Last of the Late-Brakers
Join Date: Dec 2009
Location: Not here...
Car: 1991 M5
Hell might as well paste the article too.
1984 Peterson’s Sports Car Magazine Article
BMW 323IS/345IS Turbo Alpina:
As Seen in August 1984 Sport Car Magazine
By John Hanson
SCC Road Test
Blitzkrieg! Alpina’s Street-Storming 3.2-Liter Intercooled Turbo 345i Blitzkrieg!
And now for something completely different; Mike Dietel’s throbbing BMW Alpina 345i
Everyone had seen the stealth blue 345i parked regularly in the pits-its open hood a subtle invitation to come take a look. But as yet no one had seen it in motion. As we pulled the car out of the staging area adjacent to the pit garages, a trio of sunglassed cocoa-buttered spotters slowly rose from their sand chairs, hoisting diet colas as if to signify the importance of the occasion.
Cautiously accelerating out of the staging area, we blended into the back of the pack of screaming baby Bimmers steaming through Riverside Raceway’s wide-open-throttle Turn One. Through the chicane of esses leading up the hill to the hard right sweeper at Turn Five, we fell back, but did not go unnoticed. Drifting into, and powering through the final blind bent at six we found the four-car pack bunched up like ducklings on the far side of the track, the driver of the rear car waving us through. We were in third gear, up on the cars at about 4000 rpm and the turbo was already well into boost. Standing on the throttle, we gathered all four cars in a sudden rash, cresting the modest rise and diving deep into the off-camber, hard-left seven. Scrambling over the crest of the hill at six, the half-dozen photographers who had followed our progress through the esses hustled into position on the backside of the embankment to grab a shot of the car drifting on all fours through seven. Out of seven and onto the flat-out, downhill back-straight, we acknowledged the thumbs-up grins and faintly muffled “Yee-Haa” of the spotters at the back-straight overpass.
Angling to the left, setting up for the wide-banked sweeper at turn nine at 120 miles per hour, it was obvious that all 200 or so people in the pit area had summarily dropped whatever they were doing and bolted for the guardrails. Braking hard and downshifting into turn nine, the tail broke loose again, but was quickly righted by the instantaneous rush of hard-throttle, turbo-boosted power. Swinging high through nine, then dropping down low as we entered the long front-straight, there was nothing in sight but the clear track lined with screaming BMW crazies.
Having dialed-in the car’s handling characteristics on the warm-up lap, while subtly announcing our track presence, it was hot lap time. The M1’s and 635’s had pulled off. The flock of baby Bimmers were pitted, their drivers queuing for the best vantage point. This was, after all, a BMW event-one of three, two-day driving school/weenie roast get-togethers held each year by the West Coast-based BMW Automobile Club (“That’s BMWAC with an A,” we were reminded). But it was also the debut of the latest automotive aberration from the Fantasyland studios of Mike Dietel – a street-legal 300-plus horsepower, turbocharged/intercooled 7-series Motronic power plant stuffed between the frame rails of a bulbous-bodied Euro spec 323.
Dietel is the owner/operator of Dietel Enterprises, a Laguna Hills, California, company that specializes in the importation, federalization and Alpinization of nonconforming, not-available-in-the-U.S. BMW automobilia. Beyond that, Dietel admits to having a twisted soft spot in his heart for 3-series muscle cars. Having learned a thing or two from his previous 330 and 333 projects-normally aspirated cars that looked showroom stock but went like stink-Dietel figured it was time to get ridiculous.
His plan was to somehow install BMW’s top-of-the-line 3.2-liter (195.8ci) six-cylinder Motronic engine into a 323 chassis. Normally found under the hood of gray market 745i’s, the engine is L-Jetronic fuel-injected, turbocharged and intercooled. It develops 252 horsepower at 5200 rpm right out of the crate, running at a peak of 7.5 pounds of boost. Figuring that if half a bar of boost was nice, a full bar would be twice as nice (one bar is equal to one atmosphere of pressure, or 14.7 psi). Dietel installed an Alpine/KKK variable boost wastegate.
This single alteration to the otherwise stock motor increased boost capabilities to just under 15 psi and bumped the output to approximately 320 horsepower in street-legal dress (which, in this case, included a Lambada oxygen sensor and a three-way catalytic converter). Mated to an Alpina close ratio five-speed gearbox, the engine installation proved to be a study in alternate routes. The 323 electricals were removed and replaced with the Motronic engine’s wiring harness assembly. The computerized Motronic controls (which handle basic timing, fuel metering and ignition duties) were grafted to the 3-series system and mounted into a custom-built air duct. This stabilized operating temperature deviations produced by the high output engine mounted in a shrink-to-fit compartment (needless to say, heat shielding was used extensively).
Although the stock exhaust manifold was used, custom dual exhaust tubing was fabricated to run all the way back to the oversized muffler cans scavenged from a BMW 3.0S. The intercooler was relocated into the passenger-side vent of the front airdam and a Wilquip oil cooler positioned into the driver-side vent. The radiator is a redesigned, high-capacity Alpina model. Finally, as if the engine compartment wasn’t already cramped, Dietel found a way to install an air conditioning system (a feat that Alpine engineers insisted couldn’t be done). With the bulkhead area directly behind the front airdam jam-packed with braided steel plumbing and relocated hardware, the stock, front-mounted swaybar needed to be repositioned-which fit perfectly into Dietel’s front suspension plans.
