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Quote from Crommi :Reason for Toyota MR-2's handling characteristics is low polar moment of inertia, caused by engine that is positioned close to car's CG. This results in a car that reacts very quickly and feels very agile, but could also feel "twitchy" on the limit. Most road cars in iRacing have the same kind of design, much weight in middle to give sharper feel. Even Corvette has it's engine moved as far back as possible.

That's not right about the MR-2. The moment of inertia has nothing to do with understeer/oversteer balance. At the limit if there's a yaw torque into the turn it'll oversteer. That comes down to tire lateral force distribution between the front and rear and that's about it. All the moment of inertia controls is how large the yaw acceleration is given a certain yaw torque. A car with a huge moment of inertia that oversteers will still oversteer. It'll just accelerate around the yaw axis more slowly than a car with a low one (it'll spin out more slowly). Low moment of inertia does equal 'more twitchy' though and typically a design goal is to get that as low as possible so the car responds to the yaw torques quickly. That part's right.
Quote from titanLS :Regarding the Skip, it is a design goal when the car itself is designed as a trainer. While massive lift-off oversteer isn't desirable in most applications, it is when you're learning to cope with lift-off oversteer. There's a reason the school designs its own formula trainers.

Fair enough. If they want to train people to drive lousy cars that don't drive like real race cars should then so be it
Quote from jtw62074 :Fair enough. If they want to train people to drive lousy cars that don't drive like real race cars should then so be it

it's still fun to drive!
The problem with the Skippy for me is the brakes :/ Even at 54% balance any more than a quarter brake pressure and they lock up on me!

Can't wait till the licence upgrades happen, as soon as Im C class I can finally race the Star Mazda and Radical
Quote from jtw62074 :That's not right about the MR-2. The moment of inertia has nothing to do with understeer/oversteer balance. At the limit if there's a yaw torque into the turn it'll oversteer. That comes down to tire lateral force distribution between the front and rear and that's about it. All the moment of inertia controls is how large the yaw acceleration is given a certain yaw torque. A car with a huge moment of inertia that oversteers will still oversteer. It'll just accelerate around the yaw axis more slowly than a car with a low one (it'll spin out more slowly). Low moment of inertia does equal 'more twitchy' though and typically a design goal is to get that as low as possible so the car responds to the yaw torques quickly. That part's right.

I don't think I claimed it having anything to do with the overall balance, just that most fast setups on forums are biased towards oversteer under almost all conditions and together with low moment of inertia, they produce this "snap oversteer" if not driven properly. On the otherhand, default setups on Dallara are good way to experience how it affects the behavior on a car that is set up for massive understeer.

Late Model, Solstice and Impala show the handling of a car with high moment of inertia, all three cars feel very "lazy" and transitions happen much more slowly, making them easy to drive but little bit unresponsive as well.


Quote from mclarenmatt :The problem with the Skippy for me is the brakes :/ Even at 54% balance any more than a quarter brake pressure and they lock up on me!

Can't wait till the licence upgrades happen, as soon as Im C class I can finally race the Star Mazda and Radical

Driving downforce cars will forever ruin your Skippy career, just because of how it affects braking
All that extra downforce means you can go 100% on brakes at the start of braking zone and then ease off as speed drops, unlike in Skippy and Solstice where you need to smoothly step on the brakes to avoid lockups and then stay fairly steady all the way.
Quote from Crommi :I don't think I claimed it having anything to do with the overall balance, just that most fast setups on forums are biased towards oversteer under almost all conditions and together with low moment of inertia, they produce this "snap oversteer" if not driven properly. On the otherhand, default setups on Dallara are good way to experience how it affects the behavior on a car that is set up for massive understeer.

I must have misunderstood what you were getting at then. The handling characteristic I was talking about was off-throttle oversteer and pointed to the MR-2 as an example. You responded:

Quote :
Reason for Toyota MR-2's handling characteristics is low polar moment of inertia, caused by engine that is positioned close to car's CG.

I took that to mean you thought the reason the car had a lot of off throttle oversteer was because the moment of inertia was low.


Quote :
Late Model, Solstice and Impala show the handling of a car with high moment of inertia, all three cars feel very "lazy" and transitions happen much more slowly, making them easy to drive but little bit unresponsive as well.

