Aftermarket wheels offset question

[Justin]

What should the offsets be for these width wheels on a TT JSpec please?

Front 18 x 8 ......................?
Rear 18 x 10 ......................?

Front 19 x 8.5 ....................?
Rear 19 x 9.5 .....................?

Cheers
Justin

[Terry S]

Justin, there is a wheel offset guide in XLS format on Supra Forums. Excellent resource mate

http://www.supraforums.com/forum/showthread.php?t=12049

[Justin]

Cheers Terry, don't forget my torque converter cheif :thumbs:

[Justin]

What should the offsets be for these width wheels on a TT JSpec please?

Front 18 x 8 ......................?
Rear 18 x 10 ......................?

Front 19 x 8.5 ....................?
Rear 19 x 9.5 .....................?

Cheers
Justin

So according to that spreadsheet I get the below offset figures but does anyone know the correct offset for 19 x 8.5 Fronts?

Front 18 x 8 ...................... +50
Rear 18 x 10 ...................... +47

Front 19 x 8.5 .................... ??????
Rear 19 x 9.5 ..................... +50

[tDR]

Standard I'm guessing is ET45, seems common with Toyota. How you adjust that is based on what you exceed the standard wheel width by. Say standard is 9" ET45 which means the wheels effectively "stick out" 45mm from the hub. Then you switch to a 10" wide rim, that's 1" wider than stock which means half of that is from the hub, the other half towards the inner arch. So take your half inch, work out what it is in mm and then you have how much more they stick out as a result of increasing wheel width. To get back to standard offset, add that number to the original ET of 45 which in effect makes the wheels stick out less. The lower the offset number, the more the wheels will stick out. For the perfect offset, you want the wheels flush with the bodywork as much as possible without rubbing problems so basically calculate how far away from this the standard wheels are to give you a target offset to work to. For example, standard wheels are say 11mm too far tucked into the arches - just deduct 11 from 45 to give you a target ET of 34. Buy wheels as close to that as possible.

To get that really wide stance look like the Jap drifters get, you usually need to go for offsets as low as ET10 and then get the rims to fit in the arches by negative cambering them with aftermarket suspension arms (Tein, Cusco etc) on the back and Camber adjustable pillowball mounts on the front..... sometimes a slight rolling of the lip of the arch is needed too but looks brilliant when done.

HTH,

Brian.

[tDR]

One of my favourite examples of offset done properly:

http://driftunit.com/photos/S14/jline/JLine_S14_2.jpg

[Gaz Walker]

Justin,

Offsets can be a funny thing to work out. It isn't just in the number. Most wheel companies have 4 different disc patterns to, with different offsets for all of those too.

What you looking at and I'll try and help further.

To clear UK brakes the smallest offset I've seen to fit is +38 (on stock arches)

Gaz.

[Justin]

Basically I'm looking for new wheels. The trouble is that I have 6 pot AP Brakes on the front. JSpec Rear Brakes.

So I don't know what offset I need for the front in either 18 or 19" wheels. I really need to drive the Supe to a local dealer to try the actual wheels over the brakes before I buy to make sure they fit. To do this the dealer is going to want me to specify the offset before he can get the wheels ordered in for me to try.

Do you see my problem.

These are the wheels I'm looking at. Preferably in 18" but can go up to 19" if they fit over brakes. I think I'm most keen on the Antera 349 but need to see them in the flesh.


http://www.topgear.co.uk/acatalog/4x_18_Inch_Antera_349_Alloy_Wheels_With_Federal_22.php

http://www.topgear.co.uk/acatalog/4x_18_Inch_Kei_Racing_D1_Silver_Alloy_Wheels_With_.php

http://www.topgear.co.uk/acatalog/4x_19_Inch_Dare_Hiro_Hi_Power_Silver_Alloy_Wheels_.php


I asked Ibrar J but he can't get the 349's in he said.

[Pete]

Of course offset isn't all about what 'fits', your handling will alter a lot too.
17" are recommended for best handling, 18" acceptable. Not sure I'd go above 18 though.

[tDR]

Widths are usually pants on UK available wheels. Not just the offset number that's important as illustrated above. Where brakes are concerned, look at the spoke design too for clearance because it isnt just a case of x offset clears. You could have ET30 on one wheel and not clear the calipers because of the spoke design yet clear the calipers fine with ET35 and another wheel.