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Quote from JTbo :This video shows tyre deformation of low profile performance tyre, I think most tires should deform more in LFS as profile is higher, but judge by yourselfs.

Another important factor in this video is that the tyres are stretched over a wide rim, which stiffens the sidewalls up a lot to improve things for drifting. The combination of this and the low profile means they will not flex a lot...
#27 - JTbo
Quote from Michael Denham :Another important factor in this video is that the tyres are stretched over a wide rim, which stiffens the sidewalls up a lot to improve things for drifting. The combination of this and the low profile means they will not flex a lot...

Yes and also they surely use lot more pressure than any LFS setup. Twice at least.
Quote from JTbo :Yes and also they surely use lot more pressure than any LFS setup. Twice at least.

Maybe for drifting, but in LFS the race tires, for the GTR's are not that far off for pressures, it's the road tires I think have the issue when you can run 25 PSI and not have sidewall issues.
contemplating this i went out and shoved around my 106 which is on 45 profile tyres and fairly stiff suspension. Nearly all the movement when shoving it by hand, comes from the tyres and the sidewalls of the tyres. If i had the strength (and if the car wasnt made from foil) then when shoved sideways hard enough im sure it would flex similarly to the in game physics.

Other things to take into account are that after races, game tyres are usually hot and sticky and clean. If cold and dirty they probably wouldnt deflect as much.
Quote from Gimpster :My question is why would anyone in thier Left mind race or do a track day with tires that are prone to excessive sidewall flex.

The cars in LFS may have accurate sidewall flex but they are the wrong dam tires for the application they are being used for.

because when using 'trackday' type tyres or even full slicks, the massive amount of extra grip they provide requires the entire suspension setup to be revised, often needing spring rates to be increased 2 or 3 times over standard, as well as damping rates. Most people cant afford this, or simply dont want to have a car with such stiff suspension for the times it isnt being used on track.
#31 - JTbo
Quote from Viper93 :Maybe for drifting, but in LFS the race tires, for the GTR's are not that far off for pressures, it's the road tires I think have the issue when you can run 25 PSI and not have sidewall issues.

Well, GTR cars can be what they are, they are no real interest to me, all I care is road cars in LFS
Quote from dynofiend :because when using 'trackday' type tyres or even full slicks, the massive amount of extra grip they provide requires the entire suspension setup to be revised, often needing spring rates to be increased 2 or 3 times over standard, as well as damping rates. Most people cant afford this, or simply dont want to have a car with such stiff suspension for the times it isnt being used on track.

Gimpster is trying to say that the road tires give over too easy this has nothing to do with revised susupensions. Gimpster has a car and has taken it onto autocross tracks and he is saying that the street tires in LFS flex too much to compair with their RL counterparts.

I think he is partly right. They do flex too much in LFS but I think that has to do with the low pressures that are used with the road tires. In RL you run performance street tires at 50PSI or so on a track to prevent the sidewall from leaning over too far and damaging the sidewall which you don't have to worry about in LFS so everyone runs 25 pounds or so because thats where optimum grip is, even for performance street tires.

You don't put 50 PSI in steet tires in RL because thats where optimum grip is, you do it purely to prevent the sidewalls from giving out is what I am trying to say. IF RL sidewalls didn't give out and breakdown then everyone would be running 30PSI or so...even on the track like LFS.
Jumped out of my car when I got home from work this afternoon and looked at the front tire because it had been getting low in air pressure (it's been really really cold out lately). I thought of this thread and looked at the tire as I tossed the door closed. Just from the force of closing the door, you could see the tire flex and move. That is after a half hour drive with pressures initially at 30 psi cold. So, for the original post about the tires flexing too much when his car was being tapped by another car, it is probably just right. A light continuous tapping from the front of another car would be much more force than me throwing my door shut.
Quote from ATHome :http://www.visionresearch.com/ ... =htm/app&page=gallery

Take a look at the Porsche at the bottom of the page

[OT] That page has tons of cool stuff! Thanks! [/OT]

Well, that Porsche vid looks just like LFS GTRs to me... What does the deformation look like in LFS with really high pressures? I've never looked!

