275/35-18 Front Fitment Question - Attn 72BB and GDart

[mosleyme]

OK... lusting after 275/35-18 on a 18x9.5

A friend loaned me his 18x8 with 6" backspace. That works out to a 1.5" offset. I stuffed a 245/40-18 on the 8 and bolted it up on my '68 Barracuda. The idea is a 18x9.5 with the same offset (6.75" backspace) and a 275 should work. The 275 being 1.2" wider overall, or 0.6" each side. I also tested with a 5/16" spacer to push it out a little to get a better feel for the clearance on the outside. So, plenty of clearance everywhere except one spot. May even run a small shim with the 275 to push it out a little. Even with the 245/40 I rub the frame at full lock. To keep off the frame I would have to drop to maybe a 255 on a 8.5 and run a bit less backspacing.

72BBSwinger, looking at your pictures it does not look like your wheels turn as far as mine?

Peter (GMachineDart) - this offset is pretty close to your set-up and I believe we are running the same spindle and brakes (Dr Diff "Brembo type"), and you are not seeing this issue either?

I guess I need to get the exact size wheel and tire and just test it or buy them and make it work.

 

[72BBSwinger]

I say limit your steering stops or notch frame rails a little. My next setup is going to be 19x10's and 295/30/19's. Basically 1" wider tire and wheel than I already have.

 

[72BBSwinger]

Also what are your current alignment settings? It all makes a difference, my lower ball joints have cast in stops on them and they might be the difference too. I don't need any tighter turning radius unless I wanted a drift car.

 

[mosleyme]

I need to look into the stops. Maybe even adding some. The angle is pretty stupid. Last time I aligned it I set it up with -0.5 camber for both sides.

 

[72BBSwinger]

Also on your particular A-body, you have the tightest front fender openings of all. So in all honesty, I should keep my mouth shut recommending anything for yours. A 275 should be doable though.

 

[autoxcuda]

All for the front tires:

I got a 275/40/17 on a 17x8 rim with 5.5" backspacing without an issue. Ever so slight rub inside rear frame rail backing up. I think I have room to spare on the outside.

Now I have cut a 2"x3" triangle out of my front bottom fender lip. And the top wheel lip is rolled under. And rolled massage out a little. And the center fender brace is adjusted all out with 3/8" of spacers on the inner fender mount.

The last picture is deceiving. I probably shouldn't post it, because barracuda have that inset recessed fender lip. I should have taken that picture from underneath looking up at exactly the distance between the tire and the inside of the fender. My bad.

IIRC, the outside edge of these 275/40/17 on 17x8 with 5.5" backspacing around 3/4" farther inward from the fender lip than my current setup.

 

[roadrunnerh]

Wow, you guys are hard core with your wide wheels - rolling the rear lip AND cutting the fenders?

 

[mosleyme]

Also on your particular A-body, you have the tightest front fender openings of all. So in all honesty, I should keep my mouth shut recommending anything for yours. A 275 should be doable though.

OK... details.

• Dr Diff big brake kit, which is about 3/16" wider on each side that the Cordoba brakes.
• Magnum Force upper tube arm I bought a long time ago (maybe somewhere around '96-'98?)
• '75 disc spindle and LCA. LCA has stock sway bar tabs. '75 K-frame with through the K aftermarket sway bar.
• C-body tie rod ends and sleeves I bought in maybe 1994(?).

Front wheels are 18x9 "SVE Drift" made to fit a 2014 Mustang. Tire is a 255/40-18. I wanted to run a 26" tall tire and the 275/35-18 was a bit short. I wanted the 26" to make sure the front corner of the fender clears since we are doing body and paint now. I knew that would be the tightest point. As you can see in the last picture below, it is very tight, about 1/4". We are going to take a small cut out of the fender, I will get a few pictures, you will not be able to tell when it is done.

Front Wheel:
Diameter: 18 inch
Width: 9 inch
Finish: Black
Lugs: 5
Offset: +35 mm.
Backspacing: 6.38 in.
Bolt Circle: 4.5 in.

I may consider the 275/35-18 in the future, but may be better off running about +40mm offset in an 18x9 for that combination. I think the room is there. The 255 is a good starting point.

Rear axle is custom, made by Dr Diff in 2006 with his rear brakes. From wheel mounting surface on one side to the other total width is 55.75". This was 1.75" narrower than my factory A-body housing with shortened C-body axle shafts and 1970 B-body drum brakes. Rear springs are mounted inboard in the frame rail and inner wheel housings are relocated flush to the frame rail.

Wheel in the picture is a 15x10 with 1" offset (6.5" backspace) and tire is a 325/50-15 Drag Radial. Rear I will run the 18x10 "SVE Drift" made to fit a 2004 Mustang. I will probably run about 1/2" of spacer. I will make that determination next week when I mount the tires. Tires will be 295/40-18 for now.

Rear Wheel:
Diameter: 18 inch
Width: 10 inch
Finish: Black
Lugs: 5
Offset: +22 mm.
Backspacing: 6.36 in.
Bolt Circle: 4.5 in.

 

[autoxcuda]

I think it would be a good idea to roll the top of the fender lip some now before paint.

And it looks like you are going to have to bent in the bottom front fender lip in some way like Steve Ekstrand did and I copied.

I know that one picture I show looks pretty drastic. But since the Barracuda fender rolls inward, it really isn't that noticeable. I probably took off too much, but I do have extra room for future tires possibilities.

 

[mosleyme]

I think it would be a good idea to roll the top of the fender lip some now before paint.

