I need some help deciding on tire size. I am running 17x9 wheels and can't decide what width tires to get. The options I have are:

Size height width suggested wheel size
255/40ZR17 98W 25.08 10.12 8.5-(9.0)-10.0
275/40ZR17 98W 25.59 10.79 9.0-(9.5)-11.0

The goal is ultimate handling. A couple reference vehicles:
2002 Camaro SS 17x9 wheel 275/40 17
2002 C5 Z06 17x9.5 wheel 265/40 17

I read somewhere that they put the wider tire on the F-Body to keep the steering from being twitchy and responding too quickly. I guess to keep novices out of trouble. This leads me to my dilemma.

Do I loose 20mm (255/40) of width to gain some handling response and live with a 25" tall tire or do I go with the larger tire (275/40) and deal with some more sidewall flex?

Currently running 255/45 17 in front 26" tall and 275/40 17 25.5" tall in the rear. I need to ditch the drag radials out back and plan on running a ~200 durometer tire all around.

Any insight?

I was debating this same thing, and ended up going right in the middle for my autocross tires... 265/40/17 Dunlop Direzza Star Specs showed up on my doorstep yesterday. :hurray:

I was strongly considering those tires. It's between those and the NT-05. Can you measure the actual tread width on them? I heard the Dunlop runs big and the Nitto runs small.

I can later tonight... won't be able to install them for a while though as Summit has my wheels on backorder. :angry:

What size wheels are you going to run?

17x9s... just called Summit, and changed the color of the wheels on my order so I should have them by the end of the week. :hurray: Silver Cragar D-hole wheels are currently out of stock, but the black ones are in.

I plan on painting them white anyway. :o The black ones cost more, but the customer service rep knocked the price down enough for me to justify the added cost to get them before the first autocross of the year. :)

http://static.summitracing.com/global/images/prod/large/crr-3455712_w.jpg

http://static.summitracing.com/global/images/prod/large/crr-342-5160.jpg

I guess I'm paying extra for that ugly pinstriping that I'm going to paint over. :o

Looks like the Cragar is becoming the budget choice.

I sent Randy a PM to chime in. I know he is also running a 17x9.

I did my first SCCA autocross this weekend. Ended up 6 of 17 in the Novice class. I'm trying to get some new tires before the next one at Daytona Speedway. Learned a lot.

I run 17x9s with 275/40/17s on them, but I am running Kumho V710's R-compounds (whopping 30 treadwear rating), not street tires. I would run as much tire as you can, as long as it fits pretty good. It's no fun to have tires that rub while driving.

Vettes can get away with the smaller tire than the Camaro with its lower CG and better frt to rear balance (and handling of course).

On the street I run 17x8s on the front with 245/45/17s and 17x9.5s on the rear with 275/40/17 (VWW V45s, Sumitomo HTR Z tires). The fronts are a bit small, as it will push the front in hard cornering. I wish I had gone with 17x9s in the front with 265 or 275s now.

Just to stir the pot, Here is what I plan to run on the Camaro when it is done:
-16 x 12 Real Racing 3-pc wheels
-Hoosier Slicks, either 25 or 27" tall, Probably either bias ply or radial version.

I think the 275/40 should fit in the fender. Right now I'm tucking the 255/45 17 a hair, but I can always raise the front a little. The 275 should be about 1/4" shorter (.5" overall/2) and 3/8" wider (.75" width difference/2).

I might pull the 274/40 555R drag radials off the back and test fit them up front.

Thanks for the help.

I'm running 245/45/17 on front and 255/55/17 rear. Z rated tires with air ride suspension. Ride is smooth, but firm, and handleing is awesome. No leaning going around curves or swaying. Stance is great on car too.

275/40-17s will tuck in the front and not rub if you have the backspacing right. I have them on 17x9.5" wheels at 5.35~" rough effective backspace.

We are running the Cragar steelies. 17x9 - 5" BS.

