BNC's E30

[Bruce Colby]

I'm generating this thread to avoid hyjacking another one. Here's the car (there are a few more pictures in my gallery):




The engine is a stock M20B25. The interior has been totally gutted and a full cage added. It has IE adjustable sway bars and coilovers front & rear (Bilstein Sports all around w/400 lb/in springs in front and 200 lb/in in the rear). I run whatever R-cpd tires I can get at a reasonable price. Initially it was Avon TechR's (205/50-15 on 7" rims) but a switch to Nitto NT01's (225/45-15) is in the works (price is right and they seem to work just fine).

Things I've removed include, AC, PS, ABS, heater core, dash, interior panels, sound deadening gunk, etc. The hood is FG (IE, not pretty but functional). I pulled the most of wiring harness, just left the engine harness, and rewired everything. It now has only 3 switches, ignition, starter and brake light. All lighting has been removed with the exception of the brake lights. Quarter windows are Lexan, there are no door windows (no motors, no central locking - empty doors!). The windshield and rear window are still glass but the rear will be replaced with Lexan fairly soon. The sunroof panel will be replaced with aluminum sheet. At present the car weighs about 2250 lb wo/fuel.

Aero is a mess on this car. The front dam is a piece of garden edging so there's no proper splitter. The spare tire well has been removed so now the rear valance is acting like a drag shoot. Once I get the weight minimized, I'll try to do something with the aero, not an easy task with an E30.

I race the car with AROSC and with TCRA in So Cal plus I run a few autoxes with the SD BMWCCA. The car, however, is intended for racing so I doubt it'll ever be highly competitive at autox. (sorry - no video)

I acquired the car in Oct 06 but didn't get it on the track until Jun 07. Since then I've been sorting things out. My best time at Willow so far is a 1:38.307.

[Hick]

Nice. Spring rates seem kinda odd. Whats your sway bar setting, and which IE bars?

[Elephant]

Nice. Spring rates seem kinda odd. Whats your sway bar setting, and which IE bars?

It seems like he is running coil overs in the rear so the rates make sense.

[Elephant]

I'm generating this thread to avoid hyjacking another one. Here's the car (there are a few more pictures in my gallery):

The engine is a stock M20B25. The interior has been totally gutted and a full cage added. It has IE adjustable sway bars and coilovers front & rear (Bilstein Sports all around w/400 lb/in springs in front and 200 lb/in in the rear). I run whatever R-cpd tires I can get at a reasonable price. Initially it was Avon TechR's (205/50-15 on 7" rims) but a switch to Nitto NT01's (225/45-15) is in the works (price is right and they seem to work just fine).

Have you tried Toyo's or Hankook? Just curious. I love Toyos' but with the contingency offered by Hankook, the price, and comparable life I'll probably switch. Remains to be seen.

Things I've removed include, AC, PS, ABS, heater core, dash, interior panels, sound deadening gunk, etc. The hood is FG (IE, not pretty but functional). I pulled the most of wiring harness, just left the engine harness, and rewired everything. It now has only 3 switches, ignition, starter and brake light. All lighting has been removed with the exception of the brake lights. Quarter windows are Lexan, there are no door windows (no motors, no central locking - empty doors!). The windshield and rear window are still glass but the rear will be replaced with Lexan fairly soon. The sunroof panel will be replaced with aluminum sheet. At present the car weighs about 2250 lb wo/fuel.

I haven't checked the gallery yet....pics of the cage? Is the 2250 with driver or w/out? BTW, if you haven't cut out the metal and factory crash bars in the doors, that's a lot of weight. The factory crash bars are friggin' heavy. The empty doors are also really heavy, more than you'd think.

Aye, scratch that, I just looked at your door bar pics. Since your bars do not go into the door I would not remove the stock crash beam, at least not on the driver side.

I forget, do 325's have a FG bumper core? I holesawed and square cut mine, while still leaving a bit of structure, and dropped 6lbs (from 15 down to 9). True, not a lot in and of itself but find 3 things like that and it starts to add up. I also cut away many of the little brackets and such that are no longer used.

Aero is a mess on this car. The front dam is a piece of garden edging so there's no proper splitter. The spare tire well has been removed so now the rear valance is acting like a drag shoot. Once I get the weight minimized, I'll try to do something with the aero, not an easy task with an E30.

Below is a pic of the airdam we fabricated for Simon's car at NASA Nationals last year. It's actually quite stout and a very nice piece. Utilizes a pretty stiff piece of fiberboard. We made a few of them.

I race the car with AROSC and with TCRA in So Cal plus I run a few autoxes with the SD BMWCCA. The car, however, is intended for racing so I doubt it'll ever be highly competitive at autox. (sorry - no video)

I acquired the car in Oct 06 but didn't get it on the track until Jun 07. Since then I've been sorting things out. My best time at Willow so far is a 1:38.307.

