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Karateman
06-21-2009, 07:09 PM
What is the max offset that will work for an MS3? I heard +45mm was the most you can go to bring the wheels out flush with the fender. Anyone know?

condor888000
06-21-2009, 07:22 PM
Depends on the width of the wheel and the tire size.

dentinger
06-21-2009, 08:39 PM
and if your lowered or going to be lowered.

here's fobio's thread.
he's running 18x8.5 +45 with 235/40R18 tires
http://www.torontomazda3.ca/forum/showthread.php?t=32186&highlight=18x8.5

there are some of us with +42 or +40 wheels too, however most of us have these on non-speed3's, if it makes a difference.

Karateman
06-22-2009, 09:15 PM
Thanks guys! I am thinking of goin' with a smaller wheel size than what the MS3 comes with for reduced weight and higher sidewalls. Thinkin' of goin' with 17" x 8" and using 235/40R17 rubber.

Enkei makes a sweet light-weight wheel known as the RPF1 with +45 offset and in the 5 x 114.3 bolt pattern.

Fobio
06-23-2009, 09:04 AM
For 17x8", I'm currently running 235/45/17 +45mm offset, no rub.

Karateman
06-23-2009, 08:38 PM
Thanks Fobio for your feedback.

As of today, I too can now vouch for the fact 235/45R17 do not rub on MS3's with the +45 offset. Note, my car is not lowered (yet). Hope it'll not rub with a mild 0.75" to 1" drop.

Fobio
06-23-2009, 08:55 PM
Thanks Fobio for your feedback.

As of today, I too can now vouch for the fact 235/45R17 do not rub on MS3's with the +45 offset. Note, my car is not lowered (yet). Hope it'll not rub with a mild 0.75" to 1" drop.

you need to come run with us on the track. :)

swales
06-24-2009, 09:34 AM
I've got 17x7.5 +42 offset with 225/45-17's and a pro kit on my MS3

Fobio
06-24-2009, 09:35 AM
FYI re: offset

http://www.mazdaspeedforums.org/forum/mazdaspeed-3-6-wheels-tires/30223-less-offset-how-bad-torque-steer.html


I copied this post from another forum. But it explains my concern for changing the offset of the wheels from stock. I am thinking of going with the RFP1's either 17x8 or 17x9 both have the 45 offset. Most likely 235/40/17 wheels.

So my questions are:

1. I am looking for feed back on how much the torque steer and tramlining is affected with this setup. Was it increased noticibly or not?
2. How much traction is gained by going with the wider wheels?
3. Basically are most people going with the 9" wide wheels for performance or looks or both?

http://images.sportcompactcarweb.com/tech/0506scc_suspension_08_z.jpg

"""All these effects consider going to a more positive scrub radius (i.e. the tire is farther out than normal, like when you put on a smaller than stock offset wheel):

1) Torque steer is increased
2) Track width is increased, allowing for slightly less load transfer in corners
3) Steering weight is increased (may not be noticeable, but the power steering pump will be working harder and the fluid may overheat in some situations)
4) increased tramlining feel on rough or grooved pavement
5) increased wheelbearing wear rate
6) increased steering instability when braking

If for some reason the scrub radius is not identical left to right, the vehicle will pull strongly.

That said, McPhearson Strut style suspensions generally benefit from a small amount of negative scrub because of the relatively high amounts of SAI and caster inherent to these suspensions. Also, negative scrub is frequently employed on FWD cars just for the torquesteer reduction.

There is an issue with having 0 scrub as well. Quoting from an online resource:
"If the scrub is zero, the scrubbing action of the contact patch is equal on either side of the pivot point causing the tire to act like a car with a welded differential, inducing a condition called 'squirm'. In a straight line the tire tends to be stable and tracks well. As you turn though, the portion of the contact patch on the outside of the pivot point moves faster than the portion on the inside of the contact patch. Since the scrubbing area is equal on each side of the pivot point, yet the forces are different, the tire tends to fight itself and it becomes 'grabby' causing tire wear to increase and the steering to become unstable."

So in short, going with less offset than stock will give a very small benefit in terms of load transfer (and thus available cornering grip) but will also yield a myriad number of minor issues as listed above ranging from increased tire wear to stability problems. I have found that the tiny increase in grip is almost never enough to outweigh the speed you find from a confidence-inspiring stable handling car so I always stick with as close to OE offset as possible.

Keep in mind, if you do go with a low-offset wheel and want to maximize your benefit, you should utilize a strut-top camber plate type device to alter the SAI and bring your scrub radius back to stock value. This will prevent the negative effects while giving you the benefit (and also you'll have more negative camber for uber cornering)"""