Changing wheels is not an option.

I'll test fit the ones I have and post back.

If the Cragars fit on the front of my car (67), it should fit on the 68-72s. The rear 17x9.5 with 5.5" bs fit on the front as well, but not much bigger is going to fit without a sawzall or torch.


I'm running 245/45/17 on front and 255/55/17 rear. Z rated tires with air ride suspension. Ride is smooth, but firm, and handleing is awesome. No leaning going around curves or swaying. Stance is great on car too.

Get some sticky race tires, then you can get some lean on, like this:
http://picasaweb.google.com/atlantamx3/2010AutocrossPoints3041110Gallery1#545906278372281 0578
or this:
http://picasaweb.google.com/atlantamx3/2009ARSCCAAutocrossYearInReviewHighlights#54145889 51043578562
That's with 1000 lb frt/350 lb rear springs and upgraded sway bar. I get very little lean with street tires, though. Must have something to do with the increased grip or something like that. :D

i have 17x9.5 w/ 5.5" bs, up front and a 275/40/17 sumitomo htrz's on the front. so far, no test drive yet, but it does not hit anything on the ground, and lock to lock there is enough clearance all around.
im actually running the same size tires on all 4 corners.

aaron

I intended this conversation to be more about tire width vs wheel width and handling performance.

I intended this conversation to be more about tire width vs wheel width and handling performance.

If the tires are the same (brand, compound, etc), IMO the 275/40 should be the better choice. 1/2" more tread on the ground. Yeah, a little taller, 1/4" taller sidewalls and therefore slightly more sidewall flex, but still pretty short...

I was talking to a tire tech once, regarding my old 15" wheels and 295/50-15. We discussed 8" vs 10" wheels, and I was told that while one would be better for handling, and the other would be better for launching ( I forget which), they difference would be minimal and probably not discernable without a lot of testing... I'd imagine the difference between the 9.0 and 9.5 wheel with the 275/40 would be much less... And therefore, all else being equal, more rubber on the road (275 vs 255) would have more grip...

Has anyone tested these wheels against others (with the same tires) to see if the wheels will make a difference? Just because they look like race wheels, and from a reputable company, are they actually "intended" (by the manufacturer) to be for racing?

I knew a guy once, ran the same tires with two different wheel types, and one set of wheels was really notcibly worse in the handling department. Near as could be determined, the wheels flexed more during cornering.

I intended this conversation to be more about tire width vs wheel width and handling performance.Yeah, sorry about that... :o

If the tires are the same (brand, compound, etc), IMO the 275/40 should be the better choice. 1/2" more tread on the ground. Yeah, a little taller, 1/4" taller sidewalls and therefore slightly more sidewall flex, but still pretty short...

I was talking to a tire tech once, regarding my old 15" wheels and 295/50-15. We discussed 8" vs 10" wheels, and I was told that while one would be better for handling, and the other would be better for launching ( I forget which), they difference would be minimal and probably not discernable without a lot of testing... I'd imagine the difference between the 9.0 and 9.5 wheel with the 275/40 would be much less... And therefore, all else being equal, more rubber on the road (275 vs 255) would have more grip...
It's not just the height of the sidewall that effects how much it flexes... on the same wheel, a wider tire will roll over more in a turn than a narrower tire. This not only effects overall grip, but also turn-in feel. The narrower tire will react quicker, and feel much more stable.

I really noticed this in the REAR of my car with some unsmooth steering inputs on a big sweeper. It felt like the axle was moving from side-to-side, but I have solid heim joints at all 8 points, so we know that it wasn't actually moving much...

Has anyone tested these wheels against others (with the same tires) to see if the wheels will make a difference? Just because they look like race wheels, and from a reputable company, are they actually "intended" (by the manufacturer) to be for racing?

