AVO BRZ: 1000km at the track

[AVOturboworld]

Temporary solution till the race seat is fitted:

[Wepeel]

Originally Posted by AVOturboworld

The other area of concern was the front lower control arms. Installing the new LCA bushings front and rear took a lot of slop out of the arm, reducing unwanted movement tremendously. It also showed that Subaru got the car as light as it is by using as little metal as possible anywhere it could. With less flex in the bushings, the arms now showed more effectively how lightweight they were designed. They were literally flexing when we applied physical pressure to them by hand. This has raised enough worries about long term effects of racing that we sent them out to our factory to get reinforced.

...you could get the control arms to flex with your hands?

And great writeup; thank you.

[spiller]

great read! id like to see a video of the control arm flex by hand. surely they cant be that weak? thats disappointing about the brakes too, particularly the calipers.

[uspspro]

Any thoughts on brake ducting? Perhaps that could help the stock brake system (obviously with track pads, fluids, lines).

[Motopythons]

The drop looks perfect. How low did you guys go?

[Hamiltonian]

Originally Posted by AVOturboworld

Yes, thinner/lighter. There's a certain logic about it - the car is lighter, so they feel they can make the components lighter. But if you are going to be tracking the car heavily like we are, we don't have confidence they'll hold up to the stresses of traction generated by bigger, stickier rubber.

Paul Hansen
www.avoturboworld.com
www.facebook.com/BRZSportsCarClub

Thank you for this great information. If owners put on bigger, stickier rubber for street use (e.g. 235 tires or larger), do you think the thinness of the LCA could be an issue, even when the car is not tracked? I was planning to use this car as a DD, but wanted to upgrade the tires a little. Cheers.

[AVOturboworld]

Originally Posted by Motopythons

The drop looks perfect. How low did you guys go?

I believe the final drop was 50mm.

[AVOturboworld]

Originally Posted by Hamiltonian

Thank you for this great information. If owners put on bigger, stickier rubber for street use (e.g. 235 tires or larger), do you think the thinness of the LCA could be an issue, even when the car is not tracked? I was planning to use this car as a DD, but wanted to upgrade the tires a little. Cheers.

I don't think it's an issue at all with normal street duty. We are at the extreme end of possible BRZ/FRS owner, with nearly 100% track duty planned for the short term, and looking at times when we'll be putting S tires or even slicks on the car. Neither of which are street legal. Normal street rubber won't put the same stresses on the suspension. And to be honest, at the track you are doing high-speed corners at the limit 85% of the time, on the street you do very little high-speed cornering. At least, I hope not!

[azian_advanced]

i can see why subaru went with lightweight LCA. they wanted the mass ratio of the sprung mass with the unsprung mass to be as high as possible for better ride quality. being really lightweight as it is, they had to go to further lengths to keep the unsprung mass as low as possible.

i wouldn't be surprised if the LCAs bent during extended track use. i'm curious to know how you reinforced them. was it simply a weld job and weld in additional 'walls' in the stamped sections of the LCAs?

[AVOturboworld]

I believe for now they are just doing that, but they are sending a spare set off to the factory to engineer something a bit better in the future.

[AVOturboworld]

Updates from the Option 2 magazine event, with Orido driving:

We fitted our 18mm solid rear bar halfway through to see how that would affect the handling. Unfortunately, not in a good way - it was nearly a second slower than with the standard rear bar. Orido said it was initially quite entertaining, the rear end would drift through nearly any sort of corner, but also quite twitchy, and ultimately harder to get through the course fast.

What we found so far is that, with the perfect 50/50 balance of the car from the factory, putting on a larger rear bar only, or a larger front bar only, will just upset that balance. Subaru/Toyota really did a good job of setting up the car out the door. Any swaybar upgrades need to be very carefully balanced front to rear, or you'll upset the balance, and ultimately, grip.

[brillo]

Originally Posted by AVOturboworld

I don't think it's an issue at all with normal street duty. We are at the extreme end of possible BRZ/FRS owner, with nearly 100% track duty planned for the short term, and looking at times when we'll be putting S tires or even slicks on the car. Neither of which are street legal. Normal street rubber won't put the same stresses on the suspension. And to be honest, at the track you are doing high-speed corners at the limit 85% of the time, on the street you do very little high-speed cornering. At least, I hope not!

What about other suspension components or their connection points to the frame? Are you seeing stress or wear that could cause failure or replacement? Replacing a control arm is relatively easy, but what about the hardpoints where the arm meets the frame? Would stiffer bushings only make the problem worse?

[Kiteless]

Fantastic write up. Great work and thanks for sharing here. What is your opinion about this car for very occasional track use in stock setup? After I get an FR-S I want to take it to a track a few times a year, otherwise it will be my weekend and once or twice a week to work car.

- J

[jmelgar23]

good read, any details on that wing? i'm in love lol