Forza 4 vs GT5 physics (read the first post before contributing)

[JeremiahTB]

I'm not sure if this has been said yet (too many posts to read through), but has anyone considered that GT5 came out an entire year before Forza 4? I know there have been updates to GT5, but I would think that there is only so much an update can fix when it comes to physics. Not to mention that PD started creating the game something like 5 or so years ago.

So, for the folks that are dead set on saying that the Forza physics are better, there is a slight technology gap that would help out in creating a better physics engine.

We'll see when Forza 5 and GT6 are released. But for some reason I think that might be more like a GT6 vs. Forza 6 battle judging by the historical timelines of the two games.

 

[hennessey86]

Having played both games (and series) a lot, it seems obvious that GT5 does a lot more shady stuff than FM4 behind the scenes.

In fact, and I may have already expressed that opinion around here, it seems pretty obvious that the physics engine of FM4 is much more advanced, in the sense of much more complex, than the physics engine of GT5.

There are quite a number of hints, from general car behavior to the damage model and tuning options, that GT5's physics engine is actually quite simple in the sense that it does not simulate a lot of components that interact with each other (like the suspensions, the brakes, the engine, the tires, etc) but has what we call in our field a more "mathematical" approach. A big equation that does a great job and is quite easy to compute (low processor usage) but is in the end a giant approximation that is tweaked to simulate a lot of behaviors without actually trying to "physically" simulate stuff.

The end result is that GT5 can be much more accurate on some behaviors but will not simulate anything that wasn't put there in the first place, whereas FM4 may be less accurate on some behaviors but will be able to reproduce a lot of stuff without the designers having to actually think about it other than trying to simulate each component as faithfully as possible.

Both approach have their merits, but now that we have so much processing power under the hood Forza's more "physical" approach put it leagues ahead of its competitor in a number of fields. Tire grip, torque steer, components damage (even if quite simple and permissive), and now with the new suspension model (FM4), FM4 does a lot of stuff better than GT5, even if of course there's a lot of stuff going wrong with FM4.

Given how differently they seem to do things, I'm all but confident that GT6 will be able to close the gap when FM5 comes out, unless of course FM5 screws it up, which is always within the realm of possibilities.

I agree with pretty everything you have said, forza has improved with each game that has been released so i do hope that continues. I think forza 5 will be a 720 title so with all that extra power it should be better in a lot of areas. As with GT6 I hope that is a PS4 title.

 

[Scaff]

I'm not sure if this has been said yet (too many posts to read through), but has anyone considered that GT5 came out an entire year before Forza 4? I know there have been updates to GT5, but I would think that there is only so much an update can fix when it comes to physics. Not to mention that PD started creating the game something like 5 or so years ago.

So, for the folks that are dead set on saying that the Forza physics are better, there is a slight technology gap that would help out in creating a better physics engine.

We'll see when Forza 5 and GT6 are released. But for some reason I think that might be more like a GT6 vs. Forza 6 battle judging by the historical timelines of the two games.

GT5's Spec 2.0 update, which did make major changes to the physics engine was released a month before FM4.

As such its not really correct to say that FM4 had a years additional time to get the physics 'right'.

 

[Spagetti69]

I'm pretty sure I remember Dan explaining the engine or calculator used for Forza 4.

In laymans terms its just a matter of entering certain values and there magic box does the rest.
This time however they had Data from perrelli.

I'm not a tech guy but I would imagine Weight, power,drivetrain, weight distribution and possibly height are the main inputs.

Stealth edit tire width too.

Double edit I remember Kaz explaining a similar protocol too. Unless I remember wrong.

 

[Exorcet]

I'm pretty sure I remember Dan explaining the engine or calculator used for Forza 4.

In laymans terms its just a matter of entering certain values and there magic box does the rest.
This time however they had Data from perrelli.

I'm not a tech guy but I would imagine Weight, power,drivetrain, weight distribution and possibly height are the main inputs.

Stealth edit tire width too.

Double edit I remember Kaz explaining a similar protocol too. Unless I remember wrong.

