318 vs. 325

[E30Driv3R]

4 cyl's aren't that bad you know!!!! i think that i am going to stick with the 318 however. the car is just in much better condition over the 325 i have. it'll be better overall in i think. Personally i don't think that the 325's are going to be that much better.

what are some decent n/a engine mods people are doing to the M42. i planning on rebuilding the top end to the engine and i hear that is where most of the power loss come from. I already have it chipped, k&n, fan delete, ac and ps(soon) delete. so it's relatively quick. i was going to throw in a better clutch and some stiffer tranny and engine mount as well. But what can be done with the head to improve it???

Looks like you will be runnin in DSP unless i missed something. Dont worry about the Head, instead buy yourself some good tires i wouldnt suggest Rcomp your first time, but thats just me. And get some Hawk HP+ and bleed brakes

[ten2doyle102]

Looks like you will be runnin in DSP unless i missed something. Dont worry about the Head, instead buy yourself some good tires i wouldnt suggest Rcomp your first time, but thats just me. And get some Hawk HP+ and bleed brakes

well there not full race tire but they're much better than your plain jane tires.

i was planning on beefing up my brakes as well.

[ten2doyle102]

I race my 318is in DSP and there my main competition is a guy with a 325is prepped to the exact same level as my car. We run almost exactly the same suspension with the exception of swaybars (he has IE adjustables mine are stock M3/cab). We run the same wheel/tire setup 225 Hoosiers on 15x8 rotas.

We are always extremely close. Sometimes he is faster, other times it's me.

The 318is' lower weight and better balance make up for the deficiency of power. I do take alot of pride in the fact that my "inferior car" is so competetive. Run whichever one seems to be in the best shape.

And I would not run the eibach kit. Those springs are too soft for anything other than a showcar.

i'd also like to know what your running as well

[Infamouscrew02]

Ive got the eibach pro kit as well and i do agree that it is way too soft. Probably over the summer im going to get some stiffer springs. Maybe go with a coil over set up.

[ten2doyle102]

alright....well maybe i will put them on my 325. the springs i have on the 318 could possibly be IE's, they're green but theyre rusted and the powder coat is peeling off. I was thinking about pulling them and sand blasting them and repainting them. they work great and they nice and stiff. I have H&R sport on the rear which work nice as well. I thought that eibachs were said to pretty good springs but.....apparently not! oh well. i want the 325 lower anyway!

[ten2doyle102]

i could go with the comso's like i had on my last 318. they were pretty fricken stiff! would my Bilsteins be able to handle those fine?

[Farbin Kaiber]

Sure man. Run those Cosmo's like you stole 'em. Get some Boge/Gabriel strut inserts to go with 'em though. I wish I could run 'em but it won't go with the rest of my ride. Those coils are just the wrong color. And, BTW, Eibachs ARE great, I'm using 'em right now to hold my car up for rolling it around the garage with the small body strut housings and solid front discs.

[ten2doyle102]

right.......

[Jean]

I have a 318iS, and in STX i am usually about 1-1.25 seconds behind the 325 in my class. WE both have coilovers but he has Hawk HP+ and Koseis w/ Azenis. I have stock brakes and Traction T/A.

But now i am going to have to be in SM due to the S50 that will be going in...

I hope you pick up good tires, there is your 0.5 to 1 second.

[Jean]

get atleast h&r race or go with something in the 400-500lb/inch front, 600-700rear. you could probably get away with less rear spring with a sway, but I would rather have more rear spring than a sway... easy for you try both ways though. changing rear springs / disconnecting rear sway takes 20 minutes tops.

[e30s52]

I like the nimbleness of the 318i, for autocross you don't need massive amount of power but my m10 of course lacks it. Are you thinking about doing this just for fun or looking to complete ? If you are talking about building a car up specifically for autocross you need to think about what specific class you want to compete in, and evaluate the bugdet / mods for it.

For example, a ST class is going to cost much less than SM or Prepared to be competitive in. Personally I would try both if you can and see which one you like the most. Suspension / tires / driver will be more important in autocross than only power. Since it sounds like your 318i is in better condition, maybe you can add the available superchager if you feel it needs more power and you want to more than just participate for fun :)

supercharger sounds like alot of fun especialy for auto cross

[ten2doyle102]

that what i was thinking!!!!

[gearheadE30]

Sorry, I thought you had an early 318. My bad. Since you have the M42, though, definitely use the 318. On a tight course that averages about a 1.02 time, the e30 M3 that is usually there ran a .56 and I ran consistently at .58. The M42 loves to rev, but the flywheel sucks because it is so heavy. Pick up an M20 flywheel and have it machined down to about 9 lbs and it will make a huge difference. A short shifter from a 2.5 Z4 is also a great upgrade. I'm running APEX suspension of an unknown rate, but they feel slightly stiffer than H&R sports. Stock sways, offset control arms, bilstein sports, and it works pretty well, but there is a lot of body roll and steering is slower than I'd like. I also have stock brakes and crappy pads, but the 318's are all about momentum and it really teaches you how to conserve speed. Oh, tires are the biggest single thing you can do, they make a huge difference.

[GoKart]

Who machines the M20 flywheels?

[rThor432]

Machine shops machine flywheels.

I have had both cars and will never go back to an M20.

I'm sorry.