I knew a guy once, ran the same tires with two different wheel types, and one set of wheels was really notcibly worse in the handling department. Near as could be determined, the wheels flexed more during cornering.
They actually really suck as "race" wheels because they're so heavy, but they're the only low-cost option in 17x9 to get some serious rubber under these cars... I'll take the weight penalty to get more tire. :)

Best handling performance? Widest tire that will fit, on the widest recommended wheel. I don't think that tiny difference in height would make much difference. Your car already handles awesome anyway!!!

See the thinking is much different when you start looking at some of the other platforms. There are people running 275 on an 11" wide wheel, which is on the wide side of the allowable width. These are much lighter vehicles than ours. I've read stretching the tire some helps keep the sidewall stiff.

I was mainly worried that a 275 would be too wide for a 9" wheel, because it is on the narrow side of the width requirement. Seems the limiting factor is my wheels. With such a heavy car we are almost forced to stay with the wider tire even if there is some compromise in sidewall flex. Otherwise there might be compromises in traction in general.

Ideally I think the 275 should be mounted on a 9.5"-10" wide wheel.

Measured my Dunlop Star Specs...
265/40/17 overall width is 11", tread width is 10"

Compared to my Kumhos
255/45/17 overall width is 9.5", tread width is 8.5"

1-1/2" difference on what is supposed to be a 10mm (less than 1/2") wider tire, so yeah, I'd say the Dunlops run big...

Intersting debate. On my C4 I ran all sorts of combinations, being in college and buying expensive tires will do that. Factory was 255/45 and 285/40s on 17x8.5/17x9.5s. I had 275s/315s on the factory 17x8.5/17x9.5s at one point, not recommended but I never had a problem. Overall grip was up but respnse did suffer some, also as mentioned earlier you could feel some flex especially loaded up in a turn if there was a bump/change in pavement.

I ran the same tires on 17x9.5/17x11s with better results the car was very predicatble and stable in those turns loaded up. Eventually I went 265/35 and 295/35 on 18x9.5/18x11s. Lateral grip was better despite a narrower tire, inline grip was not quite as good as the 315s.

275s should be fine on a 17x9 if you are after max performance on an autox 255s maybe better due to response and sidewall flex. Also as has been discussed a 275 from one company may not be as wide as another. Sidewall stiffess can also vary greatly.

Thanks. We are on track.

Anyone else have input?

Looking back at the topic. I used Goodyear GSCs factory, then Yokohama AVS Intermediates for all of the 275s & 315s which ran large for their size and Yokohama AVS Sports for the 18s. The 275 was pinched on the 8.5, IMO it would have been fine on a 9" at street pressures around town and spirited mountain runs, Autox would very much be the driver's call. The wiggle I spoke of in turns was more noticeable in the rear.

I did run the 17x9.5s with 315s on the front after getting a nail in the 17x9.5s with 275s. Turn in was not razor sharp but you did change directions in a hurry especially changing lanes on the hwy.

The last set of tires I had on the car was back on factory wheels with 255/45 and 285/40 Nitto NT555s (regular street tires not the Drag radial) and grip was almost even with the 275/315 Yokos. You could tell especially in decreasing radius sweepers where front end grip was at a premium but the car was surprisngly quick. Granted the Koni single adjusts and allignment was very much dialed in (old roommate was a suspension tech at a local dealer, we played with the allignment alot early on)

Thanks. We are on track.

Anyone else have input?

I would run the 275/40-17s all the way around.

Andrew

Thanks. We are on track.

Anyone else have input?


I run 275/40/17 on all 4 corners with 9" wheels. No problems-in fact it handles very well. The Firestone Wide Ovals that I run, are approved for 9"-11" wheels as stated on the Firestone site.
http://www.chevelles.com/forums/picture.php?albumid=251&pictureid=1846

I ended up going with 275/40 17 NT05. Should be at the tire shop on Friday.

Not to thread jack but as someone said that Nittos run small, does anyone have access to both the 275/17 and the 315/17 nt05's? With a 17x10 the 315 is supposedly too skinny for it but Im wondering if the smaller size will make it a good fit.

