XRG Drift Setup Questions
(8 posts, started )
XRG Drift Setup Questions
Well, before I start, I want to thank the developers for creating such a wonderful game. It is not that I haven't known that for the last year or so, but it's good to know that the development of such a potential - full game is still on.

Anyways, recently, I am reading the Advanced Setup Guide by Bob Smith. I am to re- read it until I am sure I know each point for sure. So this is the question (edit: QuestionS).

I'm trying to tune the XRG for drifting BL1, and later when I get S2, the other maps (yes, with the XRG). Before I continue, I want to get the laughs out of your system...
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There we go. Ok. I am trying to tune the XRG to Keiichi's TRD AE86 specs, as drifting is what I am trying to achieve here, and the specs are similar, or so we speak. Anyways, I've gotten mostly what I wanted. I have fitted Normals on the front and back, as opposed to Knobs on the front, which I've done before I lost my previous setups.

I like a slippier drifty feel, rather than an understeery setup which I liked before, where I could accomplish higher speed drifts.

I've got -.9 and -1.2 camber (live) front and rear respectively, with pressure at stock in the front, and raised at the tad, maybe 10 PSI in the back. I am going to fine tune the camber figures.

* I am currently using a Clutch - Based LSD. Here is a problem. I'm using the hard track's LSD setting. There is a locking setting, and a preload setting. I'm presuming the preload is the amount of force that pushes the clutch plates together, but I can't exactly make out the locking setting; the percentage of lock? It seems like I am working with two variables here; rather hard.

Suspension. Here, I chose to utilize the suspension stiffness to tune my handling, and rather use the others to achieve neutral handing.

I have thought of a formula; rather a method that should help me here. I use information from the f-r weight distribution, and see how much weight is applied respectively to the front and rear tyres.
Thus, with my settings, I have 629.65 Kg F, and 595.35 Kg R (with driver, and ~10% fuel), thus I have 90N (72mm)R 111.5N (55mm) F.

The others settings are set stock for the hard track settings. I played around with my damper settings a bit. But, here I hope to achieve neutral handing, as stated before.

* Dampers vs. Stiffness. I know that dampers provide "resistance", but in the same sense, stiffness provides stiffness. What is the difference, or are they applied to a different part of the 'strut'? How am I supposed to tune them. Again, I feel like I am working with two very close variables. Without a thing I can rely on, I don't know which one, or how to tune them correctly.

I have not installed VHPA yet; well rather I have, but it is currently running horribly with my computer. There must be certain components with my OS missing. I am planning to install a fixed version of it tonight, and install VHPA tmr. I know it provides a lot of useful information.

Another question:
* Drivetrain - I am again, using stock Hard Track Gear Ratios with the exception of final and fifth gear. This is a bit less technical, but rather, I am trying to get maximum performance out of my engine in a drift, and maximum acceleration. (BL1)

I have read that torque is used in the midst of a drift which is makes sense, because there is that 'momentum' as I'd like to call it, for the wheels to continue spinning. However, I have noticed that if I drift at ~ 5000 RPM, I lost the 'power' which is essential to drifting. I can however feel the power for which I can drift, and I like to drift for @ 6000RPM which is rated the HP Peak point where I receive all the 140 Horses. Is it just me or should I tune my drivetrain such that I am @ ~6000 RPM @ ~90-km/h (speed at which I normally drift at for BL1).

Acceleration. I accelerate the fastest with more horsepower right? So is it logical to bring my RPMs down (such that I shift up and end up @ ~ 5000 RPM to better use my horses in 2nd gear, 4th gear, and 5th gear). I've read that these figures drop a lot faster after the peak, where as there is a steady increase before the peak, such I get 120 HP @ 4500, 130 HP @ 5500, 140 @ 6000, and maybe 125 @ 6500). Is it possible for someone to provide me with a chart with such figures?

Brakes. 1000NM with 65 % Front brake dist. I still need to work on this. Further tuning when I get the respective programs. What do you guys use *for your respective drift machines*.

Toe - in and out figures, I will fine tune after all this is sorted out. I will also deal with maximum lock and parallel steering.

EDIT: Last question - what is this maximum lock degree figure anyways? I am rather confused by this. Can someone enlighten me with this?

Any suggestions, or articles that can help me, explanations, ideas, exact procedures that I can apply by myself to help myself (such as using VHPA), or do you guys just want to laugh and flame me for using a boring car for drifting.

Last thoughts; I don't think an XRG lacks power to drift. It is rather fun, and in my thought easier to drift with an XRG than XRT etc, at my level (Stop, I went to my friends house and did that). I guess its a personal thought. Such an S2 member once stated that he used a BMW E?? w/ 75HP to drift. People also drift with AE86, and low powered Silvias, old ones ofc. I think there is also a RX-7 with such specs also!

