17x9s have arrived
03-02-2011, 01:01 PM
#76
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Here's video I shoot of John's car --> Powell's Car! on Vimeo
you'll see that John's wheels stick out about the same as these 17x9's
you'll see that John's wheels stick out about the same as these 17x9's
03-02-2011, 09:34 PM
#77
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I think the Ions have a little more rear fender to cover the tires. But, the fronts seem to be the same. Nice video.
I finally rubber today on the highway with my GF and son in the car (and the 50+ lbs of stuff that comes with a 1 year old) Coming off a bridge on the highway where they were doing construction there was a sharp drop off. I didn't feel or hear it but, after getting out of the car there was a small scuff on the tire where it hit. If I had to do it again I would probably go for a +40 offset in the rear. But, I still don't think it will rub on track with the sway bars doing their job in the twisty bits. I won't truly know until I get some heat in the tires.
I finally rubber today on the highway with my GF and son in the car (and the 50+ lbs of stuff that comes with a 1 year old) Coming off a bridge on the highway where they were doing construction there was a sharp drop off. I didn't feel or hear it but, after getting out of the car there was a small scuff on the tire where it hit. If I had to do it again I would probably go for a +40 offset in the rear. But, I still don't think it will rub on track with the sway bars doing their job in the twisty bits. I won't truly know until I get some heat in the tires.
03-05-2011, 05:57 PM
#80
jboogie, where on fender did the tire rub the fender it self, or the plastic? I think I am going to get the same wheels as you. I wonder if +35 would work (I want to be able to rotate my tires).
I am about to get the wheels, but I want to know some more about the physics behind 17x9 vs 18x9.
At first I was with out a doubt going to get the 17 because they are lighter and less rotational mass. Easy right? Then I started to think some more. If the side wall of the tire on each wheel was the same the 17x9 wheel would obviously be 1 inch smaller. So would the contact patch for the 18x9 be slightly larger, because the larger wheel can contact more of the ground?
I am going to throw out some numbers to show my theory, but these numbers are totally not correct.
Wheel: 17x9 Tire: 255/40ZR17 Contact Patch Area: 9in Wide 1in Long
Wheel: 18x9 Tire: 255/40ZR18 Contact Patch Area: 9in Wide 1.1in Long
So(in my theory) even if the contact patch is slightly bigger is worth it because of the excess weight and rotational mass?
Is my thinking even correct lol?
I am about to get the wheels, but I want to know some more about the physics behind 17x9 vs 18x9.
At first I was with out a doubt going to get the 17 because they are lighter and less rotational mass. Easy right? Then I started to think some more. If the side wall of the tire on each wheel was the same the 17x9 wheel would obviously be 1 inch smaller. So would the contact patch for the 18x9 be slightly larger, because the larger wheel can contact more of the ground?
I am going to throw out some numbers to show my theory, but these numbers are totally not correct.
Wheel: 17x9 Tire: 255/40ZR17 Contact Patch Area: 9in Wide 1in Long
Wheel: 18x9 Tire: 255/40ZR18 Contact Patch Area: 9in Wide 1.1in Long
So(in my theory) even if the contact patch is slightly bigger is worth it because of the excess weight and rotational mass?
Is my thinking even correct lol?
Last edited by Ronn2005; 03-05-2011 at 06:06 PM.
03-05-2011, 11:04 PM
#81
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17x9's vs 18x9's
jboogie, where on fender did the tire rub the fender it self, or the plastic? I think I am going to get the same wheels as you. I wonder if +35 would work (I want to be able to rotate my tires).
I am about to get the wheels, but I want to know some more about the physics behind 17x9 vs 18x9.
At first I was with out a doubt going to get the 17 because they are lighter and less rotational mass. Easy right? Then I started to think some more. If the side wall of the tire on each wheel was the same the 17x9 wheel would obviously be 1 inch smaller. So would the contact patch for the 18x9 be slightly larger, because the larger wheel can contact more of the ground?