I need to ditch the drag radials out back


Just curious - what are your concerns with the drag radials? I figured they would be decent for a non-daily driver.

Autocross and drag radials don't mix well. Other than that they are fine and I have driven about 3000 street miles with no problems.

I'll try and get some pics up tonight. Got the tires mounted and on the car.

whats the issue with the DR's on an auto-x? too soft of a sidewall?

aaron

Autocross and drag radials don't mix well.

I've actually heard the opposite- that in some cases, the DR's were an advantage, especially on longer/faster courses. Some guys were 'cheating' with DRs on some shorter road courses for the same reason.

I can't afford to try such experiments, but I'm intrigued by stories like this.

I guess I will find out this weekend. I know from looking at the way my tires were wearing that the drag radials were definitely rolling over pretty far even with 40# of pressure. The 555's I had on the front showed much better wear at the edge of the tire.

The driving instructor was explaining that the sidewall slip angle was one thing and then the tire tread is actually rotating when turning as well. When you would apply the gas while turning it wanted to straighten out the rotation and keep pushing you straight. Could also be running a 300 TW in front and a 100 TW in the back was throwing the balance off.

I personally don't have enough experience to know myself, but I feel having 4 matched tires with decent sidewalls will get me on a the path to improving my driving skills faster than the mismatched setup I was running. As well as help sort out the suspension tuning.

I've actually heard the opposite- that in some cases, the DR's were an advantage, especially on longer/faster courses. Some guys were 'cheating' with DRs on some shorter road courses for the same reason.

I can't afford to try such experiments, but I'm intrigued by stories like this.

I would think if you had the choice of running a drag radial or a DOT approved (road race/autocross) slick the slick would perform better. Not knowing much I could be totally wrong. I would love to hear the physics/theory behind what you said.

I would think if you had the choice of running a drag radial or a DOT approved (road race/autocross) slick the slick would perform better. Not knowing much I could be totally wrong. I would love to hear the physics/theory behind what you said.

Me too!

It was online chatter- interesting, but nothing I was personally involved with. With oversteer being such an issue with my car, and since I'd chosen to run Nitto 555s, I looked at their DR when I was buying them. I decided against it, but if I had a spare set of wheels and some extra cash, I'd love to have a spare set of rear tires. I'd run them at the drags for certain, but I'd love to try some testing on some twisty tracks too.

I would think if you had the choice of running a drag radial or a DOT approved (road race/autocross) slick the slick would perform better. Not knowing much I could be totally wrong. I would love to hear the physics/theory behind what you said.

A drag radial would lose outright to a DOT R-comp tire in autocross/road racing. The only way a DR would be helpful was if the driver was doing a literal point-and-shoot driving style, but the DOT's would still be better. Soft sidewalls are great for drag racing but not cornering.

Randy- Have you looked at or seen the Nitto 55 DR in action? It's atypical with a bit stiffer sidewall than you'd expect in a DR. Quite a tire, and in the right situation, under the right car, I think there's a place it could be an advantage. But, I haven't run them under my own car - as much as I'd like to! Oh- I'm not comparing it to a DOT-R compound tire either- I'm comparing it to an extreme performance street tire (200+ tw rating).

I belive Jeff Schwartz won Car Crafts Real Street Eliminator years ago in his Cadillac Attack with Drag radials front and rear.

I've been on these sites a looonngg time, ;) .

I've actually heard the opposite- that in some cases, the DR's were an advantage, especially on longer/faster courses.

That seems backwards, since the longer faster courses would require less longitudinal grip than a shorter slower course.

My opinion is that they may be an advantage to a driver who's too agressive with the throttle, and experiences a lot of corner-exit oversteer, but not to a smooth driver.

