Aerokit rear wing finally installed.

OK so we've had this GT3 like, mk1 Aerokit rear wing sitting around for months and finally have found some time to paint it and get it installed.

This is an OE factory Aerokit wing found, like the other items, on ebay. It's made in a small town in France right on the German border by a company called Turnwald.... but I digress :)

The wing arrived already primed and since we were very happy with the PPG products used earlier to paint the other components knocking this out in a weekend was going to be no problem. The same paint, bonding agent and clear coat was used. Thw wing was disassembled to allow painting all edges. Also we decided to paint the underside semi-gloss black. This was done for a few reasons. One it made setting it down to paint easier, Two, it should reflect less heat back into the engine compartment and finally because we had seen factory Carrera Cup cars in Germany with the inside painted black.
The wing was then re-assembled by reattaching the plates, pins and hinges that allow the wing to be adjusted to different angles of attack. (Another reason to get a true factory wing)

Finally the wiring harness, engine bay fan and weather stripping were swapped over from the original Carerra rear decklid. Note: We were told the C2 harness would work as is. This is not actually correct. The C2 wiring harness can be used but it needs to be cut and this destoys the ability to simply reinstall the C2 decklid if you want to retrofit it easily. We would suggest you source the proper Aerokit decklid harness from a dealer.

And there you have it. The complete mk1 GT3 look... finally.

Track Alignment

Now that the GT3 wheels and track tires have been on the car for a while it was time to take a good look at the alignment. So we headed over to our friend's shop who has a hunter machine. After taking a look we discovered the rear toe was off and that the camber settings would have to be adjusted to keep from destroying the R-compound Pirellis on the track.

After reviewing a number of setups and especially looking over the GT3 recommendations from Porsche race engineer Roland Kussmauls, we came up with the following track / street compromise.

Front axle:
Toe total: +4'
Camber: -1.7º

Caster: 8° +/- 30'

Rear axle:
Toe total: 33’ +/- 2'
Camber: -1.8°

These are our starting points. Depending on the performance on both street and track we will adjust from here as time goes on.

If we were going to optimize for track use we would go with Roland's Motorsport recommendations:

Front axle:
Toe total: +5'
Camber: -2.5º

Caster: 8° +/- 30'

Rear axle:
Toe total: 32’ +/- 2'
Camber: -2.4°

Fabspeed Mufflers

We've been running the stock mufflers / exhaust system on this 996 ever since we tried the muffler bypass pipes. Those pipes were fine for the track but we just too loud for a daily driver.

So when the opportunity came along for us the grab a set of Fabspeed mufflers we took it.

Nice and throaty but definately not too loud when you are not on the gas hard.  The manufacturer claims 8-12hp.  We're not sure about that, but the reduction in backpressure should help in some areas and they definately remove 12 lbs of weight from right were you want to get rid of it!  Oh, and they do sound sweet :)

There are also headers available in the aftermarket for these cars. However the exhaust manifolds on the 996 are superior to those found on the 997 Carreras. They are similar if not dentical to the headers found on the 996 GT3 so changing out the headers (manifolds) is not required.

Here is a video from Fabspeed of their 996 muffler's sound.

Installation of the mufflers on a 996 is extremely simple.  They are fastened by 2 bolts per side which fasten the muffler to a mounting bracket. Then there is a clamp on the crossover pipes.  That's it.  Loosen the clamp, slide it out of the way toward the cat. After you remove the 2 bracket fasteners, the mufflers simply slide back and down out of their position within the rear bumper cover.  It's easier without the tires in the way but can be done with the tires in place. A simple mod and definately worth it if you like the music of the Porsche flat 6.

mk1 GT3 wheels

We found a set of mk1 GT3 wheels from a bloke on Rennlist. (If you dont know about www.Rennlist.com, its the oldest and perhaps best Porsche owners forum on the web)

I say mk1 because these wheels are 8" wide in the front. Later GT3 used the exact same style however the front wheel width was changed to 8.5". The plan is to use the GT3 wheels primarily as track wheels mounted up with some good race rubber.

We're going to run a set on the street with Michelin Pilots and/or Continentals. For the track our second set of wheels will be shod with Pirelli PZero Corsa race rubber.

The track wheel/tire specs we run are as follows:

Front: 18 x 8 ET 55 with 235/40 Pirelli PZero Corsa

Rear: 18 x 11 ET 65 with 315/30 Pirelli PZero Corsa

996 engine videos

Great series of Boxster/996 engine rebuild videos

Spacer & Stud Kit Install

While we had already installed slightly wider Carrera 2 wheels on our 996, they still did not 'fill' fenders completly. Maximizing the track of the vehicle is almost always a benefit to handling plus a wide stance just looks better and is in keeping with our project's purpose of making our 996 as much like a GT3 as possible.

Keep in mind that the following recomendations are for the Carrera 2 wheels (or similar) shown below and for the original 996 twist wheels which are slightly narrower. Any other wheels such as GT3 or aftermarket (non-factory offset) wheels may need their own analysis to determine proper spacer & stud selection.

As an authorized H&R dealer, we have a full selection of wheel spacers from 7 to 45mm available to us. The goal was to widen the track to the width of a GT3 keeping the various tires sizes and wheel width options in mind.

We started with a 14mm H&R spacer which we trial fitted to both the front and the rear. Some have used a narrower 7mm spacer at the front of the 996 so we were hesitent to immediately put 14mm spacers on all 4 corners. However after testing the 14mm at all for corners and checking the clearances we determined this was well within fender. This also maintained the factory's original front to rear track difference and brought the tire out to about the same position it would be had we installed a set of wider and deeper offset GT3 wheels.

In the rear we determined that a slightly wider spacer could be used due to the additional fender clearance. So for our final setup we selected a 14mm spacer for the front and a 15mm spacer for the rear. An 18mm spacer could also have been used at the rear however we made a concession to the width as this car would also be regularly street driven. The concern was that 18mm would cause dirt and water coming off the wheel to splash down the side of the bodywork.

Any spacer for the Porsche 996 is going to require either longer wheel bolts or a conversion to a a stud & nut kit such as our "Track Stud" conversion kits. The first thing you need to do is determine what type of wheel nuts you will need. This will be determined by the type of wheels you have. If you have factory Porsche wheels you will need spherical seat wheel nuts such as those found on earlier Porsches. However if you have aftermarket wheels they often use a conical seat and you will therefore need a wheel nut with a matching 60 degree cone seat.

If you change your wheels often like we do then on of our ACS "Track Stud" wheel stud kits will make your lfe much easier.  In addition to the extra strength affored you by these kits, repeatedly mounting a heavy wheel/tire combo become a "peice of cake".   No more balancing the wheel on your foot while you struggle to thread that first wheel bolt in.

Sway Bars

In order to dial out some of the understeer of our 996 an adjustable H&R rear sway bar was installed.  We left the original front bar alone as a larger front bar would just bring more understeer back into the equation.

Removal of the original rear bar is simple and straight forward on the 996.  Simply unbolt the inner pivot mounts and then disconnect the end links.  Installation of the new H&R bar is simply the reverse.

The H&R rear bar will give us the adjustability needed to help dial in the supension the allow more neutral handling.  Unfortunately the H&R bar is thicker, solid and therefore heavy.  The last thing we want is more weight in the rear of a 911.  So eventually we will be locating a set of factory GT3 hollow sway bars. They are adjustable front and rear and very light.