I think the only problem (as stated) is that low pressures in LFS don't have the pitfalls of RL yet. The deformation for given pressures seems correct based on any video I've seen. That vid of the tire being tested was pretty tell tale IMO, as are many others.
Quote from Viper93 :Gimpster is trying to say that the road tires give over too easy this has nothing to do with revised susupensions. Gimpster has a car and has taken it onto autocross tracks and he is saying that the street tires in LFS flex too much to compair with their RL counterparts.

I think he is partly right. They do flex too much in LFS but I think that has to do with the low pressures that are used with the road tires. In RL you run performance street tires at 50PSI or so on a track to prevent the sidewall from leaning over too far and damaging the sidewall which you don't have to worry about in LFS so everyone runs 25 pounds or so because thats where optimum grip is, even for performance street tires.

You don't put 50 PSI in steet tires in RL because thats where optimum grip is, you do it purely to prevent the sidewalls from giving out is what I am trying to say. IF RL sidewalls didn't give out and breakdown then everyone would be running 30PSI or so...even on the track like LFS.

Good point. This is also especially true in real life because a lot of cars are seriously limited with regards to camber adjustability, maybe only getting a maximum of 1 degree in some cases. This of course results in an even higher pressure needed to prevent rolling over onto the sidewall.
Viper, I meant to ask Gimpster what tires he expected should be used, instead of those in LFS.
That's what dynofiend was responding to, too.
And as rodgers said, LFS probably is not that far from reality... if you're going to assert otherwise, please show some proof.. without any, you're only speculating.
Well my prouf is that nobody in their right mind would run 30PSI in their street tires on a track. try it and see what happens. I can almost gaurentee that those tires will be toast within a few laps and will roll over easier than anything I have ever seen.

Soory I don't have any graphs depicting this, I wouldn't know where to start in the first place. I am going off of personal experience with a car thats equivelent to an FXO, well faster actually, and runs performance street tires
Quote from Viper93 :Well my prouf is that nobody in their right mind would run 30PSI in their street tires on a track. try it and see what happens. I can almost gaurentee that those tires will be toast within a few laps and will roll over easier than anything I have ever seen.

I agree that in LFS we can get away with way too low tyre pressures for the road tyres.

All tyres are designed to operate within certain peramaters and attempting to run them outside these peramaters should result in performance hits not gains. Thinking about tyres and pressures several things come to mind well before sidewalls rolling over and getting damaged

A tyre that is under inflated or over inflated will not have the optimum contact patch size. An underinflated tyre will distribute load to the outside of the tyre more than the middle, will give mushy response to steering input and allow deforming of the tyre longitudinaly causing a standing wave to form infront of the conact patch (underinfalted tyre will not be at the proper circumferance and the excess rubber has to go somewhere) thus adversally effecting rolling resistance.

So a tyre running at pressures under what it is designed to run at should give poor handling response, grip levels should drop off and rolling resistance should increase. If this all happened no one would be using unrealisticly low pressures

At the moment underinflated tyres in LFS do give some degradation in handling response and increase in rolling resistance, but this is far outwieghed by the increase in grip I think an underinflated tyre should have a more serious impact on rolling resistance and be accompanied by a decrease in cornering (lateral) grip...
#39 - JTbo
Also when tire rolls over that means very big decrease in grip.

My tires were sold as performance tires, also speed rating tells that these are not normals, but guess what, text at sidewalls get scrubbed even if I do over inflate them, also at one nice corner on track I could not go as fast as I wanted to go as that horrible sound of my alloy hitting tarmac kept me off, well tires are not too good indeed, send me your money and I get better ones

Money is biggest issue why people do use street cars on track in first place, whole year's car expenses has to fit under 1000 euros with my income so that means track day is not every day at summer and it also means that you can't test many tires or have much custom work done to car, running costs + little driving and that is about it. Money have to come somewhere and I have not found very good money tree yet.

Sure rich guys buy separate car for track days or even special track day vehilce like radical which is really expensive to run too, but there is more those that are not rich guys
Wow those tires were bad. What was the tire size, profile, and speed rating.

