track width?? wtf!

[MR2boy]

im trying to get my head around the new law that says when u get new mags u cannot increase the track width by more than 25mm without needing a cert

so after ringing the cert guy the track width is the distance from the center of one mag to the center of another mag

so how are u supposed to work out if the mags you want to get will increase the track width? is there some formula to use? anyone who knows how to do this wanna fill me in

cheers
kurt

[wde_bdy]

Say your mags are 6 inches wide (150mm) with a +25mm offset (this is the distance from the centre line of the wheel to the mounting face). If you go to an 8 inch (200mm) rim you want to retain that same +25mm offset. You will then have your rim edges 25mm further in and out (half each side of your increased rim width). Can cause clearance issues depending on the car.
The tricky part is if your new rim/tyre rubs on the struts. To give more clearance go to a +15mm offset. This will increase your track by 20mm (10mm per side) and move the wheels away from the struts. Still legal as you are within the 25mm tolerance allowed. You may need to flare the guards though to ensure the tires are not sitting uncovered or rubbing on the guards.

Callum

[rxtoy]

if the track width is from the centre of one mag to the centre of the mag on the other side then the rule must be for spacers cause otherwise your track width would be the same no matter what width your wheels were cause the centre would still be in the same place, hard up against the mounting point.

cheers
Matt

[wde_bdy]

I think your a little confused, the offset tells you how far from the centre line of the wheel the mounting face is. Most wheels are not centred. Problems arise when you have to change offset due to clearance problems with wider rims.

Callum

[rxtoy]

yeah, i think i got my head round it now, i was thinking of the centre of the wheel as the hub rather than the centreline of the wheel,

cheers
Matt

ps: when are you going to put those starlet pics up on this board? i've seen them on toymods, looking very good.