Am I overdoing it???

[greg1333]

Building a pretty much gutted e30 for Autocross/weekend toy.

The car will have a S52 converted to OBD1 ,a five lug conversion with ground control coilovers, an z3 steering rack and flared wheel arches.

My rear 5 lug is off a e30 M3..pretty straight forward.

My front 5 lug utilizes e36 spindles (via ground control custom strut assembly) While collecting parts I have gotten both a set of e36 325i spindle/brakes and a set of e36 M3 spindle/brakes. Research shows that I could stay with a 15" wheel for the 325 set up but would have to upgrade to a 17" for the M3.

Here's my question...are the e36 325i brakes enough for a light weight autocross e30...or is bigger always better...... looking at wheel/tire weights and combos...

thanks
Greg

[IronFreak]

I went with the M setup for my 5-lug. Stopping power is nice, nothing quite like the feeling of your brains trying to push out of every opening in your head when you slam on the brakes haha! Fully gutted e30, 325i would do the trick, it's not ideal but the spece30 guys use stock brakes and race. It depends on your budget and what you want for performance.

I have seen a thread somewhere with more information, but I know that there are some 16" wheels that clean M-system brakes. What they are I have no idea. Back spacing and offset are your enemies with the M setup.

[greg1333]

Thanks,

the 325i brakes i would be using in the front are e36 and are larger than the stock e30 brakes.

as for the 16" wheels over e36 M3 brakes, the selection is very very limited and the selection of "sticky" tires is also limited.

I was looking at using a 9 or 9.5 inch wide wheel

[IronFreak]

Yeah, I'm still learning about the 5-lug setups. I think you'd been fine, I do know you need to use m3 control arms otherwise you'll be modding the crap out of the upper shock mounting location. The standard e36 control arm doesn't give you the proper caster.

[greg1333]

the conversion is done with e30 control arms and the ground control hybrid strut housings are shorter than stock e36 ones to fix the length difference between the two models.

I am using a set of aluminum e30 M3 arms combined with treehouse racing "eyeballs" and ground control camber plates ..plenty of camber and caster.

[IronFreak]

oh wow, that is quite the hybrid setup haha

[greg1333]

lol...hence the title of my post...

[IronFreak]

Well then, no you aren't over doing it!

[robgoesvroom]

don't underestimate a good brake pad

[IronFreak]

don't underestimate a good brake pad

This too!

[einstein57]

I'm not auto x king but the times i have gone the stock brakes with good pads were not an issue. You won't see any brake fade. Change the booster to a e32 setup if you want more initial bite feel. If i were to build an auto x xar i'd just use a 4 pot wilwood caliper and make a bracket to use on stock, redrilled e30 m3 or corrado rotors.

[Vtec?lol]

the conversion is done with e30 control arms and the ground control hybrid strut housings are shorter than stock e36 ones to fix the length difference between the two models.

I am using a set of aluminum e30 M3 arms combined with treehouse racing "eyeballs" and ground control camber plates ..plenty of camber and caster.

You still wont have enough caster with the e36M spindle and that setup.

With a gutted e30 stock or standard e36 will be fine. This also depends on the width/weight of tire you're running all around.

I would probably run brembo rotors and some hawk pads with a stock setup. Then do a little duct work to make sure they're cooling effectively. This will give you the lightest wheel selection.

Either way it'll be fun

[Gary Horneck]

Standard 325i brakes are enough for either AutoX or weekend play. Hawk HP+ pads clamping new rotors, and SS lines stop fine. I have never had a heat problem with the E30 brakes. I don't use brakes that much in the 6-8 runs in a day. What are your goals for AutoX class? SM is a tough class.

[greg1333]

not enough caster you say.... interesting, from what I have seen thus far my wheel is now sitting forward of where it was with the e30 struts and stock LCBs. I know wheel location is not a scientific method to measure caster, but from what I had researched I "assumed" I would be golden... The camber plates have a caster adjustment I can make.

What would you suggest as far as degrees of Caster and Camber.
And while we are throwing around numbers, how about toe...
Of course the numbers for the rear would be nice too...
rear camber and toe handled by weld-in slotted adjusters..i had luck with them on my e21 until it saw its untimely demise... sad story...

[Earendil]

Did anyone else read the title to this thread and answer "probably" before even opening it? ;)

I'd stick with "stock" brake rotors and good pads until you decide you need them. Likely you'll be A-Okay, and can use the money in other areas.
As a data point, The PRO3 and SpecE30 guys can lock up racing slicks using stock rotors and race pads. Until you can't lock up your wheels, or you experience brake fade, I'd hold off. The choice of brake pad will probably have more on an effect.