put my summer wheels back on...
at any speed over 30 mph the abs acts like im in sand or snow and the pedal is high and pulsing
under that speed the pedal seems fine

my rears are the stock size
but my fronts are smaller than the usual smaller fronts on the "03 with brembos

could the smaller fronts cause the abs to think it needs to come on ?
my winter tires are all the same size and had no issues

 

Yes. Verify by using the tire size calculator link in here https://g35driver.com/forums/wheels-...m-weights.html

 

not sure what you are getting at...
my rears are stock
my fronts are smaller than stock... i dont need the calculator for that...

the abs must have a window of acceptable difference... last summer this setup
was fine... no brake issues... did lots of hot laps at mosport...
im thinking the front which are already too small... have worn down to a ratio
out side of the limit set by the abs...

i wonder if disconnecting the battery with the winters on... reset the abs to that
ratio of fronts to backs ?... I will pull the battery cables or abs fuse today and test it out

 

Obviously you don't know how to use the calculator I posted. Saying bigger and smaller rather then giving actual tire sizes doesn't help much either. The VDC does have an acceptable tolerance, its 3%. Meaning the overall diameter of the front and rear tires can't have more then a 3% difference, which the calculator will tell you if used properly. And no, you can't change/reset the values of the ABS/VDC.

 

the tire size of the fronts is on the side walls... i really dont need a calculator to tell me they are smaller..
its kinda in your face... ok so the acceptable tolerance is < 3% again... the calculator's function (mazda) has been around for a while and ive used it to fabricate speedo gears for about 5 years...
sooooooo aftar all that... the front to rear ratio can not be more than 3% from stock.
cutting different teeth into the part that the abs sensor reads is no big deal... been there done that
knowing what the abs tolerance level is... priceless

 

Why go through the trouble of fabricating new gears when a proportional set of tires will fix the issue?