Yes, of course that's right. It has nothing to do with what I was talking about though.
Yeah, little miscommunication there. You were talking about "how much" and I was talking about "how quick", it was probably the MR-2 mention that threw me off since on paper that sounds like quite twitchy car in hands of inexperienced driver. It makes for better discussion if both side would talk about same thing

Anyhow, about Skippy and SRF. As I mentioned earlier, you need to take in account the possibility that most setups you see on forums are dialed in to have oversteer available at all times and never understeer. I don't think Skippy has received any changes since beta and old setups work just fine, the fastest way to go around was to set stiffest rear-ARB and front suspension to lowest setting for high caster. That gave very pointy car that was easy to balance even in middle of a highspeed corner without major lifting. Last time I tried the car, it felt very understeery but that's probably down to steering that requires a lot more work compared to Mazda and Dallara.
Brands Hatch
iRacings version of Brands is now having its building & objects added.
Attached images
brands.jpg
Looking good. I can't wait for this. It's the only real racetrack I've ever driven on and I've been there as a spectator so many times. Hopefully it'll make it for next season. I just hope it appears on lots of the scheduless. With the indy and GP tracks it should suit most classes.
Looking forward to buying Mosport, will be like visiting an old friend .
Quote from JeffR :I thought the latest update reduced the excessive engine braking. Was that fix only done for the Spec Racer Ford? I'm not an iRenter, but follow what's going on at a few forums.

Quote from jtw62074 :I just tried both again and the Skippy seems a lot better than it was before (default setup). Perhaps that's my imagination since it's been so many months since the last drive in it. Pretty sure I remember it being a lot worse than the Spec in this regard.

I did the one one free Radical trial a while ago. Since I didn't buy the Skippy I don't know about it, but read many posts that stated the SRF was much worse than the Skippy. As you mentioned ealier, lift throttle resulted in spin, not oversteer in the SRF (and perhaps the Skippy).

Before the recent update, rather than mess with setups, some players adjusted the throttle throw so that zero throttle pedal translated into 10% to 20% throttle input, and then adjusted the brake bias in the setup rearward to compensate when driving the SRF (or the Skippy?). I don't know if any players are still doing this with the current update.
Very good deal! $75 for a year of iRacing for old and new members.

New members use the following code.

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I bought the Skippy today, driving it at Limerock It seems stable and predictable as long as you watch what you doing with the right foot, Initially I was a little disappointed with the FF, the car feels like it wants to steer all by Itself ( using corrent polarity in FF settings) but at Mosport even on lap one it was being five again at Xmas.

It maybe partly nostalgia for GPL , but one thing I do know the track is in another league since I drove it In GPL ,combined with this car driving the same corner always feel that little bit different each time, the Solstice is the same.I think thats whats makes you want to try one more lap.
Quote from JohnPenn :I bought the Skippy today, driving it at Limerock It seems stable and predictable as long as you watch what you doing with the right foot, Initially I was a little disappointed with the FF, the car feels like it wants to steer all by Itself ( using corrent polarity in FF settings) but at Mosport even on lap one it was being five again at Xmas.

It maybe partly nostalgia for GPL , but one thing I do know the track is in another league since I drove it In GPL ,combined with this car driving the same corner always feel that little bit different each time, the Solstice is the same.I think thats whats makes you want to try one more lap.

It's a great car the skippy.... I'll try to find you when you're on
Runs out on monday at some point..


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When do the licences next upgrade?
Quote from JeffR :Dual view video of the GPL version of Mosport (Greger Huttu replay), with graphic updates from GPLPS installation pack:

http://rcgldr.net/gpl/gplmsltgh.wmv

Great lap..track looks much improved from my time in gpl, I always thought calling it the 'mini ring' was very apt.
Quote from mclarenmatt :When do the licences next upgrade?

not sure but i think fast track is now operative, if so then licences upgrade as soon as all requirements are met
Something about Dallara Indycar seems to fit my driving style, grabbed another win! :woohoo:
It's because your rapido Crommi

Radicals at Road America is my favourite combo. My last race there people were asking whether to use tall or medium gears and how much fuel to use just before the race started! I found this a bit worrying

Wow just noticed I'm leading Div 2 of the Radicals, my best ever position in any series
Quote from Crommi :Something about Dallara Indycar seems to fit my driving style, grabbed another win! :woohoo:

well done (and you AlienT, can't leave a fellow celt out)

i really like the dallara and i'm finally getting my head round the setup, found 1.5 secs in just 5 laps yesterday after just 1 little change. i know i could (should ?) just find someone else's setup that suits me but i prefer to work the damm thing out for my self
Quote from AlienT. :It's because your rapido Crommi

Radicals at Road America is my favourite combo. My last race there people were asking whether to use tall or medium gears and how much fuel to use just before the race started! I found this a bit worrying

Wow just noticed I'm leading Div 2 of the Radicals, my best ever position in any series

Send me your radical set for RA will ya?
well today i came across my first fasttracked A licence holder. if this guy is an accurate example of fastrackers then all the doom sayers will be disappointed. he was obviously slow as he's only been an iracer for this season and had qualified as an A licence half an hour earlier so was attempting to learn watkins and the dallara from scratch. but he was safe and despite being an australian (just kidding) he was courteous, pleasent and polite. infact the only issue i had with him was him saying i was english despite celtic logos all over my wings and sidepods
Heck, then I should be able to get Pro in 10 minutes.. I'm safe and clean, but slower than death
This thread is closed

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