With considerably more weight, horse-power and chassis-twisting torque to contend with, Dietel wanted a heavy-duty, bully adjustable spare-no-expense underpinning. The front setup is a far-from-basic lower arm / strut / rod design, featuring a rear-mounted drop-ink / Heim joint swaybar, threaded chrome-moly front strut towers (for ride height adjust-ability), a chrome-moly front strut brace, gusseted reinforcement between the strut and brake caliper, a strengthened lower A-arm with adjustable inner pickup points at the lower subframe, Alpine variable rate springs and Alpine/Bilstein struts. The hubs are 635 five-lug units (front and rear). The front brakes are M1 discs mounted to Lockheed four-piston, magnesium-body calipers (similar to those found on the Lola T-600 and Porsche 935). The hydraulic/nitrogen brake booster system is a modified 635 design with manual brake biasing and an integrated reservoir of nitrogen for improved sensitivity, less pedal travel and improved braking force.
The three-piece wheels are custom built by BBS (15x9 front, 15x11 rear) with three-inch outer shells and a deep center hat section to handle the oversized calipers and cope with the increased bearing load. The tires are Pirelli P7s, 225/50VR-15 in the front and 285/40VR-15 in the rear. The rear suspension is a modified, late-mode 6-series independent / trailing arm subframe with the largest third member assembly available. The assembly is grafted to the two existing 323pickup points, with the third mount (at the member) fabricated into a notch in the trunk floor. The system features a 3.07:1 final drive gearing with a 75 percent limited-slip and integrated oil pump / oil cooler / oil filter. The rear brakes have Oldsmobile Toronado front rotors mated to BMW 323 ventilated front calipers.
Like the suspension system, the body and frame were heavily reworked to handle the substantial bump in torque, isolate flex and establish a solid platform for the car’s high-speed capabilities. To strengthen and stiffen the body and help reduce flex, both sides of the car’s rear quarter were peeled back in order to integrate a triangulated network of chrome-moly tubing into the car’s backbone chassis. The front and rear airdams and wedged fender flare/kick panel treatment was a joint effort between Dietel and Wayne Hartman Fiberglass (and will soon be offered in Dietel’s parts catalog). The final Scotch welding, molding, finishing and paint treatment was handled by Saddleback BMW Autobody. Inside, the 345i boasts impeccably tailored tan pigskin upholstery by ASS of Germany, who also built the seats. The dashboard is scheduled for an extensive redo, with additional gauging, an onboard computer and top of the line Blaupunkt stereo system. Variable boost is controlled by a valve on the center console and an emergency battery shutoff switch is mounted prominently under the driver’s seat (the battery was remounted in the trunk due to space limitations under the hood).
Like all BMWs, the interior of the 345i is ergonomically correct, well-insulated and comfortable, with easy to read gauges and accessible controls. The big difference between this 3-series cockpit and any other – especially after a few hard driving hours – is that it offers a safe and secure suede sanctuary from the rest of the car’s unadulterated craziness. And make no mistake, this care is automotive craziness. Listing the minutia of fabrications, relocations, gusseting, swapping and cussing it took Dietel and Chief Engineer Tom Coleman to complete this project would be impossible. Although the 345 is endowed with the kind of race-ready good looks necessary to stop traffic at any L.A. intersection, it’s a car that must be driven to be fully appreciated. With a muscular power to weight ration of 9.6:1, the heavy-breathing Motronic engine propelled the 345i’s 2980 pounds through the standing quarter-mile traps in 13.75 seconds at 99 miles per hour, sprinting 0 to 60 in 5.5 seconds and 0 to 100 in a scant 14 ticks. Of course, the NHRA Pro-Gas bracket was not what Dietel had in mind when he created his hell-bent-for-Bavaria Bimmer (although maybe he should reconsider). Instead, the 345 is most impressive out where it belongs, hustling around a long-legged road course like Riverside Raceway with 200 fanatics waiting impatiently to be beamed aboard for a fast-lap thrill ride.
The 345’s debut at Riverside was important in that it offered Dietel’s engineers their first opportunity to fine-tune the car’s suspension to road course demands – illustrating again the degree of race emphasis Dietel designed into his Sport GT/Racer. Adding a little oversteer, backing off on the rear brake biasing or adding a touch of camber or caster to the vehicle’s suspension geometry with little more than the turn of a wrench, the 345 proved supremely programmable to the individuality of driver and environment. With a calculated top speed of 150 miles per hour (Riverside’s straights simply weren’t long enough to test the car’s top speed capabilities) and full race suspension to match, the 345 is a legitimate Sunday road racer. With its 18 miles per gallon economy, hedonistic creature comfort, street worthy compliance and excellent around town manners, it is a bonafide, Monday through Friday family sedan. In short, the consummate enthusiast sports car.
Mike Dietel got into the enthusiast market out of self defense about ten years ago. Actually, he got tired of fellow BMW owners chasing him down and demanding to know what had been done to whichever heavily modified Bimmer he happened to be driving at the time. He builds cars like the 345 for the sheer fun of it, with an enthusiastic “Yeah,-but-what-if-we-tried-this?” attitude. With the 345i project, Dietel has outdone himself by answering the proverbial automotive question, “Does anyone really need this much car?”
Yes. Next question.
Somewhat haphazard paragraph breaks are my own, to aid readability.
Last edited by nonlocal; 02-24-2011 at 06:02 AM.