CadVetteStang

Test Fitting Wheels & Tires for looks and performance

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Shortly after getting the car in Oct

of 2013, I started researching

various tire and wheel

combinations. My goal was to find

a workable setup that I could use

on the street as well as the

autocross track.

After making a few measurements

and considering the planned brake

upgrades, I establish the

parameters I wanted to work with.

Once I install the 12.75" front

rotors, the 16" stock wheels will

not fit. Therefore, 17" wheels are

the minimum diameter I am

looking for. Because of weight, I

limited the maximum size to 20"

(not to mention that 21" and larger

wheels on the mid-sized Eldorado

looks too Gangster for me.

1023131510-1.jpg

These are 20 X 8.5" wheels with 245/35 R20 tires.

So far, it is the only 20" wheel that I like on the car. I don't want bling bling rims, I am after a light weight performance wheel that looks sporty.

I will post more pics when I can.

Thanks to Arch Street Pawnshop in Little Rock, AR for hosting a half day of wheel fitment tests and pictures. I learned a lot and now have a clear direction to shop for a winning combination.

Edited by Cody

Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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Here are some more pictures of the 20" X 8.5" wheels on my car. (I fixed the problem with sharing photos using my phone. I have to get the link without using the Android app.

These wheels are almost as light as the 18" wheels that they had in stock. However, from a racing, braking and fuel economy stand point, even if they were the exact same weight, a smaller diameter wheel would be better since most of the wheel's weight is with the rim and that extra diameter creates leverage against the acceleration and deceleration of the rotating mass.

1023131508-1.jpg

1023131509a-1.jpg

[url=http://s798.photobucket.com/user/kaywoodcove/media/2002%20Eldorado%20ESC/02%20Eldorado%20ESC%20Build%20Thread/1023131511e-1.jpg.html]1023131511e-1.jpg[

/URL]

There is still plenty of room under the rear fender wells. The front is starting to fill up, but I think that 9.5" under the front and 11" under the back is doable with a lowered car depending on offset. However, I think that a deep offset to get anything wider than a 9.5" wide wheel under the back would interfere with a Touring Coupe's motion sensors that control the stiffness of the computer suspensions.


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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Nice +4 match for your original wheels/tire size (so total diameter equivalent). Are you happy with the ride quality and handling?

When you write that the front could take 9.5" and the back 11" you mean in wheel width? Are you taking into account slightly greater offset as well for wider wheels?

225x60xR16-245x35xR20.png


Bruce

2016 Cadillac ATS-V gray/black; 2013 Cadillac ATS 2L Turbo Premium (Wife's)

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Thank you. I did not buy these wheels; this was part of the test fitting. my minimum rolling diameter will remain within 90% of my current size so that I do not loose any fuel economy. I am willing to go a little larger in diameter but want to remain within a half inch.

Yes, I was talking about wheel width and was considering deeper offsets. I will post more pics of the other wheels I tried on as I get time.


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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Before I go to the next wheels, here are a few more pics of the 20s.

1023131456a.jpg

1023131456.jpg

1023131457b.jpg

1023131509.jpg

1023131509c.jpg

1023131509a.jpg

I didn't get a clear shot of how much room is still left in the back fender wells, but maybe if you look closely you can tell that there's a lot of options back there for larger tires and shallower offsets... It's like a cave back there.

Edited by Cody

Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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The next test fit was 17” CTS wheels. These were 7” wide in the front and 8” wide in the back. The fronts were 235/50 R17 and the backs were 255/45R17. For my purposes, the fronts were way too skinny, but had the right rolling diameter. The 255MM width of the back tires was okay, but they were too short for street use since it would downgrade my gas mileage. There are a limited number of 17 tires with my correct rolling diameter.

These are good looking wheels, but they are also not what I am after.

1023131558.jpg

1023131558b.jpg

1023131601.jpg

1023131601a.jpg

1023131603.jpg


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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Maybe 255's (all around); can you get two more 8" wheels (looks like they will fit). They do look good IMO; very similar (if not the same) as my '11 STS wheels.


