BMW 330i '05

CyKosis1973 · Feb 11, 2011

Hi folks,

I've got the above car, BMW 330i, and I know it's a fast car, but I just can't drive the damned thing consistently. I've installed all the non power increasing parts, and stripped out the weight, to my allowed limit (1250kg, or as close as I could get it). I've increased the power to as close to 355BHP as I can get it (another of my chosen restrictions). With the suspension set to default, and the LSD to default, I can post reasonable times. If I drop the ride height by 10 clicks, I can improve on them. I've applied some variations of suspension settings, with varying success. And the LSD, oh my dear god. Unless I wait until I've pretty much exited a corner, I can't get on the gas soon enough to make this car competitive. Also, the slightest touch on a curb and it spits me out like wad of chewing tobacco

Please help me cure my sad, and make this car as quick as I know it can be. Thanks for listening...

<Cy>

EDIT: Added 'Request' prefix, sorry for being a nub...

PS - Just in case it helps, our Rep Mobile restrictions are as follows;

Max Power: 355BHP
Max Weight: 1250kg
Max Tyres: Sport Soft
NO AERO

CyKosis1973 · Feb 12, 2011

Nobody..??

budious · Feb 12, 2011

CyKosis1973
Hi folks,

With the suspension set to default, and the LSD to default, I can post reasonable times. If I drop the ride height by 10 clicks, I can improve on them. I've applied some variations of suspension settings, with varying success. And the LSD, oh my dear god. Unless I wait until I've pretty much exited a corner, I can't get on the gas soon enough to make this car competitive. Also, the slightest touch on a curb and it spits me out like wad of chewing tobacco

You've answered a few of your own questions there without even realizing it. Dropping the ride height and seeing an improvement means the springs are too stiff at neutral ride height (RH 0), springs either get adjusted to higher rates for lowered cars or lower rates for jacked up cars. If you had luck with RH -10/-10 then a good spot to start looking might be -10% spring rate (loose example) then make small incremental adjustments from there up and down until you find improvements on handling and lap times you are looking for. LSD is dependent on getting the rest of the ride setup first, try to eliminate overly stiff dampers and anti-roll bars as much as you can, you should find some of the wheelspin will naturally phase itself out. LSD at 15/35/20 should work for most cars, try the one that comes stock on the car also (not the default values on the FC LSD; the actual one that came with the car). Oh, and also, try single plate clutch with stock flywheel or sports flywheel, semi-race flywheel only tends to exacerbate stiff setups.

CyKosis1973 · Feb 12, 2011

budious
If you had luck with RH -10/-10 then a good spot to start looking might be -10% spring rate (loose example) then make small incremental adjustments from there up and down until you find improvements on handling and lap times you are looking for.

I'll try this, impatience maybe my enemy. I'll persevere.

budious
Try to eliminate overly stiff dampers and anti-roll bars as much as you can, you should find some of the wheelspin will naturally phase itself out

I'll try this too.

budious
LSD at 15/35/20 should work for most cars, try the one that comes stock on the car also (not the default values on the FC LSD; the actual one that came with the car).

I did revert to the original diff, and it was even worse than the FC on default settings. I might try the original diff default settings on a FC one, however, I think you may have struck on something more important than that, see below.

budious
Oh, and also, try single plate clutch with stock flywheel or sports flywheel, semi-race flywheel only tends to exacerbate stiff setups.

This I will certainly look into. I've not boosted power much, but suspect I've probably added all the Drivetrain parts. I'll scale some of these back, and take a sensible look at the power upgrades.

Thank you for taking the time to reply...

nomis3613 · Feb 12, 2011

budious
Dropping the ride height and seeing an improvement means the springs are too stiff at neutral ride height (RH 0), springs either get adjusted to higher rates for lowered cars or lower rates for jacked up cars.

Agreed!

budious
try to eliminate overly stiff dampers and anti-roll bars as much as you can, you should find some of the wheelspin will naturally phase itself out.