Mine are 225/45/R16 W rated BFgoodrich KDW2 TA's and I don't have a problem. I definatly dont hit my factory BBS's on the ground during a corner, even at 35PSI, I do scrub off the little arrows on the tire though.
Quote from Viper93 :I am going off of personal experience with a car thats equivelent to an FXO, well faster actually, and runs performance street tires

Hmm, so what does the FXO run in the quarter? Less than 13.9?
Quote from Ball Bearing Turbo :Hmm, so what does the FXO run in the quarter? Less than 13.9?

Not sure really, but I would guess something in the 14's And as you know I have my car running 13.7's =) Gotta love Dodge and their factory equipment =)
Quote from Breizh :Viper, I meant to ask Gimpster what tires he expected should be used, instead of those in LFS.
That's what dynofiend was responding to, too.
And as rodgers said, LFS probably is not that far from reality... if you're going to assert otherwise, please show some proof.. without any, you're only speculating.

The tires I have on my car right now are Yoko 195/50R15 all the way around. These have a max pressure rating of 36. These will roll over to scrub the sidewalls if I dro the pressure to 30psi. These are rated for 150 MPH. I would consider these to be equivlent to the Road Normal. At 35psi they will retain a full contact patch on the tarmak even when pushed past their grip limit. There is no wear on on the sidewalls.

The tires I want to get are Advan 205/45/15 and have a max pressure rating of 50psi. These will have a sidewall about the same higth as the one I have now, but the sidewalls are designed to resist rollover more. These are what I consider Road Super. Race compounds in a DOT legal street tire with tread. This will probaly also be able to be run down to 35psi with out deforming.

When I drive in LFS the one thing I feel about the current street tires is they feel like 135mph rated 60-65 series buget all season radials. They don't feel right until you get the pressure way up there but then they do not ever get warm. Its like the compound of the tire is mismatched to the design.

Edit:In case you need a point of refference.

My car is a 1994 Mazda Miata 1.8L with 140BHP and 100FT LBS of torque. The car weighs 2300lbs with the roll bar, is lowered with sport suspension and shocks, upgraded swaybars, about 2 degrees of negitive camber and has a weight distibution of 50/50. Its much like the XR GT but a little lighter and a little less power. The handeling though is completely different for some reason. I would be more then willing to take the time to take mesurments and do some testing if the devs want an additional refference model to verify their physics on.
Quote from JTbo :Also when tire rolls over that means very big decrease in grip.

My tires were sold as performance tires, also speed rating tells that these are not normals, but guess what, text at sidewalls get scrubbed even if I do over inflate them, also at one nice corner on track I could not go as fast as I wanted to go as that horrible sound of my alloy hitting tarmac kept me off, well tires are not too good indeed, send me your money and I get better ones

Money is biggest issue why people do use street cars on track in first place, whole year's car expenses has to fit under 1000 euros with my income so that means track day is not every day at summer and it also means that you can't test many tires or have much custom work done to car, running costs + little driving and that is about it. Money have to come somewhere and I have not found very good money tree yet.

Sure rich guys buy separate car for track days or even special track day vehilce like radical which is really expensive to run too, but there is more those that are not rich guys

I wish I could afford more then to autocross. The track days here are expensive. The local track has a requirment of their advanced training day first. $500+ then the first HPLD is 250+ instructor for the first time 200+, then after that its about 250 a session for a half day and 400 for a full day. Couple that with having to do an oil change before and after, brakes and maybe a dedicated set of tires for the cause and if you need to an alighment a track day is pushing upwords of $750 for people in this area.

Hell it only costs me $15 to autocross, but its not as much fun and my car is ment for the track damit.
Quote from Gimpster :My car is a 1994 Mazda Miata 1.8L with 140BHP and 100FT LBS of torque. The car weighs 2300lbs with the roll bar, is lowered with sport suspension and shocks, upgraded swaybars, about 2 degrees of negitive camber and has a weight distibution of 50/50. Its much like the XR GT but a little lighter and a little less power. The handeling though is completely different for some reason. I would be more then willing to take the time to take mesurments and do some testing if the devs want an additional refference model to verify their physics on.

One difference is that the suspension is MacPherson Strut on the XR GT, rather than double wishbone. I don't know how much difference this makes, but surely it's significant as you don't have as much control over camber compared to a double wishbone setup.