That sounds like standard methodology. You turn real things into parameters that react to different inputs, and you get a physics engine.

Based on playing the games, I'd expect Forza to go into more detail, not just having parameters for the car overall, but for different parts of the car. There parameters probably extended over a wider range of variables than they do in GT as well.

 

[Stotty]

GT5 ABS also adds in a form of EBD (Electronic Brake Distribution) which acts as a form of stability control under braking.

Its fairly obvious in is application as brake bias does pretty much nothing at all with ABS is on (even set to 1), switch ABS off and you now have the brake bias having an effect, and as the default setting for GT is equal Bias front and rear you now have cars that are unstable under braking.

I do agree that ABS acts as some sort of stability control when the brakes are applied, but I'm not sure I agree with the rest of your statement above, Scaff.

It might not make as big difference as with ABS off, but adjusting BB with ABS on does have an effect on the way a car behaves under braking. Take the current SLS TT at SSR5. With stock BB (5,5) the car understeers badly when trail braking. Increase the rear BB (to say, 5,7) and you can trail brake much more effectively.

There is a side effect of this that is completely unrealistic... Oversteer when you release the brake too sharply whilst still turning. I can honestly say that whilst I've driven a lot of cars that liked to oversteer if I trail braked too hard, I've never driven anything that oversteers when you release the brakes!

 

[Spagetti69]

Based on playing the games, I'd expect Forza to go into more detail, not just having parameters for the car overall, but for different parts of the car. There parameters probably extended over a wider range of variables than they do in GT as well.

That's true also. Each and every mod adds/minus weight.
Example a rear engine car with a 40% front weight bias would benifit with a lighter exhaust.
The weight would come of and the forward bias would increase to say 42%.
So in effect your not just shredding weight but altering the balance.

I would like to see Forza implicate some ballast as a tuneable option. WTCC/BTCC use ballast for handicaps.

 

[Tornado]

It might not make as big difference as with ABS off, but adjusting BB with ABS on does have an effect on the way a car behaves under braking. Take the current SLS TT at SSR5. With stock BB (5,5) the car understeers badly when trail braking. Increase the rear BB (to say, 5,7) and you can trail brake much more effectively.

I have to question this too. I haven't driven a car with stock balance in forever, but I do explicitly remember back in the immediatly-before-and-after-Spec-II days where changing the default balance levels made the second Top Gear Challenge and a couple of the licence tests (IC-10 in particular) far easier then when I tried them with 5/5.

 

[JeremiahTB]

GT5's Spec 2.0 update, which did make major changes to the physics engine was released a month before FM4.

As such its not really correct to say that FM4 had a years additional time to get the physics 'right'.

Are the updates that strong where the game's physics could improve that much? If so, the physics should be improved on both games more than they are. If not, GT5 won't be able to achieve the types of physics that Forza is able to produce.

I'm not knocking either game; it's a genuine question. IMHO, a game that must rely on updates to get better will always be at a disadvantage to a game that had better technology in the first place. But I'm not a game programmer, so I would be interested in knowing what advantages there are in the Forza/GT physics debate when it comes down to technology available at the time of development.

 

[Scaff]

I do agree that ABS acts as some sort of stability control when the brakes are applied, but I'm not sure I agree with the rest of your statement above, Scaff.

It might not make as big difference as with ABS off, but adjusting BB with ABS on does have an effect on the way a car behaves under braking. Take the current SLS TT at SSR5. With stock BB (5,5) the car understeers badly when trail braking. Increase the rear BB (to say, 5,7) and you can trail brake much more effectively.

There is a side effect of this that is completely unrealistic... Oversteer when you release the brake too sharply whilst still turning. I can honestly say that whilst I've driven a lot of cars that liked to oversteer if I trail braked too hard, I've never driven anything that oversteers when you release the brakes!

I have to question this too. I haven't driven a car with stock balance in forever, but I do explicitly remember back in the immediatly-before-and-after-Spec-II days where changing the default balance levels made the second Top Gear Challenge and a couple of the licence tests (IC-10 in particular) far easier then when I tried them with 5/5.