Agreed!

budious
LSD at 15/35/20 should work for most cars, try the one that comes stock on the car also (not the default values on the FC LSD; the actual one that came with the car).

Agreed!

budious
Oh, and also, try single plate clutch with stock flywheel or sports flywheel

Disagreed! Sure, the clutch and flywheel upgrades make power spikes sharper, causing more wheelspin. But removing them is just a band-aid fix and will slow you down elsewhere, the problem is else in the setup. The above LSD and suspension changes should reduce the problem heaps.

CyKosis, are you using the analogue stick (or R2 or- best of all- pedals) for throttle? If not, just letting you know that the X button sucks for throttle and will be adding to your setup problems!

CyKosis1973 · Feb 12, 2011

nomis3613
CyKosis, are you using the analogue stick (or R1 or- best of all- pedals) for throttle? If not, just letting you know that the X button sucks for throttle and will be adding to your setup problems!

I've remapped L2 & R2 for brake and accelerator, I use an auto box always, so wanted the best control over both inputs. I use the left mushroom to steer. I like to think I have reasonable fine control. Control that improves of degenerates, depending on what kind of pressure I'm under :sly:

I'm going to strip this back and build it up, taking advice as and where I can. I should, I need to learn. Thank you for taking the time to post...

nomis3613 · Feb 12, 2011

You're welcome!

CyKosis1973
I've remapped L2 & R2 for brake and accelerator

Woops, yeah I meant R2 (instead of R1), the analogue trigger.

budious · Feb 13, 2011

nomis3613
Disagreed! Sure, the clutch and flywheel upgrades make power spikes sharper, causing more wheelspin. But removing them is just a band-aid fix and will slow you down elsewhere, the problem is else in the setup. The above LSD and suspension changes should reduce the problem heaps.

Disagreed with your disagreed! Single Plate clutch is faster on rolling starts and multi-lap runs. Twin Plate clutch only produces faster laps from stationary grid starts or when you spin out or come to a complete stop and need to get back up to speed faster. Flywheel upgrades reduce flywheel inertia, greater inertia can assist with engine braking and acceleration curve consistency by stabilizing engine revolutions. Stock flywheel can be measurably faster on Trial Mountain, Sport flywheel can be measurably faster on Deep Forest over stock and semi-race, Semi-Race flywheel only typically shows a benefit on tracks with long straights and wide high speed corners in which speed transitions are minimal. You can test all these conditions for yourself, you will see improvements.

nomis3613 · Feb 13, 2011

^ thanks, I'll try it out.

CyKosis1973 · Feb 13, 2011

budious
Flywheel upgrades reduce flywheel inertia, greater inertia can assist with engine braking and acceleration curve consistency by stabilizing engine revolutions.

Sage advice. Trial Mountain is on the list of tracks I'm likely to punt this car around. Along with suspension suggestions from above, I'm obivously going to have to look more closely at drivetrain parts as well :guilty:

Thank you for your time, budious (and nomis3613)...

CyKosis1973 · Feb 14, 2011

budious
If you had luck with RH -10/-10 then a good spot to start looking might be -10% spring rate (loose example) then make small incremental adjustments from there up and down until you find improvements on handling and lap times you are looking for.

Ok, so I stuck with reducing RH by -10, F & R (I believe the front can be lowered slightly more, but am sticking with an neutral stance for the moment). But found that increasing the SR slightly was more beneficial than lowering it. So, to clarify a couple of points. Firstly, when you say -10% SR, do you mean -10% of the max SR (15 = 1.5 clicks). Or -10% of the default SR (7.8 = 0.8 clicks). Secondly, when you say -10% SR, do you mean moving the SR to the left and lowering the number, or to the right and increasing it?? I only ask, because there's plenty of confusion regarding other settings in this game, and what increasing and reducing actually means/does. Sorry for asking dumb questions.

