Need more negative Camber - coilovers or lower control arms?

Hi All,

I've been developing my car slowly over time and have taken it to a few trackdays here in the UK, I've reached the point now that I want (need?) to do something more with the front suspension, as I'm scrubbing the outer shoulders off the front tyres.

Last week I destroyed one front tyre as deformation mid-bend meant it rolled right over on the sidewall - photos below of the tyre afterwards (wires poking through the sidewall!) and of the car on track.

Current suspension spec:

Classic Swede 40mm lowering springs - I asked Dai and he said they're 180lbs
Gaz adjustable shocks
Polybushed apart from the trailing arm to axle bushes which are rubber
IPD 25/22mm swaybars
Hydra wheels with 205/55 16 tyres

To fit but not fitted yet:
Set of BNE spherical offset strut mounts
https://www.bneshop.com/products/240-spherical-offset-strut-mounts but I'm aware these won't allow much negative camber with stock sized spirngs


So, the direct question then - should I rebuild the front suspension as coilovers, to allow the tops to be moved further in, or go for a set of extended lower control arms from KL racing?
https://shop.klracing.se/sv/artiklar/bararmar-undre-240-special-.html Additionally I might need extenders for the steering rack, it's not quite clear from their website.

Just wondering if anyone has any suggestions, given at this point I could choose either. I should say I'm happy with the suspension ride height and the spring ratings, of course if I was unhappy with one or the other it would make sense to go for coilovers so I could adjust either/both.

I'm also aware of the roll centre correctors, although BNE is sold out of those at the moment.

Comments welcomed.

Cheers

I have both the BNE adjustable top mounts, smaller diameter Eibach springs, luxe steer, BNE QSRC, and KL racing 25mm longer control arms. I get -4 degrees of camber. It definitely helps with the edge wear but you need more air in your tires in the interim. Do you chalk the edges of your tires to see how they rolling over? Chalk the tires and add air until you're not rubbing the chalk off the sides.

The strut mounts have an advantage over the control arms in that they increase your wheel / tire clearance to the fenders. The control arms decrease it.

You also should have a solid footing for your dampers in order for them to work effectively, the stock mounts are not it.

IMO, if you are wanting to excel in trackdays. 180 lb/in springs are way too soft.

Seems like there are a lot of reasons you should be switching to coilovers and an adjustable strut mount

Are your wheels wide enough to go to a 225/50/16 tire? 20mm wider, same diameter.

Also a 200 treadwear tire like the Hankook RS4 or Falken RT615K+ are great for the track. Some higher treadwear tires will wear faster on track or chunk. The 200 treadwear obviously wont last as long on the street.

The sidewall height isn’t helping you at all, and the stock-ish suspension alignment is not anywhere close to what you want for track driving.

There’s not a lot of good track tires, in an appropriate size, that work well on a 16” wheel. You will need 17” most likely (which can kill the gear ratio). You can also go down to 15”, but even good 15s are harder to find now.

As far as alignment goes, the BNE select top mounts are a great product for the money. You’ll definitely want to get 2.5” springs and stiffer ones at that (as mentioned). If you use wider controls arms you’ll want to push the fenders out in the front and roll the lips.
My car sits at 2.5?- camber and 7.5? of caster with KL arms and BNE select upper mounts.

Ok great - thanks for the replies so far.

Didn't know about using chalk to check tyre pressures/deformation - a sensible and obvious thing to do, thanks

Ok, seems like the general consensus is leaning towards coilovers rather than control arms. I'm not interested in having to roll the fenders to fit both - thanks for the heads up.

I thought 180lbs sounded low, but for reference Dai suggested a 2.5inch ID spring 8 inches long in 250-300lbs would be close to what I have now.

As ever, there has to be some compromise and it is primarily a road car not a track toy, so I don't want to go too far and make it too unpleasant on the road.

Based on what replies so far I'm leaning towards:

Coilovers with suitable springs, using the BNE select top mounts I have
Boxed in standard lower control arms

Then on the maybe list:
Adjustable top mounts (over the BNE select which I have already)
Set of 17X7.5 volvo alloys with track tyres and spacers to suit (like Orestes or similar)
Roll centre correctors

Cheers

culberro said:

The sidewall height isn?t helping you at all, and the stock-ish suspension alignment is not anywhere close to what you want for track driving.