Setting a brake bias to a higher level at the rear should not have anything like the effect described, as the EBD effect of the ABS is removing pretty much all the effect it should have.

I have never once come across a single car in the real world that runs a rear biased brake set-up, for the very simple reason that it would be lethal, even a 7:5 ratio to the rear would see the back end lock up first under heavy braking and the car swap ends.

As such I maintain that ABS makes the setting of brake bias fairly meaningless in regard to the effect it should have, please keep in mind I didn't say that brake bias had no effect with ABS on, rather that it does 'pretty much nothing at all', which in comparison to what it should do is not that far off the mark. Try setting a 10:1 rear bias on a car and take it for a drive with and without ABS on and see what difference it makes.

 

[Tornado]

As such I maintain that ABS makes the setting of brake bias fairly meaningless in regard to the effect it should have, please keep in mind I didn't say that brake bias had no effect with ABS on, rather that it does 'pretty much nothing at all', which in comparison to what it should do is not that far off the mark. Try setting a 10:1 rear bias on a car and take it for a drive with and without ABS on and see what difference it makes.

Which (my apologies, as I didn't make it clear that I wasn't referring to rear biased specifically so much as a change from the default) is almost exactly what I did back then. Ramp up the front to 7 and drop the rear to 1 (for the Top Gear Elise Challenge) or 2 (for the licences). The differences in how the cars would react under heavy braking were very pronounced from the default 5/5.

 

[Stotty]

Setting a brake bias to a higher level at the rear should not have anything like the effect described, as the EBD effect of the ABS is removing pretty much all the effect it should have.

As such I maintain that ABS makes the setting of brake bias fairly meaningless in regard to the effect it should have, please keep in mind I didn't say that brake bias had no effect with ABS on, rather that it does 'pretty much nothing at all', which in comparison to what it should do is not that far off the mark. Try setting a 10:1 rear bias on a car and take it for a drive with and without ABS on and see what difference it makes.

Scaff, I agree with you 100%, any real car with those sort of balance settings would be properly lethal!

I do understand what you're saying regarding GT5, but BB + ABS is not 'meaningless' or does 'pretty much nothing at all' as I can often improve my time or driving enjoyment significantly using 5,7 or 7,5 (car dependant), even though it might have a relatively tiny effect vs no ABS. Should it work? No. Does it work? Yes.

Not trying to be pedantic, but it's probably better to say the effect of BB on ABS equipped cars is significantly less than the effect of BB on non-ABS equipped cars.

PD are clearly trying to create something that allows the lowest common denominator to enjoy it, and in the process this creates some gaps in the physics engine - gaps often made bigger as some more experienced users are able to exploit them in a manner that's unrealistic. But it's hard to blame PD when the range of player abilities and control methods is so wide... this is a commercial game afterall.

 

[Exorcet]

That's true also. Each and every mod adds/minus weight.
Example a rear engine car with a 40% front weight bias would benifit with a lighter exhaust.
The weight would come of and the forward bias would increase to say 42%.
So in effect your not just shredding weight but altering the balance.

Not just that, but I think Forza might factor in yaw angles when it comes to aerodynamics, for example. In GT, it's hard to feel any such effect, a car with an understeery downforce set up will understeer heavily even if it goes sideways, as if the downforce at the rear doesn't change with yaw. This is highly inaccurate.

I haven't felt this aero "bite" in Forza 4 yet, and I don't recall feeling it in FM3. In GT, the issue is probably also tangled with the limitations of the tire model.

Then of course, there is the whole torque steer issue which shows that Forza can laterally offset the Traction vector from the center of mass. In GT, they are always perfectly lined up.

 

[Lock2Lock]

Not just that, but I think Forza might factor in yaw angles when it comes to aerodynamics, for example. In GT, it's hard to feel any such effect, a car with an understeery downforce set up will understeer heavily even if it goes sideways, as if the downforce at the rear doesn't change with yaw. This is highly inaccurate.

I haven't felt this aero "bite" in Forza 4 yet, and I don't recall feeling it in FM3. In GT, the issue is probably also tangled with the limitations of the tire model.

