The new 991 C4S!!
#1382
02-17-2013, 09:48 AM
Sid,
I must have missed something in all of that. I understand that you don't like the stock rubber. First question is why? Second question is why the bigger tires? I assume that there are true equivalent sized tires from Michelin and othere- arn't there? Why not go with those? Sorry if you answered this before, but I know next to zip about tire and that was, I hate to say it, fascinating and educational!
Thanks in advance
I must have missed something in all of that. I understand that you don't like the stock rubber. First question is why? Second question is why the bigger tires? I assume that there are true equivalent sized tires from Michelin and othere- arn't there? Why not go with those? Sorry if you answered this before, but I know next to zip about tire and that was, I hate to say it, fascinating and educational!
Thanks in advance
See the dilemna?
If you don't care about ride characteristics (soft, firm, or ultra stiff), stability control, spedometer accuracy, or wear, you can put just about any size tire you want front or rear, as long as there is no rubbing of suspension parts or bodywork. The problem is that Porsche has calibrated all of those things based upon the size of the rubber it puts on the car. So keeping the overall diameter of the wheel/tire combination as close to stock is very important. Traditionally, if you wanted to increase the width of the tire significantly, you would need to decrease the aspect ratio (sidewall height) to keep the new diameter close to stock. This will lead to a stiffer ride, if nothing else is tweaked.
Currently, just looking at the Tire Rack's website, Michelin makes the Pilot Super Sport in the same size as Pirelli for the front, but not yet for the rear.
Last edited by Ajax-Prime; 02-17-2013 at 09:50 AM.
#1383
02-17-2013, 03:56 PM
DO IT!! Just pull the trigger and don't look back...well this place doesn't help much...hang out here for a bit and you start dreaming Porsches...heck I saw one of those new beetles from the back a light or two ahead and weaved through traffic to see if it was a Porsche....addicted? No...only to oxy
And the insane thing is...I've got two-tone int in Pebble grey/Agate Grey....
I know I know everyone is going to yell at me for light int car..and black looks much more racing inspired and what about the maintenance!!!...but....ehh...the pebble LOOKS incredible..especially in the vids I've seen
High-5 on the career choice...my drug dealing buddy
#1384
02-17-2013, 04:13 PM
I kept up with you there and it explains A LOT...so thank you so much for that...for starters I'm sure most of us (me included) wouldn't know where to even obtain that specified information....you lived a life before this didn't you
Thanks Sid...keep us posted...if I may...why do you hate Pirellis?
OH THE WEALTH OF KNOWLEDGE ON THIS FORUM!! LOVE IT!!
#1385
02-17-2013, 05:28 PM
So what you are saying Sid, is that the Pirelli's are the only tires that match the OEM wheels. The other options really push the limits of capability possibly warranty. Thats not a good situation because I was thinking of moving to the Michelin's for everyday use (noise control) once I wear my P0s. I haven't even starting thinking about the track and winter. Winter will buy OEM 19" wheels with probably Michelin winter tires. For the track I am looking at 19" wheel options with Yoko rubber.
Does this make sense? Or am I off base???
Does this make sense? Or am I off base???
#1386
02-17-2013, 06:33 PM
So what you are saying Sid, is that the Pirelli's are the only tires that match the OEM wheels. The other options really push the limits of capability possibly warranty. Thats not a good situation because I was thinking of moving to the Michelin's for everyday use (noise control) once I wear my P0s. I haven't even starting thinking about the track and winter. Winter will buy OEM 19" wheels with probably Michelin winter tires. For the track I am looking at 19" wheel options with Yoko rubber.
Does this make sense? Or am I off base???
Does this make sense? Or am I off base???
#1387
02-17-2013, 07:51 PM
Lots of folks, whenever they are replacing the factory rubber, look to upsize tire width, especially up front, in order to reduce the stagger front to rear. OEM's will put smaller width tires on the front as an easy way to dial in more understeer to a cars handling (less grip at the front.) Understeer is a 'safer' handling characteristic than oversteer, and the 911 (without electronic nannys) is inherently prone to oversteer, with its rear engine placement. If you put larger rubber up front, or reduce the width in the back, you will generally have a more neutral handling car, that is, it will be easier to make the car rotate. This is a good thing, IF you know what you're doing. However, having more width in the back also provides more grip, which helps with straight line acceleration.
