[superhighperf]

i race my 06 CS with my local club and the Autocross season is coming to an end. i am looking to do some suspension upgrades but stay in my class. i am using the stock Bilstein shocks/springs. my club uses a points based system and i can upgrade my shocks/struts to single adjustable units for 0 points but i haven't been able to find anything available that will use the stock springs and has a dampening adjustment? there is the Bilstein B6 Performance shock at a reasonable price but don't have any adjustment and are advertised as Heavy Duty when the stock shocks are too stiff. i would like something more compliant.

are the B6 shocks a good upgrade or should i look elsewhere? but where? i would consider the CR strut/spring upgrade from Suncoast but i think that would be considered a race upgrade and put me out of class.

there is a shop that i have talked to about re valving the stock struts but i am skeptical. it is fat cat motorsports in the bay area but it seems like a bunch of hype and i am waiting on pricing.

here is the set up i have at the moment
stock shocks/springs
GT3 front sway on full soft
Tarret rear sway 1 off soft
Quaife LSD
Bridgestone Re71-r tires 245/40/18 front on 8.5" wheel and 265/35/18 rear on 10" wheel i should be upgrading tire size to 255 front and 285 rear but same Re71-r compound
street alignment
i am planning on upgrading to the GT3 lower control arms to get some neg camber which should help a lot but a more compliant suspension would be ideal.

any help would be appreciated

 

[newold_m]

I’ve had FatCat revalved Bilstein coilovers on two Miatas I owned and can vouch for them. Both rode beautifully given the fairly stiff spring rates (one had 550f/350r and other 400f/350r) and had I known they can revalve Bilsteins for a Cayman I would have seriously considered them over the Ohlins I currently have. Be aware though it is a one man shop, or at least it was when I deal with them a number of years ago, and wait times can be long especially before season starts and delivery estimates are ‘approximate’. Also the non-adjustable shocks are custom valved based on your input on driving habits and spring rates and down the road if you want something stiffer or softer you’ll need to go back for another revalve (on Miatas they used to say valving was good for +/- 100 lb/in spring rate variation).

 

[superhighperf]

thanks for the input on Fat Cat. i am considering jumping up a class and getting some Ohlins. i think that is the best option but if you are saying the performance of a Fat Cat tuned set up would be comparable to the Ohlins you have... i got a reply back from Fat Cat and the cost for a stage 2 set up would be about $1500. i would add the GT3 lower control arms to get neg camber and the total would be about $2,500. Fat Cat is not sure if i can use the stock shocks and might need to buy the Bilstein B6 shocks for him to upgrade. putting the total at $3,500 to $4,000.

about the same cost as Ohlin or JRZ coil overs and, from what I've heard, they don't need the lower control arms to get neg 2 to neg 2.5 camber because of the adjustable top hats.

i have been looking at our point system and it looks like the best solution would be to use the ohlin shocks with my stock springs. if i can get that to work i could stay in the same class. the top hats cost 10 points, the height adjustment is 20 points and i could get 5 points back by putting the stock ecu tune on the car. non stock springs cost 45 points and we use a 50 point tier system.

it might be time for me to put on my big boy pants, pull the trigger on some ohlins and jump up to AX06

i have some decisions to make
thanks for the help

 

[Apex1]

You may have to have a stock spring perch welded to the Ohlin shock body. Maybe a shop that works on SCCA or PCA autocross cars nationally to do this work as the top mount will also be a problem, mating the stock spring to the bearing/top hat for the Ohlin shock.
Ryan Clark, who won the BS class of Tire Rack Solo Championship with a 06 Cayman S had a stock shock set up (PASM), not a JRZ or Ohlin set up. You can check out his set up on a thread under Porsche Wheels and Tires, its on the second page under title of wheels and tires that work on page 11. He used RE 71 R 265/35/18 Front and 285/30/18 rear on wheels similar to yours.
By the way, I have Ohlins R&T on my car and I love them, especially when mated to race wheels and tires that are spaced to the outboard lip of the fender wells. Currently, no camber plates or lower control arms, as PCA prohibits these camber devices in certain classes. Camber -1.6 F and -2.1 rear. Lowered 30 mm by corner balance process with 200 lbs in the drivers seat. Tarett GT sway bars and drop links. I went with RE71R's 255/35 F on 9 inch forged monoblock 18 lbs wheels and 275/35 R on 10 inch 19 lb wheels. By pushing the wheels out to the wheel well lips, I find that the spring rate is manageable for street driving on rough back roads using 20 damping setting on the adjustment knobs. I use 2 setting for autocross.

 

[Apex1]

superhighperformance said "I am planning on upgrading to the GT3 lower control arms to get some neg camber which should help a lot but a more compliant suspension would be ideal".


