Appropriate Wheel Offset for 18" Wheels?

[MuuMuu101]

So what size offset do you think I'd need front and back. Due to the small wheel wells, I'll constrict myself to 245/40/18's for now (8-9.5" wide wheel). Using the same tire size and offset, I don't see how wheel width would matter. All it would do is stretch or bulge the sidewalls.

Just surfing CL these are some of the wheel specs I found that might work with or without spacers...

1) XXR wheels
Bolt Pattern: 5 x 4.5" / 5 x 100mm
Hub Centerbore: Unknown
Width: 8.5"
Offset: 35 mm

Not a fan of the duel bolt pattern. Not a very wide wheel. Need spacers for rear.

2) Unknown make or Varrstoen ES2 (found two different wheels)
Bolt Pattern: 5 x 4.5"
Hub Centerbore: 73.1mm
Width: 9.5"
Offset: 22 mm

Based off of my research, I feel like I could get away with this combo without or with very skinny spacers front and rear. Plus the width may end up helping me out if I choose to go wider tire in the future. Both wheels are built to clear big brakes.

3) Enkei RP01
Bolt Pattern: 5 x 4.5"
Hub Centerbore: Unknown (could find them if I searched hard enough)
Width: 9"
Offset: 42 mm

Would definitely need spacers.

I kind of like option two as they look nice and may seem to fit both the front and rear with little work. All wheels are $650-800 w/out tires. The ES2's come with NT05 245/40/18's for an extra $500 if I want them. The Enkei's are about $1400 for wheels and tires but they're on RS-23 265/35/18.

Pictures are posted in order of how they're listed... XXR, Unknown, ES2's, Enkei...

 

[MuuMuu101]

Thinking about possibly just getting some quality wheels and using a spacer... I'm kind of liking the Enkei PF01. I kind of like black but silver is cheaper and will get here sooner if I order them. I know I'll need spacers in the rear, I'm just not sure how wide.

http://www.summitracing.com/parts/enk-4608956635bk

I think they should look good with big brakes.

 

[MuuMuu101]

I'm reading up on spacers and I'm not sure I like the idea of them. Even bullet hub centric ones.

 

[DNasty777]

Spacers... where to start. The topic of spacers has come up multiple times on every auto forum I've been a part of and it is a very dividing one. My thoughts on them, run them if you have to and don't if you don't. I have them on the rear of my valiant for now because I can't justify spending the money on a set of wheels for a rear end I'm not going to keep.

 

[MuuMuu101]

Spacers... where to start. The topic of spacers has come up multiple times on every auto forum I've been a part of and it is a very dividing one. My thoughts on them, run them if you have to and don't if you don't. I have them on the rear of my valiant for now because I can't justify spending the money on a set of wheels for a rear end I'm not going to keep.

See, that's the thing, I'd like to have a set of wheels where I don't need to run them. I know, with the proper maintenance and quality parts, they can be perfectly ok. I'm just one of those guys who only likes to worry about things once.

 

[72bluNblu]

Spacers aren't a big deal. They're run on autocross cars and off-road trucks all the time. They're just like aluminum rims, you have to periodically check them for the correct torque. That's it. And really, once they've been properly torqued the first time, and then again after about 100 miles, they usually don't require much torquing. I've run them on both cars and trucks without issue.

As far as the spacer goes for the rear, your A-body rear, stock spring location, and disks mean you really need to end up close to 0 offset. Maybe a little on the +offset side of that because of the slight increase in track from the disks, but that extra offset is only 1/8" so really just +3 or +4mm. So, whatever the advertised offset is you'll need that size spacer. +35mm offset? +35mm spacer. The large, stud equipped spacers usually start at 1" and go up in 1/4" increments. So 35mm is 1.37", but if you get a 1.25" spacer (31.75mm) you should be close enough.

If you're going to stick with 245's all the way around you don't need a 9.5" wide rim. 8.5" or 9 would be fine. Not sure what you have for UCA's in the front, but the wider rims don't usually clear the stock UCA's at full droop and lock. Even my 18x9's didn't, and they have 35mm offset that I run on DR. Diffs 13" rotors. I'm running 3mm spacers in the front now, so 32mm. And I still have a little room to the outside, so you can probably run your 245's with as little as 18 to 20mm offset, which would give you more room for the UCA.

Personally, I'd try to go 18x9" with 255/40/18's. The problem with 245's is the 245/40/18 is only 25.6" tall, and the 245/45/18 is 26.7". So you need 245/40/18's to run square, and that's a little short for the rears.. The 255/40/18's are 26" tall, which is just about perfect to run front and rear.