Chuck

'17 XT5, '04 Bravada........but still lusting for that '69 Z-28

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Chuck, I could get two more 8” wide wheels, and would consider it if I was not going to be racing the car. The CTS wheel retains the expensive, classy look that the OEM 16” wheels have and are an appearance upgrade. But performance is going to take precedence here. There are many racing tire options in the shorter diameter, but to use a 255MM wide tire with a 17” rim, I need the 255/50R17 tire, and currently it is mostly used as a sport SUV tire. That would be great for the daily drive. However, I am building a racecar; and although the 17” rim size has the advantage in keeping the rotating mass closer to the hub, there are not enough street performance tire options for me in the diameter I need.

So the search continues…. We will look at some 18s next.


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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These are 18 X 7.5 Dodge Challenger wheels. They do not have a deep offset, so they do fill up the fender wells even though they are narrow.
The tires are shown here are too tall; they were already on the wheels, so we just bolted them up. They were the stock tires on the Dodge, and the Eldorado is a smaller car than the Challenger.
A good tire choice for these wheels would be 245/45R18. They would have the correct rolling diameter and would not be too wide for the wheels.
There is also a caliper scraping problem if you dont use spacers. I think ¼ inch spacers would be enough.
I LOVE the aggressive look of these wheels and wish I could find them in 8.5 "to 11" wide.

1023131538.jpg

1023131537.jpg

1023131532c.jpg

1023131532d.jpg

Edited by Bruce Nunnally

Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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My car uses 245x50 tires on 18 inch wheels...

There is a pretty fair selection of 18 inch tires available.


Posted Image

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@ Bruce ; you are welcome.

@ Jim ; yes, I have discovered that the 18" diameter wheel has the best variety of performance tires in the 26.5"-27.5" rolling diameter. My goal is to get 275/40ZR18 in the back, and if they won't fit under the front, to use 255mm wide tires under the front fenders.

I have chosen 245/45R18 as a minimum acceptable size in all four corners.

275MM wide as maximum width for the front.

I don't have a maximum for the back, but I don't think anything wider than a 315MM tire will fit


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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For info, the STS-V came with 255/45-18 front, 275/40-19 rear (6 lug)

The current gen CTS-V comes with 255/40-19 front and 285/35-19 rear (5 lug)


Bruce

2016 Cadillac ATS-V gray/black; 2013 Cadillac ATS 2L Turbo Premium (Wife's)

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This is where the Dodge wheels scrape against the Cadillac calipers and why you need a spacer to run them.

1023131609.jpg

And this is where it carves grooves in the back side of the Dodge Challenger/Charger wheel. These groves were carved with less than an 1/8 mile of driving. The front calipers did this damage. The back calipers made contact, but I think they would have “clearance themselves” with a little more driving and would have left less than an 1/8” groove in the rear wheels. Still, I feel that this could weaken the wheel; especially in racing situations.

1023131608a.jpg


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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Cody have you considered how to test cornering limit via skidpad or slolam or similar testing? My thinking was to use g-force measure by meter but g-force can be calculated by raw speed around a 200' circle. An alternate is a specific, repeatable cone marked course similar to autocross. The attraction of a circle is if it was more repeatable - since that is the hardest part of testing.

Not mentioned in mag articles is the heavy toll on tires during those tests. My impression is a cone marked figure 8 may be a better gauge, while still leaving room for safe errors at the limits?


Bruce

2016 Cadillac ATS-V gray/black; 2013 Cadillac ATS 2L Turbo Premium (Wife's)

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Bruce; I hope I get a chance to test the handling capabilities of the car before I begin the modifications, however, I don’t know if my schedule or finances will allow it. I have made some connections with the local chapter of the SCCA, so hopefully I will get to do some G- testing.


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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These are the wheels from the test fit as compared to the stock 16s in the lower left.

The 17” CTS wheels (upper left) have a poor choice of available tires for my application.

The 20” split spoke star wheels (lower right) have sidewalls so short that I would be in constant fear of bending them when I hit bumps due to my planned increase of spring rates.

The 18” Dodge Challenger wheels are the right diameter for a great choice in tires, but at 7.5” wide, are too narrow for my racing plans. However, 18” is the winning diameter and will be the focus for my search from this point on.

