[Kgolf31]

Originally Posted by 02rsxpilot

That looks silky smooth, exactly what you want.

My last event at Thunderhill I rode with one of our race group members who has a turbo charged Miata and I couldn't believe the steering inputs he could get away with. But that's what you get with a 2,000 lbs. car on track suspension and r-comps. 3,400 lbs. 1er on stock suspension and RFTs (in my case)...not so much.

Working on a mounting point for my GoPro that will let me catch my steering wheel in the frame too. So far I've had it too far forward mounted from the sunroof so all I see is dash. Used to be perfect in my RSX because you could see the track well, the steering wheel, and even my rear view mirror and what was coming up in it.

Speaking of the RSX (also totally stock suspension), I can definitely say that typical of a FWD car, it seemed like it wanted to understeer on entry, but if you just smoothly rolled in, it would set its weight and you could drive it on rails all the way to corner exit after that. In the beemer, I get that weight set and then the RFTs run out of grip and my DSC kicks on and...my lap times weep for Star Specs.

On FWD you really need the front to plant before you do anything or else you're asking for trouble. I drove a Focus ST a couple times and it needs front grip before turning.

Unfortunately, there is no good way to mount a camera, you're going to compromise somewhere.

BTW - I feel sorry for your car and its weight. I'm at 3053 lbs with 1/4 tank.

Originally Posted by dcaron9999

Thanks for the heads up. I was afraid of that.
Would shocks alone address the problem Im trying to solve though (reduce plowing and outside tire wear)?

No, you're going to need alot more factors (higher spring rate, shocks, camber...etc) to avoid outside wear.

For reference, I'm at #400 fronts (which are relatively soft in the game of springs) with TCK DA Shocks at -3* camber and still getting outside wear. I'm actually going to -3.5* on the car.

BMWs chew through front tires, you will never eliminate this.

Originally Posted by jafo1701

Hey how about this camera angle. From my sunroof with my Go Pro with an extender to get it so I can see the track.

Good camera angle, but I don't have sunroofs on the Z4M or my 128i

Originally Posted by 02rsxpilot

That was the first setup I tried but it felt like the track view was too small and the rear view mirror was a major obstruction (the RSX has a smaller mirror). Thinking there's gotta be something in between that won't also interfere with my helmet. Outside the car like Kgolf might be the way to go, but you lose the view of the apex on right handers...

Here is my set-up on the 128i. Camera could probably be lower to look out the windshield easier.

I typically run an external mic to the exhaust, but I didn't have batteries this weekend.

Originally Posted by fe1rx

The faster you are going the slower and smoother your steering inputs need to be. I think driving is driving and how abruptly you present your car to a corner is inversely proportional to speed of corner entry. I have observed that many beginning drivers need to be encouraged to speed up their steering inputs at slow (2nd gear) corners at the track and to slow down their steering inputs at faster corners. Of course many tracks don't have such slow corners.



A firm ride is likely attributable to excessive high speed damping. That is what make the M-sport springs on OE shocks feel firm. Also, the rear of the 135i rides on the bump stops even at static ride height, meaning the supposedly linear rear springs are far from linear.

A dual duty car needs as a minimum to have single adjustable digressive shocks so that firm springs feel acceptable daily but can be tightened up at the track. Try any high-end sports car with adjustable suspension modes. The spring rate is constant but the difference comes from adjusting the damping. We can achieve the same thing manually with a single adjustable shock.

A shock that provides reduced damping at high shaft speeds (i.e. digressive damping) is key to smoothing out the fine sharp texture of daily roads. The OE shocks don't do this, hence expansion joints and speed bumps feel harsh.

Adjustable shocks on springs that are too soft encourage you to overdamp to get the controlled body feel you want but then they feel harsh because the transmissibility increases with increased damping. That can make you think your springs are too firm.

My suggestion would be to live with your tire wear for now - manage it by flipping your tires and by being a bit less aggressive (damn hard to do when you are chasing a Cayman or an M3!) until you can get an adjustable coilover suspension. Shocks with sport springs are an expensive half-measure that you will outgrow quickly if you track your car extensively.

By the way OP, good call on developing your car incrementally and not being in any hurry to lower it.

Nailed it on the head. OP - Educate yourself, and buy once, IMO.

BTW, with #400 fronts, #700 rears...the car is just a bit stiffer than M Sport.