Fit to be tied with backspacing.

[Old5.Oguy]

Went to a custom rim place. Got a staggered setup 19x9 and 19x10. 255/40/19 in the front 285/35/19 in the rear. Told the guy the wheels I wanted and the slightly more aggressive stance I wanted with the rear wheel. Gave all my info about the car, tires I’d be using and that it was lowered an inch. Picked out the rims and had them make them. Guy plugged all the numbers Into a computer as well as speaking to his wheel guy in the shop. They came up with 25 backspacing fo the front and 30 for the back. I questioned it numerous times and I was told they’re done them before it will be within the fenderwll and line up nicely with it. Well have. A look at just the rims on the car. There isn’t much in the way of the rim to be shaved down anymore. I’m fit to be tried. Any advice would be appreciated.

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[Skye]

From the photos, the rear does look to be way out. And, the backspacing is not too deep, relative to what others have done with a rear, 10" rim (often a +35 offset or more). The front, not so far out.

But the car appears to be on a slope, the suspension unloaded, at least partially, no tire on rim, car not on ground, etc.

While I've used tire and rim tools on-line, I've not used one which accounts for a lowered car. IDK if the programs they used could compensate for that. Or if the alignment had been adjusted from the factory settings after lowering and they could compensate for that as well.

With the rims now made, the only way you're going to know how things fit while getting true measurements is to go all-in, with tires on rims, the car then put on level ground.

I'd pause, put everything back in their respective boxes. Re-read the agreement you signed, gather your thoughts and return to the shop.

Maybe things will be obvious from photos or a test fit of rim only. Maybe they'll want to put everything on the car to measure. It'll be part of the overall discussion.

However the talks go, have an agreement for what-ifs before proceeding. For example, it's not worth pursuing if, once on the car and not meeting expectations, they balk at making a new set or giving a refund.

https://tiresize.com/comparison/

Attached is a comparison between the two tires you intend on using. The sidewall height and the height of the front tire will be .1" / 2.54 mm taller than the rear. I did not compare what's on the car, factory sizes or what you're going to use amongst one another. One ideal to be aware of is the 3% rule.

A general rule of thumb is to stay within 3% of the previous tire circumference. While you can stray and go a bit bigger or smaller, once you get too far, shift points, speedo and other driving behaviors can begin being impacted.

If things work out between you and the shop, great. If not, I'd consider purchasing something ready made from the sea of available offerings, the most difficult problem sorting through and having to select only one.

Good Luck.

 

[WItoTX]

It looks fine to me. Put the tires on and compress the suspension, I'd bet it's flush with the arch. The rears will be close. I just went outside and looked at mine, and they sit almost exactly the same, and both wheels tuck into the wheel well nicely.

Or didn't you want it flush?

 

[Old5.Oguy]

From the photos, the rear does look to be way out. And, the backspacing is not too deep, relative to what others have done with a rear, 10" rim (often a +35 offset or more). The front, not so far out.

But the car appears to be on a slope, the suspension unloaded, at least partially, no tire on rim, car not on ground, etc.

While I've used tire and rim tools on-line, I've not used one which accounts for a lowered car. IDK if the programs they used could compensate for that. Or if the alignment had been adjusted from the factory settings after lowering.

With the rims now made, the only way you're going to know how things fit while getting true measurements is to go all-in, with tires on rims, the car then put on level ground.

I'd pause, put everything back in their respective boxes. Re-read the agreement you signed, gather your thoughts and return to the shop.

Maybe things will be obvious from photos or a test fit of rim only. Maybe they'll want to put everything on the car to measure. It'll be part of the overall discussion.

However the talks go, have an agreement for what-ifs before proceeding. For example, it's not worth pursuing if, once on the car and not meeting expectations, they balk at making a new set or giving a refund.

https://tiresize.com/comparison/

Attached is a comparison between the two tires you intend on using. The sidewall height and the height of the front tire will be .1" / 2.54 mm taller than the rear. I did not compare what's on the car, factory sizes or what you're going to use amongst one another. One ideal to be aware of is the 3% rule.

A general rule of thumb is to stay within 3% of the previous tire circumference. While you can stray and go a bit bigger or smaller, once you get too far, shift points, speedo and other driving behaviors can begin being impacted.

If things work out between you and the shop, great. If not, I'd consider purchasing something ready made from the sea of available offerings, the most difficult problem sorting through and having to select only one.

Good Luck.

Appreciate the input. So far the guy at the shop has been decent. I sent him the same pics and explained to him that the car was indeed jacked up however the rear wheel seemed wayyy too far out even for the suspension being alleviated of the wheel. I sent photos to the guy and he said ok bring the wheels in and we will see what we can do. Of course contrary to all the times I buy parts I paid cash so no disputing it on the credit card. I did tell him exactly what springs I used and how much the car was lowered. I gave him the factory offsets for the front and rear direct from ford and told him the tires I was using. I told him I wanted a slightly aggressive stance in the back to highlight the tire size difference and pretty much the stock look in the front with maybe a 1/4 inch bump out. When he arrived on 25/30 I questioned it. He called his wheel cutter and said the guy confirmed it would fit perfectly. He pulled up other mustangs and their offsets that they did and I said I hope so. When I got the boxes with the wheels I saw the offset was rated between 15-35 so it’s not even within the stock range for the rears, I knew then I could possibly have trouble. There’s nothing left to shave down without compromising the integrity of the wheel. One plus is I have an email from them stating they could make the wheel in the 35-50 offset range. Bringing them back in tmrw and I guess I’ll see if I’m out $1200 clams. Always small claims court too. Thanks again.

