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points for suspension upgrade

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points for suspension upgrade

Post by superhighperf » Thu Nov 02, 2017 9:02 am

the end of the Autocross season is here and its time for some upgrades. i am using the stock 987 cayman s shocks springs and think they are a bit too stiff, i want something more compliant. i want to stay in the same class and i have 25 points to spare.

i could get a shock upgrade to Bilstein B6 Performance shock at a reasonable price and 0 added points. add GT3 lower control arms for 15 points and i could add some camber. i could get the shocks tuned with custom valving but the cost for all that would be approximately $3,500. that price is similar to the cost of some good coil overs but i am unclear on the points coil overs would cost.

i could put the stock seats, intake and ecu tune on the car to get 25 points back giving me 50 points to spend and get a set of ohlin coil overs but what is the point cost for coil overs? the coil overs would come with :
custom top hats which sounds like #64. The car has non-stock adjustable spring plates. for 10 points
new springs which sound like #65. The car has non-stock springs or torsion bars. for 45 points
height adjustable threaded shock body which sound like #67. The car has non-stock adjustable coil spring platforms. for 20 points
that's a total of 75 points for coil overs. is that right?

i could get the Cayman r suspension upgrade form suncoast for $2,500 and 20 points but that is advertised as stiffer than stock and i think the stock set up is too stiff and want more compliant.

it seems like using the stock springs with the coil over shocks and top hats would be the best solution but i'm not sure that would work. is there a solution i am missing? any help would be appreciated

it might be time for me to put on my big boy pants, buy some coil overs and go to AX06.

have a great off season,

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Re: points for suspension upgrade

Post by syeo86 » Thu Nov 09, 2017 3:05 pm

Hi Derek,

Given I have the exact same car, this might be a question I can help with.

First and foremost, forgive me for being nosy, I looked at your car under the classification system. Based on where the points fall, I assume you have the following:
MSPP Tires or RE71Rs?
GT3 Master Cylinder
Bucket seats or something similar
Wevo SS engine mount or something similar
Softronic Tune
GT3 style front/rear bars

You've led your class, AX07, all year. Congrats! Are you trying to fend of any advances from your fellow classmates? Does the compliant complaint come from daily driving the car or do you feel the car is too stiff for the autox? If the complaint stems from daily driving the car, any recommendation I make would go out the window. I'd even argue that the stock suspension is just fine for the autox. It is what I've used for the last 3-4 years. Ride compliance is a personal preference though, which makes it difficult to get just right.

Personally, I'd "spend" points on tires and an alignment to maximize the tires on the car. Do you use the RE71R tires already? If you don't mind me asking, what specifications has the car been aligned to?

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Re: points for suspension upgrade

Post by superhighperf » Tue Nov 21, 2017 10:42 pm

sorry about the long delay. i thought i would get an email when there was a reply. i checked that box now.

you are right about most of the stuff. i'm at 675 points now
i am running re71r tires 245-18 f Front on an 8.5" wheel and 265-18 Rear on a 10" wheel. the wheels are a bit big for the tires i am using and i could get 30 points back by getting some 8" fronts and 9" rears and the same tires.
i do have the GT3 Master Cilinder
aluminum Kirkey intermediate Halo road race seat but could get 10 points back by using stock seat
Function First engine mounts.
Qualife LSD
80mm Throttle Body and GT3 Plenum. i could put the stock back on and get 10 points
APR tune. i had to remove the Softronic tune to pas CA smog
Milltek exaust
GT3 front sway on soft and Tarett rear sway 1 off soft
Front -0.1 deg camber, 7.5 deg caster, .03 deg toe about the same left and right
Front cross camber 0 deg, cross caster -.02 deg, total toe .07 deg
Rear -1.1 deg camber, 0.45 deg toe left, -0.45 toe right
rear cross camber -0.02 deg, total toe 0.01 deg

I don't daily the car and couldn't care less about street drive ability. the car just feels stiff on autocross not much lean over on turning or dive under braking. i feel like a softer suspension would get me more performance. i remember watching Steve Lau drive his black Cayman with the Ohlin coil overs and it looked soft but fast.

i have been having a good time this year competing with Boris in his Boxster. he got me a few times this year and is getting faster all the time. Doug in the Spider has at least a second on me but he only attended 3 GGR events. Doug suggested that i get the GT3 lower control arms for the front and a race alignment to get -2 deg of camber, that's what he has.

