GT Sprint Cup - Season 2, Round 6, Spa - Jan 17

[mo]

Depends on driving style imo, just as in real life where two drivers in the same car and same team will have different setups
Softer bumps mean the car absorbs the kerb shock nice as the wheel hits the kerb and moves up and therefore does not upset the car balance too much.
Harder bumps makes the car jolt more from kerb shock and unsettles the car more.

You've also got to think about the landing back down off the kerbs bit though.
Softer bump means the ssupension gets compressed more on landing which can unsettle the car.
Harder bumps means that the suspension remains more static on landing and gives more stability.

Softer gives faster entry but slower exit (in teh 550 and GT3 anyway), and harder gives the opposite.

However the spring and rebound settings all come together with bump to give an overall effect so again for me I use stiff springs so need to increase bump accordingly.

Sadly the bump and rebound settings are not given in real pressure units in GTR. Does anyone know if these settings are time related or just an easy scale to remember or something?
Also, does anyone know if GTR auto selects a bump/spring and rebound/spring ratio when you change the springs? the physics are a bit wishy washy but it appears that it does not.


Anyway Jon's prolly the man to listen to on this as he clearly outclassed us all at Spa, although I screwed some decent laps out of the 575  after making the above changes.
I chose higher bump setting for braking not for kerbs btw.

[PaulW]

The weather idea is really neat. Love the idea of checking the weather in the days preceding a race

[fozzmeister]

I've always believed bump and rebound are according to time, but I can't remember if I read that somewhere, or its something I invented to get my head around how the settings effect the car.

[JonM_uk]

Had spring set to Min. as always. Set bumps about the same but rebounds about 2-3 lower, diff power and coast set 20% lower brake balance down to 53f 47r the car seemed to take a balance set more to the rear in the wet which was good for braking further into bend. Thought it would slide the car round more but it seemed to suit the rainy conditions. I was suprised at the amount of grip on the curb sections, I really hammered it at places but the rears didn't spin like I was expecting. Don't know if that's a bug or not 

[silver53]

Hi Guys real world shocker valving is calibrated in what used to be redwood seconds  its some new fangled thing now. Basically the time a known quantity, of a known viscosity fluid ,of a known temperature takes to flow throuhg the valves. Last night F***k though I had a god set up for race half way round pace lap Mary(my step daughter) slipped and threww her dinner at me , straight in the barriers end of race . bye for now.geral;d

[fozzmeister]

Lol Gerald, I'm always asked at some point if I want a cup of coffee, I've spun off once and scraped a wall once because of it, usually its OK tho :-)

[LEUVEN]

I had an idea about weather a while ago that I totally forgot to share with you....

Instead of the dice, how about we use the actual weather conditions from the venue, say 5 mins befiore the server goes up, the Admins check weather.com (or whatever) and set the in-game weather to the real weather at the time.

This could add an extra layer of interest to the race as you'd have to check the weather conditions in the days coming up to the race to decide whether to practice in the wet or the dry! Or gamble on a last-minute change  

Of course, there's a lot more potential weather conditions than 'dry' or 'raining' but I'm sure it would be fairly easy to sort out.

Pops

Superb idea  , all we need is a game that can replicate weather/grip good enough to feel realistic.

[mo]

Hi Guys real world shocker valving is calibrated in what used to be redwood seconds  its some new fangled thing now. Basically the time a known quantity, of a known viscosity fluid ,of a known temperature takes to flow throuhg the valves. Last night F***k though I had a god set up for race half way round pace lap Mary(my step daughter) slipped and threww her dinner at me , straight in the barriers end of race . bye for now.geral;d

The joys of domestic racing.

Thanks for the clarification about shock resistance Gerald - GTR's measurements may be in redwood seconds that you mention.
Do the numbers make sense if that's the case?

Springs are measured in newtons/meter now but I'm not sure about dampers.

[Dave 'Gizmo' Gymer]

Hi Guys real world shocker valving is calibrated in what used to be redwood seconds  its some new fangled thing now.

From http://www.carbibles.com/viscosity.html, we have some units measuring oil viscosity:

First up we have the Redwood Viscometer, also known as the Standard British viscometer. Redwood Seconds refer to the number of seconds required for 50ml of the oil to flow out of the device at a predefined temperature. The instrument is available in two sizes: Redwood type-I and type-II. When the flow time exceeds 2,000 sec, the type-II must be used.
[...] there's also the Engler Viscometer. This measures in Engler Degrees, rather than Redwood Seconds, and is preferred by the rest of Europe. On the Engler Viscometer, the reading is the time (in seconds) required for 200ml of the oil to flow through the device at a predefined temperature. The conversion of Engler degrees to absolute units requires an appropriate table, a degree in rocket science and an intricate knowlege of fluid dynamics.
[...] Finally, in the category of "America" = "The World", there's what is affectionately referred to as Saybolt Viscosity seconds [...]. For the Saybolt Viscometer, the amount of oil to be measured is 60ml. There's two types of Saybolt Viscometer, as with the Redwood system. Type-I is called the Furol Viscometer, Type-II is called the Universal Viscometer. "Furol" is a made-up word based on "Fuel and Road Oil" - ie. that's what's used to test the oil you put in your car. The Universal Viscometer is used for other industrial lubricants and oils, and has largely been superceded by kinematic viscosity methods - those performed using the type-I system.