See the dilemna?
If you don't care about ride characteristics (soft, firm, or ultra stiff), stability control, spedometer accuracy, or wear, you can put just about any size tire you want front or rear, as long as there is no rubbing of suspension parts or bodywork. The problem is that Porsche has calibrated all of those things based upon the size of the rubber it puts on the car. So keeping the overall diameter of the wheel/tire combination as close to stock is very important. Traditionally, if you wanted to increase the width of the tire significantly, you would need to decrease the aspect ratio (sidewall height) to keep the new diameter close to stock. This will lead to a stiffer ride, if nothing else is tweaked.
Currently, just looking at the Tire Rack's website, Michelin makes the Pilot Super Sport in the same size as Pirelli for the front, but not yet for the rear.
See the dilemna?
If you don't care about ride characteristics (soft, firm, or ultra stiff), stability control, spedometer accuracy, or wear, you can put just about any size tire you want front or rear, as long as there is no rubbing of suspension parts or bodywork. The problem is that Porsche has calibrated all of those things based upon the size of the rubber it puts on the car. So keeping the overall diameter of the wheel/tire combination as close to stock is very important. Traditionally, if you wanted to increase the width of the tire significantly, you would need to decrease the aspect ratio (sidewall height) to keep the new diameter close to stock. This will lead to a stiffer ride, if nothing else is tweaked.
Currently, just looking at the Tire Rack's website, Michelin makes the Pilot Super Sport in the same size as Pirelli for the front, but not yet for the rear.
Thanks again. And if you don't mind a follow-up, why is everyone so down on the stock rubber, or is it the Michelins are that much better?
#1388
02-17-2013, 08:01 PM
Yeah I hear ya, I'm actually looking to do it before I even take the car on the road for the 1st time... I just really, really hate Pirelli's.
The stock sizes are;
C2 = Front 8.5 x 19 235/40 ZR19 Rear 11 x 19 285/35 ZR 19
C2S = Front 8.5 x 20 245/35 ZR20 Rear 11 x 20 295/30 ZR 20
C4 = Front 8.5 x 19 235/40 ZR19 Rear 11 x 19 295/35 ZR 19
C4S = Front 8.5 x 20 245/35 ZR20 Rear 11 x 20 305/30 ZR 20
The Sport Techno (regardless of 991 model) = Front 9 x 20 245/35 ZR20 Rear 11.5 x 20 305/30 ZR20
OK now if you check on both the US and Canadian Porsche configurator and tech specs it will give you different sizes than listed above... it's wrong!
You actually have to go to the individual model info pages to get the right psecs, crazy I know but that's the way it is.
With the awd you can't just change tire sizes because outside of throwing the ECU, ABS, speedo etc, etc. out of whack (same on 2wd 991's) it will also destroy your awd system... while having killed your warranty at the same time!
Soooo you need to take into consideration the rotaions per mile, hight of the side wall, tire circumference, if a larger tires will still clears the inside suspension components, the outside fender etc. etc.
Now most assume that the rotations per mile of the front tire/wheel would be the same as in the back... makes total sence to me too... ehmmmm it's not!
Yep Porsche has engineered into their specs a way to ensure we wear out our tires regardless of driving style, PDCC etc.
The stock difference between the front and rear for a C4/S is 13 rotations per mile...
So when you start playing with different sizes you have to take into account all the above mentioned, this of course really narrows your choices...
There is however a factory variable of 4% that you can play within and not effect the above mentioned systems negatively.
Michelin PSS tires jump from 295's to 335's so if I want to go bigger than my stock 305's I HAVE to go with 265/35R20 front and 335/30R20 rear.
This gives a rotation per mile difference of 16 (instead of OEM 13), the side wall will be 10mm higher, the speedo will read 2,7% faster, stick out at the fender side by 15mm, inside towards the suspension by an extra 15mm, fill out the wheel well by 10mm... but it fits on an 11.5" rim.
