Will this work

[2020gtrwd]

So I bought some wheels and tires and looked through the wheel and tires thread but could not find a definitive answer

I bought some 20x9 et 35 with 255/30/20 tires squared. It seems there were differing opinions on if it will fit or not on the front as far strut clearance. Any help would be appreciated. I also bought some 5mm spacers for the front just in case.

 

[Hawk853]

So I bought some wheels and tires and looked through the wheel and tires thread but could not find a definitive answer

I bought some 20x9 et 35 with 255/30/20 tires squared. It seems there were differing opinions on if it will fit or not on the front as far strut clearance. Any help would be appreciated. I also bought some 5mm spacers for the front just in case.

It will be close. Give them a test fit. The tire won’t be an issue as much as the wheel. You should be safe with that setup.

This is a 32mm offset. I think the lip is extra thick compared to some wheels and creates a larger backspace.

 

[2020gtrwd]

It will be close. Give them a test fit. The tire won’t be an issue as much as the wheel. You should be safe with that setup.

This is a 32mm offset. I think the lip is extra thick compared to some wheels and creates a larger backspace.View attachment 55675

Would a +35 be closer or farther away than a +32?

 

[2020gtrwd]

Nvm it will be closer. I just looked it up. So yea it will probably be close. I have seen others run the 35 offset on lowering springs didn’t know how being on stock suspension would effect it

 

[Hawk853]

Would a +35 be closer or farther away than a +32?

Closer

 

[2020gtrwd]

Closer

Thank you for your help I bought some 5mm spacers just in case. The wheels and tires are coming already mounted and balanced so I hope it works out

 

[Hawk853]

Nvm it will be closer. I just looked it up. So yea it will probably be close. I have seen others run the 35 offset on lowering springs didn’t know how being on stock suspension would effect it

Fortunately lowering springs won’t change that wheel to strut distance. That will remain constant.

Lowering springs just tuck the wheel into the well a little more, so people go with a smaller offset to keep things flush.

You’ll likely never fit aftermarket coilovers though.

 

[MerlintheMad]

What is the range for offsets? I've seen as close as 45 and as far away as 20 (and when I'm not concentrating, I reverse them; much like the issues I used to have with oversteer and understeer: always using them backwards; the shortcomings of not being a car guy, hah!).

 

[Hawk853]

What is the range for offsets? I've seen as close as 45 and as far away as 20 (and when I'm not concentrating, I reverse them; much like the issues I used to have with oversteer and understeer: always using them backwards; the shortcomings of not being a car guy, hah!).

Not a car guy? Didn’t you rebuild your car from a wreck salvage?

 

[Silverghost]

Not a car guy? Didn’t you rebuild your car from a wreck salvage?

I think that was General Vodka.

 

[MerlintheMad]

Not a car guy? Didn’t you rebuild your car from a wreck salvage?

I think that was General Vodka.

Silver is absolutely correct: @General_Vodka is a legend on the forum.

 

[Hawk853]

Silver is absolutely correct: @General_Vodka is a legend on the forum.
View attachment 55703View attachment 55704View attachment 55705View attachment 55706

That’s the one!

 

[MerlintheMad]

Anyway, back to my question: what is the range in offsets? I've never seen a minimum and maximum listed anywhere.

My reason for asking is informational only: I want to understand offsets, because they've been so mysterious to me the entire time. When I saw the 20mm I was frankly surprised: it's the only offset that low that I've heard of: Wheel/size/offset and tire/size/profile...can be confusing. (and the most recent example of me reversing offsets: the 20 would be way out there; the 40 would be risking rubbing: my own offsets are really close, at 39 and 40 Aftermarket Wheels )

 

[Hawk853]

Ok, so a range might be difficult to pinpoint, but... on a 9” (228.6mm) wheel with 0mm offset, the wheel mounting surface (WMS) to tire bead surface is 114.3mm.
With the above 35et wheel, he is at 149.3mm (which is moving the barrel further in towards the strut, or the WMS out towards the outside of the wheel depending on how you look at it).

But that doesn’t account for the extra material on the lip of the wheel which adds to the backspacing.

I wish I saved all the measurements I took after getting my wheels, but I think the rim was an extra 1/2” or 13mm. We’ll use that...

So now we have 114.3 + 35 + 13 = 162.3mm (6.4”) which is backspace
I have 7 or 8mm to my strut, so we have approximately 170mm from WMS to strut with a 20” wheel. Probably less, my wheel is a 32mm offset.

Since the strut is angled inside the wheel barrel on a bias, smaller diameter wheels will generally have a smaller amount of space to work with.

If my math is right, for an 8.5x20” (216mm) wheel to match the flushness as the above 35et wheel you’d take out 1/4” (6.5mm) of offset = 28mm
8.5”
Inside 108 + 28 = 136mm
Outside 108 - 28 = 80mm
9”
Inside 114.3 + 35 = 149.3
Outside 114.3 - 35 = 79.3

With the 8.5” you can bring the wheel out flush, but have more room for activities on the inside for larger coilovers.

So you can quickly make adjustments in your head since others before us blazed the trail and gave us something to work with. 6mm is 1/4” and 13mm is 1/2” approximately. You can move the wheel in and out for desired tuck/flushness/poke within the constraints of strut contact and fender rubbing.
You can also find the stock widths and offsets and make a few educated guesses on how much more your new wheels will stick out.
Hope I clarified part of your question.