Then of course, there is the whole torque steer issue which shows that Forza can laterally offset the Traction vector from the center of mass. In GT, they are always perfectly lined up.

Agreed with the downforce problem. It has got better with the last update but it isn't perfect.

And yeah the torque steer problem is there in GT5. It is in no way modeled correctly. It only shows when taking off in first gear with really long gear ratio for first gear.
I have shown the inaccurate model of torque steer before.

But i am still amazed on everything else PD has got right. The realism of driving is still there. That's what keeps me playing.

 

[Mike R]

Agreed with the downforce problem. It has got better with the last update but it isn't perfect.

And yeah the torque steer problem is there in GT5. It is in no way modeled correctly. It only shows when taking off in first gear with really long gear ratio for first gear.
I have shown the inaccurate model of torque steer before.

But i am still amazed on everything else PD has got right. The realism of driving is still there. That's what keeps me playing.

Have you played Forza 4? ( I have not read all the pages so its a serious question ) Are you playing with a wheel or controller?
The reason i ask is, i was very unwilling to even give Forza a try, but once i did GT5 got put on the shelf real quick.

 

[machschnel]

Are the updates that strong where the game's physics could improve that much? If so, the physics should be improved on both games more than they are. If not, GT5 won't be able to achieve the types of physics that Forza is able to produce.

I'm not knocking either game; it's a genuine question. IMHO, a game that must rely on updates to get better will always be at a disadvantage to a game that had better technology in the first place. But I'm not a game programmer, so I would be interested in knowing what advantages there are in the Forza/GT physics debate when it comes down to technology available at the time of development.

Not relevant at all. If Gran Turismo's physics are lacking when compared to Forza's then that's it - no excuses.

It's like saying because Usain Bolt has access to more modern training, his times aren't really quicker than Carl Lewis over 100m. Truth be told, we'll never really know, which is precisely why it can't be used as an excuse.

But not only that, arguably the biggest omission from GT5 (tire model) has been around since the "earlier" sims. No reason not to have one as "technology was available at the time of development", just (as always) a poor design choice.

 

[Scaff]

Scaff, I agree with you 100%, any real car with those sort of balance settings would be properly lethal!

I do understand what you're saying regarding GT5, but BB + ABS is not 'meaningless' or does 'pretty much nothing at all' as I can often improve my time or driving enjoyment significantly using 5,7 or 7,5 (car dependant), even though it might have a relatively tiny effect vs no ABS. Should it work? No. Does it work? Yes.

Not trying to be pedantic, but it's probably better to say the effect of BB on ABS equipped cars is significantly less than the effect of BB on non-ABS equipped cars.

To be honest all we are disagreeing over here is the verb and strength of its use, the effect of brake bias with ABS on is significantly reduced in comparisons to its use with ABS off (a quick 10:1 rear bias test demonstrates that quite well), so for me it makes brake bias settings with ABS on 'fairly meaningless'.

PD are clearly trying to create something that allows the lowest common denominator to enjoy it, and in the process this creates some gaps in the physics engine - gaps often made bigger as some more experienced users are able to exploit them in a manner that's unrealistic. But it's hard to blame PD when the range of player abilities and control methods is so wide... this is a commercial game afterall.

I don't disagree that they need to appeal to a wide range of audiences, however I think the method they have used in this instance is a poor one.

 

[Zer0]

Its fairly obvious in is application as brake bias does pretty much nothing at all with ABS is on (even set to 1)

Is not that another myth?

Check:
http://www.youtube.com/watch?v=UV4TLN7gSnM&t=12m21s

The end result is that GT5 can be much more accurate on some behaviors but will not simulate anything that wasn't put there in the first place, whereas FM4 may be less accurate on some behaviors but will be able to reproduce a lot of stuff without the designers having to actually think about it other than trying to simulate each component as faithfully as possible.

People like to asume a lot of unknown things that don't know to build points against GT5, but that is exactly how drifting was found in GT3. The same credit that you give to FM4 in your reply were exactly the words of Yamauchi in an interview when he was talking about the unexpected drift movement in GT3 and how that was not planed in the physics engine, just a result of it.

