Thinking it with velocity vectors is imho just a different way of thinking about it. And takes more words.

In a way it is backwards to think about the corner radius as the limiting factor and not the car speed itself but it makes it much simpler to understand imho.

I don't think it is terrible way to put it. It's beautiful.

Quote from jtw62074 :

... check out the attachment. It's something I made for one of the iRacing forum discussions on this...

Just caught up with reading latest posts. I'm understanding what you are saying and have no further arguments (for now anyway). Thank you for taking the time to post such thorough responses.

These kinds of threads are what makes me come to this forum! I love it!

This stuff really make me get a better appreciation of what goes into a sim, and I can really understand why mass produced sims like rFactor get it wrong. That a high-profile sim like iRacing does is unforgiveable, though. DK should know this stuff, and probably do. So why did he still make is so, I wonder?

@Shotglass and Hyperactive

Both ways of thinking about it have their benefits. I tend to go more with Shotglass' way because it includes situations that the steady state doesn't. I.e., Hyperactive's example of steady state slip angle definitions works only for steady state. If the rotational velocity is anything different from this it doesn't quite get the whole picture. I.e., if the car was spinning into the turn more or less quickly there's another component added to it that changes the slip angle away from the steady state picture.

In my hobby sim (and every other sim these days probably) I use the velocity and orientation vectors directly as Shotglass described, so I tend to think of slip angles as working that way since that's how they're defined. But at the same time, in a steady state corner those are equal to Hyperactive's description and excellent illustrations, so sometimes I think of it that way.

To be a truly powerful vehicle dynamics sorcerer, it's best to be able to think about it both ways so you can adapt to the situation, I suppose

What you guys need to remember though is that my only goal with that example was to "prove" that slip angles on front and rear are different and also to find out what causes them to be different. It was never meant to be an example about what happens to a car in a corner. It was about the slip angle differences only and that there is a slip angle difference .

Ok. You did a fine job proving it

Why would they add more road cars when it seems like alot of road series already have a tough time getting splits? Alot of series I have a tough time finding a race!. Weird.

Pretty clear they were paid by Cadi to add the CTS-V to the roster of road cars. It sounds like they have also made a deal with GM so you could probably expect more from them in the near future when it comes to cars. Could finally get a Chevy Cruze from BTCC or some other GM product raced in Euro series. However many (me included) would rather see a Euro brand make it into iRacing.

No doubt they needed a touring car, but this isn't exactly the best fit. At first I thought they would try to squeeze this into the GrandAm series but it seems like they are making a whole new series for this and the "future". Obviously it doesn't fit the wide range of consumer wants quite like it should, but in the end they are getting paid to put GM vehicles into the game by advertising iRacing/sim racing.

The iRTV episode was pretty dry in terms of current stuff being fixed. Seems the "thing to do" now is to talk about forward progress in a sense of "new" things rather than fixing "current" things. Obviously they are working on the NTM but they really need to get a big improvement on it. Many top level guys (especially real life) drivers seem to be protesting this current NTM in the top series, hopefully they get a fix so this changes.

The road going version would have been much more interesting imho. Looking at the info I found googling the r car is not very recent:
http://www.racecarsforsale.com ... ars/cadillac-cts-v-r.html
http://www.motortrend.com/road ... v_comparison/viewall.html

Wonder what kind of horsepower the car has? The sales ad for that one r car says just 361 (rwhp? or just different class spec?) but in the motortrend they say 515hp...? From the stats it says lat G peak is 1.04g which sounds nice as it would mean it is not just yet another aero obsessed gt car even if it will have slicks :/

Well this is the series it ran in: http://www.world-challenge.com/series.php?page=carfacts

And it says the class ranges from 425-525hp.

The 2011 version: http://www.firstsupercars.com/ ... cts-v-coupe-scca-race-car

Can't find any information on it however.

Quote from PMD9409 :

Well this is the series it ran in: http://www.world-challenge.com/series.php?page=carfacts

And it says the class ranges from 425-525hp.

The 2011 version: http://www.firstsupercars.com/ ... cts-v-coupe-scca-race-car

Can't find any information on it however.

Says 460hp here:
http://www.world-challenge.com ... dChallengeMediaGuide2.pdf

Oh good find.

