Fissionx

I just put a GT3 suspension on my ’99 Carrera and wanted to share some pictures if anyone wanted to do this install in the future. I followed the thread for the ROW M030 install on renntech for the most part, only a couple of things were changed.

http://www.renntech.org/forums/index.php?showtopic=7073

To get a MK2 GT3 suspension working on a MK1 or MK2 996 C2 you will need the following:
1)GT3 dampers and springs
2)GT3 upper strut mounts
3)GT3 sway bar mounts and links for the rear

Often times you will find a used GT3 suspension with just the dampers and springs, the seller will keep the monoball front strut mount and sway bar mounts. You will need to then purchase items 2 and 3 from the list above. I purchased my upper strut mounts from Suncoast for roughly $450 new. Look carefully at the pictures below to see which parts you will need to order. You will need anything and everything on the parts diagram that your kit is missing…



The OEM sway bar mounts cannot be purchased through your dealership. These are only available through Porsche motorsport for about $200+ EACH. I bought an aftermarket version from Arlan Motorsports. The owner is VERY knowledgeable about 996 suspension setups, so feel free to have an extended discussion with him about your setup. I also purchased adjustable sway bar links from Arlan as well. Another $500 spent

**It is possible to reuse your front sway bar links (they mount at the pinch bolt), but not the rear; you need OEM GT3 or aftermarket links. I suggest getting adjustable links front and rear while you’re at it.**

Once you have the strut mounts, I chose to swap the bolts to get extra camber in the front (that’s what they are there for). You can get (I THINK) a max of -1.8 camber on the front with the factory holes and anywhere from –1.8 to -2.5 MINIMUM with the bolts swapped, depending on your ride height. The choice is up to you. To swap the bolts, you will have to hammer them out and back into the new holes, mark the holes you want to use with a sharpee and knock the bolts out. You need to be very careful not to damage the threads when doing this. I put a nut on the top of the bolt so I wouldn’t miss and destroy my threads. It is better to give 2 or 3 really strong hits with the hammer rather than tapping at it all day, and it go nowhere. Next, swap the bolt locations and hammer them back in. The back end of a 3/8” extension works well to hammer the bolt in. I laid the mount on a big *** socket I had where the bolt can pass through the center.

Now you need to assemble the front and rear coilover assemblies. The height specs for the GT3 coilovers are shown below.
**NOTE that to achieve factory GT3 RIDE HEIGHT, the height adjustor collar will be about 1” lower than the ‘spec’ height since the C2 wheel carriers and control arms are different. The front can be assembled without a spring compressor, in fact you won’t be able to get the craftsman compressor to even fit. The rear will need a spring compressor. I would start off running 1” lower than GT3 height and go from there once the car is on the ground.

Next remove the caliper, loosen then strut mount bolts and pinch bolt rip out front suspension and install. Similar procedure for the rear.
Once the coilovers are installed, drop the car and set the ride height with the sway bars dethatched. I would recommend driving around a bit to try and get the suspension to settle, but I did that and the car still dropped 5-10mm a week after the alignment.

You can run the stock C2 sway bars on the GT3 coilovers and have a pretty good setup. The GT3 sway bars will provide some additional grip, and are adjustable.

Fissionx

will add more later

juankimalo

fantastic!

Thanks for sharing this reportage

Wellardmac

Nice job!

CWay27

I did the same a couple of months ago but got lucky and had a full suspension where I didn't need anything. Fast forward 3 months and now I run GT3 suspension, sway bars, wheel carriers and brakes. Since I had gotten tarrett front end links before swapping the carriers, I still use them has pinch bolt configuration and not with the collar like on the GT3.

Great write up!!

pete95zhn

Thanks for excellent write-up! I have few question though...:
-Do you use GT3's adjustable front sway bar? If yes, how did you connect it to the wheel carrier, if you're not using sway bar mounts at dampers? Any pictures?
-I've seen a discussion about a necessity to use a sleeve between damper and wheel carrier, when installing a cup car suspension to a GT3...if I understood that correctly then... In the picture you poster is no sleeve, so it was a perfect match..?
-Did you change lower suspension arms to GT3's adjustable ones?

