Wheel sizing / offset advice?

[ruredi]

Can anyone confirm that the HSV's guards are more pumped or not?

I really do like the Koya's and really love the look achieved on the HSV's above. I really would have to get the Bilsteins and springs installed before attempting it because it doesn't look like there is much room for error. Any significant suspension travel is likely going to rub so would need to make sure its nice and firm?

If going 20 x 10 35+ (Same as 8.5 +20?) on the front I would be running a 255/35 tyre which is the 'minimum' reccomended tyre size for the width of the rim. Is this combo going to require any modification to the front arches or will it clear?

20 x 11 I assume I would be running a 275/30 tyre which is also the 'minimum' reccomended tyre size which is not ideal but at least it's still accepted.

 

[ruredi]

I have vertini dynastys 275s on the rear with a +40 offset and the guards rolled and dont have issues with scrubbing.

What width are your rear dynastys?

I have a friend with the sfo4 koya wheels and he has had problems running a ssl spring with rolled guards and 245s stretched all around. He has the deep concave with +32 . From what ive seen the best offset for the koyas with the deep concave is with the 20x11 option.

What width are your mate's wheels? Is his SS a Series I or Series II? What issues has he had? Front or back? Series II I'm led to believe have rolled fronts from factory.

 

[ruredi]

The 20 x 10 (35+) with 255/35 will poke 25.1mm more than the 20 x 8.5 (36+) HSV's with 245/35.

The 20 x 11 (43+) with 275/30 will poke 33.1mm more than the 20 x 9.5 (57+) HSV's with 275/30.

 

[ruredi]

It seems that 20 x 10 (+35) would fit the front with no problems which is essentially the same as 20 x 8.5" (+20). In fact the 8.5" (+20) has 4.1mm LESS poke than the 20 x 10 (+35).

I'm more leaning toward going with the 8.5" wide rim on the front as it is essentially going to sit in the same place at the 10" fronts (pictured on the HSV's above) but I'll be able to use 245/35 tyres which I already have (Pirelli) and are almost new so saves cost on having to buy 4 new tyres instead of 2.

The only thing I'm concerned about is that Grennans wagon is running a 20x8.5" +30 front and he reports that it sits flush with the front guard. He has also stated that next time he would go 20 x 8.5 (+20) which would 'poke' the wheel which is not what I want. For this reason, should I also go with the +30 offset and play on the safe side because a flush / tucked look is what I'm after? +20 is right on the limit from what I've read.

Rear I'm thinking a 20 x 10 (+35) with a 275/30 tyre. This has been reported to work with a guard roll no problems on a 255 tyre (Grennan have you tried it with the 275's yet?).

The poke is 4.7mm LESS on the 20 x 10 (+35) when comparing to a 20 x 11 (+43) so again it's going to sit very similar to the above HSV's.

Could play it safe again and go with a 38-40 offset on the rear which I know will fit and def keep it within the confines of the bodywork being 7.7-9.7mm less than the 20 x 11 combo.

Bearing in mind I won't be running coilovers so I won't have the adjustment hence why I'm hestitant to choose an offset right on the boundry!

Thoughts?

So to summairise, I'm contemplating:

Front: 20 x 8.5" (+30) with a 245/35 Tyre
Rear: 20 x 10" (+38) with a 275/30 Tyre

Might not be as aggressive fitment as the HSV's above but would be close and lets me run ideal tyre widths for the size of the rims instead of 'minimum' / stretched tyres (which I get is part of the look but I'm not fond of it).

Only options to consider is bringing down the offsets slightly Front (+25) and Rear (+35). Lower offsets give more concave but doubt 5 and 3mm would make that mich difference to the wheel visually?

EDIT: Just discovered on the Koya Website that there is different versions being Standard, Concave and Deep Concave. The Concave and Deep Concave is only available in the 10 and 11 inch widths so it probably does make a difference

 

[ducker85]

So to summairise, I'm contemplating:

Front: 20 x 8.5" (+30) with a 245/35 Tyre
Rear: 20 x 10" (+38) with a 275/30 Tyre

With the 20x8.5 20P you can lean it over with say neg 1 degree of camber to adjust any fitment where the 10" 35P will hit the front strut. The 20x10 38P with still poke 28mm(??) more then a HSV so if your not will to get a guard roll I'd be hesitant on this fit.
Simmons have recommended this fit for there new FR-C wheels in 8.5s and 10s for perfect fit with no mods [20x8.5 front with +43 offset and 20x10 rear with +48.]

If you cant achieve the look with your wheel widths and offsets you may need to look at other wheels or con sitter guard rolling.

 

[ducker85]

I have a friend with the sfo4 koya wheels and he has had problems running a ssl spring with rolled guards and 245s stretched all around

Then he need to get them re-roll the more clearance

 

[ruredi]

As I said, I've accepted that I'll be rolling the rear guards and don't have a problem with doing so to achieve the look I'm after. You were referring to the rolling the rear guards correct? Front shouldn't need it?

I've just been advised that the Red HSV is Deep Concave front and rear. Stylish wheels seems to think that the rear HSV Guards are more pumped than standard SS. They have reccomended a +48 offset if going the 11" but doesn't think this will clear the brembos.

I certainly don't want a flat face rim so Deep Concave is what I would want. However the Deep concave only comes in 10 and 11" wide wheels.

 

[ruredi]

Has anyone got this setup on a Series II SS?

Front: 20 x 10 35+ with 255/35
Rear: 20 x 11 43+ with 275/30

Thats the exact setup on the HSV in Deep Concave (which obviously has large brakes)

 

[ruredi]

If I went a 9.5" Front, I can opt for "Concave" and still run a 245/35 tyre. Will I have any issues on the front with a 20 x 9.5 +35 with 245/35.

I can then fit the 20 x 10 (Deep Concave) +38 with a 275/30 tyre.

Should give me the look I'm after.

 

[ducker85]

As I said, I've accepted that I'll be rolling the rear guards and don't have a problem with doing so to achieve the look I'm after. You were referring to the rolling the rear guards correct? Front shouldn't need it?

Correct, I see no need to ever roll the front plus due to the lip on the front you wont roll it flat, you''ll just pump the guard.

If I went a 9.5" Front, I can opt for "Concave" and still run a 245/35 tyre. Will I have any issues on the front with a 20 x 9.5 +35 with 245/35.

I can then fit the 20 x 10 (Deep Concave) +38 with a 275/30 tyre.

Should give me the look I'm after.

A 9.5 35P front will fit great.

With the 10 38P its the tyre that'll force you to have a roll if you went with a 255 you might get away with it. I've got 20x9.5s with 245 all round and its gives maybe a 10-15mm sidewall tapper so the slight stretch allows for extra clearance.