Take a look at Tarett Cup LCA's instead of GT3 LCA's. They will take your suspension to another level. The solid thrust puck adds adjustability to the caster and wheelbase. The inner monoball allows some complience but not nearly as much as the OEM rubber bushing. The outside monoball is much more robust and has a 14mm bolt. The total response is a very accurate steering input, excellant in slalom, and trail braking. Much of the positive drivability is due to the monoballs, but the solid thrust puck takes away the forward/back movement of both the front axle and the rear axle. The rear tire with OEM thrust bushing can move a total of 2 1/2 inch forward on acceleration and back on braking vs. not much movement with the solid thrust puck.

The combination of the Ohlins and Tarett LCA's in outstanding. You can use the stock springs with a shock perch welded to the Ohlin body. The Tarett LCA's will allow you to use much less compression/rebound settings (7 f and 8 r) on the Ohlins to reduce nose dive on braking and to reduce weight transfer in the corners. They really work together. For daily drivability Ohlin setting could be 15 front and rear.

 

[superhighperf]

thanks for the help Apex1. i was able to get 30 points back by going down 1.5" in wheel size, with an 8" front wheel and 9" rear with 245/40/18 F and 275/35/18 R. that is the size available that would work on the rims according to tire rack but i think i could fit a 255/35 on the front 8" wheel? i did indeed go with the Tarett arms even though the spherical bearings cost the same points as the control arms, 15 points each. i also got the toe arms front and rear and i think those cost me 20 points but haven't confirmed that yet, i have plenty of points to spare now with the smaller wheels.

i was not able to get the camber i wanted on the front or rear but ended up with just under 2.5 on the front and just under 2 on the rear. i have driven the car 2 events so far. it does feel faster and more responsive with mixed results. first time out with sticker tires i was slower than a gut i usually beat but next time i was faster than a gut who is usually faster than me.

your idea of using the stock springs with upgraded shocks is a good one. i have a set of JIC coil overs with adjustable top hats that would get me the camber i want, -3 F -2.5 R and only cost 10 points. welding a perch to the shock body is not a bad idea because i would save the 20 points for having the threaded body but i think that would ruin the threads. i will see how the season goes and think about how serious i am about upgrades again this winter. i might just put on the coil overs and start tracking the car. i just got a 2014 CS that i am learning how to autox with some other clubs in the area and i am definitely ready to upgrade my track car which is an 2001 Miata.

thanks again for the help

 

[Apex1]

Glad I could help! Not sure about the spherical bearings, are those the thrust bearings in the Tarett Cup LCA's or the end spherical bearings on both ends of the LCA's. Did you use the GT3 internal shims to push out the track on the LCA's to gain negative camber? How much shim did you use? The toe link is a must if you are using the internal shims front and rear as you suggested.
I found that using these new Tarett Cup control arms improved my turnin, trail braking and throttle modulation all in one package do to the three bearing referred to above. I also found that they changed my wheel rate, meaning that I could use less shock compression/rebound to achieve better complience in cornering. I am just getting used to this upgrade and will be using higher compressions/rebound levels as the autocross season dries out. So far, two wet days with these new arms on 18 clicks from full stiff out of 20 with the Ohlins. The spring rate is 400 lbs/in f and 458 lbs/in r along with Tarett GT swaybars, which I backed off to second hole from soft in f and same in the rear. I found with my wider, lite weight wheels (9 in, 18.5 lb f & 10 in, 19 lb r), running RE71R's 255/35/18 f and 275/35/18 r, I was able to lower my PSI to 26 f and r with great results. This was on a cold, wet, continuious raining track. I am running -2.6 camber f and -2.5 r.
The car will be back to the shop for new Elephant toe links in a couple of weeks, while there I am going to have the track pushed out to 15 mm with internal GT3 spacers on the LCA's per wheel f and r. I also am getting 5 minutes of toe out in front. The new thrust pucks on the LCA's allow for much more accurate steering, so with the larger front tires, this toe out will help get faster turnin results. I also am changing my camber to -2.7f and-2.4 r to help take away some throttle on oversteer out of the corners. So, we will see how all these changes come together as I have a competitor that is breathing down my neck.

 

[wagzhp]

Say Apex1, with all of your changes what class do you end up in at PCA autocross events? I'm currently running in the s07 class with my car, but would really like to try some stickier tires. I'm pretty sure running any tire that is not stock size or N (Porsche) rated, would bump be in to the p16 class, but I'm not ready to add coilovers or GT3 LCAs or sway bars yet. I don't want to jump to a different class just for better tires.

