AST's at buttonwillow raceway
 

Hi guys-

Last weekend I was at buttonwillow running CW13 in my FR-S. The folks at 949 Racing helped me do a bunch of testing. Here is the cliff notes for those that don't like clicking links:

stock with Carbotech pads - 2:12.1
plus camber bolts, Mach V wheels, and 255/40/17 RS3's - 2:07.1
plus AST 4150 prototype dampers - 2:03.75

i was really impressed with the new valving AST is releasing. there is still time in fine tuning and cooler weather. I'm still aiming at being the first person under 2 mins at Buttonwillow, but the last couple seconds are going to be harder to find than the first 8.

There is a significantly longer recap with more data and pictures in my blog linked in my signature. I also have a lap video there as well.

You will be the first under 2:00 in an FR-S there. I'll see to it.

The more I think about it, the more I think the FR-S with a reflash, cat delete and fully dialed suspension could go under 2:00 there in cool weather.. on RS3's. Tremendous potential. You guys with FR-S's and BRZ,s the best is yet to come.

That's crazy. You should just find out whatever it takes to get that fast and just market it as a kit

call it the 2 minute kit. I like the idea. :)

I enjoy your informative writing...keep it up!

Hi,

Anyone knows how AST came up with the damper characteristics for this car?

Was it based on a car with similar platform or did they had a test car to qualify this 4150?

I am assuming the shocks will do well on track but as a daily drive its a bit more subjective.

Also, what will be the final improvements to the 4150 in terms of tuning? I am hoping they will do some driving on their own as well?

Very cool. Excited to see how this develops! Great work guys.

Matt, what are your thoughts on the possible benefits of alignment kits such as the Whiteline stuff, and other chassis mods such as bracing etc.? I would also be interested to know where your alignment setting ended up. :)

Also noticed you guys haven't mentioned much about weight reduction yet. Do you think stuff like a Braille battery, washer fluid delete, header and exhaust might be worth it?

Also seems you were pretty happy on the stock brakes + Carbotech pads since you didn't mention them after the beginning. Did that setup hold up merely adequately in the end or did you manage to achieve full non-fade status?

Been aware of you and Emilio from the Miata world so no questions when it comes to your collective Buttonwillow knowledge.

Also - the camera mount. Noticed that the videos were cropped - what's the widest angle you can get with the iPhone?

Don't want to sound too pedantic, but calling the AST coilovers as "the 2 minute kit" is largely misleading.

OP,

How many track days do you have under your belt? +100?
How many laps have you driven this particular track? +1000?

See where I'm going with this?

For average Joe, bolting this suspension onto the car WILL NOT automatically result in a sub 2:00 at the buttonwillow.

it wouldnt be coilovers alone as they still arent there but its no more misleading than car and driver posting 0-60 times or skid pad Gs.

I meant it a little tongue and cheek. I'm not a parts vendor, and don't really care how they market things, but to respond to your comments...

When I suggested a 2 min "kit" I was thinking more along the lines of all the parts it would take to make a FR-S 2 minute capable. Like AST's, wheel/tire, wing, blue valve stems, and JDM stickers for the windows. Not just the dampers themselves.

I've been around Buttonwillow a couple times, yes. I don't personally think anyone would take it that if you put the same parts on your car as I eventually have on mine that you wouldn't have to actually drive the car in a manner that would get it around the track quickly. People who buy high dollar road bikes or basketball shoes don't expect to be able to ride the tour de france competitively or play in the NBA. I am 100% with you that the nut behind the wheel matters.

Best,
Matt

questions answered inline

I've been trying to attack this car with incremental changes so you know what each part actually does instead making a bunch of mods and then hitting the track. This car is really stiff compared to what I am used to. So I haven't spent a ton of time looking at the different chassis braces available. With more grip or speed, maybe weaknesses will start to show up and I'll go looking for parts.

As for alignment adjustment, this car is not as adjustable as the miata or other double a arm cars are. The car needs it. I don't have concrete opinions as I haven't tested any of those parts you mention yet, but in general I am not in favor of offset bushings, or parts that could move under stress. The amount of camber I can get out of the final design from AST will dictate if I do anything additional in the front. The rear needs an adjustable arm to control camber. The only way you can effect this now is with ride height. I'm not really happy with most of the offerings I see as they have a failure point in the eccentric they use to make camber adjustment.

As for final alignment specs, I did intentionally leave that out. But I would also say we didn't spend a ton of time perfecting it. You can read anywhere that the RS3 likes camber. So we simply maxed out what we had available to us, got the toe close to what you would think a rwd car would want, and went out. I'll spend more time focusing on this later.

I will eventually be addicted to weight reduction. Its the best way to impact acceleration in all directions, part ware, and ultimate laptime. "worth it" is relative to budget. I think my car eventually will have a header back exhaust, and Berk Technologies is working on at least a light header back exhaust for me. Removing washer fluid is a no brainer. I believe the Braille batteries are just rebranded Deka ones. So I won't pay for that, but I do think a light weight battery makes sense. stock seats are about 40lbs. stock brakes are heavier than other options, etc. [/quote]

The brakes worked. Didn't fade at all. Emilio seemed happy with the pedal feel - I wasn't as much so. I'm not sure if this was the tires or the brakes however. I am looking at the Essex AP thread - just need to do the cost / benefit analysis of them.

great question. I will edit another video that won't be cropped when I get back from the east coast. The case can either shoot iphone footage with the standard camera or with a wide angle attachment. I just don't know the spec. I'll try and find out.

Matt

Hmmmm. A legitimate review of suspension with lap times proving how much faster they make a car? Haven't seen that in the 37 other "review" threads of some crap coilover set we have going.

2:03 with no power and no aero is FAST and that extra 4s really shows how much of a difference good suspension makes. Someone needs to send you a set of custom valved BC racing coilovers so we can see the difference.

Great post and great review Matt I was looking forward to this all week.

The 4150's on Matt's car are the prototypes. AST started with original engineering drawings for the suspension. Factor in stuff like motion ratios, bounce frequencies, roll couple bias, static weight distribution, experience with similar dynamic platforms (Vette,Miata,S2000) and we know where to start.

949 Racing is spearheading the track development. Matt's experience and input as well as the use of his car, is invaluable. We (949 Racing & AST) will make a few tweaks for the final production kit.