The Independent American Magazine for all Mini Owners
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Interestingly, the ignition system and wires are the stock factory parts. Having built race and street engines for many, including RSR Motorsports, he’s not sold on the use of aftermarket ignitions, but he is sold on Brisk spark plugs. With temperatures and boost pressure so high in a small engine, he’s using their Silver Racing in his GP, and the LGS-T for the more-sedate engines. The throttle body is an OEM part. The ECU is by Vipec, but tuned by RMW. The exhaust is a stainless steel, 4-into-1 design, that has a increasing pipe size. He admits that it starts out as 1 5/8-inches and increases in diameter to 1 7/8-inches toward the reducer cone. This aids in scavenging exhaust and increasing velocity. It’s referred to as a “stepped” exhaust design. The argument you’ll hear from various tuners and racers is that 4 into 2 into 1 is better than 4 into1 designs. The reality is that both are better for different desired outcomes, as they produce torque at different RPM bands given the convergence of the piping. The RMW header system is built for high-revving track engines that commonly see 8,000 rpm. RMW engines are built as “stroker” engines, where the bore and the stroke are increased from factory to gain a larger displacement with greater piston travel. They use Darton sleeves, proprietary Arias pistons and ring sets, RMW billet cranks, and all the usual “hot rod” parts, as well as the usual CNC machining by RS Machine, align-boring, honing, balancing, blueprint- ing and such. This GP has a 1.8-liter displacement as it revs near 8,300 rpm. The larger bore dimensions nearing 2-liters rev near 7,500 rpm. Most R53 engines operate in the range of 10-11 psi for the S and 13 for the JCW, with the R56 engine near 13 and 18psi when stock. Although capable of operating closer to 25psi, this engine is presently operated at 17psi to produce 375 wheel horsepower. The engine horsepower would be about 10-15 percent greater as there’s a differential due to horsepower lost for driving the wheels. The next step of 21psi pressure will take the engine to over 400 hp using pump gas. The Howerton Engineering water/methanol injection system is going to be even more critical for the life of the engine at that point! Boost by Rotrex The Rotrex is a European-designed, belt-driven supercharger that not only has a small size; it creates a lot less heat than other designs MC2 has evalu- ated to date. The unit RMW uses is the C30-94, for the C design and 94 is the compressor wheel size. Like the stock system it uses a V-belt drive, however it’s quieter and far more efficient, and with its small size it’s located on the front of the engine, behind the custom-made RMW two-core radiator. RMW also has an intercooler made for their needs. The oil cooler is a Setrab. Jan’s says the retail pricing for his kits are near $5,000. Each kit/system is individually tailored to the buyer’s needs; it comes ready to assemble to your MINI with Rotrex blower, brackets, hardware, plumbing, and water pump. In addition, Jan has spoken of another supercharger system that’s been in development for R53 MINIs which will replace the factory M-45 Eaton unit. That should be available this fall with a retail of $3,000, plus installation. This TVS supercharger will be a bolt-on job with an improvement in torque, horsepower, and maybe even MPG, says Jan. It will also retail near $3,000. Suspension & Brakes With the intent of setting new class or track records across the nation, RMW driver Ian Stewart is knocking down records set by V8s and MINIs from Buttonwillow, Thunderhill, and The Streets of Willow in California, to his home state of Florida at Homestead, and Sebring. The Buttonwillow record was beaten by two seconds, with this GP being driven three hours from Jan’s Irvine base, changing to the R-6, 225x45x15 Hoosier tires at the track and then racing. They’re positive they can lower that 1:58 down to 1:53 later this year. And remember, this GP is an original, all-steel body and bonnet, there are no carbon fiber or fiberglass parts, and with the alloy bellypan in place, the car weighs more than stock! Even though you can find Jan driving this GP around S. California, the Hans/Recaro race seat isn’t something he finds comfortable. As we stressed earlier, he shares few details, but we now there are Hotchkiss anti-sway bars front and rear, Hotchkiss rear control arms, Powerflex urethane bushings all around, Cusco front strut brace, and all four corners have JRZ 2-way adjustable shocks with external reservoirs 26 www.mc2magazine.com 5DFLQJ :KHHOV ZHLJK MXVW OEV DSLHFH DQG FDUU\ &RQWLQHQWDO; 5DFLQJ VOLFNV -DQ GULYHV WKH FDU RQ WKH VWUHHW VR KH·V JHWWLQJ UHDOO\ JRRG at swapping out the tires! ,QWHULRU PRGLWLÀFDWLRQV DUH PLQLPDO +$16 HTXLSSHG 5HFDUR 6HDWV DQG VWHHULQJ FROXPQ PRXQWHG HOHFWURQLF V\VWHPV PRQLWRULQJ HTXLSPHQW )URQW VSOLWWHU LV DGMXVWDEOH YLD WXUQEXFNOHV DQG ZDV GHYHORSHG E\ 50: ZLWK *URXS $XWRVSRUW ZKR DOVR GHYHORSHG WKH VPLOH OLQH FDUQDUGV ZKLFK LPSURYH DLU ÁRZ RYHU WKH VLGHV RI WKH YHKLFOH