One of the 1200c RC Engineering...
One of the 1200c RC Engineering low-impedance injectors that feed the beast
The system is fully automatic. When methanol is detected, higher boost and timing is provided and fueling compensates for the methanol in the system. It's like having race fuel when you need it, and HPF reports up to a 60?F drop in charge temps as well.
Turbo Stages
HPF's entry-level stage 1 turbo system uses a Precision T67 turbo with a P-trim turbine encased in an .81 aspect ratio housing. Because of the stock 11.5:1 compression and 91-octane pump fuel, stage 1 is conservatively tuned to 6psi and 450whp with flat torque curve peaking at 330 lb-ft. With 110-octane, however, HPF tunes it to 626whp and 455 lb-ft at 13psi.
Stage 2 benefits from the meth injection, allowing more aggressive tuning. Here customers see 595whp and 430 lb-ft on pump gas at 13psi - more than double the stock output. With racing fuel, the number jumps to a whopping 655whp and 470 lb-ft.
Considering we're still talking stock compression, this power output is amazing for the S54 engine. In fact, while trying to find the limit of the engine, HPF found the limit of the 67mm turbo first. "We tested the stock compression motor with three back-to-back runs at a maxed-out 24psi, and while we all stood back expecting something to blow, it held together with all three pulls over 720whp!" reported Chris Bergemann, president of HPF. "And they're reliable, too. Collectively our customers have covered over 750,000 miles. My car alone had over 2000 dyno pulls with the bone-stock motor."
Stage 2.5 goes a step further with a built short-block, including forged rods and pistons for a lower 9.5:1 compression. With higher boost and more aggressive tuning, this stage sees an average 580whp on pump gas, rising to 630whp with methanol. With race gas and meth, it jumps to 690whp and 570 lb-ft.
Stage 3 is where things get a crazy. A large 74mm turbo with a giant GTS turbine provides a ton of flow. On 91-octane alone, HPF has seen 637whp, jumping to 780whp with meth, and 820whp on race fuel.
Finally, stage 4 uses a massive 76mm GTS dual ball-bearing turbo and 4" intake. With racing fuel and meth, Bergemann's own car has repeatedly surpassed 900whp and 679 lb-ft, and he aims to crack the 1000whp mark soon.
Each turbo kit includes stainless feed and return lines, a motor mount, silicone couplings, all hardware and instructions. It should be noted that a sturdier clutch is also required.
>strong>Stage 4 Experience
By now you're asking if these cars are streetable. To answer the question, we rendez-voused with Oscar Trevizo's HPF stage 1 '03 M3 and Chris Bergemann's own stage 4 '02 M3 to find out.
At first glance, the cars look menacing. The amazing Azuka Design carbon fiber body kit is to blame, with wheel arches so wide they easily accommodate the Enkreuz HS10 19" wheels wrapped with 285/30 Nitto Invos up front and Viper-sized 345/30s in the rear.
"Warp speed, please, Mr S...
"Warp speed, please, Mr Sulu."
Any other day, I'd normally drive stage 1 first, but I wasted no time and jumped in Bergemann's monster. Inside, the car looks and feels stock, until you fire the motor. Thanks to its 4" exhaust, it's one of the loudest streetcars I've driven.
The triple-disc OS Giken clutch is very aggressive, taking calf muscle and finesse to properly slip. The fact I didn't stall it makes it almost streetable, but I wouldn't want to be caught in traffic...
Despite the clutch and decibel level, the car is docile to drive. I took my time warming it up, and I'm sure Bergemann thought I was a pansy. But having never driven anything with over 700whp, I wasn't taking any chances.