19" wheels offsets & tire sizes?

[RICKYRJ1]

I am looking to pick up some new wheels & tires for the Z season. I want to go with 19's. what are the offsets needed? I have C6 ZO6 brakes frt/rear. Michelin or Nitto tires? I like the tires right to the edge of the wheel well like I have now but would like to do coilovers in the future. will that matter? like to hear from the brain trust. Thanks in advance, Rick :flag:

[KILLSHOTS]

I am looking to pick up some new wheels & tires for the Z season. I want to go with 19's. what are the offsets needed? I have C6 ZO6 brakes frt/rear. Michelin or Nitto tires? I like the tires right to the edge of the wheel well like I have now but would like to do coilovers in the future. will that matter? like to hear from the brain trust. Thanks in advance, Rick :flag:
ZR-1 offsets are +56mm front and +36mm rear, both with 7.4" backspacing. You can play with width and diameter but the offset and backspacing shouldn't be changed. These are very odd and rare offsets and are virtually impossible to find on any aftermarket wheel, lest you have them custom made. This is why you hear about guys having to run spacers on the rear wheels and conversely, see some guys' front wheels protruding past the lip of the fender. If you order new wheels, my advice is don't mess with offsets and backspacing.

Good luck

[cvette98pacecar]

Ricky, I got these measurement from Phil W.

Front 18x10 57MM offset 1.5" lip 8.5" barrel
Rear 19X12 38MM offset 2.5" lip 9.5" barrel

Profile 10. Cant wait to see the wheels on the car.

http://i1199.photobucket.com/albums/aa468/rdemarco06/Open/20131224_162444_zpsiuj2ie0z.jpg (http://s1199.photobucket.com/user/rdemarco06/media/Open/20131224_162444_zpsiuj2ie0z.jpg.html)

http://i1199.photobucket.com/albums/aa468/rdemarco06/Open/20131224_161842_zpssxviuxjw.jpg (http://s1199.photobucket.com/user/rdemarco06/media/Open/20131224_161842_zpssxviuxjw.jpg.html)

[RICKYRJ1]

wheels will be made to my specs, thats why i'm trying to make sure. Im running the OEM C6 Z06 wheels now and use a wheel adapter in the rear only. Carter from CT Machining made them for me and have worked flawlessly for several years now.:dancing Eye candy Robert expect nothing less from ya, thanks for the specs. maybe dumb question but since I want to go with 19's in the front also does your specs remain the same?

[cvette98pacecar]

wheels will be made to my specs, thats why i'm trying to make sure. Im running the OEM C6 Z06 wheels now and use a wheel adapter in the rear only. Carter from CT Machining made them for me and have worked flawlessly for several years now.:dancing Eye candy Robert expect nothing less from ya, thanks for the specs. maybe dumb question but since I want to go with 19's in the front also does your specs remain the same?

When I seen these wheels on Phil's car I thought they were the best looking wheels I have ever seen on a Z on a Brite Red car. Now on a Purple or Ruby car you would probably have to go with OZ. Black, definitely Shelby's I saw Jim V LPE in Florida 4 years ago and that car was hot. I am sure whatever wheel you choose your Z will look spectacular like always.

I would not see it changing as all you are changing is the diameter of the wheel

Ron K has 19" front and rears on his LPE. Hopefully he will chime in here.

[5ABI VT]

wheels will be made to my specs, thats why i'm trying to make sure. Im running the OEM C6 Z06 wheels now and use a wheel adapter in the rear only. Carter from CT Machining made them for me and have worked flawlessly for several years now.:dancing Eye candy Robert expect nothing less from ya, thanks for the specs. maybe dumb question but since I want to go with 19's in the front also does your specs remain the same?

wheel diameter does not change anything. Beautiful wheels up there !!

