Tire pressure etc
11-28-2011, 02:47 AM
#16
Nordschleife Master
Our "new" to us 06 997S Cab rides very hard....19" Conti Sport 3 (N1) tires 05-09 vintage....I have the pressures at 29 front 34 rear now but still rides hard.
This is a garage "toy" used on weekends, in South FL, basically smooth roads.
What do I need to do the make this acceptable.
I remember back to the 911 days when I liked the 15" over the 16's for "ride" quality...do I need to change wheels or tires to a "softer tire"?
This is a garage "toy" used on weekends, in South FL, basically smooth roads.
What do I need to do the make this acceptable.
I remember back to the 911 days when I liked the 15" over the 16's for "ride" quality...do I need to change wheels or tires to a "softer tire"?
The 19" actually doe not make the ride harsher than the 18". Both have the same sidewall height.
11-28-2011, 08:24 AM
#17
Three Wheelin'
Thread Starter
"Ahh, once again the old guy cruisin' wash my car get all the scratches out person vs. the younger (at heart) thrill seeking harsh ride racer person. How fun."
And the problem with that is?
The tires on the car now have a mfg date of 05/09 so they are not that old, and not flatspotted, no "lumpy" ride...and, yes "old guy" (you young un's will get there soon enough) who just likes Porsches and has been a PCA member (and BMWCCA) for over 30 years...
So best advice for an O/F who enjoyes a nice cruise........go to non N ratred tires. what brand, 18" wheels?
C'mon...be serious, no wise remarks...(or I'll have to give you a "time out")
And the problem with that is?
The tires on the car now have a mfg date of 05/09 so they are not that old, and not flatspotted, no "lumpy" ride...and, yes "old guy" (you young un's will get there soon enough) who just likes Porsches and has been a PCA member (and BMWCCA) for over 30 years...
So best advice for an O/F who enjoyes a nice cruise........go to non N ratred tires. what brand, 18" wheels?
C'mon...be serious, no wise remarks...(or I'll have to give you a "time out")
11-28-2011, 11:39 AM
#18
Poseur
Rennlist Member
Rennlist Member
Tires with a manufacture date of 06/09 certainly could have been exposed to sufficient heat cycles to leave the rubber lifeless by now. Recall, "new to us" which tells me you have no idea how the car was driven before you got to it, and the tires.
11-28-2011, 01:46 PM
#19
Race Director
PAG has been revising tire pressures (down):
2005 997.1 -- 33/39 PSI
2009 997.2 -- 34/39 PSI
2012 GTS -- 34/37 PSI (same weight/tires as 997S)
991 (above 160MPH) 31/39 PSI (same basic weight as 997S)
991 (below 160MPH) 31/34 PSI (same basic weight as 997S)
Note: all for light load (up to 2 people no luggage) and referenced to 68F.
Given those recs,and further private analysis, I use 33/37 PSI and all is good. When hot, my tires measure 37/42, which is just fine.
This is the 991 tire pressure label:
2005 997.1 -- 33/39 PSI
2009 997.2 -- 34/39 PSI
2012 GTS -- 34/37 PSI (same weight/tires as 997S)
991 (above 160MPH) 31/39 PSI (same basic weight as 997S)
991 (below 160MPH) 31/34 PSI (same basic weight as 997S)
Note: all for light load (up to 2 people no luggage) and referenced to 68F.
Given those recs,and further private analysis, I use 33/37 PSI and all is good. When hot, my tires measure 37/42, which is just fine.
This is the 991 tire pressure label:
11-28-2011, 04:16 PM
#21
Nordschleife Master
11-29-2011, 01:10 AM
#23
Instructor
You're rolling around on 6+ year-old tires and wondering why the ride is harsh?? Hmmm......
First things I did when I got my '06 was to replace the tires and the battery. The ride on the OEM Michelin PS2's - with only 8K miles - was TERRIBLE.
Changed to cheaper Bridgestone Potenza's and wow, what a huge difference - and much more safe as well.
Git jurself some new shoes there buddy....
First things I did when I got my '06 was to replace the tires and the battery. The ride on the OEM Michelin PS2's - with only 8K miles - was TERRIBLE.
Changed to cheaper Bridgestone Potenza's and wow, what a huge difference - and much more safe as well.
Git jurself some new shoes there buddy....
11-29-2011, 02:37 AM
#24
Rennlist Member
11-29-2011, 06:48 PM
#25
Three Wheelin'
Thread Starter
GUYS
the tires are vintage 5-09.... MAY 2009 2+ years old and with 80% tread remaining...so probably NO hard use
What brand of tires in 19" would give a softer ride?
the tires are vintage 5-09.... MAY 2009 2+ years old and with 80% tread remaining...so probably NO hard use
What brand of tires in 19" would give a softer ride?
11-29-2011, 08:59 PM
#27
ADias-
Where did you get this info? I am wondering why there was no recommendation in the mail from PAG.
Thanks
Where did you get this info? I am wondering why there was no recommendation in the mail from PAG.
Thanks
PAG has been revising tire pressures (down):
2005 997.1 -- 33/39 PSI
2009 997.2 -- 34/39 PSI
2012 GTS -- 34/37 PSI (same weight/tires as 997S)
991 (above 160MPH) 31/39 PSI (same basic weight as 997S)
991 (below 160MPH) 31/34 PSI (same basic weight as 997S)
Note: all for light load (up to 2 people no luggage) and referenced to 68F.
Given those recs,and further private analysis, I use 33/37 PSI and all is good. When hot, my tires measure 37/42, which is just fine.