Quote :

CADILLAC CTS-V Coupe
Class: GT
Year Models Eligible: 2011
Vehicle Type: Front-engine, rear-wheel-drive, coupe
Engine Layout: V-8, aluminum block and heads
Displacement: 6200cc
Valves: 16
Compression: 12.0:1
Induction: Naturally aspirated
Maximum Boost: N.A.
Maximum Engine Speed: 7000 rpm
Horsepower: 460 bhp
Torque: 435 lb-ft.
Wheelbase: 113.4”
Base Weight (pre-season): 3200 lbs
Wheel Size (F-R): 11x18” - 13x18”
Tire Size (F/R): 305/645/18” – 315/675/18”
Forward Gears: 6
Differential: Limited Slip
Restrictor: Sonic restrictor size tba

Other modifications: 0.5 mm (.020 in) overbore permitted. Alternate approved camshaft, crankshaft
and heads permitted through GM Motorsports. Approved alternate body panels, hood and doors
permitted. Transmission tunnel alterations permitted to accommodate ride height. Engine may be
moved eight inches rearward from V-6 location and 1.5 inches downward.

Since most road cars have the new tyre model now is the new model actually any different, or in any way better?

is the skippy not a piece of sh*t any more?

the Skippy is terrible now. It's a lot more unrealistic than before and drifts and slides ridiculously.

I used to love the Skippy, but then I took an arrow to the knee...

No, seriously, the Skippy is a pile of shivering, steaming dung.

And just to counter Andy I love the Skippy now and think it slides much less. I just find it so much more intuitive to drive now, much more consistent than on the old tyre model.

It slides LESS, but not at all predictably or realistically.
I wish we'd come off the "harder is more realistic" thing years ago, but it seems that one is here to stay....

The Skippy is now a steaming pile of shite. It's a mess.

Quite frankly most cars on the NTM are shite. Some are slowly improving ( Honda) but most are getting worse (Skippy, MX-5)

Not saying the old tyre model is good, but the NTM is still in a right old state. If the rest of the road cars get it in the next build then i'm done with iRacing.

I'm not paying to beta test their broken tyre model, they have staff earning good money to do that.

Even the Honda is a bad car to rate the NTM on currently, as it is 100kg lighter than what it should be. They somehow read the specs wrong and it should be fixed this next build. That's why the car is now the easiest to drive.

I'm unimpressed by the NTM so far. Count, I find the skippy totally slippy and horrible. Used to love it....

Yeah the oval side is a pretty big fluke currently. I'll say again that there are many racers in the very top series (most being real life racers) that are protesting the oval side simply because it is just that wrong. For example this is coming from one of the best oval setup creators:

Quote :

Yeah that's why I think all that stuff is useless right now. For the most part, "realistic" settings are not anywhere close to the fastest.

The "stuff" he is talking about is real life books and studying all about how to set up the car. He is also talking about setup analyzers etc. The fact that those are all wrong is just something not many want to hear.

I fully understand that the NTM is a WIP and might not ever feel right for a while, but it's still hard to read how "revolutionary" and "amazing" it is when it is performing so horribly.

yup... my thought is that the NTM currently is about ready to go from Dave's hands out to the beta testers to start getting right and developing before putting out to the paying customers once better.

Quote from StableX :

yup... my thought is that the NTM currently is about ready to go from Dave's hands out to the beta testers to start getting right and developing before putting out to the paying customers once better.

Spot on.

This makes no sense if it's a complete pile of shit as you're saying. DaveK's held lap records and won races in the real car. He ought to know himself if it's this far off.

Personally, I think it's off when it slides. It does odd things then. Not to mention it loses all grip in the next turn. When out of shape it can feel like the sidewalls have lost rigidity and squirts you this way and that. But generally, it feels there's no tolerance around the limit - one moment there's grip (such as there is) next it's ice - "i(ce)Racing".

But I still say we don't know how much of that is lack of physical forces telling us what's about to happen - only eyes and ears. What *should* that be like to drive?

Ah - memory, the subtle and wonderful veil over fact...

If your assumption should be true and DK lets himself inspire by his experiences rather than cross-referencing the results with the tons of data they claim to have gotten from CALSPAN, then I feel he's way too hung up about the "oh god that went wrong"-feeling he got when overstepping the limits...