By all means, take it out and have fun as it is. Coilovers will make the car handle better, but they are not a requirement. There are several threads over the last few days discussing suspensions for track setup you might want to take a look at.

Good luck with that!

Jon

 

OK, so the understeer is fairly easy to address.

I just know I'm not going to want to take the time to do the camber changes. I'm pretty handy with a wrench, but I start to whine once I have to do more than swap brake pads/wheels at the track.

Is there anyway to mount a set of camber plates to the front struts instead of using the GT3 control arms?

 

Ah, I missed that point. If you are driving your car to the track and setting it up there, then this is probably too much work. I set mine up at home, and trailer it back and forth to the track.

There are several people on here who are able to get a lot of negative camber just by adjusting the tops. Most of them seem to have JIC coilovers. Several of us, including me, could not manage to get more than -1.9 degrees. My car came with PSS9's, so I couldn't tell you about stock struts. You can increase the adjustment distance by grinding the slots that the struts move in. On my car, the spring interferes on the inside of the well before I get to -2 deg. That is why I went to the GT3 arms that adjust from below.

Either way, though, you also need to adjust toe after changing camber. I use the Longacre toe plates, and it's not too hard to do, after you've done it once and know pretty well how many turns it takes. I still have to measure and tweak it after setting it. I adjust the toe to about zero, then make the jam nuts on the tie rods finger tight. Then, I drive the car. It almost always tracks straight (means I set the toe right), but sometimes the steering wheel isn't centered. I then go back and adjust the toe setting by adding the same amount to one side as I subtract from the other. 1/4 turn changes the steering wheel position by about 5 degrees (not scientific - just an observation). If the steering wheel points to the right, you want to make the left tie rod shorter.

Maybe a good compromise for you is to set your car up at home, drive it to, from and on the track, and then reset it for normal street use when you get home. You're going to trash the outer edges at the track, so the small amount of excessive wear on the insides from the travel to and from the track will be ok. Incorrect toe will wear tires much faster than incorrect camber. The latter is just riding more on the edge than necessary, whereas the former is consistently gridning the tire against the road.

 

The way I have my M3 toe set is that on the street camber setting the toe is fine, then I slam the plates over and end up at a happy toe setting for the track.

I can probably find that happy medium on the 996 as well I bet. So even with a 60mm/2.5" spring it'll contact the fender well before you can get to -2.5 camber with a set of upper camber plates?

 

Maybe you can. I know that I couldn't. Trust me, I tried.

Setting toe really is not all that hard. If you want to do it by counting turns without measuring, it adds 5 minutes per side when you change the pads. Loosen the 21mm jam nut, crank the requisite number of turns with a 13 mm open-end, and retighten the jam nut. It's easy to reach from the fenderwell when the wheel is off.

Again, I tried and could not do it. Others here seem to be able to, others not. I really don't know why some can and some can't. The upper camber plate doesn't help when the strut is hitting the fender.

I think that my front springs are 3.5" in diameter. Too cold to go out and measure, but scaling from the photo below, where the rotor is 350mm, I get 3.5". Maybe a 2.5" diameter spring would work.

 

Most coilovers use either a 60mm or a 2.5" spring. I'd be really surprised if your springs were 3.5" in diameter.

I'm surprised to hear that there's so little room that the springs contact the fender well.

That should make things interesting...

 

doc that is way too short of a spring, dampening must be terrible and then you hit the bump stops if going too low IE: GT2/GT3 ride height.. This is my setup for my triple adjustable motons, it took me over 2 years to perfect it, then after talking to Lex at Moton and Sofronas at GMG, we came up with a potent track setup... This is what was recommended off my previous feedback from on and off track data, but some points can be universal as spring length...

I will put this up here for everyone to see. All of this info was sent to me after opinions from Vic (VA122) on rennlist, Lex at Moton and Vic I believe spoke to Sofronas at GMG! It transformed my car..... Hope it helps!

"I'm still waiting for Lex at moton to call me back, he was racing.

