Related Manuals for Lotus Europa Twin Cam
Summary of Contents for Lotus Europa Twin Cam
- Page 1 LOTUS EUROPA TWIN CAM COMPETITION MANUAL JENSEN MOTORS, INC. PREPARED BY: 19200 SUSANA RD. COMPTON, CALIF. 90221...
- Page 2 ( i ) FOREWORD Modifications of the type described in this booklet and/or the use of the Lotus Europe Twin-Cam for competition render the vehicle warranty null and void. Jensen Motors, Inc. and/or Lotus Cars, Ltd. will not be held responsible for any damage or injury, which may occur in the following of...
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Page 3: Table Of Contents
( ii ) CONTENTS FOREWORD....................( i ) INTRODUCTION..................( ii ) Section CHASSIS...................... 1 SUSPENSION AND STEERING..............4 BRAKING SYSTEM................... 11 COOLING SYSTEMS (WATER, OIL AND DRIVER)......12 ENG I NE..................... 14 TRANSMISSION AND CLUTCH.............. 15 BODY......................21 ELECTRICAL....................21 FUEL SYSTEM.................... -
Page 5: Introduction
We would like to wish you every success in your competition endeavors with the Lotus Europa Twin-Cam, and if technical assistance is ever required please do not-hesitate-to contact the writer. -
Page 6: Chassis
CHASSIS In order to provide maximum safety for the driver a full roll cage was added to the basic chassis. The backbone type design of the chassis necessitated a very unorthodox and intricate cage. (See Figure 1.1A and 1.1B) The cage was bolted rather than welded to the chassis at several points to allow removal of the body from the chassis, although the cage could not be removed intact from the body. -
Page 9: Suspension And Steering
SUSPENSION Front Suspension The front suspension uprights and hubs were from the Triumph GT6 Mk II!, to enable the use of larger 9 3/4 in. d i3meter brake discs and calipers from the same car. The suspension arms inboard rubber bushings were changed to "Nylatron" (Holy Disulphide) bushings to eliminate any uncontrolled movement in the suspension. - Page 10 The optimum size of the front sway bar was found to be 7/8 in. in diameter. The bar was non- adjustable and installed in approximately the stock location. The sway bar had Fabroid rod end spherical bearings on each end and was attached to the lower shock absorber mounting bolts using spherical bearings.
- Page 11 Rear Suspension The modifications made to the rear suspension consisted of mainly eliminating rubber mounting bushings and strengthening chassis attachment points. Full adjustment capability was also provided. An adjustable sway bar was added to enable fine suspension adjustments to be made to compensate for different circuits.
- Page 13 The trailing arms were relieved to provide clearance for the wide section Goodyear cantilever-type tires and wide wheels. The rubber chassis mounts were changed to "Fabroid" bearings and the trailing arms were modified to accept the "Fabroid" bearing rod-ends. Stiffening plates and reinforcement brackets were added to the chassis at the trailing arms attachment points.
- Page 15 The rear stub axles were installed using "Loctite Shaft and Bearing Mount" on the threads. The locking nut was torqued to 160 lbs ft. The hubs should be checked for tightness after every track session as problems have been experienced with stretching and consequent slackening of the axle shaft nut.
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Page 16: Braking System
BRAKING SYSTEM The standard vacuum assisted tandem master cylinder was replaced by separate non-assisted master cylinders for the front and rear brakes. The two master cylinders were coupled by means of an adjustable, pivoted cross-bar to enable front to rear brake balance to be changed. Due to the proximity of steering rack, it was necessary to mount one master cylinder at 45°... -
Page 17: Cooling Systems (Water, Oil And Driver)
1 ½ in. width brake shoes and still maintain the desired rear track dimension. This entailed recessing center of plate approximately 1/8 in. so that shoes were 1/8 in. closer to center of the car. (Same position as with standard backplates.) Aeroquip steel braided brake lines were used throughout and routed through the cockpit to prevent damage and facilitate inspection. - Page 18 Oil Cooling It was found essential to use two front mounted oil coolers from an MGB (Part No. ARO 9809). The coolers were mounted in tandem in the side of the radiator ducting. The air from the coolers was ducted out underneath the car through an opening cut in the floor of the nose. (Consult SCCA GCR pertaining to oil cooler ducting limitations.) The oil lines to the coolers were routed through the chassis backbone for safety purposes.