And it looks like you are going to have to bent in the bottom front fender lip in some way like Steve Ekstrand did and I copied.

Steve - both are already in the works. The fender rolling tool was borrowed yesterday and I have the UPS tracking # in hand, delivery by Tuesday. For the front edge of the wheel opening the plan is to take a triangle cut out of the fender. About 1" at the bottom with the top of the triangle a little above the point you did. Then the existing lip will get pushed forward to fill the hole and welded to the fender. Once finished it will look almost the same and you will not be able to tell it was done.

 

[mosleyme]

Compare side by side 17" front vs. 18" front. 245/45-17 to 255/40-18
Difference in height is only 0.3"? There is a little difference in the angle of the picture that makes the car look a little shorter in the new picture.

 

[72BBSwinger]

Mike im going to use this opportunity to make pic for pic comparison of A-body Barracuda and 67+ Dart front fender openings

 

[mosleyme]

Mike im going to use this opportunity to make pic for pic comparison of A-body Barracuda and 67+ Dart front fender openings

Wow, that is quite the arch, never noticed the difference before. Mine is almost square in comparison. Body line is much higher on the Dart.

 

[mosleyme]

Steve - both are already in the works. The fender rolling tool was borrowed yesterday and I have the UPS tracking # in hand, delivery by Tuesday. For the front edge of the wheel opening the plan is to take a triangle cut out of the fender. About 1" at the bottom with the top of the triangle a little above the point you did. Then the existing lip will get pushed forward to fill the hole and welded to the fender. Once finished it will look almost the same and you will not be able to tell it was done.

Fender adjustment...

before vs after:

 

[72BBSwinger]

Awesome, you're doing this thing right. Make sure caster is pretty much where it is going to be while your at it. That can make clearances vary some, most of the time for the better in my experience.

 

[blue missile]

Hey Mike how are you doing?
I raised the front wheel openings 2" and notched the frame for my 255/40R17s.
Andrew

 

[mosleyme]

Hey Mike how are you doing?

Pretty good - things are coming along. Cut outs for the exhaust done today. Not much left in the body department.

Car should be in "high build primer" next week. Ready for lots of sanding.

I will put the rear tires on Saturday and do some work on the front end.

 

[mosleyme]

Fender adjustment...

before vs after:

Now, body work is done and front lip is rolled flat on the top. Minimum clearance at the front edge increased from about 1/8" to over 1".

 

[DA4AD]

I love the 18" look.
Been watching ebag for those mustang 18" rims. Hope to land some soon.
Keep up the good work.
:burnout:

 

[mosleyme]

Hope to land some soon.

Brand new these were $150 each for the front, $160 each for the rear.

 

[pauly v.100]

Hey Mike how are you doing?
I raised the front wheel openings 2" and notched the frame for my 255/40R17s.
Andrew

Just curious why, especially the raised wheel arch. What suspension are you running to allow your front to be so low that those mods are necessary? Nice work by the way! -pauly

 

[DA4AD]

Brand new these were $150 each for the front, $160 each for the rear.

I've been watching these in a black finish. I will paint or powder coat to my color.
http://www.ebay.com/itm/191119882152?ssPageName=STRK:MEWAX:VRI&_trksid=p3984.m1423.l2661

 

[72BBSwinger]

Those are wrong offset. You need 05+ Mustang.

 

[72bluNblu]

Now, body work is done and front lip is rolled flat on the top. Minimum clearance at the front edge increased from about 1/8" to over 1".

Very nice work! Only a purist would notice it, and only if they were looking for it.

The barracuda openings are better at the top, but narrow at the bottom. Similar to the Duster actually, wheel openings are more square. I know I have very little room with my 275/35/18's in the front on my Duster, if I ran 255/40/18's I would probably have had to do some work to the front corner as well. As it is, I just used the lower fender brace to push the corner out as far as it would go.

The Darts have less room at the top of the arch, but a much wider lower opening.

Here are the 275/35/18's on the front of my Duster. I've lowered it a bit more in the front since the bottom picture. It looks like a ton of room to the bottom front corner, but it barely clears when the wheels are turned.

 

[mosleyme]

I've been watching these in a black finish. I will paint or powder coat to my color.
http://www.ebay.com/itm/191119882152?ssPageName=STRK:MEWAX:VRI&_trksid=p3984.m1423.l2661

72BBSwinger - "Those are wrong offset. You need 05+ Mustang. "

72BB is correct. These are 1994-2004 mustang fitment. The 22mm offset on the 18x10 may work in the rear, you will need to measure, it will depend on your axle. But 18x9 w/ 24mm is not going to work in the front.

18x10 w/ 22mm offset is roughly 6-3/8" backspace.

18x9 w/ 24mm offset is 5.95" backspacing. That is not quite enough. That backspace will work in an 8" wheel, but not a 9" wheel.

My front wheels are 18x9 for a 2005-2014 Mustang. They have a 35mm offset which works out to be 6.38" backspacing. They fit, and they are tight. Depending on brakes, yours may fit better with the 35mm than mine. I have a Dr Diff kit that moves my wheel out 3/16" more than stock. Assuming yours is stock, that would be the same as putting a wheel with 30mm offset. Either way I do not think 22mm offset would work. Maybe if you stretched the fenders, cut the lips, and etcetera.

My rear wheels are 18x10 for a 1994-2004 Mustang, but my axle has been narrowed. The rear wheel would actually have fit better if I still had the stock width axle.