To Be S2 Driver - GenesisX - Hope this isn't too much to read; who am I kidding?
I don't know if bumping is allowed here. If it is not, I will edit my previous post... but mainly, I just want to post my changes that I have done so far. The setup that I posted, had changes made to the suspension, namely the stiffness, without real testing. The method that I used, I had just thought of, and the F/R Stiffness ratio was based off Keiichi's 86 which was 8 - 6.5 kg (1.23 : 1), thus 90 : 111.5 or w/e. I've done not much real - world testing, mostly theoretical.

However, because not everything is the same between or cars I had to make minor changes. I am planning to increase front anti - roll bar, and raise rear damping (I think my suspension is bottoming out, (orange in rear - right [f12]).

Also, I am thinking of increasing the preload setting or locking setting for the clutch based LSD. I am noticing that the engine would rev up dominantly when I drive over a bump. Signification of such a problem, feels rather close to the open - diff.

- LSD settings currently are: 30% locking - 70 NM preload.
- Change to : 50% locking - 70 NM preload [remain the same as I do not know the differences)

-Suspension: (f/r) -Damping: 9 / 10.5
- Anti - Roll: 18 / 22

-Drivetrain - either decrease gear 2 ratio, or decrease final drive ratio; I am at redline when I prepare to brake after straight - away (~200 km/h).

EDIT: I found a dyno chart for the XRG. Apparently, I get a bit more power @ 7000 revs than at 4500 revs. Thus I will put my rev down points (ex. from 1st gear 7000 to 2nd gear) @ 5000 rpm, to maximize the power, unless torque is what is valued. \\

What anti - roll and damping settings do you normally use? Since my springs are rather stiff, compared to, let's say Hard Track, do you think the Anti - Roll Bars are stiff enough?

One question to add... I've noticed that my rear tyres are heating up to the point where my tread temps are ~ 70 - 80 degrees where my front tyres are just near 40 degrees (left one - dominant one ~ 45 - 49 degrees or so). Well, actually this is not a new problem. I've noticed this since I began here, which was with a joystick.

However, I noticed a few months ago, that if I installed Knobs in the front, that the problem would go away, or the temps would be more even through the 4 tyres. Is there a method of doing something similar, (the temps don't need to be perfectly distributed, but something close would be great)?

Would giving the front tyres less grip ease the problem. I noticed if I gave the rear springs some more 'NM', hence introducing understeer (front tyres less? grip) my front tyres would heat up a bit more.

EDIT: What does Ns stand for? Newton per sec? Really haven't learned such a unit before =D.

Thanks... - Can we double post, in my situation?
Quote from GenesisX :I noticed if I gave the rear springs some more 'NM', hence introducing understeer (front tyres less? grip) my front tyres would heat up a bit more.

Increasing rear spring stiffness should give oversteer, not understeer.

Quote from GenesisX :EDIT: What does Ns stand for? Newton per sec? Really haven't learned such a unit before =D.

I assume you are referring to Ns/mm. Dampers produce force in relation to motion, since there is no SI unit for speed, we just use distance over time (m/s, or in this case, mm/s). Hence the gradient of the damper velocity-force graph is N/mm/s, which can be more neatly written Ns/mm.

Quote from GenesisX :Thanks... - Can we double post, in my situation?

So long as you don't make a habit of it, or the time between posts is long enough.
Final Thoughts, and Requests
Quote from Bob Smith :Increasing rear spring stiffness should give oversteer, not understeer.





I assume you are referring to Ns/mm. Dampers produce force in relation to motion, since there is no SI unit for speed, we just use distance over time (m/s, or in this case, mm/s). Hence the gradient of the damper velocity-force graph is N/mm/s, which can be more neatly written Ns/mm.





So long as you don't make a habit of it, or the time between posts is long enough.

First off, thank you for the quick reply! I really appreciate you explaining this stuff to me. I find myself baffled from looking at alien units that I have never seen before, like rad/s, or m/s, in such context.

Anyways:
I am starting to understand a bit more of the physics involved in racing, given that I know the result of an input, such as increasing stiffness on a rear spring will induce oversteer, not understeer.

Things like this help me develop a 'model' as I'd like to say it, and it should help me further learn about suspension tuning, as such. - I can't wait to take physics in gr. 11.

Anyways, I've gotten much what I want. I've gotten VHPA to do most of the work for me. I have gotten my suspension setups to do what I want. I dropped my previous approach. The XRG currently has virtually no over/understeer at corner entry or exit without throttle. - My approach for a neutral handling setup.

