C6 Z51 Stock Rims: Best Street Tire Size
10-14-2013, 10:01 PM
#1
C6 Z51 Stock Rims: Best Street Tire Size
I'm in the process of researching which street tires to get on my C6 Z51 on stock rims. Car will be driven about 8,000 miles a year with 15 or so autox events during that time. It looks like the most common combination that people go to without causing T/C issues is the 265/35R18 front and 305/30R19 rear combination.
Is the 265/305 combination better than the stock 245/285 combination for autoX performance? Most of the previous threads I found when I searched did not focus on the autoX performance. For my street driving either size combination would be acceptable.
I'm looking to pick up either RE-11's or PSS's. I still need to make that decision as well. I currently have Yokohama Advan Sports in stock sizes that the previous owner put on the car so either the RE-11's or PSS will be a nice upgrade from what I currently have.
I'm planning on using Pfadt's "Performance Street - Track Use with Street Tires" alignment if that makes a difference.
Thanks for any advice!
Is the 265/305 combination better than the stock 245/285 combination for autoX performance? Most of the previous threads I found when I searched did not focus on the autoX performance. For my street driving either size combination would be acceptable.
I'm looking to pick up either RE-11's or PSS's. I still need to make that decision as well. I currently have Yokohama Advan Sports in stock sizes that the previous owner put on the car so either the RE-11's or PSS will be a nice upgrade from what I currently have.
I'm planning on using Pfadt's "Performance Street - Track Use with Street Tires" alignment if that makes a difference.
Thanks for any advice!
10-14-2013, 10:39 PM
#2
Safety Car
I know a guy that uses the RE-11's as his street tires when not running Hoosiers. It is a C6 Z51. He occasionally auto-x the RE-11's for fun runs.
Says they are better than the Kumho XS's he had.
To bad you cannot get them in Dunlap Dizzera ZII's or BFG Rivals. Those are the hot tires.
Says they are better than the Kumho XS's he had.
To bad you cannot get them in Dunlap Dizzera ZII's or BFG Rivals. Those are the hot tires.
10-14-2013, 11:23 PM
#3
Instructor
Here's some limited info I can provide....
I have a 09 w/Z51 narrow body and run stock wheels on all my set-ups.
I chose the RE-11's as my track day tires and wet AX day tires. (I run 315/30 Hoosier's in the dry.) For the RE-11's I went with the 275/35/18 and 305/30/19 combo. In AX, my car is a team car so it pulls double duty at 15-20 AX events per year. After seeing a significant difference in wear on the Hoosier's between 295's on the front vs the 315's on the front, I chose to go with the 275 fronts for better wear.
With all alignment settings, there are trade offs on everything. The alignment setting you will be using is relatively mild for AX and the tires will wear as "camber challenged" (hard on the outside edge) for AX. They will show inside wear for street use. With low negative camber settings, you can compensate for AX by using a slightly wider tread and pulling in the sidewall a bit. It helps to round the outer edge of the tire which helps keep the contact patch flatter in high G turns. If you plan to try to get 8k miles plus 15 AX's out of them, you can help the street wear by keeping the toe as close to zero as possible. If you stay with the Performance Street setting, I would suggest favoring the more aggressive side of the spec (-1.3). I run -1.9 on the front of my car.
You can debate over turn-in response times with wider treads, however my experience with both sides of the discussion shows it is a just a timing matter. I see better performance with the wider rubber and the turn-in timing adjustment is negligible. Especially if you are using the same tire on the street and AX, you will compensate without realizing it.
I have not AX'ed the RE-11's yet, but I do have several track sessions on them and there is no TC or AH issues with the 275/305 size combo. I have run them up to 120 MPH. From a F/R diameter ratio perspective, it is equivalent to having worn out rear tires and new front tires in the stock sizes. The computer manages that scenario just fine.
From a track perspective, my initial impressions with the tires are that they are significantly better than Gen 1 Supercars and notably better than Pilot Sports. They consistently pulled over 1.2G's in the bottom of T14 at Barber this past weekend. I don't have any experience with the Advans you are currently using, but I've heard they are a good tire.
I think you'll be happy with either a 265 or 275 front set up. Here are links to pics of the tires on stock wheels.
275/35 on front wheel:
https://www.dropbox.com/s/bp5sarghc1...G_00000112.jpg
305/30 on rear wheel:
https://www.dropbox.com/s/tfy0szntut...G_00000110.jpg
Hope some of this is helpful.
I have a 09 w/Z51 narrow body and run stock wheels on all my set-ups.
I chose the RE-11's as my track day tires and wet AX day tires. (I run 315/30 Hoosier's in the dry.) For the RE-11's I went with the 275/35/18 and 305/30/19 combo. In AX, my car is a team car so it pulls double duty at 15-20 AX events per year. After seeing a significant difference in wear on the Hoosier's between 295's on the front vs the 315's on the front, I chose to go with the 275 fronts for better wear.
