kjchristopher

I'm told a GT3 bar works well for AS. Keep in mind that a stiffer front bar doesn't automatically mean more understeer. Sometimes a stiffer front bar maintains a better front contact patch up front (camber challenged cars) and helps getting the front end more stable. It can also help plant the inside rear tire, although with a C4 you may not have an issue with getting the power down out of corners. You're issue is carrying around that extra weight.

Yomi

Good points. I've added it to the wish list, along with some quality time looking at tantalizingly tasty TRG toys.

That and slowing down just enough that I can actually get on the power early. That pesky driver again.

After talking to TR, I called up Koni to see if they had any more info on the part numbers, and their response was that they'd never tried a front unit on a C4S, so had no idea whether it would fit. Hence they list no product for the 996 C4S / TT in Sport fronts. I heard they've gone into C4S's before but have no real documention about it. I'll find out next Wednesday whether they fit. TR said I could return them if they don't (I'll still be out shipping, some labor, and a bunch of my time). If they don't, then it's stay stock or abandon the SCCA stock class and go X73, PSS10, or hang out on the For Sale section looking for something with a good price (like the JIC Cross's for $1500 that just sold).

knfeparty

sorry I never answered back, I've been taking time off of RL.

Anyways as I guess you found out, to adjust the rears you just remove the subwoofer and then pull out those two little carpet squares. I leave the two squares permanently out of the car and leave the subwoofer at home for track days/autocross.

I am interested in getting a front bar now but am trying to hold off on my spending.

I ran the konis full stiff at that track day as an experiment but it made the car a bit unstable; it wasn't well planted. At my most recent autocross there was a light turnout so my codriver and I got to run the snot out of the car with like 16 back to back runs or something so I got some great koni tuning in. At least on mine, I found some definite gains. I started around 1 turn off of full stiff on all four corners and when I increased the front damping towards 1/2 to 1/4 I was able to help reduce the massive on-throttle front end lift.

I remain very pleased at the DD ride quality. I adjust mine before and after every event but at the last event I forgot to re-adjust the rears and really can't complain.

I am still terrible at autocrossing this car. I recently got the car re-aligned, bascially zero toe on all 4 corners, 2.2* of camber in the rear (an increase from 2.0* which was giving me pretty even tire wear after all of the autocrossing) but maxed out at like 0.7* negative in the front, which is abysmal. We'll see how this setup tweak helps me out but I could not keep the car in-shape and on line through the slaloms. It's just too fast to stay on the throttle and I can't keep the car stable when I'm not on the gas! I'm too used to just flooring it all the time from the old 944.

balefire

I'm jealous of those prices. I paid more for the shocks and the install. The price I pay to be an early adopter I guess.

I had no idea the front shocks might be different on the C4S. Hoping it works out for you. If they don't fit, and you want to stay stock, you could consider the US OEM TT shock or the ROW OEM TT shock which might be stiffer.

Muffler bypass pipes saves 40+ lbs in the rear, is super cheap, and takes a newb like me only 20-30 min each side to change for an autox event. To save you some time, here's some sway bar info I compiled before I got my RUF Eibach FSB.

C2/GT3 Sways
Normal front 23.1mm x 3.4mm / rear 18.5mm x 2.5mm
ROW M030 front 23.6mm x 3.6mm / rear 19.6mm x 2.6 mm
GT3 front 26.8mm x 4.0mm / rear 20.7mm x 2.8 mm (5 way adj
front, 4 way adj rear, end links needed)
Eibach C2 front 24.0mm x solid / rear 19.0mm x solid (only rear 3 way adj)
H&R C2 front 26mm / rear 23mm - rear only adj

RUF resells Eibach sways (painted green)
Gemballa resells H&R sways

C4S/Turbo
C4S/TT front 23.6x 3.5mm/ rear 21.7x 3.0mm
GT2 front 26.8x 4.0mm/ rear 20.7x 2.8mm
Eibach TT front 24.0mm x solid / rear 23.0mm x solid (only rear 3 way adj)
H&R C4S front 25mm / rear 24mm - both adjustable
TechArt TT front 23.8mm x ? / rear 23 mm x ?? (front and rear 3 way
adj, end links may be needed)

My alignment settings:
front: zero toe, -0.4/-1.0 camber (ouch!)
rear: -0.15 toe in/side, -1.5 camber
I ran -1.0 rear camber last year to compensate for my terrible front camber and thought my car was too loose for my liking (It was pretty funny watching me drift my first autox in this car. My wife though vowed not to ride with me again.)
This year, the increased rear camber, shocks, and FSB made my car much more stable, but it still has some agility. I found I could attack the slaloms with a lot more confidence. I still have a lot to learn though since none of my previous cars had any power, and if I slam on the throttle like I used to, i'll spin.

Yomi

I really hope the ride quality is good, as I'll be taking the car in 2 weeks on a 3-day trip with the local PCA, with my wife along (her first time in the car for more than 5 minutes). I'm not too worried, as stock springs plus soft(ish) settings really shouldn't make a bad ride.

I'm looking forward to the shocks, alignment, and new tires. It'll make a big difference, I'm sure.