1023131554b.jpg


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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I really like those challenger wheels to bad they won't handle a wide enough tire for your needs.About those wheels rubbing the calipers ,instead of spacers you could grind off the edge of those calipers ,that's the way us old farmers do it !!!

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I thought about grinding the calipers, but I didn't want to take a chance on weakening it or causing harmonic vibrations when braking. But that might work fine... These wheels are cheap too. I found a perfect set on Craigslist for $100 (painted, not chrome). I thought about using them as my "street wheels" and adapting some 17" Corvette wheels with Autocross tires as my race -only setup. But, I know me.... I'd wind up keeping the short tires on it and trading my gas mileage for the fun of the drive..... So, I need to have one set that can be left on the car full time.

Why don't you pick up some chrome Challenger wheels for your car?


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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I'm just an old man ,think I'll stick with my stock wheels.No really my ELDO is so original I don't want to change it. I may buy another one just to modify it .That would be another project,like I need another one!!!

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This is a for sale Eldorado that is wearing Dodge Charger wheels... While I still prefer the Challenger wheels over the Charger wheels, I thought this looks good on a silver car.

26524740006_large.jpg


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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This is a good example of what I do NOT want; Bling Bling... Whereas the first 20" wheels I tried on gave the car a sporty look, these 20's do a good job of downgrading the appearance of the car and make me wonder where the circus clowns are.

20587510080_large.jpg


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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Someone Photoshoped a set of C6 Corvette wheels on to this 93 Eldorado. Looks like they raked a staggered set in the wrong direction with the 19s up front. This might look alright if all four wheels were the 18 X 9.5 inch. I also think that the chrome grille and early style front bumper ruin the effect.

The C6 Vette wheels are my favorite rims and this is a possibility for my car if all four are 18s.

1994_cadillac_eldorado_2_dr_std_coupe-pi


Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

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18 X 8.5” with 50 MM offset Wheels & 255/45 ZR18 tires on my Eldorado

[/url]">http://0701150649-1.jpg

Two of my stock wheels were slightly bent and the two front tires were worn to the casing; I was trying to hold out until I had the budget to get 18 X 10 wheels and 275/45 ZR18 tires, but due to medical bills and other expenses, that didn’t work out. I had to get something right away. I was looking for a set of Mustang wheels cheap enough to be my winter wheels anyway, and I found these 18 X 8.5’s on craigslist for $100 (no tires). Most sets like this cost between $300 - $400 depending upon finish and tires.

[/url]">http://0701150649b-1.jpg

The owner had had them in storage for several years and wanted to get rid of them. He posted the ad very late Friday night and I happened to be online searching at that time. I made the 130 mile trip the next day and got them after a test fit and spin test. Several others were also trying to buy these wheels; thankfully, the seller allowed me first shot since I was the first to respond to the ad.

[/url]">http://0701150649a.jpg

My stock wheels have a 44 MM offset and these have 50 MM offset, so they actually come inboard a little more than I wanted them to, but they clear everything even when the wheels are turned from lock to lock. They have 6.75” backspacing whereas my stock wheels had 5.75” backspacing.

[/url]">http://0701151204-1.jpg

The tires stick out just enough to protect the wheel lips from curb rash and the sidewalls have a vertical look. The Corvettes use 255 MM wide tires when they use 8.5” wheels, and it’s a nice fit. The wheel/tire combination has a 6 – 7/8” or 6.875” backspace. The tires clear everything with room to deflect under hard cornering. I have not yet measured the tire to strut clearance yet, but it looks like about .25” before contact with bolts and .3” before contact with the welded ridge of the sway bar attachment. (pre 96 models will have this located in a different place on the strut – so the 97 – 02 up clearances will be different.

[/url]">http://0701151204a-1.jpg

They will be my winter wheels and the ones I use on long trips; that way, I can use summer tires on the 10" wide wheels when I get them.... someday..

[/url]">http://0701151203-1.jpg

for now, I have used tires on the car, but they are all Z rated all season with good tread. until I get my front suspension rebuilt and aligned, I don't want expensive tires on there.

Edited by Cody

Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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photo links are fixed.

Edited by Cody

Click here to visit the main directory for my subforum about my 2002 Eldorado build for autocross racing:

http://caddyinfo.ipbhost.com/index.php?showforum=96

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