time666

Yet another question on wheel spacers, I have searched back to 2006 and for some reason I can't work this out and I know these questions are always being asked, I tried the calculators but not sure so I was hoping someone has similar set up could just say yes likely to fit or no chance!

I am looking for rear spacers, I currently have cup 1 wheels to:
8inch offset 52 with 255/40/17

I am looking to just improve the look by filling the rear arch, car is fitted with lowering springs (say 30-40mm)

I have had geo done, but don't think camper was set to much in, as I said not looking for track use, just fast road.

Has anyone a similar set up with spacers? I was going to chance 15mm, but given cost in would be pain to have to re-sell them on eBay if they didn't work out.

If you could be kind enough to offer any advice, it would be appreciated.

Thanks
Tim

Marc Shaw

The lowest ET you'll likely get away with is about 44 so 15 mm spacers would likely be a waste of money.

I'd get some 7 mm spacers and longer studs.

Marc

time666

Thanks Marc.

(The spacers I am getting will come with studs and bolts etc)

I think I follow you, so my current et52 plus the spacer of 7mm takes it to a virtual et45? Which is the max limit you would advised.

And i was looking at the current gap under the wheel arch and thought I'd get away with moving the wheel out at least 10mm!

Good job I didn't just go ahead and buy the 15mm ones then!

So someone with an ET60 could put on a 15mm spacer and end up with the same result as mine with a 7mm spacer basically? I.e. ET45

sml

It is dangerous for you guys to talk ET numbers without adding the wheel width. I think you should always write, for example ... 8ET52 or 10ET44 etc. Just writing ET44 is dangerous.

Anyway the above advice is incorrect.
He has an 8" wheel.
So you are recommending an 8ET44 which will not fill the arch very well.

Using this calculator ... and comparing an 8ET44 to a 10ET45 (which is a nice fit for the rear) ..
http://www.rimsntires.com/specs.jsp

The edge of the rim on the 8ET44 is 203mm wide subtract 159mm backspacing = 44mm
The edge of the rim on the 10ET45 is 254mm wide subtract 185mm backspacing = 69mm

So 8ET44 is not great ... you need another approx 25mm.

Try reading this thread slowly and work it out yourself ...
https://rennlist.com/forums/964-foru...el-offset.html

time666

Ok I tried your link, thanks for the info.
Given that I am not changing the tyre size or the wheel width, assume a lot of the info and calcs are not relevant, although interesting all the same.

For me having an 8ET52 rear wheel sporting 255/40/17 tyres, I only changed the ET setting from 52 to 67 (allowing for a 15mm spacer) and result show Backspace changes from 167mm to 182mm i.e. 15mm.

So unless I am missing something blatantly obvious, the tyre moves out by the same width as the spacer.

I guess I was being a little lazy hoping someone would say they have same size 8inch wheel with similar offset and they used a spacer size of X and it filled the arch without rubbing the tyre.

I was estimating that I got an outside clearance of 15 - 20mm looking at the edge of the fender/arch, hence why I was going to try 15mm.

Again much appreciate your efforts and reply.

sml

You mentioned that you read a lot of posts, so you may have read that a 10ET44 or 10ET47 is perfect, for example. You can then use the link to work out the same position of the outer rim edge to the guard, by comparing a 10" wheel to your 8" wheel, or 9.5" wheel to a 8" wheel. Similar to my comparison above.

Personally, I would just get a ruler and measure the distance from the tyre edge to just inside the guard and that is your spacer thickness.

time666

OK cheers sml, I will do that.

Thanks

Marc Shaw

He asked about 8" wheels so we both know we are talking about 8" wheels.


You are confusing tire width, "arch filling", backspacing, ond offset.

The simple calculators you directed the OP, while giving some nice numbers, are not always useful nor relate to the real world as the OP discovered and commented on in his post.

On the rear, I have run Boxster 17" rims (8.5ET50) with a 7 mm spacer, Fikse 18" rims (9.5ET51) with 5 mm spacers, and now use MY02 18" rims (10ET65) with a 21 mm spacer. All filled the arch nicely and none rubbed anywhere. All of these combinations came from lots of trial and error, initial use of calculators (that turned out to be wrong so I wasted money on a cr*pload of useless spacers), and lots of tire rubber rubbed off on suspension pieces until I got it right.

The reality is, at least in my experience, is that regardless of the tire width, if the ET is in the 43-47 mm range, everything fits well.

I guess you can go by the math or go by experience - your choice.

Marc

Dwane

I run a 15mm spacer on the rear with 17x9 et55 wheel...If that helps.
Marc, Got any 19mm spacers you want to sell?

sml

Well I guess the answer to the original question really depends on how much he wants to 'fill the guard'.

Marc Shaw's suggestion is a slight improvement, but you can definately go further out with zero problems ... by another 19mm from my calcs (compared to the 8ET44 suggestion).

OK .. so I think the easiest solution is as per my suggestion above .. he can simply measure the distance with a ruler and make his own decision how much he wants to 'fill the guard'.

time666

Hi Marc,
yeah to be honest I was hoping to go by other peoples experiences with what works with similar wheel size and offset.

Just thinking now, I'm going to jack the car up on one side so the other rear wheel fills the arch, then measure the clearance available to the fender/arch.

With the car sitting normal, looks like I have about 15-20mm available, but assuming when the suspension compresses, I thought that the wheel/tyre would slightly move inwards following the 'pivot line of the suspension' maybe I have this wrong though!

Either way, I think jacking the car up then measuring is now my best bet! As you said, I'm hoping not to end up with a load of spacers.

sml

Dwane is suggesting 9ET40.

Marc is suggesting 10ET44, 8.5ET43, 9.5ET46.

I suggest 10ET40 with full neg camber and slight guard roll.

You can use that in the online calculator to compare with your 8" rim width.

sml

Just so that is clear ... obviously the wheel width makes a significant impact to the position of rim edges - inner & outer, so you cannot just summarise and say ET43-47 is great.

sml

Yep Good plan.

time666

Thanks for you help sml, Marc and Duane. Think I'm good to go. Possibly 15 to 19mm is where I need to be.

6mm shims for the front? .....