 

[Old5.Oguy]

It looks fine to me. Put the tires on and compress the suspension, I'd bet it's flush with the arch. The rears will be close. I just went outside and looked at mine, and they sit almost exactly the same, and both wheels tuck into the wheel well nicely.

Or didn't you want it flush?

How’s it going. I told the guy it was lowered 1 inch. I wanted the fronts to be about 1/4 further out than they sit now and the rears to sit just about flush with the fenders to give it a little bit more of an aggressive look. He put the tire sizes in and came up with 25 for the front and 30 for the rear. I questioned it a number of times he called his wheel cutter and said they will sit flush and he pulled up other mustangs he did and said they fell within the parameters. I said ok but when I picked them up I saw ET range 15-35 on the boxes and knew I might be in trouble bc if they were too far out they don’t have much wiggle room on the rears. Plus on the back I’m adding a tire that’s 1.3 inches wider so it’s another .65 of an inch more than it sticks out now. Going back tmrw and I’ll see what they have to say.
What size tires are you running and what’s your offset? Thanks

 

[WItoTX]

I run 19x11.5s, with 305 falken 660s (11.4" wide). They are a track day set up, but the location of the lip on mine is very similar to yours. I think you will be happy with how it turns out.

Keep inind, if the tire is massively winder than the rim, you will not be happy with the handling characteristics with the new set up. It will feel floaty and vague with steering inputs.

 

[Old5.Oguy]

I run 19x11.5s, with 305 falken 660s (11.4" wide). They are a track day set up, but the location of the lip on mine is very similar to yours. I think you will be happy with how it turns out.

Keep inind, if the tire is massively winder than the rim, you will not be happy with the handling characteristics with the new set up. It will feel floaty and vague with steering inputs.

Are you lowered? Do you remember your offsets? I’m only running a 285/35/19 so it’s the perfect size for the 10 inch tire. I’m aware they stick out a little when the suspension isn’t compressed but the rears look wayyyyyy off to me on mine. I guess I’ll find out.

 

[WItoTX]

It's lower, like 12 mm in the rear, and about 15 mm in the front. Also a 30 profile tire. And I have 3.1 degrees camber in the front as 2.1 in the rear.

It's a ET56 rim, but it's not apples to apples with yours. Let us know how it ends up.

 

[GregO]

@Old5.Oguy
Offset and Backspacing are two different things.

S550 Mustang with a 10” wide wheel = +35mm to +40mm offset.

 

[TonyNJ]

The OP is talking about 30 and 25 back spacing. I have to believe he means 30 and 25 offset. Back spacing is usually discussed in inches. A 30 offset in the rear might poke out a bit. 35 in the rear is pretty flush. Example is the LMR GT350 10" wheel kit. All 4 are 35mm offset. They are pretty flush in the rear.

Is it possible the wheels the OP got weren't built correctly? Or maybe this is just the suspension hanging. Time to install tires and see.

 

[Old5.Oguy]

The OP is talking about 30 and 25 back spacing. I have to believe he means 30 and 25 offset. Back spacing is usually discussed in inches. A 30 offset in the rear might poke out a bit. 35 in the rear is pretty flush. Example is the LMR GT350 10" wheel kit. All 4 are 35mm offset. They are pretty flush in the rear.

Is it possible the wheels the OP got weren't built correctly? Or maybe this is just the suspension hanging. Time to install tires and see.

How’s it going. Yes I meant offset. The fronts are 9 inch rims with a 25 offset with 255/40/19’s. I’m thinking when the suspension drops they will tuck in decently. But the back to me looks wayyyy off. 10 inch rim 285/35/19 tire 30 offset. I’m going back tmrw to talk to the guy he can get 5mm more off the rear wheels as the box the wheels came in said the the offset is 15-35. What I’ll probably do is when I get the rear tires I’ll make a suggestion that they put the tires on the wheels and I’ll pay for the mounting and balancing, if they don’t fit properly it’s on them bc they made the suggestions as far as the offset. If it fits then I won’t be fit to be tied anymore. Thanks for the information.

 

[m3incorp]

You aren't going to be able to tell if it works until you mount the tires and take the car off the jack. Keep in mind, a little camber adjustment can sometimes correct a slight poke.

 

[WItoTX]

OP, any update?

 

[shogun32]

When I got the boxes with the wheels I saw the offset was rated between 15-35 so it’s not even within the stock range for the rears

That pattern is for Nissan.

Have them recut the rears for at least 35mm.

Can you make those work? Yeah but you'll need to camber the snot out of them.

 

[Old5.Oguy]

OP, any update?

How’s it going. I’m going tmrw to have them install the rims. If it doesn’t fit properly they still have 5-7mm they can take off the rears and 10-12 on the Fronts. I’m not too concerned with the fronts bc it’s an entire inch smaller and the tires are 1.4 inches narrower plus the amount they can still take off the rim itself. I’ve had a few people tell me I will probably be able to get away with it because they are running the gt 350’s squared from American Muscle and they are all 35mm offsets. We will see

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