M2 madness

[M3M3]

No adjuster pics. It was the kind with the eccentric washer/bolt. It had held for four years of racing, then the nut loosened. It self adjusted back to max toe. We just realigned it, snugged it up, and it should be good for another 4 years. We hope.

Incident did cement for me that am installing the indexed kind in my m2 this winter.

[Barrosco]

Good to see the ole' M2 is still at it.

 

Going back through your thread has been immensely helpful for me to start forming some brake/suspension plans for my M42 car. As well as some of the trial and error you've gone through.

 

I do have a question about your brake setup though. It looks like you've got Wilwood SL4's with lug mounts  (from the looks of it you've got 1.75" pistons in your calipers), and the Wilwood kit that Ireland currently sells comes with Dynapro Radial mount calipers. I've decided that I'm going to make myself an SL4 kit, but I'd like to know what dimensions your rotors are. The Dynapro kit Ireland is selling uses 300mm (11 3/4") x 20.5mm (.81"), is your setup the same size?

Edited September 21, 2014 by Barrosco

[M3M3]

glad it is a help!

 

my willwoods are superlight 4's, 1.75in as you guessed.  300mm x 0.81in rotors

 

I would NOT do this again.  i would stick with the 320i rotor size and the dynapro's.

 

why?  the rotors are too big and heavy.  the size has a negative impact on how the brakes work.  the 2002 (and tii) bearings are not that precise.  there is just enough play in them (even when adjusted tight) that the large diameter rotor wobbles slightly and knocks the caliper pistons back in the bores.  this makes braking bad.  i have to left foot pump the brake pedal once before every brake zone to push the pistons back out so the brakes will work.  i never had this issue with the 320 rotors.  they are smaller in diameter and do not have as large a wobble at the edge as the 300's do.  newer cars like e30's and e36's have much more substantial and sealed wheel bearings and do not have the inherent play that 2002/320 bearings do.

 

i have tried everything to combat the knock back issue with zero luck.   knockback springs, pressure retention valves, bearing adjustment, rotor truing, everything.  nothing fixes it.  

 

my advice, do not go to 300 mm rotors or huge calipers.  the cars do not need it.  the 320 size and good pads are more than enough brakes for the car, even on a track.  plus, the 300mm rotors are 3x the price of 320i rotors, and do not last as long.

Edited September 22, 2014 by mlytle

[Barrosco]

I highly appreciate that info, Marshall. Honestly, I could see my car needing what those rotors and calipers have to offer. It'll have a higher weight than most 02' track cars, and 245 Hoosiers would probably make good use of that much brake. Obviously the bearing is the weak point in that system as you've figured out.

 

I've been pondering what options there could possibly be in order to retrofit a newer, more substantial bearing. The only thing I've come up with so far is to use an E30 strut, which as you know is a completely different approach to front suspension geometry. I suppose it would be plausible to come up with a tubular control arm much like the DTM E30 M3's and find a suitable mounting place on the frame rails similar to the E30's. That would definitely take some serious engineering to make sure the geometry is correct though. That mechanical engineering degree sure is going to come in handy....

 

We should have just bought E30's, huh?

 

By the way, I've been meaning to ask if you're ever planning on moving to a true rear coilover rather than continuing to fight that rear spring perch.

[M3M3]

LOL....I have several E30's, including race cars.... they are so much better than 02's in every way.

I am going to move the lower spring perch in the back forward an inch to align the spring. Don't see a need for rear coil over.

[ray_]

LOL....I have several E30's, including race cars.... they are so much better than 02's in every way.

I am going to move the lower spring perch in the back forward an inch to align the spring. Don't see a need for rear coil over.

 

So then, ya wanna rationalize your '02 involvement?

 

[M3M3]

There is no way to rationalize trying to make a 40 year old econobox do things its designers never imagined. It is a stupid and pointless exercise in burning money and time.

But I do it anyway. .......

Edited September 25, 2014 by mlytle

[M3M3]

ran in a 13hr SCCA endurance race last weekend in an e30.  great team that included 02's Jim G and Daron B as part of the all star pit crew.

 

 

race unfortunately ended for us just under two hours in when a piston wrist pin decided to leave the block by creating a hole right above the oil filter.  oh well!

 

today started the tii trailing arm modification project.  goal is to move the lower spring perch forward about an inch to better align the shorter springs.  started by just drilling out the little spot welds that hold it on.  started with a spot weld bit, but it made too big a hole on the on the old "practice" trailing arm i had in the pile.  just used a 3/16 in drill bit on the tii arm.

 

Edited November 2, 2014 by mlytle

[Guest_anonymous]

next time I'll bring my welder, I still promise not to be under 18, smoking, pregnant and wearing 3"heels

[M3M3]

pulled rear wheel and spring, then flexed the trailing arm up to normal position so i could measure where to move the lower perch.  looks like lower perch needs to move forward 5/8 in, and inboard 1/8 in in order to get the spring in the right alignment.

 

while car was in air and spring out to allow easy trailing arm range movement, tried test fitting some 225/45 15 tires on it that i usually have on the E30 race car.  they fit...sort of.  rear would need much more fender lip rolling.  fronts wont work at track ride height.  tires would be just inside the fender, but no room at all for actually turning to go around a corner. oh well.

 

for sport...here are some dimensional details between a yoko s.drive 195/50 15, a hankook 214 205/50 15 and a Toyo RR 225/45 15.  all were mounted on 7x15in wheels.

s.drive 8 3/8 in wide

kook's  8 1/2 in wide

RR        8 7/8 in wide

 

height difference

L to R...RR, kook, s.drive

 

then tackled a simple project.  I have no real spare tire, so i toss a track tire in the trunk for emergencies.  it is way too tall(wide) for the trunk boards to fit on top of, and the stock tire hold down does not appear to work.  took what i think was anE36 spare tire hold down that i found, filed the hole in the  middle to be offset and used a lug nut to hold it on.

 

 

 

new Carbon Fiber hood and deck lid sked to arrive on friday...hope they fit!

Edited November 11, 2014 by mlytle

[Barrosco]

new Carbon Fiber hood and deck lid sked to arrive on friday...hope they fit!

 

Scandalous! It seems like Ray's constant nagging is extremely effective.

 

Are they the ones from American Racing?

Edited November 12, 2014 by Barrosco

[M3M3]

Yes...Ray is unrelenting....;-)

 

Correct, ordered from John at American Racing.  one week to make them, one week to ship across US.  

[ray_]

What? Who? Me?

 

 

Good luck with fitting them. There may be some words needed!

 

Oh you may also need to loosen the spring on the hood, and it might be good to remove one of the spring steel rods on the decklid.

 

Cheers,

Edited November 13, 2014 by ray_

[M3M3]

Do not intend to use either hood or trunk springs..... Hood system already long gone!

They arrive tomorrow.

Edited November 13, 2014 by mlytle

[ray_]

Bring your broomsticks!