I spent all day today deciding, and ordering my mods, for my turbo coming in next week!! Here is a list of what I ordered:

-19" HRE 545R (4"lip) in brushed alum. finish (decided to listen to my dad and not get black )

-Fabspeed Super sport exhaust (loud)

-RUF Pedals (Thanks Weissach and a good guy Asgar)

-Bumper Plugs (Thanks to Bumper Plugs)

-Clear Side markers

AND THE BEST:
-Imagine Auto Stage 2 PKG(W/O the exhaust) (Thanks to Stephen, you sound like a great guy, can't wait to send you my ECU, and I look foward to talking to you again).

Only things I have left to order are Bilstein Coilovers, and Tires, which I am going to wait a bit since I don't plan to install them till the HRE's get here (4 weeks ).


My question:
My contact at HRE told me that they reccomend 245-35-19/285-30-19 for the rear tire!!!!!! Now I have seen everyone on here has 295 or bigger, and I told him this. His response to me was that, they have tested and proven that they got the best ride, and handleing quality with the 285's on the rear. I asked why all my "board buddies" had bigger, and his response "Its hard to get a Porsche guy to come down in size" . How does this sound, I know this guy knows his stuff, and he would not lie (friend of mine). I also called Tire Rack to see where their stance was, and they too said 285 is what they are showing reccomended!! Whats the deal??
Regards, and thanks,
Evan

 

i'm using 285 ^___^
i don't really notice any difference...
but I'll for sure get a 315 next time when i wear out my tire...
if you put 285 on rear, when you jack up the car, u'll see a portion of the wheel is not covered by the tire... and i certainly don't like the way it looks when jacked up...

try at least 295 for rear ^___^... since factory uses that too...

 

I think one of the issues here of Plus One tire sizing (going from 18" wheels to 19" wheels) is maintaining the same approximate outside diameter on your new tires/wheels as compared to your OE tires/wheels.

I think another issue is keeping the difference in OD from front to rear tires/wheels close to each other, due to the all wheel drive aspect of a TT. This is what Guy Atherton at HRE told me last year when I was shopping for wheels.

There's a website where you can compare tire/wheel OD, revolutions per mile, etc. I didn't enter the values for the tire sizes you mentioned, but I did when I was deciding on which tires to use on 19" wheels. I went with the 235/35/19 and 315/25/19, like most people seem to do.

Here's the tire size website: http://www.powerdog.com/tiresize.cgi

Good luck.

 

Also, keep in mind all tire sizes differ from mfgr to mfgr.

 

wider rear tires might cause excess tramlining, like when you're driving over a poorly surfaced road, and the back end seems to want to go everywhere but straight... you may have experienced this when driving diablos, countaches, etc. with ridiculous tires like 315 or 335 in the rear.

excuse my ignance, but what the hey are bumper plugs for? I just took a look at my bumper, and there's nothing that needs plugging...

 

Evan,
I can't wait to see your car when its done.

 

Evan;
congrats on getting all that on order. regarding 19" rear tires...
OEM Conti 2's are 12" section width and 25.5" OD. Those are your target numbers. Based on all I have heard, you need to keep within a half inch or so of the OEM OD or else there may be problems. Someone will likely add to the data.

Conti 2 285/35-19 are 11.1" section width - 27" OD, 295/30-19 are "11.9" section width - 26.1" OD. Both seem too tall.

Pilot sports; 285/30-19 are 11.1" section width - 26" OD (too tall?) and 295/35-19 are 12.6 section and 25.5 OD = close enough.

SO3's; are... 285/30-19 = 11.4" section and 25.7" OD. Maybe OK, but may look to narrow for the rim.

and as a point of reference - the GT2 OEM is 315/30-18 at 12.6" section and 25.5 OD.

Good luck!

 

The car I bought is from the northeast, and has a front plate on it, all the bumperplugs do is put little "dots" in the holes from the front plate bracket when I take it off.

Everyone Else:
Thanks for the kind words, and advice on the tires. I have 4 weeks to think this situation over, and hopefully get more feedback . Hopefully within this time I will figure somthing out.
Regards,
Evan

 

AMG-ETR, I hate you and am extremely jealous! You lucky SOB!

 

Soon2be993tt,
That is a bit harsh, wouldn't you say? LOL

AMG-ETR,
The mods sound great! Regarding the tires, the single most important thing to consider is that the overall diameter of the front tires are within 1/4" of the overall diameter of the rear tires. These figures are available in multiple sources on the web. The point of this is to avoid undue heat build-up in the viscous coupling. As a secondary consideration, the overall diameter of the tires should not vary too much from the factory tires so that the speedometer and odometer remain fairly accurate. I, as many others, am running 235/35/19 fronts and 315/25/19 rears in the Yokohama AVS. The rears are not approved by the DOT here in the states. They are approved by the european community's TUV (comparable, yet more stringent, agency). I knew of only one other tire brand that produced the 315/25/19 size. That was Continental. I also understand they may now be DOT approved. They are available through Weissach with which it sounds you already have a relationship.
From an overall diameter standpoint, the AVS rears are 640mm and the fronts are 646mm. That is 6mm difference in overall diamter which equals .2362 inches.
Hope this helps.

 

KVP;

FYI - Conti 315/25-19 are DOT approved.

 

Evan - congrats!! Looks like its gonna be one nice TT...
I just think you might wanna rethink the H&R springs. I had them on my 01 TT (see sig) and the car was toooooooo low!! They also made the ride very roough. I think M030 sorings would be a better choice unless you feel like doing coilovers..Just my 2 cents

 

Thank you for the advice. I am not going to be able to do coilovers, as it is my dad paying for all of this, and that would be going over the top!! I am going for the low look, and it isn't much of a problem down here in FL since roads are somewhat smooth. The only problem down here is driveways, but I don't mind it I will just be carefull. As for the rough ride, this doesn't bother me either, I am young, and I am used to it. Hey worst comes to worst I will be out 300 bux, I figure its worth a shot. However where can I find the M030 springs??
Thanks,
Evan

 

You can get them at any porsche dealer or through Gert at Carnewl.
It is not as easy as only 300 buks because changing springs or suspension requires the same labor (about 10-11 hours) and so this is the big cost not the parts. Gert has the PSS-9 for reasonably cheap...I think it is the best mod I have done so far...

 

Evan;
I like it !
"No son, the limit is $130,000.00 and not one penny more!"


and... my 2 cents regarding the lowering springs - save your money and at least do adjustable coilovers. msindi is right, the expense of changing the parts and a new alignment is the factor and it is better to pay for that only once. The spings are what, about $300 a set? And you can get coilovers for around $1,100 a set? Dude, work a few Saturdays or sell something to make it happen!