 

[MerlintheMad]

Ok, so a range might be difficult to pinpoint, but... on a 9” (228.6mm) wheel with 0mm offset, the wheel mounting surface (WMS) to tire bead surface is 114.3mm.
With the above 35et wheel, he is at 149.3mm (which is moving the barrel further in towards the strut, or the WMS out towards the outside of the wheel depending on how you look at it).

But that doesn’t account for the extra material on the lip of the wheel which adds to the backspacing.

I wish I saved all the measurements I took after getting my wheels, but I think the rim was an extra 1/2” or 13mm. We’ll use that...

So now we have 114.3 + 35 + 13 = 162.3mm (6.4”) which is backspace
I have 7 or 8mm to my strut, so we have approximately 170mm from WMS to strut with a 20” wheel. Probably less, my wheel is a 32mm offset.

Since the strut is angled inside the wheel barrel on a bias, smaller diameter wheels will generally have a smaller amount of space to work with.

If my math is right, for an 8.5x20” (216mm) wheel to match the flushness as the above 35et wheel you’d take out 1/4” (6.5mm) of offset = 28mm
8.5”
Inside 108 + 28 = 136mm
Outside 108 - 28 = 80mm
9”
Inside 114.3 + 35 = 149.3
Outside 114.3 - 35 = 79.3

With the 8.5” you can bring the wheel out flush, but have more room for activities on the inside for larger coilovers.

So you can quickly make adjustments in your head since others before us blazed the trail and gave us something to work with. 6mm is 1/4” and 13mm is 1/2” approximately. You can move the wheel in and out for desired tuck/flushness/poke within the constraints of strut contact and fender rubbing.
You can also find the stock widths and offsets and make a few educated guesses on how much more your new wheels will stick out.
Hope I clarified part of your question.
View attachment 55707

Thanks!

A pic is worth a thousand of your words. I'm more visual than verbal.

All this time, I was looking at how close my spokes on my TSW "Watkins" wheels are to my front Brembo calipers, and thinking that is an offset situation; when actually the offset is "inside" where I can't see it; and backspace likewise, but as a measure from the mounting surface to the inner rim (TSW measures backspace in centimeters, e.g. my front backspace is 6.3); mounting surface to center of tread is the offset.

My wheel guys measured the TSW "Watkins" to a nicety on the outside (clearing, barely, the calipers in front). What I've been reading about (offset and backspace) was all on the inside. The only way I'd get more clearance from the calipers is either spacers or a deeper concave on the spokes.

If I understand this, a super deep concave wheel could actually (theoretically?) have a "negative" offset: with more of the barrel (the center point of the tread) outside/beyond the wheel mounting surface. This would be the type of wheel to suit a wide body abomination. Hah!

 

[westcoastGT]

Thanks!

A pic is worth a thousand of your words. I'm more visual than verbal.

There are thousands of us laughing at this Merlin , I can only imagine the Theatre in Your Mind !! Bawaaaaaaaa , !

 

[MerlintheMad]

There are thousands of us laughing at this Merlin , I can only imagine the Theatre in Your Mind !! Bawaaaaaaaa , !

Consider the context: I learn better visually. You're conflating verbiage with learning. It could be argued that if I talked less and read more that I'd probably learn more too. Hah.

 

[Hawk853]

Thanks!

A pic is worth a thousand of your words. I'm more visual than verbal.

All this time, I was looking at how close my spokes on my TSW "Watkins" wheels are to my front Brembo calipers, and thinking that is an offset situation; when actually the offset is "inside" where I can't see it; and backspace likewise, but as a measure from the mounting surface to the inner rim (TSW measures backspace in centimeters, e.g. my front backspace is 6.3); mounting surface to center of tread is the offset.

My wheel guys measured the TSW "Watkins" to a nicety on the outside (clearing, barely, the calipers in front). What I've been reading about (offset and backspace) was all on the inside. The only way I'd get more clearance from the calipers is either spacers or a deeper concave on the spokes.

If I understand this, a super deep concave wheel could actually (theoretically?) have a "negative" offset: with more of the barrel (the center point of the tread) outside/beyond the wheel mounting surface. This would be the type of wheel to suit a wide body abomination. Hah!

Yeah, TSW probably had a certain car in mind when they built those wheels and didn’t take big brakes into consideration.
They have drawings like this to build around.
I went with a company that builds the wheels to the millimeter to get them exactly where I wanted.
I think Stance, Forgestar, and lots of the fully Forged wheel companies like HRE, BC Forged, etc build to order like this and ensure caliper clearance.

 

[2020gtrwd]

So I put my wheels on today. I ended up having to run a 10mm hub centric spacer in the front because the wheels were not concave enough to clear the brakes I was able to get around 9 turns on the extended lug nuts . Should this be ok there wasn’t any vibrations while test driving the car.

 

[MerlintheMad]

So I put my wheels on today. I ended up having to run a 10mm hub centric spacer in the front because the wheels were not concave enough to clear the brakes I was able to get around 9 turns on the extended lug nuts . Should this be ok there wasn’t any vibrations while test driving the car. View attachment 56116

They are very pretty. I recall reading here recently that the minimum turn is five to secure the wheel. But if I remember correctly, that doesn't mean it's true, unless it is. Hah.