I've gotten the car to this point using dampers, as I found more convenient. Then I utilized my spring stiffness to 'complement' the setup. Basically, I have the damping ratios at near 100%, with 98.6% on the left side (rebound). Then, I used the sway bar stiffness to adjust my suspensions overall handling, which I set to a tad oversteer, as my tyre pressure settings cause understeer. Overall, this setup is what I wanted. Maybe because before, my car would feel extremely bumpy, and unstable caused by my bad damper settings, they feel great now. However, it can simply a placebo effect, which screws me up a lot, as my driving is really unstable.

*I've raised the ride height by my default settings by 10mm, to be on the safe side. This is using my previous approach for ride height. I can seldomly see my suspension bottoming out if I jump a bump too aggressively for example, which rarely happens.

My next goal is to get good camber settings, and then work towards the toe - in / out settings. I've still got to finish off my drivetrain setup, but generally I am kind of pleased with it, for BL1. I can get it to get the tail out full throttle in 2nd gear for T1, and gear 3 with throttle control the rest of it. Max speed, I can do about 190 - ish. EDIT: I'm planning to increasing my final drive setting, and make the indiv. gear settings closer so that the RPM after up-shifter is closer to 51-200 rather than 4900. I think that'd be a bit better for acceleration... Do you think this will work? Also, I'm also using a locked differential. I feel a bit more torque at the wheels when I throw the tail out. However, if someone can help me an optimal clutched - based setting, I'd prefer to use that instead.

Can you guys give me some feedback? Also, is there a reliable method for tuning dampers, or the suspension in general, without the help of VHPA. I don't want to rely on it for the remainder of my LFS career. How do you know if the dampers are actually 'damping' out the forces put upon it in one motion, or in multiple ones without testing multiple times. Is there math that I can do just to figure this out? How does VHPA do it?

The setup is attached at the bottom as you can all probably see... I hope!
Attached files
XRG_DriftXOV.set - 132 B - 3941 views
Quote from GenesisX :Also, I'm also using a locked differential. I feel a bit more torque at the wheels when I throw the tail out. However, if someone can help me an optimal clutched - based setting, I'd prefer to use that instead.

I'm not aware of any inherent loss in the LSDs, so in a straight line, given no traction issues, they should be equally as fast as not using a diff (i.e. locked).

There's certainly a very useful extra degree of customisability from fitting a clutch pack diff, and one certainly worth experimenting with. If at first it seems to cause incurable handling issues, remember that a locked diff is very good at masking other issues in your setup, and this is also true to a lesser extent of the clutch pack, depending on how high you run the settings.

Quote from GenesisX :Can you guys give me some feedback? Also, is there a reliable method for tuning dampers, or the suspension in general, without the help of VHPA. I don't want to rely on it for the remainder of my LFS career. How do you know if the dampers are actually 'damping' out the forces put upon it in one motion, or in multiple ones without testing multiple times. Is there math that I can do just to figure this out? How does VHPA do it?

If you wanted to setup your suspension with mathematical analysis (the only sensible way unless you want to entirely rely on feel and tried and error), then you'll just have to do the same physics calculations that VHPA does (admittedly not ALL of them), but in some other way (spreadsheet, calculator, paper, abacus, whatever).

If you want some example equations, here's how to calculate absolute and relative roll stiffnesses (the most important values for basic spring setup)

AbsRollStiffness = (0.5 * SpringWheelRate + ARBWheelRate) * TrackWidth ^ 2
RelativeRollStiffness = AbsRollStiffness / SprungMass

<repeat the above for both the front and rear axles>

RollBalance = FrontRelativeRollStiffness / (FrontRelativeRollStiffness + RearRelativeRollStiffness)

And for dampers, you want to know the critical damping rate so you can compare your dampers to this (and obtain the % figures shown in VHPA):
CriticalDamping = 2 * (SprungMass * SpringWheelRate) ^ 0.5

dude if i was a demo driver i would be able to type that much xD

im s2 and i dont type that much lol

sorry for offtopic
Thanks again, Bob.

@Grigg94 Sure. But anyways, I'd do the same if I had S2. It has nothing to do with what license I have. It is the fact that I want to learn the process, to become better at making setups, and thus driving the car, and having it perform in a way I want. I'm getting my S2s shortly, and I'm probably going to write as much, if not more!
I don't mean to revive a dead topic but I want Genesis to know that his setup is right on, I've tuned my car so you have that "slippery drifty" feeling and it just doesn't suit me well I like how a simple throttle lift and tap of the brake is enough to set the car into a drift (well in my case more of a powerslide)

so thank you much for the setup!

XRG Drift Setup Questions
(8 posts, started )
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