I am going to throw out some numbers to show my theory, but these numbers are totally not correct.
Wheel: 17x9 Tire: 255/40ZR17 Contact Patch Area: 9in Wide 1in Long
Wheel: 18x9 Tire: 255/40ZR18 Contact Patch Area: 9in Wide 1.1in Long
So(in my theory) even if the contact patch is slightly bigger is worth it because of the excess weight and rotational mass?
Is my thinking even correct lol?
I am about to get the wheels, but I want to know some more about the physics behind 17x9 vs 18x9.
At first I was with out a doubt going to get the 17 because they are lighter and less rotational mass. Easy right? Then I started to think some more. If the side wall of the tire on each wheel was the same the 17x9 wheel would obviously be 1 inch smaller. So would the contact patch for the 18x9 be slightly larger, because the larger wheel can contact more of the ground?
I am going to throw out some numbers to show my theory, but these numbers are totally not correct.
Wheel: 17x9 Tire: 255/40ZR17 Contact Patch Area: 9in Wide 1in Long
Wheel: 18x9 Tire: 255/40ZR18 Contact Patch Area: 9in Wide 1.1in Long
So(in my theory) even if the contact patch is slightly bigger is worth it because of the excess weight and rotational mass?
Is my thinking even correct lol?
03-06-2011, 12:14 PM
#82
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Like autoxr said the main reason for going to 17s are the price of tires. I'll save $300 a set over the 18s every year. You right it your thinking, a taller tire will add to the contact patch but only wery slightly. Plus, you've got to look at tire selection there really aren't any good tire available for a 255-40-18 you'll have to go to a 255-35-18 if you wanna go with 18s.
The tire rubbed on the outer lip of the fender not on the plastic. A +35 will work fine you'll just be held to under 2* camber up front and 255s. Most casses that will be fine but for me I want to try 265s next season and experiment with heavier camber if I want to. I don't think +35 will be enough to stop the rubbing in back but every little bit will help.
The tire rubbed on the outer lip of the fender not on the plastic. A +35 will work fine you'll just be held to under 2* camber up front and 255s. Most casses that will be fine but for me I want to try 265s next season and experiment with heavier camber if I want to. I don't think +35 will be enough to stop the rubbing in back but every little bit will help.
03-08-2011, 04:51 PM
#83
I'm trying go decide if I should get 17x9 +30 or 18x9.5. +22. With the 18x9.5 i can run a 285. With the17x9 I can run a 275. Is the extra .5 in from the 18x9.5 is it worth the extra weight? Keep in mind its 2in more total contact patch for all 4 tires. Again is it worth the extra weight?
03-08-2011, 05:00 PM
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Depends, what do you do with the car? I wouldn't go over 255s for a street car. For 285s your gonna have to run some heavy spring rates that are just gonna get annoying on the street
03-08-2011, 11:40 PM
#85
I would one day just like to run my car around sebring (i live in FL), but for now I'll live vicariously throw you all. I don't mind having a crazy car to drive on the street(i would never street race). My goal is to run the widest tires as possible (I'll roll the fenders out) I have pedders and the ebach 25mm rear sway bar, is that stiff enough? So again which would get better performance, 17x9 (less weight, less contact patch) or 18x9.5(more weight, more contact patch)? By the way thanks for the advice.
03-09-2011, 12:28 AM
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285s are just gonna be overkill. Look at even Doug Wind, one of the fastest FWD guys your ever gonna see. 500+ whp and in the classes he runs in (SLB, Redline Time attack) he still only runs 275s which he fairly recently upgraded from 255s. Your just making the car less enjoyable where your gonna do 99% of your driving,on the street. Plus, adding that much grip with little track experience your not gonna improve your driving as much as you would starting out with stock sized tires.
I grew up on the east coast of Fl just 2 hours from Sebring and never knew it. I was into drag racing then and spent most of my time at Moroso.
I grew up on the east coast of Fl just 2 hours from Sebring and never knew it. I was into drag racing then and spent most of my time at Moroso.
