USMARINE1108

iTrader: (2)

I've got a set of 18x9.5 ZR1's. I'm wondering if it's possable to have 2 of them widened to 18x11? Anyone know? Has it ever been done? Will it throw the offset off too much? Thanks for any info!

DMH Fabrication

iTrader: (126)

On ws6.com that guy got his widened. Hope that helps somewhat

blue01ta

iTrader: (4)

www.fixrim.com I've read that there Miami shop is the only one that widens aluminum wheels. So you may want to contact them to know for sure.

thesoundandthefury

iTrader: (3)

www.weldcraftwheels.com

I've already had them widen a set for me. $200 per rim if they're painted, but the price goes up if they're chromed. (They have to strip the chrome in the spot they're gonna weld.) Turnaround time was 5 days. Hope that helps.

USMARINE1108

iTrader: (2)

Thanks! Are you happy with them? Do they drive okay?

thesoundandthefury

iTrader: (3)

As far as their service goes, couldn't have asked for better. The operation was quick and painless. The welds are top notch. I haven't gotten to put them on the car yet because I'm polishing them, but I'll be sure to give a full report once they're finished and mounted.

I know this is a crappy pic, but here's what one looks like from an angle:

IMJ

iTrader: (1)

ALL U NEED IS 1.5" tell them u want a discount your a member of ls1tech!!!!

Blackbird

Are you going to have to put spacers on to fit those back on the car?

Won't they hit the inner fender well now since I assume the offset is going to be totally wrong for the width of the wheel?

I would love to widen my wheels but I don't see how this will work well.

thesoundandthefury

iTrader: (3)

Whether you'll have to end up using spacers depends alot on what the original offset of the wheel is before widening. On my rims, the original size was 18X8, with a +38mm offset. The lip of the rim sits dead even with the top of the fender, which is right where I wanted it. After the rims were widened, this brought the offset up to +56mm. What you have to remember is that offset is measured from the wheel's centerline, (widthwise), and anytime you widen a wheel this moves the wheel's centerline over depending on how much you widened it. Alot of people make the mistake of converting the strip of aluminum being welded into the wheel from inches to millimeters, then just add that to the original wheel's offset measurement. Then they end up with this ridiculously high offset and compare it to the "what will fit" chart and discover that the offset they came up with doesn't fit.

Here's the formula for calculating the new offset of a widened rim:

Example rim: 18X9.5 +56mm offset and 7.4" backspacing
Target width: 18X11

1 inch= 25.4mm

The wheel's new centerline after widening is calculated by:

width/2

We'll make this easier by converting inches to millimeters:

25.4*9.5= 241.3mm
241.3mm/2= 120.65mm

25.4*11= 279.4mm
279.4mm/2= 139.7mm

The way to calculate the wheel's new offset is to take the distance from the wheel's edge to centerline measurement on the original wheel, subtract that amount from the measurement of the distance from the widened wheel's edge to the new centerline, and add that amount to the original wheel's offset.

So:

139.7mm-120.65mm= 19.05mm
19.05+56= 75.05mm

So from this, we can see that a wheel that was originally 18X9.5 with a +56mm offset that is widened to 18X11 will have a new offset of +75mm. If we look at the "does this fit" sticky, we can see that it won't fit. Going by the chart, we can see that the maximum offset allowed for an 18X11" wheel is +56mm, so how do we fix this? We add a spacer.

We calculate spacer thickness by subtracting our target offset from the offset measurement of the newly widened wheel. For this example, let's say we wanted our target offset to be the "optimum" offset suggested for 11 inch wide wheels by the "does this fit" sticky. That offset is +50mm.

So:

75mm-50mm= 25mm

So as you can see, after all our calculations are done, in order to fit an 18X9.5+56mm wheel widened to 18X11+75, we need to use a 1 inch spacer.

Hope that helps.

Blackbird

very helpfull.

now how does one figure out what the offset of their wheel is?

I have 17x9 aftermarket wheels that I have no idea what the offset of them is and the manufacturer is long out of business.

Blackbird

Also what is the consensus on spacers?
In years past I have always read they are dangerous to use.
Is this still the case?

thesoundandthefury

iTrader: (3)

Offset is the distance from the wheel's hub to the wheel's centerline. An easy way to calculate is this:

Take a ruler and butt it up against the wheel's inside hub, then see where the measurement comes out at the wheel's inside lip. (The side of the rim that faces the wheel well.)

After you get this measurement, divide your wheel's total width by 2.

In your case: 9"/2= 4.5"

Next, convert the measurement you got with your ruler into millimeters. Just as an example, let's say you came up with a 7" backspace measurement.

7*25.4= 177.8mm

Then you convert the centerline measurement to millimeters.

4.5*25.4= 114.3mm

The final calculation for determining offset is to take your measurement from the wheel's centerline, (114.3mm), and subtract that from your backspace measurement, (177.8mm).

177.8-114.3= 63.5mm

+63.5mm offset (Just an example.)

Blackbird

any opinions on the use of spacers?

Spinmonster

You have two good choices with no adverse affects....and one that is not so smart.

Choice 1: best: get arp studs to replace your existing ones and billet spacers frpm thunder racing

Choice 2: also good even in drag race power: http://www.ezaccessory.com/.sc/ms/dd...2E75%26quot%3B

no stud change necessary to the car so it is fully reversible in minutes. Great for any drag application.

Good luck.