The comments about slaloms reminds me of when I switched from my stock 96 Miata -- full throttle most places and plenty of time to drive precisely -- to the STi which can spin all four tires if you have some angle or are in 1st gear. I was lucky to have a 3-day Evo school within a few events of getting my STi, which helped immensely in learning to control the car (as well as autocross in general). I'm really trying to get back into the swing of it after time off -- it's slowly coming.

For an example, here are the two TRG droplinks made for the 996 (grr, rennlist doesn't have tables enabled):

996 2WD: 996 AWD:

OTOH, the standard Tarett links are identical for "all 996/997, Boxster & Cayman." But even their site is a little confusing as the trick extended drop links say "986/987/996/997/997TT" for one set and then "996TT" for another.

I guess I'll find out if they work or not. I was just looking at the Koni USA page where it indicates both front and rear as "Carrera 2 Coupe, Targa, Convertible excl. Carrera 4, Turbo, GT2 GT3". (the 2800 series are only $1700 each on sale, yay). I really don't know -- stuff like that makes me think they will not fit, but then the comments from TC Kline and the person I spoke to on the phone at Koni make me think they might. The worst would be getting them in the car and only find out a week / month later that they're all messed up.

Thanks a lot for the swaybar info. Tarett says theirs are OEM Porsche GT3. I believe GMG's bars are Eibach. The TRG endlinks look beefier than anything else, though they're also a bit spendy at $400 for the set, and Tarett's look decent at only $275 for the standard ones, $625 for the combo of GT3 bar + links.

Unfortunately it does seem like the 996 C4S/TT is unique once again. TRG has separate part numbers for their 27mm adjustable bars for the 996/986 and the 996 AWD. H&R's 25mm is unique for the C4, C4S, and Turbo. I'm leaning toward the TRG's, but this is all for later, after the shocks are all sorted out.

I was amazed at how much difference my STi had when going from the stock 224/194 springs to their (Japan-stock-only) sport 257/217 springs. I felt almost no difference around town and driving 300 miles to my first event with them, but the first slalom was hugely different. Much, much better than stock. Then I went street prepared with 600 pound springs on KW coilovers and ... well it didn't roll very much.

For alignment I was planning on maxing out front camber while keeping it even, and whining if they can't get it to at least -1. Rear at (front - 1.0), though I've seen recommendations of (front - 0.5). An alternate plan would be to run ~ -2.0 rear camber regardless of where the front lands and adjust front/rear balance some other way (e.g. shock settings, tire widths, rear spacers (0.25" in to 0.25" out), tire pressures, front bar if I had an adjustable). Toe is the big unknown for me. I was thinking 0 toe in the front and a smidgeon of toe in in the rear, until I know what the car will do with the new shocks/tires/alignment. That should keep it reasonably tame until I get used to it, then I can think about whether I want toe out in front and want to adjust the rear any.

knfeparty

The advantage of zero toe is that it really reduces tire wear, especially when running aggressive camber like you're going to want to. You just have to be ready to countersteer if you don't run a smidgeon of toe in the rear which helps stabilise. I've spun the 944 so many times now that nothing sneaks up on me anymore so I went ahead with zero in the rear.

The other "mod" I made was wider front tires. 245/35/18 is a MUCH better fit in the front. It also looks a lot better and doesn't rub on the BFG KDW2s I got. They aren't the best autox tires but they hold up well and were "cheap" for 996 tires. I stuck with 285s in the rear.

The muffler bypass pipes are scca legal as long as they are downstream of the cats, but aren't they really loud?

knfeparty

I forgot to ask what hot pressures yall are running at autox. I am running 50 psi in the rear which is the max for my tires and 38 or 40 psi in the front. Rollover is not too bad

balefire

I was worried that the OEM GT3 bars were too stiff even at the softest settings.
Is there any benefit to sturdier endlinks if the sways don't require it?

I used to try and keep the front camber even. On my current car, I gave up on the idea so I could get max camber wherever I could (-0.4 L / -1.0 R) and it tracks perfectly straight, but probably will have differential tire wear.

They are obnoxiously loud. I drew a 97-99dB at the last autox. We'll see if it remains there in warmer conditions. But I love the sound of it. My kids do too.

I'm running 42 front and 37 rear on my R-comps. Its probably not ideal though as I've been titrating tire pressure for roll over on my camber challenged car instead of tire temperature.

Yomi

It will depend on which tires you're running. My Hoosier A3S04's always needed about 10 pounds more than the Victoracers and V710s. I used to run the Hoosiers in the high 40s, Kumhos in high 30s. On my factory stock 996 C4S with Pirelli Pzero Assemtricos I'm running 31 front 36 rear hot pressures. I've lowered to that point to get rollover where I think it should be. I haven't used the pyrometer however, and I will freely admit I'm no expert at driving 911s. I'll get to relearn it all over again with the changed car and new AD08s.