[5ABI VT]

I am looking to pick up some new wheels & tires for the Z season. I want to go with 19's. what are the offsets needed? I have C6 ZO6 brakes frt/rear. Michelin or Nitto tires? I like the tires right to the edge of the wheel well like I have now but would like to do coilovers in the future. will that matter? like to hear from the brain trust. Thanks in advance, Rick :flag:

If you like how they fit now, just measure your current wheels. Very simple to do. Or if you know the offset of the wheels add the spacer thickness to it and it will give you the offset number you need out back.

[XfireZ51]

Ricky,

I think the one issue when using the Z06 brakes, up front in particular, is clearance for the calipers. As u know, they are massive and it's not just a matter of clearing the wheel drum. It's also a question of clearing the front face of the caliper. My hunch is that a wheel w a dished face would be problematic without pushing the tire towards the outer edge. One reason the OEM wheels look the way they do w a flat outer face.

[XfireZ51]

BTW, I have coil overs now on mine. There's no impact from that but you do need to be concerned about how deep the wheel goes into the wheel well. Without the spacer on the Z06 rear wheel, they would rub onto shocks. And with spacers, I have gotten tire to rub on inner wheel well on high transient dips. However, there's only one dip I know of where that occurs.

[Jagdpanzer]

Ricky,
Dom's right
The front ZO6 caliper will require a little more wheel center clearance.
We worked it out on David's car but I'm on the the west coast this week and don't have accesss to the information.

[5ABI VT]

There are measurements you can do from the rotor hub to the caliper to determine if the wheels will fit. most manufacturers of custom wheels have a 'bbk' (big brake kit) friendly spec for most wheels. the offsets will remain the same but the hub will be deeper (kind of like oe zr1 rear wheels with the deep lugs) pushing the wheel center outwards allowing for big brakes. If you ask for the biggest lip possible like some people mistakenly do, they may interfere with big aftermarket brakes.

[RICKYRJ1]

The wheels I'm going with are Niche competition series, wheel name is Intake-H82. Spoke with them today and they will work with a BBK. 4-5 week build time so I want to put the order in soon. Really trying to make BG this year. I will also go with Michelin tires, I had PS2's before do I do the same or different? :saluting:
Robert, the wheel it seams looks somewhat close to the pic you posted. :-D

[KILLSHOTS]

The wheels I'm going with are Niche competition series, wheel name is Intake-H82. Spoke with them today and they will work with a BBK. 4-5 week build time so I want to put the order in soon. Really trying to make BG this year. I will also go with Michelin tires, I had PS2's before do I do the same or different? :saluting:
Robert, the wheel it seams looks somewhat close to the pic you posted. :-D
That's a really sharp-looking wheel. Should be totally badass on a ZR-1.

[USAZR1]

My 19x11.5 CCW's have +44 offset (8" backspace) I don't remember what offset the front 19x10's are but they were made with a smaller lip so C6 Z06 brakes would fit.
Rear:
http://i148.photobucket.com/albums/s6/sherryle/Clint/photo_zpse44ab732.jpg

Front:
http://i148.photobucket.com/albums/s6/sherryle/Clint/photo-1_zps27976273.jpg

[XfireZ51]

The wheels I'm going with are Niche competition series, wheel name is Intake-H82. Spoke with them today and they will work with a BBK. 4-5 week build time so I want to put the order in soon. Really trying to make BG this year. I will also go with Michelin tires, I had PS2's before do I do the same or different? :saluting:
Robert, the wheel it seams looks somewhat close to the pic you posted. :-D


Ricky,

The H82s I just looked at are a simpler pattern than what Robert posted. Nice wheels. I would still get them w a flush face to the drum rather than a lip. JMHO. The Pilot Sports should be great. Just make sure they work in the Kentucky rain in May.

[RICKYRJ1]

Ricky,

The H82s I just looked at are a simpler pattern than what Robert posted. Nice wheels. I would still get them w a flush face to the drum rather than a lip. JMHO. The Pilot Sports should be great. Just make sure they work in the Kentucky rain in May.

even for the rear?