Randy- Have you looked at or seen the Nitto 55 DR in action? It's atypical with a bit stiffer sidewall than you'd expect in a DR. Quite a tire, and in the right situation, under the right car, I think there's a place it could be an advantage. But, I haven't run them under my own car - as much as I'd like to! Oh- I'm not comparing it to a DOT-R compound tire either- I'm comparing it to an extreme performance street tire (200+ tw rating).

The comparison to R-comps is valid as most classes (except for Street Touring) run them or race slicks. Even the Street Touring classes have some fast street tires with treadwear in the 140+ range. Now if it is a fun event, the DR would be good tire, but for serious competition, you need the best tires you can get (or at least afford). Unfortunately, I know this too well, as I run 275/40/17 R-comps against cars with 12-13" wide slicks (C-prepared) and the difference shows. :(

Pic of the NT-05 in 275/40 17.

http://bionicengineering.net/media/IMG_1523.JPG

Any more pics? I'd like to know how these fit if they are narrow or not. Im running the drag radials 315 nitto's on my lemans and 255 street nittos on the front. I'm having quite a bit of understeer autocrossing.

Pic of the NT-05 in 275/40 17.

http://bionicengineering.net/media/IMG_1523.JPG

Where did you find or better question who makes those 17 inch steelies? I know Aero Wheels makes the Nascar wheels but didnt think they were making anything larger than a 16"

Summit an Jegs sell them.

Those are Cragar Soft 8 wheels, they also have a D-hole one now, there is a thread about them in Pro-touring.

Geezus those are freakin cheap!!! Is it known if they fit over typical 13" big brake kits or even say C5 Z06 brakes like I have? I can foresee some widened versions of those for my car if they will clear those brakes.

C5 brakes are no different on a C5 or C5Z, just a different pad compound. They fit fine over my C5 brakes.

My D-hole wheels required a 1/4" spacer to clear the C5 front caliper abutments...

C5 brakes are no different on a C5 or C5Z, just a different pad compound. They fit fine over my C5 brakes.

I dunno if Im wrong but the Z calipers had larger ribs on the top of them than the regular ones. Also I heard they were casted differently rotocasted low pressure vs normal pour casting.

Either way if it needs a small spacer, great Ill make sure to keep that in mind when I order the offset. They look like a great race wheel when looks arent of primary concern.

Also my pops ls1/t5/ford 9 1970 MG BGT is getting them as primary wheels except he will be throwing a fat red pinstripe on the lip.

Im happy I found this thread. Thanks guys.

They work, but they are HEAVY... the boxes they came in from Summit each said "40lbs" on them. :eek:

I just put on 17X9 20mm offset fronts on my 71 chevelle with eibach lowering springs and stock controls arms. 255/45/17 to replace my 235/60/15, both same height tire. My 235/60/15 rubbed a bit on the outside during full turns. Now I have a nicer wider tire and no rub thanks to the 20mm offset. I have front wilwood brakes, not sure if that changes the centering of the wheel.

Does anyone have pictures of your chevelles that you can post with the crager 17 x 9s

I am looking for a low cost 17x9 wheel and the black ones might just work for me. is the 5 inch back spacing recommended for both front and rear?
I am also wondering how they will hold up as a weekend driver? you know rock chips and powder coating cracking off.....

I will be putting them on a 68 btw...

Does anyone have pictures of your chevelles that you can post with the crager 17 x 9s

http://www.chevelles.com/forums/showthread.php?t=318455

http://www.chevelles.com/forums/showthread.php?t=317613

http://www.chevelles.com/forums/showthread.php?t=318455

http://www.chevelles.com/forums/showthread.php?t=317613

Derek69ss... so do you think they would survive on the street? do they chip easy?
My car is jewel red tintcoat with black ss stripes and these black rims would look great and they are cheep

My first set of wheels were rusted chrome steel rims. I spray painted them black, everyone told me the paint wouldn't stick to the chrome. Well it did and I drove it around some strange places for years and it still has the black paint on it today. So I can't picture anything going wrong with a basic steel wheel like that Cragar. Heavy but good value and strong.