SP Wheel off sets

[SeiW500]

I am selling a set of SP12's off my Tamora & keep getting asked what the off sets are, tried getting hold of Silverstone Performance but they don't seem to be in business anymore, i rang Team Dynamics and they told me some off-sets for the Pro-Race 1.2's (ET35 for both F & R with 8"F & 9"R) but they don't seem to tally up?
When i have measured the Back Space and they are coming out at 151mm(3.85") for the fronts(8") & 158mm(4") for the rears.
According to my calculations this makes the fronts ET21 & rears ET25 which is a long way off ET35 ???

Confused!!!!!

[SAGRIFF]

SeiW500 said:

I am selling a set of SP12's off my Tamora & keep getting asked what the off sets are, tried getting hold of Silverstone Performance but they don't seem to be in business anymore, i rang Team Dynamics and they told me some off-sets for the Pro-Race 1.2's (ET35 for both F & R with 8"F & 9"R) but they don't seem to tally up?
When i have measured the Back Space and they are coming out at 151mm(3.85") for the fronts(8") & 158mm(4") for the rears.
According to my calculations this makes the fronts ET21 & rears ET25 which is a long way off ET35 ???

Confused!!!!!

ACT sell em now, might be worth giving them a bell.

[SeiW500]

ACT?

[SAGRIFF]

http://www.actproducts.co.uk/

[fredd1e]

I asked SP this when they were around and they confirmed the front offset as being the same as a spider with the SP 3mm spacer which by my reckoning puts it at ET39 (oem ET42-3mm)
They didnt say what the rears were but said they were optimised to avoid wheelarch champering that could occur with wider rims/tyres so mayb in the ET35~40 range (ie more inset than the stock spider rear at ET35).

[SAGRIFF]

It's just a shame they didn't do a 8.5 front so you could get a 255 tyre on it.

[Laser Sag]

Andy
Have you checked the inside of the wheel as a lot of alloys have the specs on the casting

[SeiW500]

Right, thanks for the tip Safgriff, i have spoken to ACT and the offsets are specifically designed for the Tamora & Tuscan, the rears are ET37 (these are the same for all the fitments) and the fronts are ET33 (T350 are ET36) so if these were fitted they would be 3mm wider!

P.S. Don't confuse the offstes with TVR offsets as the wheels are different widths!!!!!!

[fredd1e]

Offset is offset regardless of wheel maker, and T350 fronts are ET42 as are Sagaris Tamora and Tuscan 18" spiders .

[SAGRIFF]

SeiW500 said:

Right, thanks for the tip Safgriff, i have spoken to ACT and the offsets are specifically designed for the Tamora & Tuscan, the rears are ET37 (these are the same for all the fitments) and the fronts are ET33 (T350 are ET36) so if these were fitted they would be 3mm wider!

P.S. Don't confuse the offstes with TVR offsets as the wheels are different widths!!!!!!

so no good for a Sagaris then, seems strange they would fit a Tam but not a T350/Sag as they are the same wheel standard.

[SeiW500]

SAGRIFF said:

so no good for a Sagaris then, seems strange they would fit a Tam but not a T350/Sag as they are the same wheel standard.

Rears are the same, fronts are 3mm futher out, but are 8" wide not 8.5" ???

[SeiW500]

fredd1e said:

Offset is offset regardless of wheel maker, and T350 fronts are ET42 as are Sagaris Tamora and Tuscan 18" spiders .

It's not to do with maker it's to do with the width of the wheels!
SP12's are 8" Front & 9" Rear, i think Spyders are 8.5" all round?

[samantha]

on the team dynamic wheels the offsets on the 9" rears are 35, on the fronts 8" 40

With 265/35/18 rears 245/35/18 fronts

Not sure if it helps on your offserts but cant be far off?

[SeiW500]

samantha said:

on the team dynamic wheels the offsets on the 9" rears are 35, on the fronts 8" 40

With 265/35/18 rears 245/35/18 fronts

Not sure if it helps on your offserts but cant be far off?

Thanks, yes i think Team Dynamics do a 'near as' off-set for there wheels & the SP12's (off-sets) were specifically designed for the cars, but it goes to show that being a couple of mm different does not make a huge difference!

[Geoff Ashcroft]

Andy, you're cock on: a 9in wheel with ET32 will be located differently to an 8.5in wheel with the same ET32. The offset of a wheel (measured in mm) is the distance between the centerline of the wheel and the face of the hub surface - therefore, wheel width has a role to play, as it determines the centreline, and therefore the amount of offset needed to position the inner/outer edges of the rim accordingly. A narrower wheel might need greater offset to keep the outer edge in the same place, for example. And a wider wheel may need less offset.
Measure what clearances you have behind the tyre and at the arches, then get your calculator out to determine what works. It's not rocket science, but it may affect your handling. Seeeemples