 

[BoneSawTX]

Which is more realistic, i have no idea. I can say after buying an xbox two weeks ago just for Forza4 i am enjoying it's physics much more.

 

[Lock2Lock]

Have you played Forza 4? ( I have not read all the pages so its a serious question ) Are you playing with a wheel or controller?
The reason i ask is, i was very unwilling to even give Forza a try, but once i did GT5 got put on the shelf real quick.

Yes actually. I bought my friend's old xbox after he got the new one (mine broke)
Also borrowed his fanatic steering wheel (intention if i liked it again I would buy it too)

I played it through and side by side with GT5 quite a few times for about two and a half months. Also I have owned many different forza titles.

I do like them. It is a great fun game. It doesn't seems like a proper simulation or should be considered as one.

I found myself going back to GT5 and playing more and more. Some of the things in forza are implemented correctly and one up GT5. Like something as stupid as torque steer which is truly modeled on forza. But the driving aspect of GT5 was better and more realistic to real life.

I was considering buying Xbox live which is the most pointless money I would ever spend. The xbox ended up getting the red light of death. So i threw it away and sold forza and gave his wheel back.

So i mean it is a great game. Just doesn't compare to GT5. That is just my opinion after driving on both games with a wheel.

 

[TokoTurismo]

I also play FM4 as well, and find it enjoyable and yes I highly agree that its physics are by far better. I just myself running back to GT5 everytime because even though it doesn't have the physics but at least its realistic, I still quiet enjoy it. My opinion of course before some BACKFIRE shows up..

 

[GTP_CargoRatt]

Scaff, I agree with you 100%, any real car with those sort of balance settings would be properly lethal!

I do understand what you're saying regarding GT5, but BB + ABS is not 'meaningless' or does 'pretty much nothing at all' as I can often improve my time or driving enjoyment significantly using 5,7 or 7,5 (car dependant), even though it might have a relatively tiny effect vs no ABS. Should it work? No. Does it work? Yes.

Not trying to be pedantic, but it's probably better to say the effect of BB on ABS equipped cars is significantly less than the effect of BB on non-ABS equipped cars.

PD are clearly trying to create something that allows the lowest common denominator to enjoy it, and in the process this creates some gaps in the physics engine - gaps often made bigger as some more experienced users are able to exploit them in a manner that's unrealistic. But it's hard to blame PD when the range of player abilities and control methods is so wide... this is a commercial game afterall.

I agree with you 100% about the brake bias having an effect with ABS on. I have done several tests regarding this just for my own curiosity. While the effect of brake bias is less with ABS on that with it off, I certainly wouldn't say that it is 'fairly meaningless'. Wording it like that, at least to me, leads people to believe that it really isn't worth adjusting the brake bias on an ABS car when that isn't the case at all. I drive with ABS and by adjusting the brake bias, I can further improve my cars' handling under braking and to me, thats not fairly meaningless.

Nothing against you Scaff, I just think your wording is/could be a little mis-leading to some people.

 

[Scaff]

Is not that another myth?

Check:
http://www.youtube.com/watch?v=UV4TLN7gSnM&t=12m21s

That brake bias doesn't act in a realistic manner when ABS is set to any value of 1 or above?

Nope its not a myth at all, set the brake bias on a car to 10:1 (rear bias of 10) and ABS to 1, brake from 100mph in a straight line. Now do the same with ABS set to 0 and then come and explain the difference.

People like to asume a lot of unknown things that don't know to build points against GT5, but that is exactly how drifting was found in GT3. The same credit that you give to FM4 in your reply were exactly the words of Yamauchi in an interview when he was talking about the unexpected drift movement in GT3 and how that was not planed in the physics engine, just a result of it.

Sorry - do you actually expect 'drift physics' to need to be planned into an engine?

Nothing against you Scaff, I just think your wording is/could be a little mis-leading to some people.

That brake bias reacts significantly different in regard to the level of effect and nature of effect with and without ABS is pretty clear, as such for me its pretty much a fairly meaningless setting.

