SpecE30 (USA) vs. E30Racing (AUS)

#1

Now that a few more people are aware of what E30Racing is about (see my sig), I thought (after some suggestion from other users) that I should highlight the main differences of this Trans-Pacific variation on racing an E30…

Engine:
E30R uses a M20B25 (325i) motor, with 9.7:1 high comp 0.5mm overbore pistons, a control reground camshaft (pretty much stock), but other wise stock internals, with many other freedoms: port/polish, flow standard manifold, exhaust free from ports back so long as steel/stainless, and exits at rear. We use a bigger 64mm throttle body, standard AFM and can use any air filter we want. Best motors currently putting out ~150 rwHP

Ancillaries:
You can remove power steering, A/C, but must run standard pulleys, alternator and water pump. OIl system is free, but no dry sump, so can add coolers, windage trays, crank scrapers and Accusump. Standard radiator, start motor & coil, but spark plugs and spark wires are free. Fuel system is free, except must use standard injectors & pressure regulator, max 3 bar pressure.

Driveline:
Standard flywheel can be machined, friction plate is free, standard pressure plate, standard Getrag 260 gearbox, shifter and selector rod are free, standard differential with 3.91 ratio, BMW LSD with free slip rate (tighten em up!). Standard bearings, tailshaft/driveshaft, output shafts etc.

Suspension:
Coil-over convert the fronts, adjustable strut tops, 2-way adjustable dampers, anti-roll bars are free so long as not cockpit adjustable, replace all rubber bits with urethane. Front strut brace only.

Roll cage & interior:
Pretty much remove anything, keep standard dash, door cards, rear trims, instrument cluster. can tie in the front strut towers, but cannot extend past the rear firewall (no trunk bars). Add quick release steering wheel, harness, seat, window net, battery isolation switch, fire extinguisher.

Brakes:
Standard fitment, can upgrade with any BMW master cylinder (E32 750i is popular), lines are free (so can go through cabin), can add solid guide pins & bushes, standard size rotors and pads, can add ducting and backing plates, can add proportioning valve to rear brake line. Must keep booster.

Bodywork:
Can remove front bumper and panels and replace with airdam, mould in brake ducts etc. All standard metal panels, all standard glass. Can run standard lip spolier only. No side skirts. Some category required signage.

Wheels & Tyres:
15x7J Single Piece rims, minimum weight 5.9kg (for 2009, to match Spec E30 13lbs)
205/50R15 86V Yokohama ADVAN AO48 Control Tyre (same as used in parent category, Improved Production)
Can replace wheel bolts with studs & nuts

Misc & Eligibility Info
Standard wiring loom must be retained, but can trim away excess wiring (I pulled out ~3lbs of excess wire!)
“Original” means BMW or OEM equivalent, so don’t have to use expensive BMW bits, can use Bosch, Luk, Sachs, Febi-Bilstein etc versions instead.
Minimum racing weight 1130kg (=2491lbs) (car, driver, fuel and everything in race trim)
Minimum ride height 100mm (=3"15/16) at centre of front cross member and differential housing
Must use pump fuel max 98 RON = 93 MON
Fuel sampling valve under bonnet before fuel rail
Maximum front and rear track, wheelbase measurements (not on top of my head)

That’s about it. More information can be found @ www.e30racing.com.au

#2

Thanks!
Very cool.
Interesting that you have more engine mods but less power.
I really like the lower min. weight. It would make the cars much more fun to drive.
How do you think the yokohamas compare to our toyos?

You are so lucky that you can race on a track like bathurst!!! http://www.youtube.com/watch?v=VYgnhMklByc
Night races too? awesome.

Forget miller. Internationals at bathurst! :stuck_out_tongue:

#3

I too like the lower minimum weight and the aussie rules show it is possible. This is an easy way to enhance performance on the cheap, as well as reduce the load on wear items and powertrain.

#4

That’s ~150 rwHp, not flywheel horsepower. I’ve seen as high as 155 rwHP on some dyno charts. Considering that 135 rwHP is the best we’ve seen from completely standard M20B25 motors, a 15 to 20 hp increase is about right for the amount of modification we’ve performed. Remember that we still run standard management, almost standard cam, standard AFM, injectors, manifold and run on pump gas. The biggest improvement is in reliabilty (no performance related engine failures in the last 2 years, only blown head gaskets and fuel issues) and in torque, which is nice and flat the whole way up and down the rev range. As an aside, what sort of rwHP are the guys in SpecE30 getting - I want shootout figures, not pie in the sky single run figures.

The lower minimum weight is still not as light as some people have been able to get their cars. Early model shells are about 75lbs lighter than late model shells, or so we’ve found. The cars are great fun to drive, and really quick through corners compared to most of the other Improved Production Cars that we have to run against some times.

No idea on tyre comparison, but we get decent life out of our tyres. Yokohama only brings in 1 compound in each size of tyre, so we get the Medium compound, most larger AO48 sizes use medium-hard compound. Seeing about 2 meetings (1x practice, 1x qualifying, 3-4x race) from a set of tyres and then using them for thrashing & practice.

Ah, Bathurst. Our own mini-Nurburgring Nordschliefe. Except it packs so much elevation into less than 4 miles of track. Looking forward to a chance to take my E30 around at the FOSC Easter Celebration in April.

Night races? Great for spectators, and again, I look forward to the chance to have a crack in the dark.

allenr wrote:

[quote]Thanks!
Very cool.
Interesting that you have more engine mods but less power.
I really like the lower min. weight. It would make the cars much more fun to drive.
How do you think the yokohamas compare to our toyos?

You are so lucky that you can race on a track like bathurst!!! http://www.youtube.com/watch?v=VYgnhMklByc
Night races too? awesome.

Forget miller. Internationals at bathurst! :P[/quote]

#5

1130kg with driver and fuel is acheivable, so long as you balance the amount of roll-over protection with driver weight.

I know I have mine down well below 1130kg, but mine has no sound deadening, no sunroof, no excess brackets, no heater box, no power steering, A/C. But I also have the bare minimum of roll-over protection, and on my next car will be doubling the amount of tube in the car.

But in terms of wear and tear items, the cars only need basic service items every now and again - fuel & oil filters, brake pads/rotors/fluid, and fuel. We normally replace front wheel bearings every 2 years or so, and that’s about it. I haven’t had any major driveshaft, gearbox, differential or suspension problems since I bought the car 5 years ago, although admittedly almost the entire car has been overhauled in those areas since 2003. But none of the new stuff has broken or worn out.