JohnTheStigGalt

Hi Gents, and Ladies?
I'm new to the list and recently acquired a beautiful black SWC. :steering: The car has 20+ year old rubber on it which is in surprisingly good condition. My plan is to preserve the current tires/rims and upgrade to 17" wheels/tires. I plan to change NOTHING else on the car (except adding aftermarket AC) so offset trailing arms are out of the question.

Sorry to re-hash a topic that has been repeatedly addressed here. I searched the archives and found no answer to this SPECIFIC question:

What size 17" (not 15" or 16") wheels (width/backspacing) will fit on an otherwise STOCK C2 coupe? Also, what size rubber?

AB7Split63 posted this info a while back:

"I think your bigest limitation of size it the width of the tire because I am runing 7 inch wheel with 4" back space I could have gone one more inch but I didn't whant to risk the fenders."

If I recall, someone mentioned the stock backspacing at 3.5"? If so, anyone know if an 8" wheel with 3.5" backspacing will work?

I understand the argument against going to a larger diameter than stock wheel, however, my mind is made up.

Thanks for any info you can provide!
Vaughn


[Modified by SeaLawyer, 3:16 AM 1/22/2003]

RichF

SeaLawyer:

I don't have an answer to your question, but welcome to Corvetteforum.com! :D I'm sure someone will respond shortly......

achapman

Welcome to the forum.... I too have a 63 SWC Black with Red interior.... nice color combo.... :thumbs:

Vetterodder

I know there are a few mid-year owners on the forum that run 17" wheels and I'm surpised that you haven't received a response from one of them. I think I can help with the backspace question though. You will want to increase back space as much as you can without creating a clearance problem with the trailing arms. A 8" rim is 2.5" wider than the stock 5.5". With the same 3.5" backspacing, you would need to flare the fenders to contain the entire 2.5" increase as it would all be towards the outside of the car. A better fit would be a 7" rim with 4" backspacing. That would move the inside of the tire in 1/2", the outside out 1". That would still make for a very tight fit but but should work without any mods if you limit tire width to about 225. Riide height and camber settings may also affect clearance.

LB66383

I can't reply specifically to 17" wheels, but I recently went to 16s. The shop I worked with did all kinds of measurements and trial fitting in the rear. I wanted 16x8s, but they advised the biggest I could go was 16x7 (stock fenders. The biggest tire that would fit (and I had to do a small amount of fender lip trimming) was a 235/55x16. I wanted 255/50x16s but there was no way. I recently saw a car with those size tires, and the clearance between the tire/fender on the outside and the tire/sway bar on the inside were about the thickness of a piece of paper.

63bruce

Hi Vaughn, welcome to the forum - I'm not a frequent poster, mostly 'cause I have more questions than answers ... however, I put a set of 17" AR 200S wheels on my 63 SWC last fall and as soon as I get out to the shop (tomorrow) I'll get the width and backspacing for you. I know I went with the stock wheel, no custom offset, and I'm running a 225-45 tire which just clears the fender. I'm pretty sure it's a 7" wheel, that's what I need to check. However, the 45 series tire is much smaller diameter than the stock tire, which is a problem on the highway. Any good tire shop will be able to give you the correct aspect ratio to match the stock diameter and not screw up your highway driving. I'll shoot a couple of digital photos to show you clearance with the fender and the trailing arm, you might gain a bit from a larger backspace, but the 225's look pretty good.

I'm also a forgetful :banghead: so if you don't hear from me by Friday am, drop me an email to :smash: remind me.

Bruce

JohnTheStigGalt

Thanks for the response so far guys... [ARE there any gals on this forum?] And thanks for the welcomes. Very excited to finally own a mid-60's Vette. Wanted one for YEARS!

I don't know what I was thinking with my question regarding AB7Split63's post. OBVIOUSLY an 8" wheel with 3.5 backspacing wouldn't work... DUH... I guess I was interchanging backspacing with offset which I didn't really mean to do.