 

[Lock2Lock]

That brake bias doesn't act in a realistic manner when ABS is set to any value of 1 or above?

Nope its not a myth at all, set the brake bias on a car to 10:1 (rear bias of 10) and ABS to 1, brake from 100mph in a straight line. Now do the same with ABS set to 0 and then come and explain the difference.

Sorry - do you actually expect 'drift physics' to need to be planned into an engine?

That brake bias reacts significantly different in regard to the level of effect and nature of effect with and without ABS is pretty clear, as such for me its pretty much a fairly meaningless setting.

Totally agree with you on the part about ABS being unrealistic and highly inaccurate.

ABS should not affect cars handling directly. Which it does. In GT5

 

[Scaff]

I do like them. It is a great fun game. It doesn't seems like a proper simulation or should be considered as one.

Given that FM4 simulates more areas of vehicles dynamics to a greater degree than GT5 (suspension model, tyre model, vehicle modifications, aero, etc) I'm at a loss to understand why its not a proper simulation and should not be considered one but GT5 should?

 

[GTP_CargoRatt]

That brake bias doesn't act in a realistic manner when ABS is set to any value of 1 or above?

Nope its not a myth at all, set the brake bias on a car to 10:1 (rear bias of 10) and ABS to 1, brake from 100mph in a straight line. Now do the same with ABS set to 0 and then come and explain the difference.




Sorry - do you actually expect 'drift physics' to need to be planned into an engine?




That brake bias reacts significantly different in regard to the level of effect and nature of effect with and without ABS is pretty clear, as such for me its pretty much a fairly meaningless setting.

Fair enough.

 

[TokoTurismo]

Given that FM4 simulates more areas of vehicles dynamics to a greater degree than GT5 (suspension model, tyre model, vehicle modifications, aero, etc) I'm at a loss to understand why its not a proper simulation and should not be considered one but GT5 should?

Is endurance races one of them? I know FM3 had them, but not FM4 for some reason...

 

[Scaff]

Is endurance races one of them? I know FM3 had them, but not FM4 for some reason...

Endurance races?

This is a discussion on physics and my comment was directly related to vehicle dynamics, as such endurance races have nothing at all to do with it?

 

[TokoTurismo]

Endurance races?

This is a discussion on physics and my comment was directly related to vehicle dynamics, as such endurance races have nothing at all to do with it?

Haha, my apologies. ^^'

 

[Ridox2JZGTE]

GT5 ABS also adds in a form of EBD (Electronic Brake Distribution) which acts as a form of stability control under braking.

Its fairly obvious in is application as brake bias does pretty much nothing at all with ABS is on (even set to 1), switch ABS off and you now have the brake bias having an effect, and as the default setting for GT is equal Bias front and rear you now have cars that are unstable under braking.

I do agree that ABS acts as some sort of stability control when the brakes are applied, but I'm not sure I agree with the rest of your statement above, Scaff.

It might not make as big difference as with ABS off, but adjusting BB with ABS on does have an effect on the way a car behaves under braking. Take the current SLS TT at SSR5. With stock BB (5,5) the car understeers badly when trail braking. Increase the rear BB (to say, 5,7) and you can trail brake much more effectively.

There is a side effect of this that is completely unrealistic... Oversteer when you release the brake too sharply whilst still turning. I can honestly say that whilst I've driven a lot of cars that liked to oversteer if I trail braked too hard, I've never driven anything that oversteers when you release the brakes!

Oversteer when releasing the brakes do happen, but it's more driver and BB dependent, as I rarely have this - only when I overcooked it or brake too late and too hard + too much rear BB. I ran no ABS from the day I have the game on release day, high BB as well, usually hovers around 9/4 to 10/9. The oversteer effect only occur frequently when the car has too much rear BB and to certain drivetrain ( FR/MR ), FF actually can reap benefits from it, reducing understeer in corner entry. With ABS 1 is different story, even with same BB as ABS 0.

