frayed

Bob, Apex et al.,

Here's what's happening with my car today:

Front camber: -2.5° +/-5’
Front toe: 0’ +/-2’

Rear camber -2.0 +/-5’
Rear toe: 16’ +/-2’

Sways: factory positions (fr 1 off full soft, rr full stiff)
Ride height: factory
Cup Car toe links

The toe values are from the track specs in the manual. Curiously, the manual calls for -2 degrees up front, -2.5 degrees out back. I find this setup suspect, based on my experience with the 996 GT3 and especially based on all the understeer threads on this board.

It's going on the rack this afternoon. Thoughts? Note that I surely don't have the track experience you guys do and the car will see dual duty street/track.

Thanks!

PS, the dealer gave me a Coxster (non S) loaner. It is a really fun car. Sure, not as intense as a GT3 but it's a car you immediately feel at home in and it carves up twisty canyon roads and the soft suspension makes short work of real world bumps. Motor is pretty responsive and reminds me of the smoothness of BMW's inline 6s.

Hank Cohn

frayed-

Looks pretty good. Are you running on stock wheels and tires (if so, MPSC or Pirelli)? I ran into Randy Pobst a few weeks ago at Road Atlanta and he suggested those same settings for the sway bars.

I didn't change mine from stock as the car was perfect at Road Atlanta with the Sport button activated.

Hank

frayed

Hank,

For now I'll run the OE MPSCs and once worn will then switch to 18" Toyos. I figure that MPSCs, even these dumbed down ones for street use, really are not an ideal street tire and give up dry grip to the 'regular' MPSC or even a Toyo.

Carrera GT

A bit late to help since your car is already done or getting done today.
In short, the "circuit" specs in the book are good -- and comparing to the 996 is not so useful -- but compared to the factory numbers, you might consider a tad more front camber and a tad less rear camber unless you're going to stiffer springs. Rear total toe of 35 or so seems adequate to keep it stable in the faster sweepers.
Cup rear toe links should be good, but I'll be interested to hear your impression of rear "shimmy" because the compliance in the hat might make it impossible for the rear to really settle down.

I'm reading mixed reviews (and general dislike) for the Toyos. While I like the Corsas and the Sport Cups, they're both pretty ordinary. I do like the car with the non N-rated 265's on the front. If you stick with 19's (do you have ceramics?) then the choices are limited of course.

If you can stand new rubber every 3K miles, the factory Sport Cups aren't all that bad. : )

Hank Cohn

frayed,
I felt the same as you until I tried them [OEM Corsas] on the track. I even contacted Mitch to find out his wheel source, CCW, and have the 18" wheels in my garage. I think my plan has changed. I've put 6 track days, ~8 hours on-track, on the Corsas and they still look great and were turning the same fast laps at the end of the last day.

Road Atlanta has just been repaved which generally means that tire wear is significantly reduced, an added bonus as long as it lasts. There is no development required as the car is set up by the book [owner's manual] and is surprisingly fast. That means that the dealership 7 miles from my house can verify the alignment any time. This will all change, of course, if I get passed on-track by another car, but that hasn't happened yet!!

Hank

gweedo911

Which wheels are you going to go with? BBS?

frayed

Well, alignment got held up. Looks like Porsche Motorsport sent only the links but not the bushings necessary to mount the links to the subframe.

GT, your comments here are confusing to me. The Circuit specs have *less* front camber and *more* rear camber than those above. To be clear:

Book............................Frayed
-2.0 fr..........................-2.5 rr
-2.5 rr..........................-2.0 rr

I am familiar with McPherson strut suspensions and have real doubt as to the workability of -2.0 up front. The numbers I was trying to pursue are the same as Bobs except: full stiff rear bar and a tad less front camber to save tires a bit and to improve steering feel.

As far as Toe is concerned, the specs are the same as Circuit and Bob's.

This if the first I've heard of this. Care to elaborate? The toe links are not load bearing components when the car is static, and from the folks I've talked to the NVH penalty is minimal at best but offers fantastic toe control under hard charging. Some have gone so far as to say that its a crime not to use heim joints for this particular suspension component. With heim joint toe links there's still a lot of rubber in the rear suspension.

This is true, but Toyos just don't have the embedded devotees in Porsche circles. They require lots of heat, should be shaved, and do really well when driven loose. I do think the Mich's are more precise but require tighter driving and aren't so great when heat cycled.

But I'm going to hold off tires until I cord the OE tires.

frayed

Thanks Hank! I guess I'm just a bit put off by all the recent threads re understeer. Would you reverse direction and swap the camber values? I can handle some moderate oversteer but understeer always erodes my confidence on track

Gweedo, I'm a big Fikse fan. Have to go with them, especially considering the BBS wheels are not cup wheels, but cup wheel knockoffs.

Hank Cohn

Frayed,

I've run MPSCs for years and understand that the ones that come on the GT3s are different from the retail version we are all accustomed to. If there were no alignment values listed in the owners manual and it were a new car with little data, I would go with my tried-and-true default of 3 degrees in the front and 2.5 in the rear. I'd make sure the rear had some toe-in and the front had neutral toe.

I do think the understeer issue must be specific to the track mentioned or the drivers have not activated the sport button or both. I was just being cautious with a new car and didn’t put it in sport mode right away. Like others, I was stunned by the amount of understeer at a specific slow corner (Road Atlanta – turn 7). Once the sport button was pushed, I was elated to discover that there was no understeer.

