hlee1169

After my 2-day DE with PCA-GGR at Thunder Hill, I feel that the stock tires probably won't last too long with a couple of more DE events. I measured the tire depth with a gauge, and both front and rear shows 6/32 inch, with 5.5K miles. So I decided to get a set of 19" wheels since tires will be cheaper for the smaller size, and should be lighter too.

Checking prices on Tirerack, I see the prices for OE Pirelli P Zero as
Front 245/35/20: $365 each
Rear 295/30/20: $525 each

Since I want to keep the same overall tire height, I went with 245/40/19 Michelin Pilot Super Sport for the front, 295/35/19 PSS for the rear. They are $287 front, $452 rear.

Now, for wheels I narrowed my search to OZ Superforgiata and HRE P43S, and decided to go with OZ since they are cheaper on Tirerack and are amazingly light. According to Tirerack's web site, front is only 16.5lbs, and rear 19lbs. So I pulled the trigger and have Tirerack mounted and balanced the wheels with TMPS installed too. Jonas at Tirerack is very professional and helpful, and two days later the whole set arrived. That's really fast!

I spent this Sunday morning swapping the wheels, and also use my bathroom weight scale to check the actual weight of OZ wheels vs OEM Sports Design wheels. Here's the result:

OEM Sports Design front: 48.2 lbs
OEM Sports Design rear: 62.5 lbs

OZ Superforgiata front: 41.8 lbs
OZ Superforgiata rear: 50.2 lbs

Needless to say, I am pleasantly surprised. 6.4 lbs lighter in each corner of left & right front, and a whopping 12.3 lbs lighter in each corner of left & right rear!

After tightening the wheels to Porsche's torque specification of 118 ft-lbs, I was eager to try it out. I decided to go for a back road drive up the mountain to the Lick Observatory in the south bay area. The drive up to the mountain is very twisty and narrow, and average speed is about 35MPH, so I won't be going too fast. It should also give me an idea how the new wheels and tires handle.

On the freeway I did not feel much difference. But once I was on the mountain road and started to take these corners, I immediately felt a difference. The car seems more nimble, and turn-in is sharper. Compliance is excellent, never harsh, and grip is phenomenal. The onboard G meter said I hit 1.0G turning left, don't know how accurate it is, but that's amazing. Usually new tires are greasy, but I didn't feel it at all. PASM & PDCC kept the car flat, and I had a blast. I have to restraint myself from pushing faster since this is not a track, but my confidence on these tires is very high.

Compared to my last 997.2 with 19" HRE P43/Michelen PS2, the new 991 does not push as much, and i have higher confidence pushing it to the 7/10 limit. The 6 piston front brakes are amazing too. Overall I am very satisfied with the OZs and Michelens. Next weekend I am going to Thunder Hill again for the Hooked on Driving event, and will see how these hold up on the track.

I took some pictures, see below:

1. Front & rear (left to right)
2. Front tires comparison. Left is Michelen PSS, right is P Zero. P Zero seems to have picked up "marbles" from the track, although wear seems to be uniform.
3. Rear tires comparison. Left is P Zero, right is PSS. Again, "marbles" and wear seems uniform. Maybe PDCC is helping the tire stay flat during cornering?
4, 5, 6: How the OZ wheels look on the car. The color is sort of muted gunmetal, compared to stock's bright silver, and seems to make the whole a bit understated.

Now I wonder if there are lighter aftermarket brake rotors...

chuckbdc

Great setup! "Compliance is excellent, never harsh, and grip is phenomenal" should be the PSS marketing byline- it is what everyone says after they get them. The difference in feel you describe is exactly what I felt when I changed to them from the OEM PS2s on my prior car. The dividend from reducing unsprung weight should be most obvious at the track. Look forward to your trackday report.

I think the setup looks great on your car. The wheels look "serious" and the 991 shapes really don't need distractions - they seem to "pop".

One suggestion- the least expenisve way to improve performance is to lower the center of gravity. The effect is substantial. The factory Sport PASM springs are shorter by 10 mm and stiffer, but not excessively so, so there is not really much of a compromise in ride. They would also "fill" the wheel wells some, with no danger of rubbing or scraping.

spourreza

Those are really nice rims. Fit nicely with the car even for daily use. Not sure why a 19 inch option wasnt available to order for the "S".

chuckbdc

HLEE,
I had to come back to look at your car again. I realized tha tbesides the super functional look of the wheels, i like the slightly higher profile compared to the stock lower profile 20' setup. I think is has a classic look. -And they give inceased suppleness (and protection from sidewall "shock bubbles" without any handling compromise with MSSs. I did a +1 sizing on the Boxter with 19s and it transformed the car to the good in every way. I am likely to go your route when the time comes.

hlee1169

Since the cab is not offered the factory Sports PSAM springs, do you think they will work on the cabs? I am just paranoid.

-Henry

hlee1169

Thanks. Looking forward to your impression when you decide to pull the trigger. These OZ Superforgiata are really light.

Henry

Alstoy

The OZ look wicked. Any idea what the stock 19s weigh? Cheers.

ScorpionT

I think they do that because the cab drivers dont generally push their cars as hard. The springs should work, but I would ask a service adviser first.

Other companies also make springs, and you could save time and money getting an aftermarket set.

chuckbdc

It is indeed worth doing research and talking to people who really understand suspensions and the effects of the other goodies in your car (sensors and PDCC in particular). I think that the old "just get lower springs" notion is fine for getting the looks- but no longer the way to go to actually improve performance. The SPASM setup on my car is really optimized.

I recommend a call to Mike Levitas at TPC in Jessup Marland- he is an engineer, successful racer, builds cars for pros, and I believe has a 991 to do aftermarkert parts development.

TT Surgeon

If your running track rims, how bout some better track tires like R cmpnd sport cups.

hlee1169

I agree, it is just that I'm still a beginner, so I want to fully explore and learn the limit of the car's handling before going for track oriented tires.

Although the owner's manual does warn about usage of "race" tires as it would lead to oil starvation during high G lateral acceleration.

John's 991

Great info, thanks! I'm thinking of doing the same thing but with some R compound tires for track days. Was going to see if 305s would fit on the back.

hlee1169

According to this link, Toyo R888 305/30/19 would be close to the stock 20" height.

spourreza

This is probably why I quickly started getting use to the 19s on my car.

Carcam

Henry- those wheels look great on your car. I usually don't like the look of aftermarket wheels on Porsches but I like these more than your stock wheels. They look light, clean and the color really compliments your cars color.