[RICKYRJ1]

those CCW look sweet I was always lead to believe that the CCW wouldnt clear BBK. learned something new today

[XfireZ51]

even for the rear?

My comment had more to do w the "look" rather than fitment.

[cvette98pacecar]

even for the rear?

Rick, That is a good looking wheel.

[RICKYRJ1]

My comment had more to do w the "look" rather than fitment.

thanks brother, sorry I misunderstood :handshak:

[Z51JEFF]

I'm having a set of wheels made as we speak. The fronts are 18-10 with 8 inches backspacing and the rears are 19-12. With 8.5 inches backspacing. The tires are 285-35-18 and 325-30-19.When I measured.The offset on both front,rear wheel I got 7.5 inches.

[WVZR-1]

I'm having a set of wheels made as we speak. The fronts are 18-10 with 8 inches offset and the rears are 19-12. With 8.5 inches offset. The tires are 285-35-18 and 325-30-19.When I measured.The offset on both front,rear wheel I got 7.5 inches.

You used "back-spacing" measurements likely in your mentioned dimensions of being built. Depending upon the rim flange width, offsets would be something near 63 - 65 front and 50 - 52 for the rears. The constructor would likely quote you an advertised offset if you asked.

What would be an interesting project for the "Registry" I'd think is to develop/adopt a particular caliper/rotor measuring template that could be used when some are attempting wheel purchases. If you supply most constructors the brake specifics they can more easily discuss wheel lip possibilities for projects. Fitment first, aesthetics secondary. CCW uses two height dimensions and what they call over-hang, others use the same or similar but change the terminology. Those three dimensions should satisfy most any constructors needs.

[Z51JEFF]

You used "back-spacing" measurements likely in your mentioned dimensions of being built. Depending upon the rim flange width, offsets would be something near 63 - 65 front and 50 - 52 for the rears. The constructor would likely quote you an advertised offset if you asked.

Offset,back spacing I get the two mixed up. I've been having wheels built for my cars for years. This is what works for me. If you want to add some width to a wheel take the stock wheel and add the width, in the case of my I want to add a 1/2 in to the front but didn't want to move the centerline of the wheel so I added that 1/2 inch to the inside of the wheel,same for the rear. The wheels will still have the factory 56-36 whatever in relation to the mounting pad of the hub and the pad of the wheel.

[XfireZ51]

You used "back-spacing" measurements likely in your mentioned dimensions of being built. Depending upon the rim flange width, offsets would be something near 63 - 65 front and 50 - 52 for the rears. The constructor would likely quote you an advertised offset if you asked.

I was just looking at that. A rear offset of 36mm is 1.44". At 7.5" the car would look like something Big Daddy Ed Roth.

http://4.bp.blogspot.com/-sE27RzKUC_4/URnvRn4SUBI/AAAAAAAAAWw/OGSbzDCIQ-M/s1600/MrGasser.JPG

[Jagdpanzer]

Here is link to a cool wheel and tire comparison tool so you can play around with various tire and wheel size fitments

http://www.rimsntires.com/specspro.jsp

[WVZR-1]

Offset,back spacing I get the two mixed up. I've been having wheels built for my cars for years. This is what works for me. If you want to add some width to a wheel take the stock wheel and add the width, in the case of my I want to add a 1/2 in to the front but didn't want to move the centerline of the wheel so I added that 1/2 inch to the inside of the wheel,same for the rear. The wheels will still have the factory 56-36 whatever in relation to the mounting pad of the hub and the pad of the wheel.

The problem when comparing "offset" and "back-spacing" some/most don't take into consideration that "back-spacing" is a measurement derived from "TOTAL WHEEL WIDTH" which is generally 1" or close to more than the advertised/specification width. 10 is actually 11, 12 is actually 13.

Here's a comparison of the 11@36 vs 12@38 (PhilW) vs yours 12@51. I used what was quoted in post #3

12@38 vs the "stock" - the inside dimension is 15mm apprx less and the wheel lip is pushed outboard 11mm approx and from all accounts PhilW's car is outstanding with that build.