For the PF01's, I'd get the 18x9's with a 35mm offset. You'll should be able to use a 1.25" spacer in the back and clear. In the front you may need a small spacer, 3 or 5mm. You will want to check your clearance on the UCA's, I had to go tubular to clear at full droop and full lock. You could run either the 245's or 255's on those. Also keep in mind you will still need to either have the hubs machined to clear the wheel hub bore, or have the hub bore opened up. Dr. Diff's rotors still have a 2.7" diameter hub, and that won't clear the hubs on the enkei's. They start at 73mm, but neck down to 2.5" (63.5mm) for the wheel cap. I had my RPF1's bored to 73mm straight through. No step, and that way they'll clear the 11.75" mopar rotors as well. I won't be rotating tires though since I have a staggered set up. If I were rotating I would have the hubs machined so I didn't have to make wheel caps for all 4 rims.

 

[MuuMuu101]

Spacers aren't a big deal. They're run on autocross cars and off-road trucks all the time. They're just like aluminum rims, you have to periodically check them for the correct torque. That's it. And really, once they've been properly torqued the first time, and then again after about 100 miles, they usually don't require much torquing. I've run them on both cars and trucks without issue. As far as the spacer goes for the rear, your A-body rear, stock spring location, and disks mean you really need to end up close to 0 offset. Maybe a little on the +offset side of that because of the slight increase in track from the disks, but that extra offset is only 1/8" so really just +3 or +4mm. So, whatever the advertised offset is you'll need that size spacer. +35mm offset? +35mm spacer. The large, stud equipped spacers usually start at 1" and go up in 1/4" increments. So 35mm is 1.37", but if you get a 1.25" spacer (31.75mm) you should be close enough. If you're going to stick with 245's all the way around you don't need a 9.5" wide rim. 8.5" or 9 would be fine. Not sure what you have for UCA's in the front, but the wider rims don't usually clear the stock UCA's at full droop and lock. Even my 18x9's didn't, and they have 35mm offset that I run on DR. Diffs 13" rotors. I'm running 3mm spacers in the front now, so 32mm. And I still have a little room to the outside, so you can probably run your 245's with as little as 18 to 20mm offset, which would give you more room for the UCA. Personally, I'd try to go 18x9" with 255/40/18's. The problem with 245's is the 245/40/18 is only 25.6" tall, and the 245/45/18 is 26.7". So you need 245/40/18's to run square, and that's a little short for the rears.. The 255/40/18's are 26" tall, which is just about perfect to run front and rear. For the PF01's, I'd get the 18x9's with a 35mm offset. You'll should be able to use a 1.25" spacer in the back and clear. In the front you may need a small spacer, 3 or 5mm. You will want to check your clearance on the UCA's, I had to go tubular to clear at full droop and full lock. You could run either the 245's or 255's on those. Also keep in mind you will still need to either have the hubs machined to clear the wheel hub bore, or have the hub bore opened up. Dr. Diff's rotors still have a 2.7" diameter hub, and that won't clear the hubs on the enkei's. They start at 73mm, but neck down to 2.5" (63.5mm) for the wheel cap. I had my RPF1's bored to 73mm straight through. No step, and that way they'll clear the 11.75" mopar rotors as well. I won't be rotating tires though since I have a staggered set up. If I were rotating I would have the hubs machined so I didn't have to make wheel caps for all 4 rims.

So Dr Diff said the new rear end with brakes are 58.175" wide or and the axle conversion adds an extra 1/4" on top of the 1/8" for the rotor hat on each side. The reason I'd go for a 9.5" wide wheel is that it will straighten out the sidewall (better for cornering), and if I wanted to go with a wider tire in the future, I'd have options. If it's a 2 piece wheel, I could break the welds and move the centers out or in. The problem with a 255/40/18 is that there isn't really a good tire selection for autocrossing. For UCA's I'm using Hotchkis's tubular so I don't think I'd have much of a problem. The hub info is good to know. I didn't know some wheels had tapered centers bores. Do you think a +22 offset would fit on all 4 corners?

 

[72BBSwinger]

No, could get by with a 28-30mm offset front minmum on an 18x9. You will kick yourself trying to fit 9.5 in the rear, wont happen. 4 wheels at 18x9 with 30mm offset is lesser of 2 evils as far as front clearance, you will -1 gegree camber or more, and the smallest spacer needed in the rear.

 

[MuuMuu101]

No, could get by with a 28-30mm offset front minmum on an 18x9. You will kick yourself trying to fit 9.5 in the rear, wont happen. 4 wheels at 18x9 with 30mm offset is lesser of 2 evils as far as front clearance, you will -1 gegree camber or more, and the smallest spacer needed in the rear.