In order to reduce some of these figures one can change the tire from "performance" pressure (OEM setting) to "comfort" as this will actually lower the rations per mile by decreasing the sidewall size/height at the contact patch... so from that point of view it will work.
However it is really pushing things both from a spec point of view as well esthetically..
So I'm leaning towards going with the Dunlop Sport Maxx GT which comes in 265/35R20 and 325/30R20.
It doesn't sound like much of a difference but with this set up there's only a 6mm sidewall increase and instead of 16 r.p.mile it's 10.. so 3 less than stock as apposed to 6 more than stock with the Michelin PSS.
Al the other figures are much closer to OEM specs as well.
The last part of this equasion is the size differences between tire manufactures... The 335/30 Michelin is only 10mm difference on paper from the 325 Dunlop... well actually the PSS tread width is 13" compared to the Dunlop's being 11.5... that's a whopping 1.5 inches on a tires which on paper are only 10mm apart... and that's just one example.
Sooo it does get complicated, but for me that's where the challenge lies... pushing the envelop while staying within the set parameters.
OK hooker and blow till the wheels come may sound better... but that brings with it a whole bunch of other problems hehehe (joking).
Hahahaha I'm sure this looooong answer is not what you where expecting... me neither!
Short answer... yes!
The stock sizes are;
C2 = Front 8.5 x 19 235/40 ZR19 Rear 11 x 19 285/35 ZR 19
C2S = Front 8.5 x 20 245/35 ZR20 Rear 11 x 20 295/30 ZR 20
C4 = Front 8.5 x 19 235/40 ZR19 Rear 11 x 19 295/35 ZR 19
C4S = Front 8.5 x 20 245/35 ZR20 Rear 11 x 20 305/30 ZR 20
The Sport Techno (regardless of 991 model) = Front 9 x 20 245/35 ZR20 Rear 11.5 x 20 305/30 ZR20
OK now if you check on both the US and Canadian Porsche configurator and tech specs it will give you different sizes than listed above... it's wrong!
You actually have to go to the individual model info pages to get the right psecs, crazy I know but that's the way it is.
With the awd you can't just change tire sizes because outside of throwing the ECU, ABS, speedo etc, etc. out of whack (same on 2wd 991's) it will also destroy your awd system... while having killed your warranty at the same time!
Soooo you need to take into consideration the rotaions per mile, hight of the side wall, tire circumference, if a larger tires will still clears the inside suspension components, the outside fender etc. etc.
Now most assume that the rotations per mile of the front tire/wheel would be the same as in the back... makes total sence to me too... ehmmmm it's not!
Yep Porsche has engineered into their specs a way to ensure we wear out our tires regardless of driving style, PDCC etc.
The stock difference between the front and rear for a C4/S is 13 rotations per mile...
So when you start playing with different sizes you have to take into account all the above mentioned, this of course really narrows your choices...
There is however a factory variable of 4% that you can play within and not effect the above mentioned systems negatively.
Michelin PSS tires jump from 295's to 335's so if I want to go bigger than my stock 305's I HAVE to go with 265/35R20 front and 335/30R20 rear.
This gives a rotation per mile difference of 16 (instead of OEM 13), the side wall will be 10mm higher, the speedo will read 2,7% faster, stick out at the fender side by 15mm, inside towards the suspension by an extra 15mm, fill out the wheel well by 10mm... but it fits on an 11.5" rim.
In order to reduce some of these figures one can change the tire from "performance" pressure (OEM setting) to "comfort" as this will actually lower the rations per mile by decreasing the sidewall size/height at the contact patch... so from that point of view it will work.
However it is really pushing things both from a spec point of view as well esthetically..
So I'm leaning towards going with the Dunlop Sport Maxx GT which comes in 265/35R20 and 325/30R20.
It doesn't sound like much of a difference but with this set up there's only a 6mm sidewall increase and instead of 16 r.p.mile it's 10.. so 3 less than stock as apposed to 6 more than stock with the Michelin PSS.