Your choice 12@51 vs the "stock" - the inside dimension becomes 28mm LESS and the outboard wheel lip is "sucked in" 2mm. I can't imagine there being room for the 28mm clearance loss.

I didn't do the fronts.

[WVZR-1]

Here is link to a cool wheel and tire comparison tool so you can play around with various tire and wheel size fitments

http://www.rimsntires.com/specspro.jsp

Hello Phil - I generally do the math to establish the real deal but for quick comparisons of "wheels only" I sometimes use this. The advantage here is that you can +/- the offset without major changes to the information required. There's no back-spacing reference but if a person understands "Total Wheel Width" that's easy.

http://kgm.tiwing.com/calcs/offsetcalc.htm

I've done the math several times before relying on this calculator's results and aside from "rounding" I've found no issues. Is there? Could be. The rimsntires displays results sometimes differently and if a person doesn't understand the math can create issues. I could show you an example but it would confuse this thread I believe.

I believe I posted this calculator years ago.

[Jagdpanzer]

Dave,
I agree, these calculators are quite helpful but you should still verify by doing the math and physical measurement on the car to confirm the fit will end up where you want it and adequately clear the fender, brakes, wheel well liner, and inner suspension components. The dimensions of the actual tire selected should also be verified against the manufacturers published data as dimensions can differ somewhat from tire to tire of the same listed size.

[Z51JEFF]

Dave,
I agree, these calculators are quite helpful but you should still verify by doing the math and physical measurement on the car to confirm the fit will end up where you want it and adequately clear the fender, brakes, wheel well liner, and inner suspension components. The dimensions of the actual tire selected should also be verified against the manufacturers published data as dimensions can differ somewhat from tire to tire of the same listed size.

I've had 6 sets of wheels made over the years and I've never used a calculator to determine if a wheel will work on a car. It's very simple, put an OEM wheel on the car that you know fits and make any changes to that stock wheel. Push it in a 1/2 inch or what ever. In the past I've tried using measuring tools,even made my own but the easiest way is what I've described above. Now,if the company making the wheels screws up the dimensions,that's another story. In getting the wheels made for my Z I want the least amount of dish in the rear wheel as possible which involves leaving as much material on the back pad of the wheel as possible,right around 2 inches. It gets a little confusing but for what I'm paying for these wheels I'll leave the calculation the the wheel company.

[USAZR1]

I'm having a set of wheels made as we speak. The fronts are 18-10 with 8 inches offset and the rears are 19-12. With 8.5 inches offset. The tires are 285-35-18 and 325-30-19.When I measured.The offset on both front,rear wheel I got 7.5 inches.


I can pretty much guarantee that a 19x12 rear wheel with 8.5" of backspace is going to have clearance issues on the inside,Jeff. Anything over 8.25" is a big gamble and especially if you lower the car.
Been there,done that and got the t-shirt. ;)

+44 offset on a 12" wide wheel = 8.25" backspace
+51 offset on a 12" wide wheel = 8.5" backspace

[Z51JEFF]

I can pretty much guarantee that a 19x12 rear wheel with 8.5" of backspace is going to have clearance issues on the inside,Jeff. Anything over 8.25" is a big gamble and especially if you lower the car.
Been there,done that and got the t-shirt. ;)

+44 offset on a 12" wide wheel = 8.25" backspace
+51 offset on a 12" wide wheel = 8.5" backspace

I've got that covered. The tire gets a little close to one area of the liner.

[XfireZ51]

Also, as Pete has pointed out, the passenger side sinks just a bit deeper into the wheel well than the D side. Not symmetrical.

[Z51JEFF]

As stated a cast wheel is only going to come in one size opposed to have a 2-3 piece wheels made which has many offset options.

[rkreigh]

with the right tire my ccw 505 19s are a very good option (hint hint they are for sale)

I went back to the 18 ccw classics as they just work better for me and I like the 335 rears