With all alignment settings, there are trade offs on everything. The alignment setting you will be using is relatively mild for AX and the tires will wear as "camber challenged" (hard on the outside edge) for AX. They will show inside wear for street use. With low negative camber settings, you can compensate for AX by using a slightly wider tread and pulling in the sidewall a bit. It helps to round the outer edge of the tire which helps keep the contact patch flatter in high G turns. If you plan to try to get 8k miles plus 15 AX's out of them, you can help the street wear by keeping the toe as close to zero as possible. If you stay with the Performance Street setting, I would suggest favoring the more aggressive side of the spec (-1.3). I run -1.9 on the front of my car.
You can debate over turn-in response times with wider treads, however my experience with both sides of the discussion shows it is a just a timing matter. I see better performance with the wider rubber and the turn-in timing adjustment is negligible. Especially if you are using the same tire on the street and AX, you will compensate without realizing it.
I have not AX'ed the RE-11's yet, but I do have several track sessions on them and there is no TC or AH issues with the 275/305 size combo. I have run them up to 120 MPH. From a F/R diameter ratio perspective, it is equivalent to having worn out rear tires and new front tires in the stock sizes. The computer manages that scenario just fine.
From a track perspective, my initial impressions with the tires are that they are significantly better than Gen 1 Supercars and notably better than Pilot Sports. They consistently pulled over 1.2G's in the bottom of T14 at Barber this past weekend. I don't have any experience with the Advans you are currently using, but I've heard they are a good tire.
I think you'll be happy with either a 265 or 275 front set up. Here are links to pics of the tires on stock wheels.
275/35 on front wheel:
https://www.dropbox.com/s/bp5sarghc1...G_00000112.jpg
305/30 on rear wheel:
https://www.dropbox.com/s/tfy0szntut...G_00000110.jpg
Hope some of this is helpful.
10-15-2013, 08:19 PM
#4
Very helpful! Thanks! I think I will go ahead with the RE-11's. Do you have any more pictures of the 275s on the front? I will also consider running a bit more camber.
10-20-2013, 03:16 PM
#6
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An interesting fact. While shopping for toyo r888. The 305/19 are 411 each at tire rack while the 295/19 are only 311 each. So for the two rear tires i could save 200 for going with 10mmless each tire. Is it really worth 200 for a total of 20mm
10-20-2013, 03:32 PM
#7
Instructor
It depends on what you are doing. For AX where a few 1000's of a second comes into play - yes, because getting the power down is important. For track days - probably not (unless you are a 10/10th's driver).
05-16-2016, 03:00 PM
#8
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Here's some limited info I can provide....
I have a 09 w/Z51 narrow body and run stock wheels on all my set-ups.
I chose the RE-11's as my track day tires and wet AX day tires. (I run 315/30 Hoosier's in the dry.) For the RE-11's I went with the 275/35/18 and 305/30/19 combo. In AX, my car is a team car so it pulls double duty at 15-20 AX events per year. After seeing a significant difference in wear on the Hoosier's between 295's on the front vs the 315's on the front, I chose to go with the 275 fronts for better wear.
With all alignment settings, there are trade offs on everything. The alignment setting you will be using is relatively mild for AX and the tires will wear as "camber challenged" (hard on the outside edge) for AX. They will show inside wear for street use. With low negative camber settings, you can compensate for AX by using a slightly wider tread and pulling in the sidewall a bit. It helps to round the outer edge of the tire which helps keep the contact patch flatter in high G turns. If you plan to try to get 8k miles plus 15 AX's out of them, you can help the street wear by keeping the toe as close to zero as possible. If you stay with the Performance Street setting, I would suggest favoring the more aggressive side of the spec (-1.3). I run -1.9 on the front of my car.
You can debate over turn-in response times with wider treads, however my experience with both sides of the discussion shows it is a just a timing matter. I see better performance with the wider rubber and the turn-in timing adjustment is negligible. Especially if you are using the same tire on the street and AX, you will compensate without realizing it.
I have not AX'ed the RE-11's yet, but I do have several track sessions on them and there is no TC or AH issues with the 275/305 size combo. I have run them up to 120 MPH. From a F/R diameter ratio perspective, it is equivalent to having worn out rear tires and new front tires in the stock sizes. The computer manages that scenario just fine.
From a track perspective, my initial impressions with the tires are that they are significantly better than Gen 1 Supercars and notably better than Pilot Sports. They consistently pulled over 1.2G's in the bottom of T14 at Barber this past weekend. I don't have any experience with the Advans you are currently using, but I've heard they are a good tire.
I think you'll be happy with either a 265 or 275 front set up. Here are links to pics of the tires on stock wheels.
275/35 on front wheel:
https://www.dropbox.com/s/bp5sarghc1...G_00000112.jpg
305/30 on rear wheel:
https://www.dropbox.com/s/tfy0szntut...G_00000110.jpg
Hope some of this is helpful.
