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les_garten les_garten is offline
Macht Schnell
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Join Date: Jun 2003
Location: PSL, FL
Posts: 861
I'll bite! I have an older BMW R100RT bike that I twin plugged long before I did my Porsche. I twin plugged the Porsche for the same reason. Back in the Late 70's and 80's when Leaded gas was going away and getting 100 octane fuel started disappearing, air cooled BMW bikes started having real problems with Fuel issues. A very common mod to alleviate this was to twin plug the heads.

I'm listing these anecdotally and without reference or Engineering facts.

1) Twin Plugging makes you engine less prone to detonation
2) Makes your car less prone to Bad Gasoline related pinging
3) Given Identical Engines, you can retard the timing on the twin plugged engine relative to the non twin plugged engine to make the same power

I am moving and have packed up my Bruce Anderson book. But I know he addresses Twin plugging in the book.

People on the Forum have done it with CIS to good effect. I've seen MSD and Electromotive systems used.
---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT
Old 03-04-2008, 08:42 AM
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