 

[superhighperf]

i understand about wanting to be competitive and stay in front, that's what prompted these upgrades. a guy in my class but in a different region with a 2012 boxster spyder would consistently be a second faster than me and he suggested the tarett LCA because that is what he is running. he was in my class but different region so he didn't go to all our events and spoil my championship completely. i haven't seen him at an event yet but there was a rule change this season that bumped up the spyders base points and put him in the next class. i would still like to beat him

i wasn't sure about the spherical bearings either. one guy i talked to said i needed to take the points if i went with the tarett cup LCA over the gt3 but the guy in the spyder and the tarett LCA doesn't take the extra points? i think it has to do with the replacement of the rubber bushing? " Solid thrust arm bushings and sealed monoball inner ends are used to eliminate the spongy rubber OEM bushings " i decided to use smaller wheels, get some points back and not have to worry about extra points for spherical bearings, toe arms or the tension/compression link. it's hard to get definitive answers from the local guys, even on our web forum, thats why i hang out here.

we did use spacers 22mm total, that was the max that would fit on the studs and still be able to screw the nut on. even with that he was only able to get -2.1 deg of camber. that seemed strange to me because reading about it on P9 a few guys got to -3 with 16mm? i trust the shop and they only work on Porsche but haven't been in the racing scene for over 10 years. i might take the car to a dedicated race shop to see what they can do. the rear ended up with -1.6 deg and i only changed to the tarett toe arms and used the OEM LCA but still less than what i was expecting.

wagzhp: he is probably in P16 a new class for the cayman s. for the showroom stock class you are in, you are limited to OEM wheels and tire size. the best tire is the bridgestone re71r and they do make the correct sizes for 18 and 19" wheels but not 20". my zone rules, http://zone7.pca.org/autocross-rules/ , say you can run 180 tread wear tires which would allow you to use michelin pilot sport cup 2 but they only make the correct size for a 19" wheel. remember you have to use a wheel that was an option for your car and the same tire width and profile as the OEM ones.

i feel your frustration. all you have to do is put a muffler or after market wheels on your car and you are in the production class having to go up against guys that have all the mods costing thousands of dollars and are still in your class. the point system we use for Golden Gate region is a pain to navigate but i think it is better than the zone rules.

 

[wagzhp]

i understand about wanting to be competitive and stay in front, that's what prompted these upgrades. a guy in my class but in a different region with a 2012 boxster spyder would consistently be a second faster than me and he suggested the tarett LCA because that is what he is running. he was in my class but different region so he didn't go to all our events and spoil my championship completely. i haven't seen him at an event yet but there was a rule change this season that bumped up the spyders base points and put him in the next class. i would still like to beat him

i wasn't sure about the spherical bearings either. one guy i talked to said i needed to take the points if i went with the tarett cup LCA over the gt3 but the guy in the spyder and the tarett LCA doesn't take the extra points? i think it has to do with the replacement of the rubber bushing? " Solid thrust arm bushings and sealed monoball inner ends are used to eliminate the spongy rubber OEM bushings " i decided to use smaller wheels, get some points back and not have to worry about extra points for spherical bearings, toe arms or the tension/compression link. it's hard to get definitive answers from the local guys, even on our web forum, thats why i hang out here.

we did use spacers 22mm total, that was the max that would fit on the studs and still be able to screw the nut on. even with that he was only able to get -2.1 deg of camber. that seemed strange to me because reading about it on P9 a few guys got to -3 with 16mm? i trust the shop and they only work on Porsche but haven't been in the racing scene for over 10 years. i might take the car to a dedicated race shop to see what they can do. the rear ended up with -1.6 deg and i only changed to the tarett toe arms and used the OEM LCA but still less than what i was expecting.

wagzhp: he is probably in P16 a new class for the cayman s. for the showroom stock class you are in, you are limited to OEM wheels and tire size. the best tire is the bridgestone re71r and they do make the correct sizes for 18 and 19" wheels but not 20". my zone rules, http://zone7.pca.org/autocross-rules/ , say you can run 180 tread wear tires which would allow you to use michelin pilot sport cup 2 but they only make the correct size for a 19" wheel. remember you have to use a wheel that was an option for your car and the same tire width and profile as the OEM ones.

i feel your frustration. all you have to do is put a muffler or after market wheels on your car and you are in the production class having to go up against guys that have all the mods costing thousands of dollars and are still in your class. the point system we use for Golden Gate region is a pain to navigate but i think it is better than the zone rules.

OK, thanks for that information! I recently picked up a set of 19" turbo wheels with half worn Pilot Super Sports on them, but they were a little less grippy than I would have liked last weekend. I was hanging the tail out way more than the previous outing on the Goodyear's that are on my 20" wheels. I suspect that could be due to their age (date code 4214) but I need to play with some pressure adjustments, and spend a little time getting used to them before I scrap them. Of course I also got a performance alignment the day before the autocross, so that could have also contributed to the tail-happiness. (From factory specs to -1.4F and -1.5R camber (as much as they could get, keeping it even on each side), 0F and .13R on each side toe.) I know, too many changes/variables at the same time, and I should know better.

At least it's good to know that I can switch to the RE-71R in the stock sizes and not jump to a different class, if I can't get the PSS's to bite a little bit more.