Don't know WS so hopefully that is good. ; ) Looks nice, enjoy it.

Cheers.

[Bruce Colby]

Nice. Spring rates seem kinda odd. Whats your sway bar setting, and which IE bars?

At least I know that the spring rates are correct, I measured them. I'd be willing to go a little stiffer in the front but not much. Also, keep in mind that the rears are coilovers so the springs don't need to be as stiff as springs mounted in the conventional location.

Front bar is 25 mm (hollow bar w/solid [rod end] links), set full stiff
Rear bar is 22 mm (solid bar w/solid links), set full soft

The front sway bar links attach to the strut towers as they do on an E30 M3, not to the control arms.

I guess I should mention that essentially all the rubber bushings have been replaced with urethane and that there is a strut bar in front. The cross corner weights are within 10 lb with me in the seat and a 1/2 tank of gas. The front/rear wt distribution is 52% wt front, 48% rear.

Did I mention that it has a 4.10 LSD in the rear?

[Hick]

Im thinking coil overs like some guys do here, with an adjustable height but the spring located in the factory location. What did you use to attach the sway bar to the strut tube? I have brackets from GC but have not put them on... i was wondering if i should make some gusset plates for extra strength.

I will be running autocross on HR race with 21mm front and 19mm rear bar

[Bruce Colby]

Have you tried Toyo's or Hankook? Just curious. I love Toyos' but with the contingency offered by Hankook, the price, and comparable life I'll probably switch. Remains to be seen.

I've only really run on the Avons so far. The NT01's just got their initial heat cycle on the 12th but I liked the way they felt. The next race is Mar 22 & 23 (back at Willow). I'll run them in a few practice session to get some temperature data and lap times.

I forget, do 325's have a FG bumper core? I holesawed and square cut mine, while still leaving a bit of structure, and dropped 6lbs (from 15 down to 9). True, not a lot in and of itself but find 3 things like that and it starts to add up. I also cut away many of the little brackets and such that are no longer used.

I think there's FG but I haven't been there yet. It's low down weight so I give it less priority than the high up stuff. I have removed a lot of little brackets and I expect it to remove a few more. Small stuff but, as you say, it all adds up.

Below is a pic of the airdam we fabricated for Simon's car at NASA Nationals last year. It's actually quite stout and a very nice piece. Utilizes a pretty stiff piece of fiberboard. We made a few of them.

I like the air dam but why no splitter? And have you done anything to generate down force in the rear?

Don't know WS so hopefully that is good. ; ) Looks nice, enjoy it.

The lap time is not embarrassing given the power/weight. It's always possible to go faster by applying more $$$$ in the proper places!

[Bruce Colby]

What did you use to attach the sway bar to the strut tube?

Welded tab. It was done at Jeff Ireland's shop.

[155///MPH]

We can't run a splitter in Spec E30.

[rwh11385]

Simon's car looks hot, and good to see it out of Vaughn's.

Bruce, hot car as well. What kinda brake setup you running?

[Bruce Colby]

... What kinda brake setup you running?

I use stock E30 brake calipers. The dust shields have been removed and the front air ducts redirected a bit for improved (I hope) cooling. When I got the car, it had drilled rotors front and rear. The rears are holding up OK but one of the fronts cracked after two races. Because the other front rotor showed signs of crack propagation from the holes, I went to solid (stock) front rotors. After 3 races, they're still in good condition. Pads are Porterfield R-4.

To be honest, I not too impressed with E30 front brakes. The pads are a pain to change and the sweep area seems small. My last race car, a '65 Alfa Romeo Sprint GT, used stock (ATE) brakes. The fronts had about 50% more sweep area per lb of car than the E30 and I could change pads in a few minutes even when they were hot. Interestingly, the rears are about the same in terms of sweep area but pad changes are still a pain in comparison.

[pedal2metal]

The car, however, is intended for racing so I doubt it'll ever be highly competitive at autox.

Make no mistake, At the SD autox's that I've seen Bruce run, this car performs very well in the parking lot. And when he says Gutted, think...cage, seat, harness, steering colum/wheel and pedals, thats it! Oh yeah, I think he has a mirror too.

[E-Thirty]

Can you explain in your experience, the benefits of a rear coil over set up?

[Bruce Colby]

Can you explain in your experience, the benefits of a rear coil over set up?

They're light weight, they make it easy to set rear ride height and adjust cross corner balance, they make changing springs very easy and they were on the car when I bought it. I've seen other ways of achieving all the things coilovers provide except perhaps having access to an abundance of inexpensive springs. Some of the alternatives look a bit contrived to me but perhaps they're necessary in order to get around a classification issue. A potential disadvantage to coilovers is that there is so much flexibility, it might be easy to get things all wrong.

[E-Thirty]

What about performance wise?