I agree with you 100% about the brake bias having an effect with ABS on. I have done several tests regarding this just for my own curiosity. While the effect of brake bias is less with ABS on that with it off, I certainly wouldn't say that it is 'fairly meaningless'. Wording it like that, at least to me, leads people to believe that it really isn't worth adjusting the brake bias on an ABS car when that isn't the case at all. I drive with ABS and by adjusting the brake bias, I can further improve my cars' handling under braking and to me, thats not fairly meaningless.

Nothing against you Scaff, I just think your wording is/could be a little mis-leading to some people.

An example of how no ABS and ABS 1 with the same BB + 5/5 BB can make huge difference, and how ABS 1 with high BB can make the car feels different than ABS 0. The car was made for FITT Race Car Tuner Challenge, 625PP, Racing Medium tires. I will link 2 videos, one is mine ( tuner ) with ABS 0, 10/8 BB, the other was done by a tester Ugabugaz, with ABS 1, 10/8 BB

Lexus ISF RM 625PP, 10/8 BB, ABS 0, test run to demonstrate threshold and trail braking to fully extract the most of the tune's potential.





Ugabugaz's test, done with ABS 1





Some test drivers do no like the high BB even with ABS 1, mostly dislike the understeer, which do not happen with ABS 0 or ABS 1 with lower BB.

500pp Spa results.

Ridox2JZGTE (PSN: GTP_Orido) - Lexas IS-F RM
Time - 1:43:416
Drivers choice - Holy crap
8 gears, decent brakes(despite lighting the fronts wheels up like a christmas tree). Think that's about it to be honest. Not a tune for me.

Testing results:

Ridox2JZGTE Lexus IS F RM '07 01:42.895 Holy Crap

• Red tires, annoying tranny and breaks.

Thank you all for this great oportunity to test and compare these jewels!

Ridox2JZGTE (PSN: GTP_Orido) - Lexas IS-F RM – 1:42.065 - Having test driven this car for a series a few months ago, I honestly wasn’t expecting much. I was pleasantly surprised, once I adapted to the lower grip just how well it handled and how smooth it was around the track. However, the high brake balance was a major flaw causing the front tires to go red with any prolonged, heavy braking. Lucky for me I’ve been driving without ABS for a couple of months now so adapting by using only partial pressure and listening for tire squeal was relatively easy, but I suspect DS3 users or even wheel users not used to that, might have a problem. The LSD Accel was a little low as well, causing the inside tire to go red in Parabolica for quite a while but the flipside of that was that it was stable when getting the power down to the ground. By default I have to give this tune a 0 for driver’s choice not because I think I would crash and burn in it because it was quite safe, but because I don’t think I can meet the criteria for the first two choices. Sorry Rido.

625 pp Race car test results sheet
5 green laps each
I used DS3, manual trans. with sensitivity set to 5

Ridox Lexas IS-F RM 1:42.272

I changed to abs1 but brake balance was too strong the fronts turned red and stayed red causing entry understeer unless I let off the brakes early. 198 mph top speed was very good. It got thru the first 2 chicanes very well but I felt the car understeered in the other corners. With a few tweaks it would be in the 1:40s for me. DC 0

Official 625PP Testing Post.

9) Riddox's Lexus - 1:40.693

What a weird car this is. I'm sorry if I sound harsh, but it is what it is. First up the brakes, the most controversial part of the car. Actually I didn't mind them one bit, and actually enjoyed smoking the front under heavy braking. Call me weird but it felt a bit more, realistic? Anyway, Like the brakes . Next up the transmission - Set up very well and the 8th gear actually surprised me (Thought I'd top out in 7th on straightaway). Felt really..luxurious having 8 gears to play with, even if I ran Auto. The car also put down its power pretty well as well. I'm afraid the positives end here. I don't know what was wrong with the car, whether it was the LSD or Suspension but something felt really off with the way the car stuck to the track. It just felt rough, felt like I had to seriously slam the car into corners to make it work. The smoothness other cars have on this track, this car lacks. I would suggest a look at the dampers or perhaps raising the car a bit. Sorry, I can only give this car...

Also, Brake point at least for me at the first chicane was probably the 175M mark.
Replay saved if you want me to upload it.