Al the other figures are much closer to OEM specs as well.
The last part of this equasion is the size differences between tire manufactures... The 335/30 Michelin is only 10mm difference on paper from the 325 Dunlop... well actually the PSS tread width is 13" compared to the Dunlop's being 11.5... that's a whopping 1.5 inches on a tires which on paper are only 10mm apart... and that's just one example.
Sooo it does get complicated, but for me that's where the challenge lies... pushing the envelop while staying within the set parameters.
OK hooker and blow till the wheels come may sound better... but that brings with it a whole bunch of other problems hehehe (joking).
Hahahaha I'm sure this looooong answer is not what you where expecting... me neither!
Short answer... yes!
Dunlop SportMaxx Race comes in 265/35/19 and a 325/30/19. I think I might try it for a track set up. The sizes should be OK for the AWD system on my C4S. Not sure if the front will rub. Planning on adding some camber up front.
#1389
02-17-2013, 08:32 PM
Aaaand we're back....
I think Ajex prime answered it very eloquantly... that said for me the estectic's of a larger tire comes into play as well... but it's very much like breasts... I love many there's a fine balance of element which goes into the perfect set...and then it has to be proportioned with the rest of the "body work".
It takes a lot of research!
You know what I mean!
Sid,
I must have missed something in all of that. I understand that you don't like the stock rubber. First question is why? Second question is why the bigger tires? I assume that there are true equivalent sized tires from Michelin and othere- arn't there? Why not go with those? Sorry if you answered this before, but I know next to zip about tire and that was, I hate to say it, fascinating and educational!
Thanks in advance
I must have missed something in all of that. I understand that you don't like the stock rubber. First question is why? Second question is why the bigger tires? I assume that there are true equivalent sized tires from Michelin and othere- arn't there? Why not go with those? Sorry if you answered this before, but I know next to zip about tire and that was, I hate to say it, fascinating and educational!
Thanks in advance
It takes a lot of research!
#1390
02-17-2013, 09:22 PM
Aaaand we're back....
I think Ajex prime answered it very eloquantly... that said for me the estectic's of a larger tire comes into play as well... but it's very much like breasts... I love many there's a fine balance of element which goes into the perfect set...and then it has to be proportioned with the rest of the "body work".
It takes a lot of research!
You know what I mean!
I think Ajex prime answered it very eloquantly... that said for me the estectic's of a larger tire comes into play as well... but it's very much like breasts... I love many there's a fine balance of element which goes into the perfect set...and then it has to be proportioned with the rest of the "body work".
It takes a lot of research!
You know what I mean!
#1391
02-17-2013, 09:44 PM
Ummm....so this is the part where we all copy off the smart kid?!?!?!?
I kept up with you there and it explains A LOT...so thank you so much for that...for starters I'm sure most of us (me included) wouldn't know where to even obtain that specified information....you lived a life before this didn't you
Thanks Sid...keep us posted...if I may...why do you hate Pirellis?
OH THE WEALTH OF KNOWLEDGE ON THIS FORUM!! LOVE IT!!
I kept up with you there and it explains A LOT...so thank you so much for that...for starters I'm sure most of us (me included) wouldn't know where to even obtain that specified information....you lived a life before this didn't you
Thanks Sid...keep us posted...if I may...why do you hate Pirellis?
OH THE WEALTH OF KNOWLEDGE ON THIS FORUM!! LOVE IT!!
That said, my pleasure... now lets hope I don't blow up the basement while I'm at it...oh the stories I could tell!
Cheers!
So what you are saying Sid, is that the Pirelli's are the only tires that match the OEM wheels. The other options really push the limits of capability possibly warranty. Thats not a good situation because I was thinking of moving to the Michelin's for everyday use (noise control) once I wear my P0s. I haven't even starting thinking about the track and winter. Winter will buy OEM 19" wheels with probably Michelin winter tires. For the track I am looking at 19" wheel options with Yoko rubber.
Does this make sense? Or am I off base???
Does this make sense? Or am I off base???
