Suspension Settings

[alucardo 55]

I have some Ohlins mp20 rear LCA and front camber bolts going on the car at the weekend. So I was just wondering what settings people would recommend. I will be following the phlins guide of 20mm front 15mm rear for lowering but as for camber toe im still undecided.

My primary use is road with the odd trackday thrown in so was basically going to set up as standard or perhaps carry some camber on the front.

I prefer my car more neutral in balance more than anything else.

Front:

Camber: 0 +/- 45' (0 +/- 0.75°) (Right/Left Difference: 0°45' (0.75°) or less)
Caster (Reference): 5°54' (5.90°)
Steering Axis Inclination (Reference): 15°31' (15.52°)
Toe (Each Wheel): 0°00' +/- 0°11' (0.00° +/- 0.19°)
Toe (Total): 0 +/- 3.0 mm (0 +/- 0.1181 in.)

Rear:

Camber: -1°12' +/- 45' (-1.20° +/- 0.75°) (Right/Left Difference: 45' (0.75°) or less)
Toe (Each Wheel): C + D: 0°10' +/- 0°15' (0.16° +/-0.24°)
Toe (Total): 2.0 +/- 3.0 mm(0.0787 +/- 0.1181 in.)

[Church 209]

For height i'd rather look primary on how much ground clearance compliance is needed daily driving (eg. roadbumps / steep driveways). My own choice would be as little lowering as possible.

For generic alignment choice depending on how much you daily drive vs how much you track:

For almost no tracking i'd put camber -1.5 front, -1 rear. Throwing few track days in, camber -2.5 front, -2 rear. If most wear happens on track (for me with around 10 trackdays per year 2/3rds of tire set are worn on track, despite total mileage being way way less then daily driven), then -3 to -3.5 front, -2.5 rear.

In all these setups i'd get zero toe front, 0.1 toe-in rear.

For adjustment worth remembering, that: 1) our cars as stock have only toe adjustment, no camber adjustment, 2) car may gain some camber if lowered, 3) for front it's cheapest to gain camber adjustment with camberbolts, with range upto -1.5 with one set of camberbolt, with two upto -2.3(-2.5 if lowered), if needed more, then one needs add to camberbolts also powerflex bushing, or camberplate, 4) for rear camber adjustment no cheap camberbolt option, one needs aftermarket LCA for that.

If absolutely cheapest somewhat performance alignment wished, that would be getting SPC camberbolts for front lower hole + put oem 14mm bolts from there to upper 16mm hole. That should be worth of upto -1.5 to -2 front camber. Rear camber left as is, at stock-ish -1, to not pay for LCA, just get toe right. Not ideal, as still if one visits track, mostly tire outside will be worn, bet still, better then stock alignment, with too lacking front camber & thus too understeer-ish grip bias and too broad passing adjustment ranges. Next step-up - add whiteline camberbolt for upper hole & some cheaper rear LCA eg. SPC/Whiteline/Eibach. Next step-up - add camberplates. Or powerflex front lca camber bushing, if NVH impact matters.

[alucardo 55]

13 minutes ago, Church said:

For height i'd rather look primary on how much ground clearance compliance is needed daily driving (eg. roadbumps / steep driveways). My own choice would be as little lowering as possible.

For generic alignment choice depending on how much you daily drive vs how much you track:

For almost no tracking i'd put camber -1.5 front, -1 rear. Throwing few track days in, camber -2.5 front, -2 rear. If most wear happens on track (for me with around 10 trackdays per year 2/3rds of tire set are worn on track, despite total mileage being way way less then daily driven), then -3 to -3.5 front, -2.5 rear.

In all these setups i'd get zero toe front, 0.1 toe-in rear.

For adjustment worth remembering, that: 1) our cars as stock have only toe adjustment, no camber adjustment, 2) car may gain some camber if lowered, 3) for front it's cheapest to gain camber adjustment with camberbolts, with range upto -1.5 with one set of camberbolt, with two upto -2.3(-2.5 if lowered), if needed more, then one needs add to camberbolts also powerflex bushing, or camberplate, 4) for rear camber adjustment no cheap camberbolt option, one needs aftermarket LCA for that.

If absolutely cheapest somewhat performance alignment wished, that would be getting SPC camberbolts for front lower hole + put oem 14mm bolts from there to upper 16mm hole. That should be worth of upto -1.5 to -2 front camber. Rear camber left as is, at stock-ish -1, to not pay for LCA, just get toe right. Not ideal, as still if one visits track, mostly tire outside will be worn, bet still, better then stock alignment, with too lacking front camber & thus too understeer-ish grip bias and too broad passing adjustment ranges. Next step-up - add whiteline camberbolt for upper hole & some cheaper rear LCA eg. SPC/Whiteline/Eibach. Next step-up - add camberplates. Or powerflex front lca camber bushing, if NVH impact matters.

Thanks for the detailed reply.

On the lowering front I am just going off what Ohlins have recommended. Im perfectly fine with stock height as I prefer function over form.

I will have camber bolts giving about 1.5degree at the front and whiteline LCA. The car for me is fine on track in standard form and im not chasing laptimes so id prefer it setup primarily for road. So adding more camber to the front and aiming for 1.5 and going 1.2 negative camber at the rear and keeping standard toe might be my best option to keep the car neutral and road friendly.

[Church 209]

Very high camber has drawback of car subjectively tending to more follow road longitudinal groves, otherwise nothing bad in road "unfriendliness". More negative static camber is mostly to get more grip and more mileage out of tires according to how car/tires are used. Hence the dependence of optimal camber on specifics of driving. If more frequent track days, more side-Gs, more tire flex, more roll, and to counter that & get optimal contact patch and more grip more static camber needed. On public roads one almost never will see that much side-Gs if driving within legal limits, which are set mostly with average cars of way less performance capable in mind. For me though with 1K km on track vs 20K km daily driving most of tire thread were worn on track, hence my own choice was choosing alignment settings better fit for track.

Simply when you'll get through current tire set, check wear pattern, and choose your own optimal settings from that . If mostly outside, clear sign of lacking camber, and there is more grip/tire mileage to be had with more of it with dd/track ratio you have. I'd still keep that ratio of 0.5 less negative camber in rear for imho more optimal oversteer-understeer front-rear grip bias ratio vs stock, of .camber other way around, 1dg less camber in front and car pushing out front too much to my liking.

P.S.

Everything in car suspension works as a system, and changing/replacing something may rise need to adjust something else. Eg. adding different rollbars or different spring/damping rates may change what might be better grip ratio dialed in by camber. If one installs something like MCA brackets, one may wish to have zero toe in rear and even some countering with less camber to get rear less grippy/easier to rotate. What is optimal also may depend on what driver prefers depending on his driving style. And then there are tires .. some may work well even with less camber. And so on and on. Numbers i cited are not ones fitting all the drivers and all the aftermarket parts setups, just that numbers most often seen in forums for alignment numbers of others.

[Ade 517]

Fronts:

set the camber bolts at the front to ass much as you can. I like a little toe out (0.05) to turn in feel.

Rears:

go for the same camber as the fronts. Tad of toe in for high speed stability.

 

Job done