So here's the question - if a 7" wheel with a 4" backspacing works, that means there is a .5" offset (I can NEVER remember whether that's a positive or negative offset....) So would an 8" wheel with maybe a 5" backspacing (and the requisite 1" offset [ again positive/negative?]) work? Is that TOO much offset? Is there enough clearance on the INNER fender or trailing arm for that size?

Thanks for the input,
Vaughn


[Modified by SeaLawyer, 9:09 PM 1/23/2003]


[Modified by SeaLawyer, 9:12 PM 1/23/2003]

grumpy55

Wheels are measured (essentially) tire-bead to tire-bead, and are actually about 1" wider than the specified width (a 7" wide wheel measures 8" outside-to-outside).
Therefore, a 7" wheel with 4" backspacing has NO offset.
A 7" wheel with 4-1/2" backspacing has 1/2" positive offset.
A 7" wheel with 3-1/2" backspacing has 1/2" negative offset.

bcwaller

I cannot say 100% for sure for a 17 inch combo, but I have 16 inch wheels that are 8 inches wide front and rear with 245/45/16 tires. I would think that you could safely use the 17x7 wheels you mentioned with a 235 wide tire and have no problems. You might even be able to make a 245 width.

In front, the places of concern are the tie rod end (prevents too much backspace), but a wide 17 inch wheel with more than 4 1/2 inches of backspace *might* just tuck inside the tie rod. You will also have minor issues like frame rub at full lock, but that has never bothered me. Of course, the body is the outside limit! If you can get a shop to help you with test fitting, that is best.

In the rear, the issues are the parking brake bracket which is mounted outboard on the trailing arm. You can get a quick 1/2 inch more clearance by relocating this tab to the top of the arm. Without moving it, I don't think the 8 inch wheel will work. I guess there is about a half inch more I could have in the rear with my setup, but I like having the same front and rear for when I abuse my tires...

JohnTheStigGalt

Thanks for educating me Grumpy! I think I've got it now... :jester

Brad, if 16x8's fit then 17x8's should too if the tire diameter remains the same, right? Or am I missing something?

How much do offset trailing arms run and who sells them? Maybe it would be worth it. Unfortunately I'd prefer NOT to drive the car on the current rubber, so having a shop measure for me would be difficult...

I kinda feel like I'm being a leech... Too much more free info, and I'll have to start giving out free legal advice...

JohnTheStigGalt

Another noob question: Vetterodder, how do you use a custom avatar?

Vetterodder

Members that have been on the forum since a certain date can have them and (I think) those that have made a certain number of posts can also have them. I don't remember the date or the number of posts required though.

thegypsie

You got that right, this place offers a wealth of info on the cheap :D . Congrats on your new ride and I am very interested in this topic as well of 17's on a 63'. See this thread I created ahwile back http://forums.corvetteforum.com/zerothread?id=452327 . That thread requested pics of mid-years (63-67) with 17 or 18 inch wheels and also asked for backspacing, etc...Responses were great with several lengthy emails about how to do it right and so on.

It looks like the off-set trailing arm allows for some nice fat meat back there but how much to get that installed? I don't want mine to be a project, just bolt wheels on. I will follow your progress and maybe it will help me decide which way to go.

Lance

Tripleblack51

Hey Fellow Floridian,
Congrats and welcome. I recently acquired my mid-year too.
Some really great people on this forum with a wealth of knowledge.

Enjoy!

:cheers:

NJCRUISER

I have 17's all around on my 66 vert. I bought Vette Brake Products set of offset trailing arms to allow an 8 inch wheel on rear, You can stop right here and just buy ARE's Torque thrust II's with 4 3/4" rear offset, 4" on front, not forgetting the vette bolt pattern. This is the widest offset you can get from ARE without ordering custom. This saves you big $. Now, Some will lower their car, which obviously involves suspension changes and clearance issues as well as diff tire series. I went with Michelin Pilot sport tires 225/50/ZR17(front), and 235/50 ZR17(rear).These tires although low profile ,
have almost the same height as the originals when mounted on the 17"ARE TT II's. So lowering car isnt necessary.Yet it has a lowered look. If the car is an orig BB, like mine was, you will likely have to remove the sway bar for clearance. Now, I went with the VBP dual mount monospring which more than makes up for the loss of the sway bar, I also purchased 4 bilstein sport shocks, and smart strutswith an adjustable camber,all from VBP. right now it's at "0" for traction.
The rear riding height is adjustable with the DM monospring, but then you
need VBP's front system also to lower the front. Unlike Some, I dont have
endless cash reserves to refabricate my milodin 7 qt oil pan, so I stayed with stock front suspension setup . Between the rear mono, the bilsteins, and the tires, It's unbelievable how you can take turns in this thing, just have a good dentist on hand, cause it's stiff! One more note, The front tires are on a 17 X 7
wheel which fits with no mods, but, they will rub slightly on the frame at a
full turn of the wheel only. Hope it helps. And for those that are wondering, YES!, they all fit inside the stock wheel well. Barely
:hurray:


[Modified by NJCRUISER, 9:58 PM 1/25/2003]

6spdNavy99

NJCRUISER: Thanks for that great info. I was planning on doing the exact same thing to my '66 Vert, and your wheel/tire info was great. Thanks!!

thegypsie

Seaway - apologize about hijacking this thread though it is not intended. There is constructive info being shared in this thread that helps us all :D.

NJCRUISER - Your ride is looking close to what I am envisioning. Very nice setup :cool: . Good info as well and I can appreciate the comment about not having unlimited supply of $$$$ to fabricate at will. Wished it was the case for me but then I would most likely get one of those C4 conversion w/suspension/updated drivetrain deals and plop the 63 body on top.

Not to digress, are there any guesses about the offset trailing arms being installed, price to install? Installing them myself most likely is not an option so a couple guesstimates for install.

Thanks

NJCRUISER

Tough to say how much, it was kindof a cooperative effort between my self and a mechanic who's a freind, we also put on gt rotors, ssbc aluminum calipers and drop forged spindles and side yokes as well as all kinds of other stuff, so a price for just the trailing arms is difficult. I can tell you though, those suckers will be hell to get off if they are the original arms! I can tell you that I saved lots by buying the Vette brakes stuff(trailing arms, smart struts). at Carlisle two years ago, they give special deals as I would assume many vendors do at carlisle. If you need specifics, Email me.

thegypsie

I've heard they (t-arms) can be a bear :banghead: to take off. That is one of the reasons I don't even feel like attempting it. I'll email if need be.

Sooo many dang projects on different cars, I would like to limit one mod or enhancement mod to be simple and relatively straightforward ($$$) sans the given price of wheels and tires. This happens to me all the time and surely many can relate. I just want the 63' to look cooler! but not dump $5K. Ah well, cars are tucked away for a few more months so this is not a pressing matter.



thanks,
Lance :seeya

JohnTheStigGalt

Hey gypsie,

Bruce emailed me pics of his 63 SWC with 17" wheels. After seeing his car, I have several thoughts...

First it seems like if I did go 8", I would need the offset trailing arms... AND it looks as though clearance on the tie-rod ends would still be TIGHT! My other concern with an 8" wheel is the negative offset. 542C2 has 9.5" with 6.5" backspace. Wouldn't that much negative offset throw the camber way off? Bruce's tire is smaller in diameter than stock, but it looks like he still has plenty of clearance (circumference-wise) in the fender opening. I wonder if I could squeeze an 18" rim with a LOW profile tire in the fender.

I read your post and 542c2's responses. I'd LOVE to go with a 255... I do NOT want to notch the frame or the inner fender. And I think an 18" wheel would be AWESOME! I don't know what it is, but big wheels on classic cars just does it for me. I MAY go the offset trailing arms if I have to. Basically my car is all original and one day when I have not so many projects I'll do a frame-off resto and show it, but for now I just want to drive it. I'd have to take the trailing arms off to do a frame-off resto anyway. I just don't want to make any changes that would be permanent OR too expensive.

I guess the real question is, since noone on this list has 18" rims, which one of us is going to go first.... :skep:
And btw it's SeaLawyer not Seaway... :lolg: Navy JAG...

Triple, where is Miramar, FL?

:cheers:,
Vaughn


[Modified by SeaLawyer, 2:46 PM 1/26/2003]