However they have revised their design (I hope it's not just the spec info
) to 10/32" which is actually more than most performance tires (generally 8/32" to 9/32").For the 20" 295 rear it's Pirelli and Michelin now has the PSS's avaiable as well.
The 19" tires there's many many more choices out there.
Contact Damon from the tirerack right here on 6 or check it out for yourself http://www.tirerack.com/tires/TRSele...akeAndYear.jsp
For winter I highly recommend the Michelin Alpine's, they come in 295 20" and are amazing on both snow and icy surfaces.
Do not get the Pirelli's! seriously they suck because they are designed to handle well in low temps and on ice... and are truly terrible in any kind of snowy, slushy winter weather... lets not even talk about getting out of a parallel parking spot!
For the track... Damon told me Toyo makes the R888 in 315 20's now so I'd definetly go with those as I find the R888 the best suited for this type of duty.
But like everything else in life, these are all personal opinions...OK based on personal experience and research but highly subjective so in the end you may find something els works better for you.
Are you referring to the Dunlop SportMaxx Race tire or is the Dunlop SportMaxx GT a different tire.
Dunlop SportMaxx Race comes in 265/35/19 and a 325/30/19. I think I might try it for a track set up. The sizes should be OK for the AWD system on my C4S. Not sure if the front will rub. Planning on adding some camber up front.
Dunlop SportMaxx Race comes in 265/35/19 and a 325/30/19. I think I might try it for a track set up. The sizes should be OK for the AWD system on my C4S. Not sure if the front will rub. Planning on adding some camber up front.
The good thing for you would be that those 265/35R20 335/30R20's look VERY much like racing slicks!
Which is awesome on a coupe!
For me it's something I'm really not sure of because I've got a cab... and as much as I'm going to add race inspired design elements to make it look more aggressive it will be purely for the sleek, mean, sexy look by taking design elements from other 991 models and adding them to my C4S cab.
The black will also make everything blend more and play the race derived design down (openings etc don't stand out as much).
So putting a GT3 front bumper, GT3RS lip, GT2 sideskirts and a turbo rear bumper + wing (all in black) will make it look mean and sexy but not like a "track car"... adding tires that look like slicks might be the equivalent of doing a full GT3 cup car paint job... thus turning a sleek sexy black cab into a "track poser"!
Not what I'm looking to do... AT ALL!
But on a coupe, that you actually do track...it would look awesome!!!
All that said... for pure track performance I'd say (as mentioned above) go with the 20" 315 R888.
Here's some shots of the type of "look" the 265 & 335 Michelin PSS's would give you on 20" rims.
Try just to look at the tires though because these are 19's with tires less wide than 335's and on wheels with very, very thick conventional track rims (which I don't necessarily think suit the design of the 991) but it in this case I do actually like how it looks!
Anyway it gives you a pretty good idea of the overall impact of the PSS "slicks" design.
Cheers!
#1392
02-17-2013, 10:04 PM
I does get complicated however I believe I speak your language, as such allow me to illustrate...
First you have to decide what type of sidewall/profile you like...
Understated street use with "comfort" and performance....
or more in your face track in spired and less practical for street use...
And of course which one in our line up of models...
Hahahahaha I love the analogy involved with our 991's!
If physics would have been explained in these terms I would have paid more attention!
#1393
02-17-2013, 10:30 PM
Sid,
I tried to order a pair of those interesting sidwalls you referenced in the top picture - but Tire Rack said they were very, very expensive, and on back order!
Cheers indeed!
I tried to order a pair of those interesting sidwalls you referenced in the top picture - but Tire Rack said they were very, very expensive, and on back order!
Cheers indeed!
#1394
02-17-2013, 10:33 PM
I like to order all of them! One can read all about the reviews on tires, but just have to try them out to get the full appreciation. If this forum is being monitor, for the record, I have no relationship with Sid, I have no idea what he is writing about half the time. I am talking about 991.
One can read all about the reviews on tires, but just have to try them out to get the full appreciation. If this forum is being monitor, for the record, I have no relationship with Sid, I have no idea what he is writing about half the time. I am talking about 991.