Mighty E30 at the races

[BruceBe]

Here is a Youtube link to a racing highlights video of our M60-equipped 3-series competing at Oregon Raceway Park over the memorial day weekend.

-Bruce

[senorcarey]

Sounds awesome, Bruce! Great work.

[bmwmech1]

Bloody hell man, that's plain friggin' awesome! Sounds great rapping out the V8, cool to watch you keep the Mustang behind you, too!

Okay, now the technical question... I see you're using an aftermarket tach, what did you do for a tach signal? Did the OE tach signal work for your tach? I have not gotten my tach to work yet, although, I must admit I have not done any troubleshooting either, lol! I'm using a VDO Vision series tach and I assumed the factory signal would give me a good source, but no... Just thought I'd ask and maybe save some troubleshooting minutes, if you used another source...

Awesome work man, great to see it in action!

Garey

[spdracrm3]

Joe Satriani?

nice

[Jean]

Bruce - awesome to see it out running and kicking butt! Looks like it's hanging in there too!

Care to share with us your suspension config, wheels/tires, weight?

What diff. ratio are you using as well?

Thanks!

[BruceBe]

Joe Satriani?

nice

Similar style - Brett Garsed

[CHIF8008]

looks like its keeping up just fine :)

[BruceBe]

Suspension config...

Jean asked, so I'll share a *few* things:
1) Wheels are 949 racing 15 x 9 6UL wheels. If you want a low race car with reasonable LCA angles and fender clearance, 15" is the sweet spot. Tires are Hoosier R6 275/35/15 at all four corners.

2) We also designed custom wheel spacers to accommodate the wheel offset, extended fenders (Group A replica in front; even wider in rear), and desired lateral placement of the wheel.

3) Dampers - Moton motorsport strut assemblies in the front, Moton club-sport in the rear.

4) Rear trailing arms have a tubular brace (a la Z3)

5) Rear suspension adjustment is via eccentric bolts and slotted subframe pickup-points.

6) Front suspension adjustment is the usual fare of GC camber plates, spherical lollipop insert, and Al (e30 M3) lower control arms.

7) Brakes are Massive/Wilwood (300mm x 32mm), with Wilwood pedal assembly for Brake/Clutch

8 ) Aero - custom front splitter and Crawford Composites Grand Am Rolex GT spec rear wing.

9) Weight - with full fuel (16gal) and 210lb driver, car weighs 2553lbs, with a 55% front weight bias. The car is about 2245lbs dry.

10) Diff is a 3.23

-Bruce

[Jean]

Nice! I tried pausing the video to check out the fenders, but the car is too fast :) :up:

Why 15x9 and not 15x10? I have similar plans for mine and want to know if you maybe tried both setups and something didn't work with 15x10?

[BruceBe]

15 x 10 was not available in a one-piece wheel at the time we did all of the work.

Having said that, we could upgrade to a 15 x 10 in the rear, but it would require us building a new rear wheel spacer, which exceeds the cost of a wheel (by about $75).

The front is a different story - moving the 9" wheel far enough outboard to clear the front strut introduces quite a bit of steering scrub radius. So, when you turn, the front wheels are moving forward and aft in the wheel-well quite a bit. We just clear the leading and trailing edges of the fender as it is. Going 1" wider might cause interference. Since we are considering 10's in the rear, I'll also take a look at the front.
-Bruce

[Jean]

Bruce,

Thanks! Let me know how that works out if you switch to 10 ok?

How is the 3.23 ratio working out? Would you happen to know what the actual top speeds are in the first 3 gears?

[BruceBe]

Funny you bring up the diff. I was just about to edit my post - the 3.23 *is* the current diff ratio, but was selected when we had an S52US engine in the car. We are in the process of obtaining a 2.93.

At 6K rpm, top-speed with a 3.23 and a 23" tall tire is 29, 50, and 78MPH respectively.

With a 2.93, those numbers become 32, 55, and 86 MPH.

2.93 would be good for an aggressive street car.

-Bruce

[Jean]

Bruce,

Thanks! I was hoping a 3.25 or 2.93 would get really close or over 60 in second (to cover most autocross runs). 3.23/25 deff won't work for me looks like so I need to see what else is out there.

[bmwmech1]

Bruce, any info on the tach signal? Didn't know if you missed it in my post further up the page...

Garey

[BruceBe]

Garey - I don't recall anything special wrt signal conditioning. It's an Autometer tach - with a V8, it should be set for 4 pulses/revolution.

-Bruce