There?s not a lot of good track tires, in an appropriate size, that work well on a 16? wheel. You will need 17? most likely (which can kill the gear ratio). You can also go down to 15?, but even good 15s are harder to find now.

As far as alignment goes, the BNE select top mounts are a great product for the money. You?ll definitely want to get 2.5? springs and stiffer ones at that (as mentioned). If you use wider controls arms you?ll want to push the fenders out in the front and roll the lips.
My car sits at 2.5?- camber and 7.5? of caster with KL arms and BNE select upper mounts.

Click to expand...

I get about 24 hours of track time on 225/50/16s before the outer edges are like the OP. Dunlop makes a 225/45/16 Direzza ZIII, but it is more expensive than the Hankook RS4. The RS4 seems to last the longest. Front edges do wear out first with just the stock upper mount front bolt rotated for max camber/caster. Rears wear more evenly.

A 245 on 17s would be nice to upgrade to.

bugjam1999 said:

Ok great - thanks for the replies so far.

Didn't know about using chalk to check tyre pressures/deformation - a sensible and obvious thing to do, thanks

Ok, seems like the general consensus is leaning towards coilovers rather than control arms. I'm not interested in having to roll the fenders to fit both - thanks for the heads up.

I thought 180lbs sounded low, but for reference Dai suggested a 2.5inch ID spring 8 inches long in 250-300lbs would be close to what I have now.

As ever, there has to be some compromise and it is primarily a road car not a track toy, so I don't want to go too far and make it too unpleasant on the road.

Based on what replies so far I'm leaning towards:

Coilovers with suitable springs, using the BNE select top mounts I have
Boxed in standard lower control arms

Then on the maybe list:
Adjustable top mounts (over the BNE select which I have already)
Set of 17X7.5 volvo alloys with track tyres and spacers to suit (like Orestes or similar)
Roll centre correctors

Cheers

Click to expand...

Shoe polish works well for the tires. The white liquid that comes in a bottle with a sponge on the opening. If you're looking for a compromise that should work for both street and track, 2 degrees negative camber should get you there once you have proper tires, springs and the tires inflated correctly. You didn't say what your current camber is or what pressure you had the tires inflated to. On a street car, anything over 2 degrees negative camber will make the car want to wander with rutted roads and eat the inside edge of the tire rather rapidly.

rb92673 said:

Dunlop makes a 225/45/16 Direzza ZIII

Click to expand...

I run these on my car and I really like them.

blkaplan said:

The strut mounts have an advantage over the control arms in that they increase your wheel / tire clearance to the fenders. The control arms decrease it.

Click to expand...

^I forgot to mention this, I'm running 275/40/17 with the KL control arms and I had to cut big ol' chunks out of my fenders. It does give you a slightly wider track though too.

rb92673 said:

I get about 24 hours of track time on 225/50/16s before the outer edges are like the OP. Dunlop makes a 225/45/16 Direzza ZIII, but it is more expensive than the Hankook RS4. The RS4 seems to last the longest. Front edges do wear out first with just the stock upper mount front bolt rotated for max camber/caster. Rears wear more evenly.

A 245 on 17s would be nice to upgrade to.

Click to expand...

I didn't know that!
225/45/16 would be nice on a brick.

We get about 40 hrs of track time on the front RS4 tires on our 850 endurance racer.
255 40 17 on a 17x9.

FWD so it puts extra stress on them.

blkaplan said:

We get about 40 hrs of track time on the front RS4 tires on our 850 endurance racer.
255 40 17 on a 17x9.

FWD so it puts extra stress on them.

Click to expand...

I wish I got 40 hours of seat time out of a set of front tires. More like 3 hours when I break it down. I get approximately 200 Autocross runs out of a set of front tires. Average run time, 50 seconds. Then, there is driving to and from some of the events which really doesn't wear the tires much.