The net result at the moment is, I've lowered ride height to F -10 R -10, and increased SR from F 7.8 to 8.4 and R 6.8 to 7.5. All this improved laptimes and overall feel of the car, which wasn't too bad initially. I've left dampers and ARB as default at the moment. I've added 1.0 camber to both front and rear, this has improved traction through the corners, and improved laptimes.

Ultimately, I want the car to turn in a bit sharper, and I wouldn't mind provoking a bit of lift-off oversteer. I drive with AT, so can't down-shift into corners (maybe I'll learn one day how to use a MT in this game :guilty:

). And I believe there is more grip to be had in the corners. I've tried toe-in/toe-out angles, decreasing the rear to 0.10 and decreased the front by anything up to -0.25. Results are varied, some improved turn-in, but ultimately they all compromised straight-line speed. During this test phase, I did increase camber to the front and rear, both independently and in tandem. Most endeavours here ultimately compromised outright speed and didn't really help enough with turn-in to warrant the sacrifice of speed.

budious
LSD is dependent on getting the rest of the ride setup first, try to eliminate overly stiff dampers and anti-roll bars as much as you can, you should find some of the wheelspin will naturally phase itself out.

I've reinstalled the original diff, and the car is much happier. As I've not really boosted power much above an extra 100bhp, I think I'll leave it as is for the moment, as per your suggestion, I think I need to sort the suspension fully first. Which leads me onto dampers and ARB. Both are currently set to default. I tried lowering them all round by 1 click. This left the car feeling wallowy into, during and out of corners. I tried just lowering the front, and leaving the rear as default, this was ok(ish), but some of the loss of rear traction under acceleration and touching curbs raised its ugly head again.

There's acres of text here about what dampers do, which way you're supposed to move the sliders (I believe you are at the forefront of that conversation). I'm guessing, that a combination of dampers and ARB might be able to produce the turn-in and possibly lift-off oversteer I'm looking for. Am I barking up the right tree..?? I've some simple text I copied from Scaff's guides, but with the uncertainty of what increasing and decreasing the numbers mean, I could move these sliders up and down all day with no real idea of what I'm doing :ouch:

I'm not looking for definitive numbers here, I want to learn how to do this myself, and maybe contribute to the wider community in the future. But suggestions on which areas I should be paying attention to and the directions I should be pushing them would be greatly appreciated. Like many things in life, I don't just want to know what to do, I'd like to understand why I'm doing it..!!

Thanks in advance...

<Cy>

budious · Feb 14, 2011

Depends on drive style, how you are playing, wheel or pad; about how loose you want the car to feel, I prefer mine on the softer and rolling side. I know others feel more inclined to use a stiffer setup, so I can't say use my method, it's best for you because I don't know what you like; but...

RH 0/0 - stock suspension settings - car felt a bit stiff
RH -10/-10 - stock suspension settings - car felt a little freer; this was because spring settings were too stiff for your preferred feel or car's optimized cornering grip at ride height 0/0... lowering the ride height effectively makes a stiffer spring behave softer; the inverse is true of raising the ride height.
RH -10/-10 - you increased the spring rate by 10%, ie. 8/6 to 8.8/6.6 and the car feels more like it did with suspension at neutral (0/0) ride height, but the car's center of gravity is lower and it rolls less (reduced weight transfer) which, depending on tune style and drive style, can vary your preference. Think of lowered rides as needing camber to produce grip through lateral g-forces because they slide out, while higher rides lean over and press down to produce more grip and sometimes work best with no camber or little camber.

I typically tune camber last if because with my style of ride setups I may find it is unnecessary, and it also changes as you make further suspension changes, so best to start with spring rate, anti-roll bars, and dampers and get it driving to taste before attempting to setup camber. More camber on rear means more understeer, more camber on front means more oversteer, camber behavior is affected by tire temperature, higher cambers make it so tires take longer to heat up. Finding the right camber ratio of front to rear (ie: 15:8) or some other ratio can take a while, and be completely unbalanced due to changes in suspension or aero downforce changes.

CyKosis1973 · Feb 14, 2011

Thank you kindly budious...

<Cy>