03-09-2011, 12:39 PM
#87
Roger that! Yeah its all making more sense to me now. When I get my new wheels I will probably run 245s, but after I get some experience I will eventually want to run 275s. Is +30 offset enough to fit 275s or would I have to get +25mm offset? Haha I don't want to have to do this whole wheel thing over again lol.
03-09-2011, 11:14 PM
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275s will clear on the strut side but you'll have to remove some of your fender liner. Plus, the more traction you have the more body roll the more your gonna need some stiff coilovers.
03-09-2011, 11:30 PM
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Very impressed, sidewalls are kinda soft but overall a pretty amazing tire. Can't wait to get them out on track and really beat on them. Gonna do a Tail of the Dragon ride in a couple weeks should give me a good idea how they'll be on track.
03-09-2011, 11:37 PM
#92
I don't know...... If I ever wanted to put on 275 +30 offset is making me feel nervous about clearing the strut. Here is my reasoning. The cobalt time attack ran +38 on 245s so +33 should work with 255s +28 should work with 265s +23 should work with 275s. I am heading towards +25 offset (rolling the fenders too), besides I ever go with coilovers wont I need more space between the tire and the coilovers?
However you said 275s will work with a +30. On a scale from 1-10 how confident are you of this? Your the expert I am not and I value your opinion. As a matter of fact I haven't read that anyone else has ever ran a 17 x 9 on a cobalt. So, your the pioneer of this! Cool!
By the way. I think this is so fun that we have a car that we can tinker with this much. Oh I am totally going to get the Hardcore Rear Bar from OTTP! Looks mean!
However you said 275s will work with a +30. On a scale from 1-10 how confident are you of this? Your the expert I am not and I value your opinion. As a matter of fact I haven't read that anyone else has ever ran a 17 x 9 on a cobalt. So, your the pioneer of this! Cool!
By the way. I think this is so fun that we have a car that we can tinker with this much. Oh I am totally going to get the Hardcore Rear Bar from OTTP! Looks mean!
Last edited by Ronn2005; 03-09-2011 at 11:47 PM.
03-09-2011, 11:52 PM
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I don't know...... If I ever wanted to put on 275 +30 offset is making me feel nervous about clearing the strut. Here is my reasoning. The cobalt time attack ran +38 on 245s so +33 should work with 255s +28 should work with 265s +23 should work with 275s. I am heading towards +25 offset (rolling the fenders too), besides I ever go with coilovers wont I need more space between the tire and the coilovers?
However you said 275s will work with a +30. On a scale from 1-10 how confident are you of this? Your the expert I am not and I value your opinion. As a matter of fact I haven't read that anyone else has ever ran a 17 x 9 on a cobalt. So, your the pioneer of this! Cool!
By the way. I think this is so fun that we have a car that we can tinker with this much. Oh I am totally going to get the Hardcore Rear Bar from OTTP! Looks mean!
However you said 275s will work with a +30. On a scale from 1-10 how confident are you of this? Your the expert I am not and I value your opinion. As a matter of fact I haven't read that anyone else has ever ran a 17 x 9 on a cobalt. So, your the pioneer of this! Cool!
By the way. I think this is so fun that we have a car that we can tinker with this much. Oh I am totally going to get the Hardcore Rear Bar from OTTP! Looks mean!
03-10-2011, 12:32 PM
#95
On second thought yeah maybe +30 is the better idea. Venom09 had his wheel bearings go out at 15K,000 km (9,300 miles). That sucks! Yeah I would love to run 275 one day but not at the cost of my wheel bearings. Too bad no one makes upgraded bearings for our cars. So yeah +30 17 x 9 flat black it is. (I am guessing flat black is .2lb lighter. My black oz wheels were 17.8lb where every other color was 18lb.
Hey good luck on your upcoming autoX. Let us know how it went. I hope you make all the imports cry!
Hey good luck on your upcoming autoX. Let us know how it went. I hope you make all the imports cry!