It seems I won't be able to win this battle unless I get a staggered setup... Off to search for more wheels. :violent2:

So another question... What difference does it make if I have, for example, an 8.5" wide wheel or a 9" wide wheel with the same offset and tire size? The tire is going to be wider than the wheel lips anyways.

 

[72BBSwinger]

A 245 on an 8 is flush and a 255 on a 9 is too. 255/40/18's on 18x9's is what Peter runs on his with staggered wheels. He can answer your question to a t.

 

[MuuMuu101]

A 245 on an 8 is flush and a 255 on a 9 is too. 255/40/18's on 18x9's is what Peter runs on his with staggered wheels. He can answer your question to a t.

O, you know what, I'm forgetting that the wheel width is measured from the inside of the lip on one side to the inside lip of the other side. The lip extends an extra inch on each side. Stupid error on my part. :violent1:

 

[72BBSwinger]

Peter gives his wheel specs in this thread, I told you would not need more than a 1/2" spacer in the rear.
http://www.forabodiesonly.com/mopar/showthread.php?t=136761&page=3

 

[MuuMuu101]

Peter gives his wheel specs in this thread, I told you would not need more than a 1/2" spacer in the rear. http://www.forabodiesonly.com/mopar/showthread.php?t=136761&page=3

I'll look it over. I'm looking through the site Tomwheels recommended to see if I have different options: http://www.americanmuscle.com/18inchwheels.html

Edit: Looked it over and it seems like he had the perches moved in allowing him to run about +24mm offset in the rear. Just an observation. I'm also looking on Summit for wheels I like and trying to see if I can find a wheel with two different offsets.

 

[MuuMuu101]

So, I know this is kind of cheesy but I made a mock up wheel out of cardboard to see what offset I'd need for the rear. It's just a cut circle with a rectangular piece taped to the circumference to simulate the width of the tire. I measured it on both sides of the car just in case my perches weren't centered on the rear axle. The wheel is cut to about a 245/40/18 tire (may be a tad taller and wider). Overall, I got that I'd have at least if not more than a finger's worth of room on both sides (leaf spring to outer trim) with about a +7-8mm offset. I measured 130 mm from the outside of the inner "tire" cardboard to the inner face of the cardboard. 245mm/2 = 122.5mm -130mm = 7.5mm. To use a max of a 1/4" spacer I have to find a wheel that offers a minimum of a +30mm offset for the fronts and about a +13-14mm offset for the rears.

So far the wheel that may fit my description on Summit is:
http://www.summitracing.com/parts/dgw-22786/overview/
http://www.summitracing.com/parts/dgw-22783/overview/

The Enkei PF01 is offered in +15mm, +35mm, and +45mm +with the 9.5" wide wheels. I'm not sure if they'll fit even though a 245/40/18 will still mount to them. The center bores may have to be bored out to 73mm as they're tapered:
http://www.summitracing.com/search/brand...mp;autoview=SKU

 

[72BBSwinger]

Those wheels from Summit might just work.

 

[MuuMuu101]

I visited my friend today and borrowed his Mustang wheels with 275/40/17's on them (he's got a late 90's or early 00's GT). He also gave me a 245/45/17 in case I wanted to swap them. The 275/40/17 is a Hancook Ventus and the 245/45/17 is a Nitto NT555. The jack stands are mounted underneath the rear end of the car with an 1/8 tank of gas (so the suspension is loaded). So, I tried the wheels on the driver's back of the Dart, no spacers or washers, it seems like the tires will fit with little modifications just with less offset. The wheel is flush on the rotor surface. and I can spin it freely without any rub.

In one picture, there's about an inch or so till you hit the outer wheel lip and if needed I could even trim that down a touch. In the other, there's a touch of room (maybe 1/4") between the leaf spring and the tire. Sorry for the funky/blurry pictures.

So, am I missing something? Is the suspension not loaded enough? How much room should I look for between the tire and the outer trim/leaf springs should I look for? With a little trimming and a different offset, it seems like a 275/35/18 should fit without much of a problem.

 

[MuuMuu101]

Picture 1: IIRC, the wheels may be 17 x 9 as the tires bulge out a bit. So, I threw almost 100 lbs in the trunk and added about 0.200" (5mm) as the suspension wasn't loaded enough. Leaf springs look almost flat now... Picture 2: About 3/4" from tire to outer trim. Picture 3: About 1/2" from tire to leaf springs.

 

[72bluNblu]

Did you do a spring offset? Or are your springs still in the stock location?

From the pictures, I would say you have less room than what you indicated. Tape measures are lousy for getting measurements that small, and you want to make sure everything is lined up straight. The tires having some bulge to them makes good measurements tricky. I know it seems nit-picky, but when the tolerances get that tight it matters.