This is the 991 tire pressure label:
2005 997.1 -- 33/39 PSI
2009 997.2 -- 34/39 PSI
2012 GTS -- 34/37 PSI (same weight/tires as 997S)
991 (above 160MPH) 31/39 PSI (same basic weight as 997S)
991 (below 160MPH) 31/34 PSI (same basic weight as 997S)
Note: all for light load (up to 2 people no luggage) and referenced to 68F.
Given those recs,and further private analysis, I use 33/37 PSI and all is good. When hot, my tires measure 37/42, which is just fine.
This is the 991 tire pressure label:
11-29-2011, 09:50 PM
#28
If I do my math right, the 19" front tires (235/35 19) have the same over all height as the 18" stock size (235/40 18), so you'll pick up 1/2 inch of rubber between the road and rim if you switched to 18's on the front.
The rear 19" tires (295/30 19) are actually almost 4 tenths of an inch shorter in overall height than the 18" stock size of 265/40 18, so if you went to 18's on the rear, you'd pick up about 7 tenths of an inch of rubber between the road and the rim (1/2 inch of rim height reduction [on one side] plus .2" of additional overall tire height).
Will 7 tenths of an inch in additional rubber make a difference? It seems like we're splitting hairs here with such small measurements. However, many new tires have tread depth of about 10/32nds, so 7 tenths of an inch is over double the depth of new tire tread depth (10/32nds = .31") and many people can feel the ride difference when going from scrubbed off tread to fresh new tires.
Others have posted here on these boards that there is minimal difference in ride quality between the base 18" rim and tire setup and the 19" setup. If I had to guess, buying new 18 inch rims and 18 inch tires won't gain you as much ride quality as you want for the outlay of cash...but you can probably sell the 19" setup quickly on eBay if you price them right to reduce your investment in new tires and rims.
If you would re-tire the car in 19's, I'd suggest a high performance all season such as the new Bridgestone Potenza RE970 AS Pole Position or the Continental ExtremeContact DWS tires. I've driven the Conti's in anger (on a different non Porsche vehicle) and they are a great all season tire that really hangs on in aggressive street driving, but offer a quiet ride and a very nice ride quality. I have the previous generation Potenza RE960 on my '84 911 and I simply love those tires. The 970 has newer technology, but a very similar tread pattern to the outgoing RE960's.
Moving to 18's and something like the Bridgestone Turanza Serenity, a Grand Touring type tire, would be the most extreme change from the OEM summer 19" tires and rims and may be your best bet for realizing an improvement in ride quality if you want to go down to 18's.
I have a 1984 911 riding on 15" Phone Dials and (the above mentioned) Bridgestone all season tires and that car rides quite a bit better than the 997. So, these 997's have a harsh ride from what you and I are used to on the old cars.
My post sure is a bunch of numbers and babbling, so I'm not sure it helps all that much...
Good luck!
Jay
84 911
90 964
06 997
The rear 19" tires (295/30 19) are actually almost 4 tenths of an inch shorter in overall height than the 18" stock size of 265/40 18, so if you went to 18's on the rear, you'd pick up about 7 tenths of an inch of rubber between the road and the rim (1/2 inch of rim height reduction [on one side] plus .2" of additional overall tire height).
Will 7 tenths of an inch in additional rubber make a difference? It seems like we're splitting hairs here with such small measurements. However, many new tires have tread depth of about 10/32nds, so 7 tenths of an inch is over double the depth of new tire tread depth (10/32nds = .31") and many people can feel the ride difference when going from scrubbed off tread to fresh new tires.
Others have posted here on these boards that there is minimal difference in ride quality between the base 18" rim and tire setup and the 19" setup. If I had to guess, buying new 18 inch rims and 18 inch tires won't gain you as much ride quality as you want for the outlay of cash...but you can probably sell the 19" setup quickly on eBay if you price them right to reduce your investment in new tires and rims.
If you would re-tire the car in 19's, I'd suggest a high performance all season such as the new Bridgestone Potenza RE970 AS Pole Position or the Continental ExtremeContact DWS tires. I've driven the Conti's in anger (on a different non Porsche vehicle) and they are a great all season tire that really hangs on in aggressive street driving, but offer a quiet ride and a very nice ride quality. I have the previous generation Potenza RE960 on my '84 911 and I simply love those tires. The 970 has newer technology, but a very similar tread pattern to the outgoing RE960's.
Moving to 18's and something like the Bridgestone Turanza Serenity, a Grand Touring type tire, would be the most extreme change from the OEM summer 19" tires and rims and may be your best bet for realizing an improvement in ride quality if you want to go down to 18's.
I have a 1984 911 riding on 15" Phone Dials and (the above mentioned) Bridgestone all season tires and that car rides quite a bit better than the 997. So, these 997's have a harsh ride from what you and I are used to on the old cars.
My post sure is a bunch of numbers and babbling, so I'm not sure it helps all that much...
Good luck!
Jay
84 911
90 964
06 997
Last edited by Jay H; 11-29-2011 at 10:28 PM.
11-30-2011, 01:34 AM
#29
Pro
I just put a set of 18" Carrera3 wheels on my 997S for the winter and the ride is markedly better than the summer tires on my factory 19s. Same pressure on both.
True, the sidewalls are probably much softer on the Pirelli winter tires, but it definitely resulted in a softer ride. Far from luxurious (I've got SPASM), but it takes the edge off.
I may go 18s year round.
True, the sidewalls are probably much softer on the Pirelli winter tires, but it definitely resulted in a softer ride. Far from luxurious (I've got SPASM), but it takes the edge off.
I may go 18s year round.
11-30-2011, 01:41 AM
#30
Pro
and, aren't the 991 wheels and tires larger overall diameter?
I would think both of the above would/could affect tire pressure reco's?