And here we have more generic units:

Poise: The unit of poise, the value for absolute viscosity, is equal to one dyne second per square centimeter. That is, when two plates have a shearing area of 1 square centimeter and a film thickness of 1 centimeter, if a force of one dyne is required to maintain a velocity of 1 centimeter per second, the fluid is said to have a viscosity of 1 poise. One poise also equals one stoke multiplied by density (at specific temperature). Centipoise: Since the poise is such a large unit it is often more convenient to use the centipoise,(1/100 poise).
Stoke: The kinematic viscosity of a substance is the ratio of the viscosity to the density of the substance at the temperature of measurement. The unit of kinematic viscosity is the stoke and is equal to that possessed by a fluid which has a viscosity of one poise and a density of one gram per cubic centimeter, e.g. for a fluid with viscosity of 9 poise and density of 0.9090 it is equal to 8.18 stokes (818 centistokes). The appropriate tube selection would be 46460-400 for range 240-1200 centistokes.
Centistoke: Again since the stoke is such a large unit it too is generally more convenient to use the centistoke (1/100 stoke).

Never mess with a man who can wield the awesome power of Google.

[mo]

Never mess with a man who can wield the awesome power of Google.

Some nice links too cheers 

Question though (well off orig thread topic I know) : the redwood seconds and all the other units mentioned are all relating to the viscosity of the oil, how to measure and which units etc.

So now we know the oil in the shock has a certain thickness which can restrict/dampen its flow and the piston movement.
But there are different settings for bump and rebound (which both use the same oil) so there has to be a secondary measurement relating to the valve or blowhole pressures inside the chamber, to allow the oil to flow freer in one direction to the other.

I suspect that it is this that is adjustable in GTR rather than the actual viscosity of the oil, but cant find much online about it without getting to complex.
I obviously haven;t harnessed the awesome power of google yet 

[silver53]

Hi The shocker valves are spring loaded, in some cases the springs being adjusted by a screw these have a ratcheting action that clicks. We would say set it on 2 clicks.Thats where the numbers come from I think. That would then relate to the more complex parameters the race engineers and designers work with. As you all know one can set the ride height with the rebound setting . A light spring in most cases cannot push the suspension up to its resting position with a high rebound setting, a point not missed by some race engineers. Car measured in pit lane passes over 1" CUBE , OUT ON TRACK BUMPS REDUCE RIDE HEIGHT(we now have better ground effects) , back in pit lane car rises up to 1" . To good to be true , set like this my car would spin like a top if it even smelled a kerb , keep it on the track lots of grip. This is how I killed the turner at Snetterton, on for a lap record time touched kerb at flat out kink , straight into barriers, body over armco ,etc etc.cheers gerald

[fozzmeister]

Sounds not good Gerald, glad your still here!

[Jamera]

Gerald,
         Can you now explain all that in laymans terms 

Seriously though I really struggle with suspension setups and as we're now teamies any advice or guidence would be greatly appreciated

[mo]

Hi The shocker valves are spring loaded, in some cases the springs being adjusted by a screw these have a ratcheting action that clicks. We would say set it on 2 clicks.Thats where the numbers come from I think.

Cheers Gerald that would make sense alright, so ratcheting up the valve a couple of clicks creates more resistance in the cylinder, which is the same in GTR.

This is how I killed the turner at Snetterton, on for a lap record time touched kerb at flat out kink , straight into barriers, body over armco ,etc etc.cheers gerald

Sounds like a serious accident Gerald glad you've still got the racing spirit.
The turner's a very small light car isn't it?

[fozzmeister]

Gerald,
         Can you now explain all that in laymans terms 

Seriously though I really struggle with suspension setups and as we're now teamies any advice or guidence would be greatly appreciated

1=short time 10=long time.

So a 1,1 setup will move up into the bodywork quickly and return to its natural height quickly, a 10,10 will move up slowly, and to its natural height slowly.

If you had 1 bump, and 10 rebound the wheel will move into the body work fast, but will return to its natural height slowly. so if your thinking of a curb, it'll move the body of the car a small amount on the way over the curb, but may not be recovered for the trip back to the road, although it will not bounce as once its on the road, it will not excert much force thus not pushing the car into the air again, if you were to hit a second curb very soon after tho, you'd have no suspension left to deal with it... This is the way I go at Enna (my take is that Enna has no corners at all, only curbs with kinks), combined with very high power diffs, really sorts out the landing and bouncing of the car.