We have a great race shop here in town, Kinetic Motorsports. Occasionally they host a test and tune session with a professional race engineer and professional drivers. When the opportunity next presents itself, I will try different settings in hopes of finding even more speed.

It took a great deal of testing, tuning, testing… with my previous car to get it to a point where it was comfortable and predictable to drive at the limit. I loathe beginning that process again when the GT3 seems so right straight out of the box. My strategy was to start with recommended settings and, over time, get a little more aggressive with alignment and sway bars without fitting aftermarket bolt-on promise-of-more-speed goodies. That’s what cup cars are for and at 60% the cost of our cars; we could have a ’00-’01 Cup.

Hank

Carrera GT

I was suggesting my preference relative to the factory number, not relative to whatever you'd chosen. I'd probably go with the numbers you're suggesting as a "see what happens" experiment.

As for struts, I'm not sure what you're familiar with other than perhaps there's no camber gain.

For the rear, going to spherical rod ends is great for toe control and consistent geometry. I imagine you're doing the Cup car links to get rid of the eccentrics. The other step is to replace the hat with a spherical solid mount -- this removes the compliance at the top of the suspension and is associated with the side-to-side shimmy that the 996 and 997 exhibit as the rear end walks over irregular road surfaces.

I wasn't thinking of NVH, although the mono-***** will give you a firm ride, I wouldn't expect it to be unlivable. I was only thinking of high speed cornering.

Some shops like TRG recommend doing everything at once, other shops (perhaps in deference to PASM and for lack of "off the shelf" common upgrades) will leave well enough alone, sell a couple of ERP links (or the PMS Cup parts) and be satisfied. I'm sort of in the latter camp for now, but will eventually do more once I've counted my pennies (and waited to see how grussel and others report their JRZ/Moton/Ohlins changes. Bang for buck is definitely the threaded toe links.

As for Toyo's, there are some great, well-loved examples in the 911 world. The RA-1 is a perennial favorite especially with guys who drive to the track and want good wear and street grip without regard to wet weather compromises. I find both the RA-1 and the Corsa to be fine in the wet. And with TC in the 997, I'm not too worried, but that's not to say I'd be relying upon it. As for new Toyo's, the R888 or whatever, I haven't tried them but I know folks with them on the car and we'll see how they go.

Edwin

frayed....I didn't have a big understeer problem at TWS on factory settings once I got my air pressures right (both sport buttons on). TWS doesn't have many slow corners though. The car came with Corsas.

I also have to second Hanks comments regarding the Corsas....they are holding up great so far. I ran MPSC's on my 996TT and would get three track weekends tops out of those.

str8ner

My car has F-2 in the front and -2.5 in the rear. Feels great. My mechanic works for Fornbacher Loles and confirmed to me that the 997 Cup were set up with more camber in the back than in the front as opposed to the 996s. Front sway bar as factory, rear in the middle. The car understear some but not terribly. I have tarett toe links. That made a huge improvement on the car. Much crisper turning. I have run the factory MPSC until I hit lost it at turn 9 at Summit. They were much less grippy than the real MPSC. I tried F235x18 and R295x18 MPSC and that felt a lot better than the original tires. Tried Nitto NT01. Terrible. Grip OK but very soft sidewalls. Made the car very unstable at high speed. Will not recomend them to anyone (for sale if you want them) Felt worse than Toyo which I think do not compare to the MPSC. Toyos also have very soft side walls. Would like to try MPSC 315x18 but are back ordred. Did 2 track days with Hoosiers 245x18, 315x18. Felt great and light. The side walls are very stiff and turning is very quick. I would recomend them to anyone that can purchase tires often.

frayed

Thanks guys.

Also, GT, I'm running PCCBs but the Fikses and BBS wheels fit over the big composite rotors. I'm not into Toyos for wet traction, I just found them fast and tolerant of heat and a bit of a slip angle. Heh. But this wasn't on a 911 so I could very well speaking against what's worked on 911s.

Carrera GT

I think the Sport Cups in 265 and 315 could be great (if a little bit like cheating almost.)

I think the Hooters in 245 and 315 on 18's is a step up (and popular on other 911's.) I haven't had it on the car because of the 19's over Ceramics (and yes, some 18's clear the front calipers, but not the Champions I already have in the trailer) so when the next car is ready, it will be running 18's over the factory steel brake calipers assuming all else is equal.

Apex Late

[QUOTE=frayed]Bob, Apex et al.,

Here's what's happening with my car today:

Front camber: -2.5° +/-5’
Front toe: 0’ +/-2’

Rear camber -2.0 +/-5’
Rear toe: 16’ +/-2’

Sways: factory positions (fr 1 off full soft, rr full stiff)
Ride height: factory
Cup Car toe links

It's going on the rack this afternoon. Thoughts? Note that I surely don't have the track experience you guys do and the car will see dual duty street/track.

QUOTE]

Sorry for the delay but yesterday was crazy. I think the set-up looks good but I suspect that you will still push depending on how hard you drive the car and the type of corners that you will have at your local track. When speaking to Bob his changes (which are similar to yours) made the car much better than stock but he still has some push. I suspect that its either the stiffer front bar or the front toe. If I were you I would strongly consider going full stiff on the front bar as that is an easy change if you dont like it.