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Page 19: Eng I Ne
ENGINE The capabilities and limitations of the Ford-based Lotus Twin-Cam are well known. Therefore, no attempt has been made to detail any engine modifications. The power output is severely restricted by the limited amount of substitution and modifications allowed under the SCCA Production sports rules. -
Page 20: Transmission And Clutch
TRANSMISSION Clutch A single plate, Borg & Beck competition clutch was used in conjunction with a specially manufactured aluminum flywheel. A hydraulic actuating mechanism was employed in place of the standard cable system. This was found necessary due to excessive pedal pressure as a result of the stronger diaphragm spring or the competition clutch. - Page 21 This single plate clutch, although rated for less power has performed very satisfactorily, and only three discs were required for the complete racing season. Transaxle The transaxle of the Lotus Europa is of Renault manufacture and three types of gearbox have been fitted. Early Europa Twin Cam...
- Page 22 The most important difference is the opposite rotation of the crown wheel as opposed to the applications in Renault vehicle, due to the rear engine location of the Lotus. The types 352 and 365 transaxles are 100 percent Renault with no "Lotus-only" parts.
- Page 23 replacing fibre washer with a brass washer of calculated thickness to give the required end-float. The latest type differential seals and caps were used (Renault No. 7700-554-257) with the cap threads sealed with Teflon tape. The drive shafts were attached with standard double roll-pins locked with safety wire.
- Page 24 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- GEAR GEAR RATIO OVERALL RATIO MPH/1O00 RPM ENGINE ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- 2.06 7.33 8.31 1.62 5.77 10.56 1.29 4.59 13.14 1.00 3.56 17.10...
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Page 26: Body
BODY The excellent low drag and aerodynamic stability characteristics of the body shape eliminated the need for extensive modifications. The fenders were flared and extended to provide the necessary clearance and shrouding required by the SCCA production sports car rules for the wider wheels and tires utilized. High speed stability was improved by fitting a full width spoiler (available from Jensen Motors, Inc.) to increase down-thrust and prevent lifting of the front of the car. -
Page 27: Fuel System
due to the proximity of fuel tank. The battery was placed longitudinally across the car adjacent to the engine bulkhead. The European-type, single-arm, two speed wiper motor was used. FUEL SYSTEM The mechanical fuel pump was replaced with a Stewart Warner electric pump, Model No. 240A, and was mounted adjacent to the left-hand fuel tank. -
Page 28: Setting-Up Car
SETTING-UP CAR There were no difficult adjustment or suspension tuning problems with the car constructed as previously described. The most difficult problem was the minimizing of front suspension bump-steer. Bump-steer is dependent upon suspension geometry, ride height and effective steering rack location. -
Page 29: Specifications
SPECIFICATIONS Suspension FRONT REAR Road Springs. Free length 6.4 in. 10 in. Rate 185 lbf/in. 200 lbf/in. Wire diameter .375 in. .437 in. Number of coils Inner coil diameter 2.6 in, 2.6 in. Safe maximum deflection 3,25 in. Shock Absorbers Koni Koni Manufacturer... - Page 30 Setting-Up FRONT REAR Koni Shock Absorber Settings (Refer to Koni Instruction Leaflet) Rebound Adjustment - Sweeps from minimum (right to left). 1 ½ 6 ½ (One sweep covers two holes and is l/4 turn) Bump Adjustment -Clicks from minimum (clockwise). Ride Height - Bottom of-spring to 3 9/16 in.
- Page 31 Final Drive Ratio 3.56 : 1 (32:9) General The many fabricated and modified parts developed for the Europa can be obtained from: Kurt Andress 1035 West Wilsop Costa Mesa, California 92627 Phone: (714)642-5524 Kurt was a member of the-Lotus Jensen team.
- Page 32 NOTES...
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