A tip for tire marking (which you perhaps already know) -- if you massively overdrive a corner (or two, or spin) then the rollover marks don't really apply for that run. That is, if you go in way too hot and keep on the throttle on the way out making the front wash out while the tires are screaming at you, well .. you'll probably see wear a ways up the shoulder, which doesn't necessarily mean it needs more pressure.


In theory they'd have less stiction (there's a thread on sccaforums I believe where Andy Hollis was talking about how he'd replaced every bushing in his ST Civic and got nearly zero friction in the whole setup), but I imagine it would be extremely minor and depends on what the stock ones are like. The aftermarket links are also adjustable which lets you remove preload. If the stock ones fit and don't break, then I doubt for most of us it'd be much benefit. I had heard the GT3 bar requires a shorter endlink however, and really stiff bars can shear end links (for example this thread).

I agree on the worry about too stiff -- it would depend on the adjustment range.

My alignment decisions will depend a lot on what choices I have. In my fantasy world I'll have one of those stock cars that can hit -1.3 or better even. Or I could end up at -0.9 even, like you with one side just unable to hit a good number, or maybe -0.4 max both sides. Eyeballing the current settings I doubt it's the last.

We had a new person come autocross with us with what must have been a mufflerless 911. It was sooo loud. Not really pleasant for the courseworkers. Now I've heard louder (the hillclimb car with open headers, not to mention the Supercup and F1 cars), but it was just too loud for me, and I believe we have a pretty strict decibel limit at our new site. At least it was a good sound, not a BRAAAAP*stutter*PPP*backfire*PPPAAAP Honda sound. We have a BSP '99 996 with trapps -- good sound, reasonable volume (he could go a bit louder with no concern).

knfeparty

well I'm still running street tires because I have no way to get to the autox with r comps right now. BFG KDW2s. I started at around 40psi in the rear but had no rear grip and was getting lots of rollover and 48-50psi seems to be about right to keep it in check. I guess it's the difference in Rcomps and street tires but I can't believe you're running such low pressures in the rear. I used to run super-low pressure in the 944 but I had 2.7* of camber so I could run 25psi and it was fine.

I also find it sort of odd that you guys are using relatively little rear camber.
Also wow on the muffler bypass pipes, 99 db? They are cheaper than a whole catback setup though right? And you said they are bolt-on and you change them before/after the autox? I don't want to have to cut up my stock exhaust any.

Yomi

I'm running 31/36 on street tires. I started higher, but it wasn't even touching the rubber nubbins at the edge of the tread. It's a bit lower than I'm used to -- I don't think I've ever run a tire under 30 hot. My STi ran in the mid-30s on its street tires. The new tires on the UPS truck right now are AD08's since I can't deal with race tires right now (just no way to transport them, plus my back doesn't want to deal with tire changing). I've been hearing high 30s on similar weight cars, but the pyrometer and roll over will tell.

Assume you had -1 front camber. What rear camber would you think appropriate? -1.5, -2, -2.5, or more if possible? I've heard a lot of negative comments about running really big camber differences front/rear.

balefire

i can only guess that the high pressure needed to prevent rollover for your tires is either sidewall stiffness or an alignment problem. don't know for sure though.

muffler bypass pipes are completely bolt on. i use a cheap o set of clamps which are easier to take on and off than oem clamps. I also reversed one set of bolts so I only have to remove 2 bolts instead of 3 bolts per side. I worry that in warmer temperatures / or different wind direction / or higher rpm range my car may blow higher than 100dB but my region isn't strictly enforcing the sound limits yet.

Yomi

Drove to the shop today to put the Konis on my C4S. Drove back with them still in the box. The C4S has the swaybar attachment point fixed to the bottom of the strut spring perch, which the Konis lack. So if I put the Konis in, I'd have no front swaybar.

I'm debating whether I want to:

1. Call it a day and run stock, returning the Konis to TR.
2. Look into getting an attachment point welded onto the Konis.
3. Look into the Tarett extended droplinks which might clamp onto the strut and work, assuming it doesn't hit the perch.
4. Look into using the TRG links that attach to a different position.

I wish I had a car that parts actually fit onto, for once.

balefire

I'm not feeling any of those options.
How about
5. run koni yellows in the rear. find another stiff likely non adjustable shock for the front (e.g. OEM turbo shock, confirm via part number). get a stiff front sway bar that's adjustable to compensate.

I currently run my front konis at less than full stiff anyway.
I still think you will have more fun, and spend less in AS than you will once you goto ASP or BSP.

Yomi

Just got off the phone with Jeff at Rothsport. He thinks it can be done using the TRG endlinks in combination with a sleeve to make the clamps fit (apparently the stock struts on the AWD's are a little bigger than the RWD ones, so a sleeve would be needed to make the clamps work).

However, he also thought the whole thing was far inferior to going with a PSS10 coilover setup, which is what he recommended for a DD/autocross car in the affordable price range. A few choices in the sub-$3k coilovers: PSS9, PSS10, JIC Cross (includes camber plates), KW, among others. Maybe I should have snapped up those Cross's for $1500 that sold last month in the for sale section.

Edit: I'm pretending I didn't hear his option of running PSS10s and not telling anyone. Cheating in regional autocross is soooooo wrong.