I have a 09 w/Z51 narrow body and run stock wheels on all my set-ups.
I chose the RE-11's as my track day tires and wet AX day tires. (I run 315/30 Hoosier's in the dry.) For the RE-11's I went with the 275/35/18 and 305/30/19 combo. In AX, my car is a team car so it pulls double duty at 15-20 AX events per year. After seeing a significant difference in wear on the Hoosier's between 295's on the front vs the 315's on the front, I chose to go with the 275 fronts for better wear.
With all alignment settings, there are trade offs on everything. The alignment setting you will be using is relatively mild for AX and the tires will wear as "camber challenged" (hard on the outside edge) for AX. They will show inside wear for street use. With low negative camber settings, you can compensate for AX by using a slightly wider tread and pulling in the sidewall a bit. It helps to round the outer edge of the tire which helps keep the contact patch flatter in high G turns. If you plan to try to get 8k miles plus 15 AX's out of them, you can help the street wear by keeping the toe as close to zero as possible. If you stay with the Performance Street setting, I would suggest favoring the more aggressive side of the spec (-1.3). I run -1.9 on the front of my car.
You can debate over turn-in response times with wider treads, however my experience with both sides of the discussion shows it is a just a timing matter. I see better performance with the wider rubber and the turn-in timing adjustment is negligible. Especially if you are using the same tire on the street and AX, you will compensate without realizing it.
I have not AX'ed the RE-11's yet, but I do have several track sessions on them and there is no TC or AH issues with the 275/305 size combo. I have run them up to 120 MPH. From a F/R diameter ratio perspective, it is equivalent to having worn out rear tires and new front tires in the stock sizes. The computer manages that scenario just fine.
From a track perspective, my initial impressions with the tires are that they are significantly better than Gen 1 Supercars and notably better than Pilot Sports. They consistently pulled over 1.2G's in the bottom of T14 at Barber this past weekend. I don't have any experience with the Advans you are currently using, but I've heard they are a good tire.
I think you'll be happy with either a 265 or 275 front set up. Here are links to pics of the tires on stock wheels.
275/35 on front wheel:
https://www.dropbox.com/s/bp5sarghc1...G_00000112.jpg
305/30 on rear wheel:
https://www.dropbox.com/s/tfy0szntut...G_00000110.jpg
Hope some of this is helpful.
(RE-11's 275/35 front and 305/30 rear)
Sadly, not only did I have scrub issues (which I have since purchased 5mm spacers for) ... but I also pissed off my traction control
. I did some calculations and opted for 265/35 fronts which should fix the issue. I will report back with results later this week.
05-16-2016, 04:20 PM
#9
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Odd, I never had rubbing issues, as for the traction control, I always turned mine off in autoX. truthfully running with it on it would react when I did not want it to, and yes it would provide traction, but when I pushed it to the limit there was no warning before I ended up spinning out. without the Traction control and nanies it performed much better, I could sort of drift it and control what I wnated it to do much more predictably than with it on.
05-17-2016, 01:03 AM
#11
Instructor
I'm sorry to hear you are having issues, especially after reading the post on my experience. Not sure why there would be any scrubbing issues if you have an all stock set up, it's relatively common sizing. A lot of folks, including myself run even much wider tires under the narrow body. I have run 315/30 A6's under both front and rear with no scrubbing. The 275F/305R RE-11 combo has worked so well I have run several sets since the original post with no issues, including a couple of times at Daytona running them up to a buck sixty with no TC issues. In fact, the only time I've seen TC come on was spinning the rear tires off the small hump coming out of T5 at Barber, but that's when putting down a lot of power going up the slight hill.
Are your wheel bearings/speed sensors all OEM? If one has been replaced with an aftermarket part, the precision and accuracy may have a different manufacturing tolerance. I have not heard anything that indicates that after '05 they relaxed the EBCM/TC tolerances, but moving to a 265 front will move your stagger ratio to the other end of the operating range.
Something to look at relative to the scrubbing is to see if your cradles are centered and mounted straight. There is some side to side assembly tolerance and if your are hard over to one side, it makes a difference of a couple of millimeters which would explain why the 5mm spacers fixed the problem.
I hope you get things sorted out as the RE-11's are impressive tires that you will enjoy on the track.
Are your wheel bearings/speed sensors all OEM? If one has been replaced with an aftermarket part, the precision and accuracy may have a different manufacturing tolerance. I have not heard anything that indicates that after '05 they relaxed the EBCM/TC tolerances, but moving to a 265 front will move your stagger ratio to the other end of the operating range.
Something to look at relative to the scrubbing is to see if your cradles are centered and mounted straight. There is some side to side assembly tolerance and if your are hard over to one side, it makes a difference of a couple of millimeters which would explain why the 5mm spacers fixed the problem.
I hope you get things sorted out as the RE-11's are impressive tires that you will enjoy on the track.