Anyone with more knowledge on how the suspension type affects the handling can comment at any time!
#46 - JTbo
Quote from Viper93 :Wow those tires were bad. What was the tire size, profile, and speed rating.

Mine are 225/45/R16 W rated BFgoodrich KDW2 TA's and I don't have a problem. I definatly dont hit my factory BBS's on the ground during a corner, even at 35PSI, I do scrub off the little arrows on the tire though.

Yep, bad as they can be bad, only bit more and would got set of Good Year Eagle DS3, but salesman was too good...

185/60/R14 V rated, even when I check from interneb they say it should be H, who knows. Pics after trackday bit melted shoulder, scrub marks at sides. Those are actually taken few days after track day.

Max pressure is 3bar and when hot I'm sure they were close to that so not much to do.

Here whole day on track is around 50€, I'm lucky to be able to live only around 40km from one of best tracks in this country, it has great elevation changes and combination of corners is just spot on, it has voted best track to drive by race drivers also.
I can take you there only trough video, but hop in

Hopefully I will soon get some proper job so I can get new tires to replace those and car needs some other work too to be more usable for track days so need to find something or it will be again another year without track days.
Off Topic:

The geomitry is a little different on the strut. The camber change is based on a triangle where the wishbone is based on a box or trapazoid. The net effect is that a stut has a more linier camber change as opposted to a wishbones more curved camber change profile. You also tend to get more bump-steer on a strut design (dynamic toe changes).

We need a car like a built sonthing like a miata, they are just so dam fun to drive.
Quote from Gimpster :The tires I have on my car right now are Yoko 195/50R15 all the way around. These have a max pressure rating of 36. These will roll over to scrub the sidewalls if I dro the pressure to 30psi. These are rated for 150 MPH. I would consider these to be equivlent to the Road Normal. At 35psi they will retain a full contact patch on the tarmak even when pushed past their grip limit. There is no wear on on the sidewalls.

195/50R15's rated at 150MPH I would rate as road super 195/65R14's rated at 135MPH is what I'd call road normal as I take "Road Normal" to mean stock standard tyres
Quote from Glenn67 :195/50R15's rated at 150MPH I would rate as road super 195/65R14's rated at 135MPH is what I'd call road normal as I take "Road Normal" to mean stock standard tyres

I don't think you would find a race track with insurance that would allow you to run any sort of high performance lapping or particapate in orginised amature racing on a tire like that. My point being that while the flex and grip may be modeled correctly in LFS, (The devs have said the grip is too high) I would like to see better tires modeled. Something more closely releated to what woudl accualy be used. Even at an autocross where the speed only get to about 60mph, that would be a dangerous tire to run. I would not be comfortable either driving that car or working the track with that car on the course.

There is more to consider then just size and shape. The construction of the tire and its compount also play a large factor in its level of grip and its ability to hold its shape. Right now road tires don't feel like they are the right combinatin of those paramiters. They are a soft compound on a narrow tire with poor lateral flex resistance. Two tires of the same size and compound can have very different handeling charistics depending on their construction. Scawen does not have a performance car as far as I know and probaly has tires on par with how the Road Normal feel. They scare me though.
#50 - JTbo
Quote from Gimpster :I don't think you would find a race track with insurance that would allow you to run any sort of high performance lapping or particapate in orginised amature racing on a tire like that. My point being that while the flex and grip may be modeled correctly in LFS, (The devs have said the grip is too high) I would like to see better tires modeled. Something more closely releated to what woudl accualy be used. Even at an autocross where the speed only get to about 60mph, that wodul be a dangerous tire to run. I would not be comfortable either driving that car or working the track with that car on the course.

Normal tires for my car have T rating 118Mph, I know that H rated tires have been used in racing here. Tire has to have rating that car is capable of running and load rating of tire have to be enough for car. Tire that is operated inside of those limits should be able to take all stress just fine.

There is many smaller cars where you even can't install any bigger and higher rating tire.

I think that LFS should have normal tires for normal cars, but also those performance tires and slicks if available for that size, all tires should act as real world versions, having all limitations etc.

FGED GREDG RDFGDR GSFDG