PRI 2015: Part 5

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This is the ZF ASC, which stands for anti-stall clutch. It’s 140-mm in diameter, and comes in 2-, 3-, or 4-disc configurations. It’s got a two-actuating mechanism location option, and ZF claims very repeatable drive-offs with no clutch pedal necessary. This allows the use of a tall first gear in road course cars.

This is the 140-mm PTC (Pull-type clutch), which is offered in either triple- or quad-plate configurations, as well as carbon/carbon or sinter/steel.

Here is a ZF eight-speed 8P 45R motorsport planetary gearbox, which allows shifting through steering-mounted paddle shifters, and offers minimized RPM drops during gearshifts. It’s also 15% lighter than ZF’s conventional 8HP45 tranny.

Having owned four different E36 M3s with a manual transmission, I suppose I can say I’ve got at least some experience with ZF transmissions. While all four of mine performed well—even in a 550whp/500 lb-ft turbocharged setup—I’ve only experienced one stripping to shreds when I was in a different turbocharged E36 M3 built by the crazy owner of ICS Performance, George Kakaletris. With an old-school Precision PT76-GTS turbocharger and C16 race fuel it had in it, he tried to put over 900 lb-ft of torque through “the Bumblebee” during a fifth gear pull on the highway, with me in it. Yeah, it didn’t go too well. The car’s tires broke loose in such a vision-blurring, forward-catapulting fury that when the boost hit at around 120 MPH, the tranny was history in a nanosecond. Keep in mind this was around 2007. There wasn't a 1000whp BMW anywhere else in the world as far as we knew.

Limping the car back through the busy downtown streets of Stamford, Connecticut, with the tranny stuck in fifth gear, is another story. The triple-disc clutch and a wide-open, 5-in exhaust didn't necessarily let us cruise in any sort of stealth-like fashion. In fact, you should have seen the looks of the people attempting to eat a relaxing lunch on the sidewalk cafes while we echoed hundreds of ear-piercing decibels off the surrounding buildings. Good times, and no tears of laughter were spared.

Back to the ZF tranny talk—before the tranny destruction from the load in fifth gear, the yellow Bumblebee's factory ZF five-speed manual transmission lasted several fourth gear rips on the dyno at over 800 lb-ft, which is impressive considering the original tranny was fitted to a car that was only rated at 225 lb-ft of rear-wheel torque!

 


Injector Dynamics has new 1050cc, 1300cc, 1700cc, and 2150cc injectors available, which are E85 compatible and use a ball and seat design, the new injectors are also less prone to fouling. The firm reports it will be phasing out its 725cc, 850cc, 1000cc, and 2000cc injectors.

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