Driveable

Ridox Lexus IS F RM 07.This car gave me a good workout.Im unfamiliar with the trail braking method involved with this tune,but I gave it everything I had in trying to master it.Unfortunately I failed miserably!I tried braking late,I tried braking early.I tried driving real slow so I wouldnt have to brake,all to no avail.There was a fatal cowl shake while braking under duress ( Holy cow I cant see the track! ) and turning at any speed was a scary endeavor.Looking past that,the car shows good grip and straight line speed,making me wonder how much better my times could have been if I was better schooled in the trail braking method.Please sign me up for some lessons as soon as possible.FASTEST LAP:1:45.950 DC:HOLY CRAP

FITT Race Car Tuner Challenge – 625PP Testing
DS3, ABS1, grip reduction real, all other aids off

Ridox2JZGTE (PSN: GTP_Orido) - Lexus IS-F RM – 142.485 - Driveable
I know that you prefer the authenticity of ABS 0, but for me, this is just a video game and not a real driving simulator. At ABS 0, I kept locking up the fronts and would have produced really slow lap times and not a fair comparison to the other entries. So I tested using ABS 1. Even with ABS 1 it is too easy to lock up the front brakes. I do believe that PD programmed the brake balance to equate higher numbers to more stopping power. When we did the rally challenge on dirt, I noticed that PD cut the engine noise when the brakes locked. On tarmac they added tire squeal sounds, but I don’t think they knew what to do for dirt, so they just made the engine stop. I couldn’t run anything above 4 on the brakes or I would get lock up. I also tested a 400PP Miata on sport hard tires on the Top Gear test track. 8/10 produced the shortest stopping distance for that car/tire combination because the brake power didn’t exceed the tire grip against the speed and mass. With heavier, faster cars, anything above 7 produced wheel lock up. I have no clue how you drove your tune at all with ABS 0 and bias at 10/8, let alone drove it fast.

The handling on this tune was pretty good. It corners well, with no real bad habits. There might be a little more to gain in the gearbox. I love that the Lexus has eight gears, but I think you made this into a six speed box with the settings. I’m not sure if this would be better or not, but I would have tested gear spacing that looks opposite of your current settings. Right now, the lower gears are closer together and the higher gears are further apart. Test the opposite and see if there would be any gain.

Overall, a good tune that I am happy for the opportunity to drive.

Some testing done, I intend to try to give cars more laps after the first cycle is complete and I've learned stuff. DC in notes so far but holding until I've completed a cycle.

Testing done primarily with G27, MT. Some very quick checks sometimes done with DS3 to check characteristics where the tuner is known to have used a DS3, but complete laps all wheel-based.

Ridox2JZGTE Lexus IS-F RM

Likes going fast. Does not much like turning; that's the tradeoff. Chassis (pre-tuning) tends to understeer, which seems to have been dealt with OK, but the LSD is set for inside tire fire, and BB is apparently calibrated for ABS 0 on a controller I don't have; the high BB renders threshold braking risky for me (with ABS off), lacking pedal range to do it, and even tends to squirm the tires under ABS. Lap times with ABS 1, per rules; but testing between BB 4/2 to 6/4 revealed this (no ABS) is what would probably be necessary to take some corners at speed, at least on a wheel. Only car that really tended to push wide for Parabolica. Suspension setup seemed good, but my style didn't get on with the diff and brakes. Could possibly have stood to flatten the peaky power band a little for more aero, maybe?
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Time: 1:42.110 so far.
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DC: Holy Crap​

Interested to find out how the car handles with ABS 0 and ABS 1 with high BB it came with ? Try the tune linked here :

Lexus ISF RM 625 PP FITT Race Car Tuner Challenge Tune

Please drive it at Monza, as it was tuned for the track in mind, try several laps with ABS 1 or ABS 0, set to 10/8 BB, then 5/5 BB, then your own preferred BB, witness the difference in how the car reacted under braking and corner entry.

The way ABS behaves in GT5 is not like real life at all, it's more suitable to call it brake stability assist with adjustable force for front and rear.