All these questions because I've been offered cup car fully adjustable dampers ( Bilsteins with external canisters and Porsche part #'s ) and I'm still figuring out if they can be mated with std wheel carriers. Future project, C4 with turbo front wheel carriers, to accommodate GT3 mkII's bigger calipers. Yes, I know, I'll need 997 turbo's discs then too...

CWay27

You can use adjustable front GT3 sway bar with stock C2 carriers but you need shorter end link from TRG or tarrett.

pete95zhn

Thanks! This clarified one part of the problem.

Actually after posting my questions I found this thread from Renntech: http://www.renntech.org/forums/index...howtopic=22097

Here's one picture:



Compared to picture above the damper ( and the car's weight ) seem to be resting on the sway bar mount, on the top of the wheel carrier. So, either one's got to get those sway bar mounts, or use an extra set of collars. Or there's a third way too...the sleeve perhaps?

And if the damper sits so low, it's in the way of the drive shaft. Unless turbo's whell carrier geometry is different.

imdrew12

Very nice

Paul 996

GT3 susp on 996 C2... Looks like a trend

In my installation the shock rests on the lower drop link collar and that is a key component to establishing the car's ride height without reducing the suspensions allowed travel. Without the lower drop link collar I don't know for sure but the pinch bolt should hold things in place... I would suggest scribing the install location and checking after heavy use/abuse to make sure it stays put.

Also, it is physically impossible to use this GT3/GT2 suspension with a C4 or Turbo in all wheel drive configuration. As you pointed out the Front shock is in the way of the front axles.

CWay27

The stabilizer block holds the strut from sliding in the carrier. I have seen guys use extra adjustment collars to do the same. For sure these shocks wont fit C4S or turbo. BTW GT3 carriers and C2 carriers are 95% the same. Beside the caliper mounting holes being 1/4" further apart, the area behind the pinch bolt is grinded down to make room for end link knuckle. Just like in the picture posted above.

pete95zhn

I've been doing some searching, and found this picture:



It shows that turbo's front geometry is indeed different. There is also be a discussion going on about this swap in both 996 turbo board and in Renntech. I'm now waiting to Ryan ( TXGold ) chiming in...

So, my future progect seems still to be going on as planned. These boards are very effective places to gather useful information. Thanks for your input, and sorry about a light thread hijack!

Pete

So far with a 951, 3.0l with GT3 mkII brakes

PFPADM

Thanks for the report. EXcellent.

I'm the process to change the C2 at a GT3 specifications.

For the suspension:

My car has the M030 stock, and in this moment I bought the GT3 sway bars, and modified front droplinks.

So I need I think:

1)GT3 dampers and springs
2)GT3 upper strut mounts

I have informacion that I didn´t need the modified droplinks for the rear.

And then a adjustment ayt trhe camber wright?

For the brakes:

I need:
- front and rear calipers
- front and rear 330mm discs

Someone can help me in this adventure?

Thanks

PFPADM

Aboult the rear droplink I have this info:

The 996 c2 rear droplink can be used with Gt3 bar.

The front 996 C2 drop link must be shortened by 20-30mm otherwise the arb touches the track control arm. The drop link is cut, joined by a cylinder and welded carefully so as not to melt the ball joint ends.

PFPADM

I finaly end to buying the suspension the GT3 MKII.

I have the struts, shocks, springs, tops, and sway bars.

The front drop link was modified to acomodate this new sway bar.

Aboult the rear droplink I have this info:

The 996 c2 rear droplink can be used with Gt3 bar, but if we used a GT3 shock, can´t be used since was different angles.

So to resolv that we have to install the GT3 rear droplink, or a Tarett.