i agree that an race alignment is the next step but i cant get enough neg camber with the stock set up. at least that is what everyone i ask has told me. they say that -2.5 deg is the sweet spot and i cant even get half of that without upgrades. here are the solutions i have thought of.

install GT3 lower control arms (15 points)
install coil overs (75 points?) and do the downgrades i mentioned. wheels, seat, intake
install adjustable top hats and use stock Bilsteins (10 points)

i have a set of JIC Cross coil overs that came with the car. they have the adjustable top plate and are able to get -2.5 deg of camber and lower the car about an inch. they are track orientated and might be even stiffer than the stock set up? if i spend the time and money for install and set up i might as well get some Ohlins.

i could use the top plates i have on the JIC coil overs and put them on the stock Bilsteins but would that work?

the off season is here now and i have some decisions to make
thanks for the interest and have a good turkey day :)

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Re: points for suspension upgrade

Post by syeo86 » Wed Nov 22, 2017 10:29 am

You and I almost have the same tire setup. I use 245/18 & 275/18. I also use the factory 8 inch front and 9 inch rear rim, as the point system only looks at the rim width. :)

As for your alignment.. :cry: You need GT3 arms in the front for sure. For reference this is my current alignment spec, take these numbers with a grain of salt. This is a grassroots alignment done in my garage, so the numbers may not come up the same on an alignment rack; I only care about relative change. Also, I'm not certain this is correct as I've had some of the other cayman drivers take the car out and they've both commented that it understeers.

Camber: -2.2(L) -2.3(R)
Toe: 4/32 Toe out per tire
Caster: Unknown (never measured because the GT3 arm only gives me two options: centric or eccentric; currently using centric)

Camber: -2.1(L) -2.1(R)
Toe: 3/32 Toe in per tire
Caster: Unknown

I'm not lowered, so besides the front gt3 arms, all alignment specs are being achieved with factory adjustments.

As for sway bars, I am using Tarett GT3 bars front and rear, both set to full soft. With a weak attempt at removing preload from the bars. I need to build a rig to lift the car high enough off the ground while still having the suspension loaded.

Regarding your comment about suspension roll, I think much of this has to do with your upgraded sway bars. I only added sway bars to the car recently, and I've notice that the sway bars have significantly reduced the body roll of the car. I personally feel it has helped a lot. Two seasons ago I upgraded tires, thinking I'd be able to catch the drivers in my class. I was sadly mistakened, and the delta in times actually grew; I think a lot of the GGR group pushes to make changes over the winter break to improve their cars/times. Only when I added the sway bars, was I able to catch up and in some instance beat the guys in front of me.

At the end of the day the old adage remains true. We are most concerned about how the tire meets the road. Whether it is alignment, spring rate, valving, sway bar setup, etc, all we care about is maximize the contact patch/contact time of the tire to the road so we can carry the most speed into, through, and out of a corner. This one reason, makes me skeptical of coilovers for your car, because we simply haven't maximize the potential of your tires yet. I'd personally make changes (IE: GT3 arms) to maximize adjustability of the suspension first.

Best of luck Derek! Happy holidays to you as well!

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Re: points for suspension upgrade

Post by superhighperf » Wed Nov 22, 2017 10:49 am

thanks for the fast reply and the good advice. it sounds like the GT3 lower control arms are the way to go. did you need to get them for the rear too?

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Joined: Sun Nov 17, 2013 2:49 pm

Re: points for suspension upgrade

Post by syeo86 » Wed Nov 22, 2017 11:31 am

No problem! Always happy to help a fellow cayman owner get faster and take on some of those 911s!! :D

The oem GT3 arms are very nice, and there are TONS of aftermarket options available too. I personally selected the factory arms because...factory, meaning they will likely last the longest and still use rubber bushings. The draw back of the factory design are the shims required to add more camber. It is a very annoying feature. Some aftermarket units mimic this design while others use a heim joint to allow extension. The bonus of the aftermarket is nearly every one has an adjustable caster puck. Also, most aftermarket arms are rebuildable, meaning you can replace the inboard bushing/heim joint or the ball joint. Keep in mind, these aftermarket arms are most likely using monoballs/spherical bearings in lieu of rubber bushings.

I didn't use the arms in the rear, the factory eccentric maxes out around -2.1 degrees. :)

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