Here goes
-center steering wheel first and lock in place (seriously no one does this for some reason.)
-Camber for DOT-Rs 2.6/2.4 f/r with shims or you'll lose your caster
-Caster 8.5
-toe 0/-2mm (toe in) per side f/r
-bar middle/1 from full soft f/r
-adjust rear dog bones for kinematic toe in (not out) if they don't know what i'm talking about leave go somewhere else.
-adjust rear toe links for 0 bump as above if they don't know what i'm talking about leave go somewhere else.
-springs 6in with 3 in helper (0-150 weight) visually it should be completely compressed when wheels are on the ground.
-600/800 or 600/900 up to 800/1000 more and you'll need slicks.
-rear locking plate for toe links help depending on what brand you have.
-re-corner balance the car with your weight in the drivers seat with sand bags. ( a LOT of shops forget the weight part)
-front bump kit is a must if you lower more then 20mm from stock
-rake/chassis height- 100/120 f/r or that ratio if you want to go lower, but too low you need the cup uprights
-canister pressure 150/175 f/r

you should be good to go from there and the rest is shock tuning. I'll get you the baseline from lex, depends on the springs you use (eibach)


"Wooo Hoo, Just talked to lex.

here we go,

yuo want a 4-5" min spring up front 600-700lbs with a 4" 150lb tender

In the rear you want a 5-6" main 800-900lbs and a 4" 150lb tender.

Canister pressure:
Front 150-psi
Rear 175 if you have the 22mm diameter shafts and 250 if you have the 14mm diameter. You have 22mm in front so you can compare to figure out which ones you have.

Shock settings.

F compression (on the shock body) 4-5 from 0
F Rebound (cans) 4 from 0
R Bump(compression) 4
R Rebound 5 from 0

From there you should be good to go, and let em know if you want to plug a pro in the car and sort her out once and for all. "

 

The 60mm/2.5" isn't the spring length, it's the spring diameter...

 

OOPS, totally missed "diameter" my apologies!

 

Couple of comments to play catch-up...

Jon and I disagree on the whole braking thing, primarily because I used to brake really hard in previous cars. In the 996TT, you shouldn't get overly aggressive on the brake pedal. My previous track car was a C5 Corvette, and you could brake late and deep, and it didn't seem to mind. It was also a little wider platform, and a little lighter... The 996TT really likes a more progressive and smooth application of the pedal. And as Jon mentioned, the more you learn and apply, the less you use your brakes. I could overpower the brakes in 3 laps in my 996TT with very few laps if I tried to drive it like I used to drive my previous car.

In regards to running more negative camber on the street... I am running the Michelin PS RIB. Do a little research, talk with the gang at Michelin and the gang at tirerack and you'll find that this tire is specifically designed for better wear with more negative camber. In 2008 I mounted a set. I did a bunch of track events with the car set up with some very aggresive camber (-2.9 front and -2.5 rear) and I drove on the street and the track quite a bit. Combined miles are well over 5K miles in that configuration, and I've got a total of 11K miles on those tires, with well over 50% tread left on them.

For the front "push" the key is to soften the front and stiffen the rear, both in shocks and swaybars. I also had one of the guys from flyinglizards tell me that some of the issue is due to the caster. We're going to play with that this coming year to see if we can dial in a more precise caster setting... more to come later on that subject.

Mike

 

So we don't really disagree - we've just had different experiences. And I think that we do agree that it makes a lot of difference how you use the brakes. These cars are heavy, and fast, and they can eat up brakes if you overuse them.

That's pretty impressive, especially for the rears.

Yes, I forgot that my car came with PSS9's. so I have always softened the front setting relative to the rear, as well as the sway bars.

Jon

 

Thanks for sharing your setup with us. I'm not sure that it helps the OP much, since as I understand it he doesn't actually own a 996TT yet. But a lot of other folks could benefit from it. I've thought about going to Motons, but I figured it would take a lot of effort to get them set correctly.

Jon

 

Josh,
I think your M3 is a very capable track car given the mods that you have. I am not sure how much $ it will cost to get a 996TT to be a better track car than a supercharged E46 with your suspension and brake setup. The 996TT may be slower on the track stock compared to your M3, but I think you will like driving the Porsche more. Just be prepared to drop some $ on upgrades on the 996tt. Oh, and I will help you install all of those expensive upgrades Good luck on the search.

John

 

Yeah, I'm gathering that the 911 turbo isn't quite as track ready out of the box as I expected. On my old 944 turbo S I literally just swapped brake pads and tires, then went out there otherwise totally stock and whupped on everyone. Sorta sad to see that the pinnacle of the Porsche's isn't the same way.

Looks like the turbo is more like my old biturbo S4's I ran, lots of power, but you need to be gentle with the consumables and give up speed on the corner entry to capitalize on the exit.

Drop me a pm john...

 

Yea, I don't think the Folks at Porsche intended this car to be tracked. It was certainly geared as a "gentleman's" GT car. That's why so many of them were on lease to business execs in the first half of the last decade. They make an excellent daily driver. But you'll need to improve upon the platform to be happy with it if you're an advanced driver.

Mike