Track widths

[shnazzle]

If anyone has a tape measure and 5 mins, it would be interesting to get some track widths front and rear with associated tyre/wheel setups.

So far I have (from Carolyn):
Stock PFL alloys  (outside to outside)
195 front - 1506mm
215 rear - 1607mm

TD 1.2 (outside to outside)
195 front, 7ej et35 - 1710mm
215 rear 7ej et45 - 1690mm

Stock pfl (off iseecars.com, probably center to center)
185 front 6ej et45 - 1460mm
205 rear 6.5ej et45 - 1475mm

Stock FL (Helen's car, outside to outside)
195 front 6ej et45 - 1680mm
215 front 7ej et45 - 1670mm

[pistol pete]

Im running et20 front and et0 on rear. (7 inch front and 8 inch rear)
Ill get some widths later when home

[shnazzle]

Noting some inconsistencies already;

Granted my measuring wasn't massively precise but still..

If Carolyn's fronts are the same as Helen's, same front size and tyres, then surely the track should be the same...
FL front alloys are the same as PFL fronts right?

Yet there seems to be a discrepancy of 26mm.
Give or take a few mm for tolerance, that's still 10mm per side difference. Quite a bit.

Rears should be about 26mm wider on the FL vs PFL given the same rear tyre size. So Carolyn's 1607+25=1632mm, whereas Helen's is 1670mm. Still about 20mm off per side.
(edit: rethought this. Alloy width is irrelevant. Same tyre size. They should match. Theoretically.)

So it seems like FL has a wider stance, regardless of wheels, by about 10mm front and 20mm rear.

Why mine are another 10mm on top of Helen's for the same tyre size I don't know... That might be measurement

[MRSwede]

Track widths must be measured differently in Britain ?

I'm nothing near 1600mm, more in the region of the iseecar.

Center to Center or Inside to Outside of the tire

[shnazzle]

Track widths must be measured differently in Britain ?

I'm nothing near 1600mm, more in the region of the iseecar.

Center to Center or Inside to Outside of the tire

Good point. I did outside to outside.

Center to center I think is the norm to remove the effect of tyre bulging, which obviously depends on the tyre, pressure and load.

I'll re-measure mine for center to center.

[SV-3]

Track widths must be measured differently in Britain ?

I'm nothing near 1600mm, more in the region of the iseecar.

Center to Center or Inside to Outside of the tire

Good point. I did outside to outside.

Center to center I think is the norm to remove the effect of tyre bulging, which obviously depends on the tyre, pressure and load.

I'll re-measure mine for center to center.

Track widths (centre to centre) for both PFL and FL:

Front 1475mm
Rear 1460mm

[m1tch]

Front is 1475mm, rear is 1460mm - when creating my string box for basic alignment I had to bear in mind the 15mm narrower rear to get the box aligned to the car.

[shnazzle]

Is that confirmed or did you guys just pull that off Spyderchat?

[SV-3]

Is that confirmed or did you guys just pull that off Spyderchat?

Apologies, should have quoted the sources:

For the PFL, the Brooklands book;

For the FL, the Owners Manual (2003).

[shnazzle]

OK. So that's very interesting...
All this "stagger" business but all the while the front track is wider?
I'm confused.

7.5mm wider each side would be pretty noticeable.

Makes me wonder, my current setup + spacers would put me at just about put me at stock variance between front and rear...

Don't even know what's up and down anymore now

[SV-3]

OK. So that's very interesting...
All this "stagger" business but all the while the front track is wider?
I'm confused.

7.5mm wider each side would be pretty noticeable.

Makes me wonder, my current setup + spacers would put me at just about put me at stock variance between front and rear...

Don't even know what's up and down anymore now

Looking at the OEM tyres(2003my):

Front using 185 tyre = 1475+185 = 1660 (outside to outside)

Rear using 215 tyre = 1460+215 = 1675 (outside to outside)

resulting in a 15mm wider "track" at the rear.

[shnazzle]

OK. So that's very interesting...
All this "stagger" business but all the while the front track is wider?
I'm confused.

7.5mm wider each side would be pretty noticeable.

Makes me wonder, my current setup + spacers would put me at just about put me at stock variance between front and rear...

Don't even know what's up and down anymore now

Looking at the OEM tyres(2003my):

Front using 185 tyre = 1475+185 = 1660 (outside to outside)

Rear using 215 tyre = 1460+215 = 1675 (outside to outside)

resulting in a 15mm wider "track" at the rear.

You're very right.

So stock it should be 15mm wider in the rear.

[shnazzle]

Just had a look at this again wrt to my existing setup.

Stock runs 15mm wider on the rear, 7.5mm on each side.
With my existing setup, I'm running 5mm NARROWER on the rear.

Putting my spacers in (8mm) it puts me 3mm wider on the rear. That's tolerable. Almost square.
It would have been better on the AD08s running 225 rear. With spacers that would put me at a near-stock 13mm wider at the rear.

One thing to note; I wonder what scrub radius the MR2 runs stock. By going ET35/spacers, you go more positive on scrub radius. 

@tommyzoom99 seeing as you run stupid wide offset... what are your thoughts on this? Do you know what kind of scrub radius you're running on yours?

[1979scotte]

I know I don't like 225 on the back of the TF.

[shnazzle]

I know I don't like 225 on the back of the TF.

I quite liked it. I've always been a  bit "meh" about 195 front but 225 rears I definitely liked.

But... Having said that..now having gone back to 215 I haven't got any complaints

[tommyzoom99]

Just had a look at this again wrt to my existing setup.

Stock runs 15mm wider on the rear, 7.5mm on each side.
With my existing setup, I'm running 5mm NARROWER on the rear.

Putting my spacers in (8mm) it puts me 3mm wider on the rear. That's tolerable. Almost square.
It would have been better on the AD08s running 225 rear. With spacers that would put me at a near-stock 13mm wider at the rear.

One thing to note; I wonder what scrub radius the MR2 runs stock. By going ET35/spacers, you go more positive on scrub radius.

@tommyzoom99 seeing as you run stupid wide offset... what are your thoughts on this? Do you know what kind of scrub radius you're running on yours?

Hi Shnazzle

By going less offset (ET28) it makes the set up have a positive scrub radius, but by also fitting a wider wheel (8inch) it will move the tire centerline away from the vehicle which helps counter the effect of less offset, reducing the scrub radius negatively. I'm not 100% sure if its around zero or slightly positive scrub radius as it sits now on our cars.

Cheers tommy