2manyturbos said:

I wish I got 40 hours of seat time out of a set of front tires. More like 3 hours when I break it down. I get approximately 200 Autocross runs out of a set of front tires. Average run time, 50 seconds. Then, there is driving to and from some of the events which really doesn't wear the tires much.

Click to expand...

Im sure they degrade over the 40 hrs. The 3rd weekend is always not as crisp as the first but we have so much grip for the car that even a worn 255 still has more grip than most of our competitors and lap time change is insignificant (probably a couple seconds over a 2 min lap). Autocross is a completely different ball game, as you know, where you only race the clock and every tenth is significant.

Yes. The 2021 Solo Nationals just concluded 11 days ago in Lincoln, NE. Most of the classes competitors were separated by less than 0.2 seconds after totalling their times for both days. I torture my tires.

2manyturbos said:

Shoe polish works well for the tires. The white liquid that comes in a bottle with a sponge on the opening. If you're looking for a compromise that should work for both street and track, 2 degrees negative camber should get you there once you have proper tires, springs and the tires inflated correctly. You didn't say what your current camber is or what pressure you had the tires inflated to. On a street car, anything over 2 degrees negative camber will make the car want to wander with rutted roads and eat the inside edge of the tire rather rapidly.

Click to expand...

All makes sense, thanks.

Current camber is just the struts pushed into the furthest inboard end of the standard adjustment slots, with standard strut tops. No I haven?t measured what that actually comes out as. I?m aware this is far from ideal.

32 f 34 r cold.

Cheers

rb92673 said:

I get about 24 hours of track time on 225/50/16s before the outer edges are like the OP. Dunlop makes a 225/45/16 Direzza ZIII, but it is more expensive than the Hankook RS4. The RS4 seems to last the longest. Front edges do wear out first with just the stock upper mount front bolt rotated for max camber/caster. Rears wear more evenly.

A 245 on 17s would be nice to upgrade to.

Click to expand...

Thanks- interestingly, RS4 tyres don?t appear to be very easy to get over here, at least from my initial googling. I?ll try again tomorrow.

Thinking a set of 17s could improve things markedly? but if i can find a set of RS4s to try on the front of the car for now, I?ll probably do that. RS4s are listed in a 205/55 16 so they should exist to buy in that size somewhere?

Cheers

bugjam1999 said:

All makes sense, thanks.

Current camber is just the struts pushed into the furthest inboard end of the standard adjustment slots, with standard strut tops. No I haven?t measured what that actually comes out as. I?m aware this is far from ideal.

32 f 34 r cold.

Cheers

Click to expand...

Those tires are probably rated for Max load at 40-44 psi. You would have fared much better running them at max pressure to stiffen the side wall to help keep them from tucking so much. Street tires were never intended to do what you were doing with them. You were probably at ~ -1 degree camber. I think that's about all you can get with stock upper mounts.

2manyturbos said:

I wish I got 40 hours of seat time out of a set of front tires. More like 3 hours when I break it down. I get approximately 200 Autocross runs out of a set of front tires. Average run time, 50 seconds. Then, there is driving to and from some of the events which really doesn't wear the tires much.

Click to expand...

I'm with you Roy.
When I was doing track days with the 242 turbo I'd have to rotate tires mid-way through the day and all 4 were shot at the end of the day (Falken 615Ks). Brake pads were also completely gone as well.

Endurance racing and track days (or time attack) are a bit different on how you use your tires.

Now I get significantly less drive time on my tires

2manyturbos said:

Those tires are probably rated for Max load at 40-44 psi. You would have fared much better running them at max pressure to stiffen the side wall to help keep them from tucking so much. Street tires were never intended to do what you were doing with them. You were probably at ~ -1 degree camber. I think that's about all you can get with stock upper mounts.

Click to expand...

They?re Toyo CF2 tyres (to save you trying to read the lettering on the tyre in the photo)

Yes, I?m well aware this isn?t what they were designed for, but it?s not a dedicated track car so tyres are one obvious place where a compromise had to be made. Hence me thinking about a set of track wheels?

Running them at a higher pressure to stiffen the sidewalls makes sense- thanks.

Cheers