Has anyone used 17x10" weld S71 wheels on a dse subframe with Z51 C6 Brakes?

[dontlifttoshift]

Originally Posted by Fastbowtie

They are the best.

That's why I asked. If you think they _look_ best, that's a personal preference and is indisputable.

If you think they are the best, as in fastest, you are wrong.

Either way, when you shrink the ID of the rim you get closer to all the moving parts. Even with DSE specs the 18x10 will rub the back of the lower control arm at full lock. If you already have a 17" wheel in the rear bolt it up and see what it looks like.

[Fastbowtie]

Originally Posted by dontlifttoshift

That's why I asked. If you think they _look_ best, that's a personal preference and is indisputable.

If you think they are the best, as in fastest, you are wrong.

Either way, when you shrink the ID of the rim you get closer to all the moving parts. Even with DSE specs the 18x10 will rub the back of the lower control arm at full lock. If you already have a 17" wheel in the rear bolt it up and see what it looks like.

Donny what is your take on this then?

What’s immediately apparent from the results is that as the wheel-and-tire packages get larger and heavier, acceleration and fuel economy suffer. Neither is a huge surprise, but we measured a 10-percent drop in fuel economy and a four-percent degradation in 0-to-60-mph acceleration from the 15s to the 19s, which is worth considering should you be thinking about “going big.” Increasing wheel diameter and width, in turn, requires wider tires with shorter and stiffer sidewalls, which we found will increase skidpad grip, but as our test shows, there is a limit to this assertion. The 19-inch package came with the widest tires (235/35R-19) mounted to the widest wheels (8.5 inches), but this setup had less grip around the skidpad than the narrower 225/40R-18s on 8.0-inch-wide wheels. We asked the folks at Goodyear why that might be, and they postulated that the added width may have given the outside tire more grip, which would increase body roll and could therefore decrease the load on the inside tire enough to lose 0.01 g on the skidpad.

Also the wheel I have does not have the correct back spacing to fit on the spindle.

[dontlifttoshift]

For those following along, that quote comes from this article. https://www.caranddriver.com/feature...d-tires-tested

Intended usage plays a large role in size and tire selection. Since this Lateral-G I will assume there is at least some autocross and track time in the future.

I want to address the economy thing. It does take more energy to get a heavier wheel and tire package rolling......but you aren't driving a VW with a 2.5l 4 cylinder either, without even trying, you have twice as much torque available. There was a 10% mileage difference between the 15 and 19 setups. A portion of that mileage change should be attributed to the width of the tire, rolling resistance matters. If you are truly concerned enough about mileage that it is guiding your wheel size selection, why are we talking about 10" wide wheels. It was a 5% difference between 17 and 18....on a VW.

So smaller diameter wheels accelerate and stop faster, in general that is true. Especially in that case where they able to use the same tire model for the whole test with all of the gains coming from keeping most of the mass of the rim close to the center of the wheel. Compound and tire design is more important than size and here in the pro touring land, there are two tire models that matter if you want to be fast and the widest 17 available is 255. A 275/35-18 will be faster than a 255/40-17 on a 10 on a typical pro touring Camaro. If you decide to open up to not being on the fastest rubber and using your rear tire for example you get one more tire to pick from that is sort of okay. Past that, we can find decent tires that will fit your size requirements but the minor gain you picked up in acceleration was negated ten fold by being on a slower tire.

If you don't care to run at the top of the list, that's fine and 17s may be the better choice for you.......but 17s are not the best.

[Fastbowtie]

Donny,
I see what your saying but not everything revolves around racing. That being said I'm pretty sure the touring part of pro-touring also includes some amount of comfort. Otherwise we'd just have aluminum racing seats with no interior. A 17 x 8 riding around on a 245 45 is going to feel a lot better then the 18 x 8 or 10 with 255 30's.

I was already peeing a lot with the 275 40 R17 and the 245 45 R17s.

[dontlifttoshift]

That's why "xxx is best" without defining a purpose can not be true.

40 series rubber has a taller sidewall than 35 series rubber if the width of the tire stays the same and in theory the taller sidewall will feel better. There is a vast difference in ride quality between tires even when the sizes stay the same. Continental ECS ride sooooo much nicer than Bridgestone RE71s. Largely due to the softer sidewall. Also, a slightly pinched tire (on a wheel that is narrower than normal) will feel better than a stretched tire.

Doesn't matter though, you already have 17s on the rear and want to stay with 17s. Take your existing rear wheel and put it on the front and see if it fits.

[130fe]

Will 17s fit the Z51 brakes? Thought you needed 18s.

[Fastbowtie]

Originally Posted by 130fe

Will 17s fit the Z51 brakes? Thought you needed 18s.

Weld RTS S71 17" have a barrel of 16.44. My current set up is American Racing and the barrel is less than that. Its touching the caliper. I need to find out more but it looks like it might work.

13.4 Is the rotor size. If you had Z06 or the Gran Sport you need 18".