3. Here is the same throttle system installed on a 3.6 XJ-S. This produced a power gain of about 50 b.h.p. from an otherwise standard engine when used with a less restrictive exhaust system. Intake pipe length was critical - shortening the trumpets by 1.5" reduced the power gain by nearly 20 b.h.p. Adjustable length trumpets were used to find the ideal dimensions to use.

4. The production version of the multiple throttle system with the main assembly machined from a casting, chrome plated bright-work and a custom made K & N filter.

5. A prototype of our Ram Plenum induction system for the AJ6 engine. This was a highly resonant tuned pipe system designed to work with the Lucas 9CU and 15CU engine management systems. The restriction of the hot wire airflow meter was resolved by adding a bypass orifice to double the breathing area, and some electronic changes to compensate for the different load signal. The throttle was 3.5" diameter mounted on ball races to overcome the effects of vacuum induced friction on the spindle. When on song it was incredibly noisy, to the point of being painful, and only became civilised by adding a resonator inside the intake duct. It produced a very strong power band from 3000 to 6000 r.p.m.

6. This shows the individual tuned length pipes of the Ram Plenum system - before the plenum chamber was welded in place. The wave action within the pipes was augmented by powerful resonances in the main intake duct.