require not much less spring force than a massive car because most of the effective weight on the springs with these cars is due to aerodynamic downforce. However, the rebound effect will be related to mass, so it makes sense to me that much lower damper settings would be suitable for less massive cars. (In fact, I would guess that aerodynmaic "weight" itself would be a damping force, since it works only in one direction, whereas mass of the chassis, or the unsprung mass of the wheel work in both directions).

Do any prototype cars use electronic dynamic suspension adjustment these days? To change the damping or springing as the forces on the car change (i.e. basically, as speed changes, but also it should react to acceleration/deceleration).

Anyway, in the hands of a slightly biased test driver (me) I ended doing both GVE and GVE ii, although I used my brake settings with your setup. (Do you know whether 14/12 is equivalent to 7/6, by-the-way?)

The first run I did was my settings at GVE ii

0:55.569 + 0:52.113(rec) = 1:47.480(rec by about 2 seconds)

After that I (by mistake) ended up at GVE

yours I got down to 1:52.322, and set fl of 0:54.355 this setup still rumbled on the straight after the first hairpin

My settings (done second) my first run was 0:57.458 + 0:51.502 = 1:49.785

My wheels still lifted, but the car did not rumble. From the ghost I could see my setup was much faster on the esses getting back to the main straight. Probably due to my aero.

I got down to 0:56.214 + 0:51.755 = 1:47.969; the above remained my fl My notes indicated that my setup did still rumble occasionally.

At GVEii, your settings did not fair so badly. I'm not sure why; you get more of a run at that bumpyish straight between the tunnel esses and the hairpin, but it would only occasionally rumble there.

I got your setup down to

0:56.674 + 0:52.886 = 1:49.560 ; pretty far from my records above

and I did not seem to be able to beat it

So I added nearly full aero to your setup, backing off the front not very scientifically just because I had noticed your setup seemed to spin more than mine.

This allowed me to get down to 1:48.269, with fl of 0:51.193 I found that hard to beat. But as I got better at coming out of those esses onto the short straight to the final hairpin, the car would rumble badly. So I gave up since even more confusing (ie blurring the distinction between "yours" and "mine") tuning would be necessary to compensate for that.

Then, I went back to my own settings (now at GVE ii, remember) and finally set a new record, 0:55.335 + 0:52.064 = 1:47.399

I think I came reasonably close to the above fl sometimes, but did not beat it. That is, I managed to set fl with your settings (with boosted aero), but not fastest time.

Anyway, your settings with high aero, seem to produce rumbling, and without the high aero do not seem to be able to come all that close to times with my settings. My settings still lift wheels occasionally (usually just rear, but occasionally just front, in addition to the occasional characteristic GT "Demio Dance"). And my settings do get the occasional rumble. I'll experiment more freely some other day, now that I see your settings are not "magic" Probably I'll try your spring rates with higher ride height and full aero, and (maybe) 2/1 stabilizer and lower dampers.

So I just thought you *might* be interested. One future approach which could be taken with the Concept Car FAQ item would be to use it as a "for instance" to indicate how one applies the tuning processes you suggest.

Oh yes, I took my settings to that nice 3-race paid Time Trial Series known as the "FR Challenge" , and set convincing personal records which actually squeaked into first of what Nick Albright shows on his pages. My settings worked okay at Deep Forest; I didn't observe horrible rumbling.

My Cerbera LM is now feeling very dejected.

FR Challenge Results:

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From usenet:


rec.games.video.sony #451922
From: Dave Connoy <connoy@students.uiuc.edu>
Newsgroups: alt.games.video.sony-playstation,rec.games.video.sony
Subject: Re: Gran Turismo
Date: Fri Mar 26 16:14:39 EST 1999
Organization: University of Illinois at Urbana-Champaign
In-Reply-To: <jyoVVAArO++2Ew2f@mfevs.freeserve.co.uk>

On Fri, 26 Mar 1999, Mike Fairweather wrote:

> Are there any differences in car content between the US version and the
> UK version. I know there was between UK and Japan.

Well, there are definitely differences between the Jpn and US versions.
To go into a complete list would be far too time-consuming, but in the
"best cars" department it sounds like the [R]Concept Car is far more
dominant in the US version than any other version.  The [R]Concept Car is
too heavy to be as good in the Jpn version, which is dominated by its much
lighter Viper GTS-R.  The Cerbera LM Edition is excellent (and perhaps the
same?) in both versions.

Judging from what someone else said about the UK version (I forget who),
the "heavy" versions of both the Viper GTS-R and [R]Concept Car are in the
UK version, making the Cerbera LM Edition the best car overall, with
probably a race-modded '89 GT-R coming in second.

Owning only the US version, I don't know any of this for sure.  Heck, why
don't owners of each version (David Ralphs, you out there?) post the stats
of the [R]Concept Car, Viper GTS-R, Cerbera LM, and race-modded '89 GT-R,
and we'll compare?  I'll start...

US VERSION
---------- 
Name                            Power   Weight  P/W
[RM]R32 Skyline '89 GT-R        913     2268    .403
(Only 5 speeds and a damn narrow powerband though)
[R]Concept Car                  560     1329    .421
[R]Viper GTS-R                  680     2753    .247
[R]Cerbera LM Edition           581     1984    .293

This will doubtless blow up in our faces because the different versions
use different units of measurement, but at least we can compare
power-to-weight ratios within each version.

Dave Connoy
connoy@students.uiuc.edu
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