Sizing between 17, 18 and 19"

Meds · Post by **Meds** » Sat Oct 21, 2023 4:35 pm

A quick sanity check please.

My E86 is running on Eiback Pro springs, Koni dampers.
I currently run 225/35/19 8Jx19 ET37 on the front axle. (Style 230)
These rub on the arch liner, where the front bumper and wing join.
The rears are fine.

I want to drop to an 18" wheel, even 17" if I can.
18" wheels in 8" width, the ones I fancy are ET34.
17" wheels in 8" width, the ones I fancy are ET34

Compared to 19x8J ET37 225/35/19:
18x8J ET34 is 3mm more outwards, this would result in more rub if I run the same width but higher profile (225/40) tyre?
17x8J ET34 is 3mm more outwards, this would result in more rub if I run the same width but higher profile (225/45) tyre?

I think what I'm wanting someone to tell me is; my only option is to decrease the poke (offset increase). Changing wheel diameter makes no differece to the effect of offset. Stop trying to stick a round peg in a square hole.

I could drop tyre width, but 225 is the happy medium for an 8", and I really do not want to decrease circumference and make the car any lower than it is.

I think I'm stuck..
Either raise the car back to stock height and have a free choice of any wheel, or go with OEM (108 / MV2 / 203) wheel designs with an ET of 47.
There doesnt seem to be anything between ET37 and 47 (OEM BMW).

I really question how other folk are running the combination Eibach Pro and any wheel with more agressive offsets other stock ET47, without rub in the front.
Maybe I have knackered/soft front springs?

Zedebee · Post by **Zedebee** » Sat Oct 21, 2023 5:47 pm

When I had my E86 I ran a winter set of 8Jx17 et34 with 45 profile tyres. This was by far the most comfortable to drive on and also filled out the arches well. But that was on SE stock suspension. I expect riding on lowered springs and 19s with low profile tyres would be quite jarring, unless the Konis are really good. A return to full height may be your best option, with the added benefit that it is so much easier to get a jack under the car

brillomaster · Post by **brillomaster** » Sat Oct 21, 2023 6:28 pm

Well, a 225 35 19 doesnt have exactly the same diameter as a 225 45 17... 640mm plays 634mm. So youd gain 3mm clearance back by switching to a 225 45 17...

You could just go back to an oem 17x8 wheel with a high offset, then space out by 10mm to make an effective et40...

Also, theres a few mm of clearance to be gained from maximising the front camber with the slotted top mount holes, could give that a go...

Meds · Post by **Meds** » Sat Oct 21, 2023 7:56 pm

Zedebee wrote: ↑Sat Oct 21, 2023 5:47 pm When I had my E86 I ran a winter set of 8Jx17 et34 with 45 profile tyres. This was by far the most comfortable to drive on and also filled out the arches well. But that was on SE stock suspension. I expect riding on lowered springs and 19s with low profile tyres would be quite jarring, unless the Konis are really good. A return to full height may be your best option, with the added benefit that it is so much easier to get a jack under the car

I dont find the ride jarring at all. It's quite refined and handels very well. I'm overall happy with the set up.
But, I need to address this rub issue.

Meds · Post by **Meds** » Sat Oct 21, 2023 8:01 pm

brillomaster wrote: ↑Sat Oct 21, 2023 6:28 pm Well, a 225 35 19 doesnt have exactly the same diameter as a 225 45 17... 640mm plays 634mm. So youd gain 3mm clearance back by switching to a 225 45 17...

You could just go back to an oem 17x8 wheel with a high offset, then space out by 10mm to make an effective et40...

Also, theres a few mm of clearance to be gained from maximising the front camber with the slotted top mount holes, could give that a go...

I really do not want to decrease the rolling circumference, it's low enough as it is.

I've already knocked over the top of the front struts all the way they can go with the camber pins removed.

I honestly think that returning to either stock springs, or settling for OEM 108/MV2/203, then spacing a little is my only choice.
Running Eibach Pro with ET37 is not working (unless I have another issue with broken springs or something).

beanie · Post by **beanie** » Sat Oct 21, 2023 11:49 pm

I’d be inclined to try heat gunning the protrusion where it catches. It’s a typical place to rub on these cars and you probably only need a few mm of clearance. Also, I ’m sure I’ve seen a couple of people ‘reverse’ the mounting of the liner so it tucks inside the bumper but I’m not sure you’ll still be able to use the standard fixings to hold it in place-which may or may not be necessary.

If they are and the liner flops about, you could try tucking the liner in behind the bumper and testing the clearance. If it works then a few small strips of strong Velcro might hold it in place sufficiently.

You could also try adding the bmw suspension turret reinforcements. Won’t add much height but every little helps.

Beyond that your only option is to change the bigger parts. Tyres, springs or top mounts to gain more space.

True-Blue · Post by **True-Blue** » Sun Oct 22, 2023 4:32 pm

: IMG_1581.jpeg (228.79 KiB) Viewed 611 times

This was running new Sachs O.E. Shocks, Eibach pro-spring kit and genuine 18” 405m’s in 8J ET34 all round with brand new 225/40/18 square set up.

They are genuine BMW, Forged, strong, lightweight alloys… look good on an E86… I’ll try and find a pic

True-Blue · Post by **True-Blue** » Sun Oct 22, 2023 4:37 pm

Here you go;

viewtopic.php?p=1724357&hilit=405m#p1724357

Meds · Post by **Meds** » Sun Oct 22, 2023 5:18 pm

True-Blue wrote: ↑Sun Oct 22, 2023 4:32 pm IMG_1581.jpeg

This was running new Sachs O.E. Shocks, Eibach pro-spring kit and genuine 18” 405m’s in 8J ET34 all round with brand new 225/40/18 square set up.

They are genuine BMW, Forged, strong, lightweight alloys… look good on an E86… I’ll try and find a pic

They look great. There's so many great 18" ET34 wheels.
But running ET34 with my Eibachs will result in more rub than my current set up, unless I can change something else.

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