To get your spring-to-tire measurement, use a straight ruler and slide it to the tire across the top of the leaf spring. For the tire-to-quarter measurement, use a straight edge across both outer edges of the tire (I use a cut down yard stick). Then measure from the straight edge straight across to the lip. That one's even more important if the quarters are still above the widest part of the tire (at the bulge).

Pictures can be pretty deceiving because of the angles involved, but I don't think you have enough room to keep from rubbing once you're driving down the road. For example, if you look at this picture you would think I probably have at least an inch or more from the quarter lip to the tire on the back of my Duster. But measured with a straight edge, keeping everything parallel, I really only have about a 1/2".

Same for this on. The 225/60/15 on the cop rim in this picture actually rubbed on the quarter lip under compression (speed bumps). Not much, I never actually heard it, but it left a scuff on the tire.

 

[MuuMuu101]

Did you do a spring offset? Or are your springs still in the stock location? From the pictures, I would say you have less room than what you indicated. Tape measures are lousy for getting measurements that small, and you want to make sure everything is lined up straight. The tires having some bulge to them makes good measurements tricky. I know it seems nit-picky, but when the tolerances get that tight it matters. To get your spring-to-tire measurement, use a straight ruler and slide it to the tire across the top of the leaf spring. For the tire-to-quarter measurement, use a straight edge across both outer edges of the tire (I use a cut down yard stick). Then measure from the straight edge straight across to the lip. That one's even more important if the quarters are still above the widest part of the tire (at the bulge). Pictures can be pretty deceiving because of the angles involved, but I don't think you have enough room to keep from rubbing once you're driving down the road. For example, if you look at this picture you would think I probably have at least an inch or more from the quarter lip to the tire on the back of my Duster. But measured with a straight edge, keeping everything parallel, I really only have about a 1/2".

Same for this on. The 225/60/15 on the cop rim in this picture actually rubbed on the quarter lip under compression (speed bumps). Not much, I never actually heard it, but it left a scuff on the tire.

The springs are in the stock location and I know there is going to be some modifications needed to make this work. The tires do have some bulge to them and I know the pictures are deceiving. If I trim the lip a bit and reduce the offset I might be able to get a little more room as I'm definitely not happy with the inner spring clearance. I've also got to check the wheel wells as I'll have to do some "massaging" to get it to work. It just looks so close and too good to be true.

 

[DNasty777]

275 on my Valiant, 7-1/4 plus 1.5" (IIRC), 17x9 33offset

 

[MuuMuu101]

275 on my Valiant, 7-1/4 plus 1.5" (IIRC), 17x9 33offset

Have you driven it? Do you have rubbing issues? Any modifications?

 

[DNasty777]

Oops! Forgot to say stock 7-1/4 with 1.5" conversion spacers. No rubbing with the tired stock leafs, just put some hotchkis units in and haven't really pushed it yet. Normal street driving and no issues so far. No mods other than the spacers.

I have to measure my hub-to-hub distance for an 8-3/4, I'll let you know what i get.

 

[tomswheels]

Hey Samy I'm now running 285/35/18 Hankook R-S3s on 18x10 inch wheels front and rear on my 1967 Valiant. I have the exact same front suspension as you, my 18x10 front wheels work with both a +24 and a +30 offset. I've obviously done some fender massaging. In the rear my 8.8 is a little wider than your rear, 59.5 inches, but the perches remain in the stock location. Again with fender massaging the 285 Hankooks on 18x10 with either a +24 or +30 offset work.

 

[MuuMuu101]

Hey Samy I'm now running 285/35/18 Hankook R-S3s on 18x10 inch wheels front and rear on my 1967 Valiant. I have the exact same front suspension as you, my 18x10 front wheels work with both a +24 and a +30 offset. I've obviously done some fender massaging. In the rear my 8.8 is a little wider than your rear, 59.5 inches, but the perches remain in the stock location. Again with fender massaging the 285 Hankooks on 18x10 with either a +24 or +30 offset work.

I have to wait another week or so before I can mock up the wheels on the front. I'm kind of on hold till next weekend as I'm settling into school right now. I think 275's should be fine for now. I'm assuming these wheels are about a +24mm offset so I guess I was right when I said I needed something around a +19mm offset. I still have to check the other side. I really like how your buddy did your rear fender flair though.

 

[72BBSwinger]

Hey Samy I'm now running 285/35/18 Hankook R-S3s on 18x10 inch wheels front and rear on my 1967 Valiant. I have the exact same front suspension as you, my 18x10 front wheels work with both a +24 and a +30 offset. I've obviously done some fender massaging. In the rear my 8.8 is a little wider than your rear, 59.5 inches, but the perches remain in the stock location. Again with fender massaging the 285 Hankooks on 18x10 with either a +24 or +30 offset work.

Pics or it didnt happen Tom.