Turbo Mini (english)


Some stuff about the fastest Production Mini.



E.R.A. Mini Turbo Special
History:

Between 1934 and 1953, as English Racing Automobiles, E.R.A. built its reputation on the design and construction of the famous E.R.A.11/2 and 2 litre racing cars. They were the most successful 'voiturette' racing cars of the period. Beautifully made, reliable, quick and solid, they frequently beat the more exotic Maserati and Bugatti opposition.

 

Now, after a 35 year gap, E.R.A. has once again put its skills and knowledge into the design and manufacture of a performance car. The E.R.A. Mini Turbo was conceived as a 1980's replacement for the Mini Cooper S. A car with all the key characteristics of the Cooper ? speed, handling, excitement ? but one which would introduce into the concept the refinement and comfort lacking the original, but so necessary for modern motoring.

The car is instantly recognisable as a Mini but with the distinctive body modifications styled by Dennis Adams* it is aggressive without being boy racer. The interior is fully restyled. Specially designed and tested sports seats have been installed, giving excellent support and comfort, along with a full range of VDO traditional dial instrumentation on an entirely new instrument panel. At op of the range Phillips in-car entertainment system is fitted to a new centre console.

 

A sun-roof lightens the interior which is trimmed in a careful combination of best Connolly hide, cloth, ambla and deep sound deadening carpet. The power for the E.R.A. Mini comes from the well tried Austin Rover A series 1275cc turbo engine, and this E.R.A. turbo variant gives a smooth and reliable 94 B.H.P. at 6130 R.R.M. and excellent mid range performance.

Installation of the turbo unit involved modifications of the body shell and extensive development to ensure reliability. Modifications to the water and oil cooling systems ensure that the power unit and transmission remain adequately cool even in high ambient temperatures. Modifications to the front and rear suspension including new front suspension arms and damper units were planned using computer simulation and tried out in practice at racing speeds on high speed race tracks. The elimination of torque and bump steer was a major priority to ensure excellent but safe handling characteristics.

The car is fitted with ventilated front discs and four pot calipers and the rear drum brakes are modified. A servo system ensures acceptably light pedal pressures. All alloy one piece 6" x 13" wheels are used with Goodyear or Dunlop 165/60 13 low profile tyres HR rated. To ensure that the highest possible assembly standards are met and maintained, each car is hand built by small teams of skilled technicians who are fully responsible for their product.

Conventional Mini rubber suspension. Early cars had Spax dampers, late cars had Konis. Metro turbo vented disks and 4-pot calipers for the better braking power.

Before leaving the Dunstable factory a system of vigorous checks and quality control is undertaken and each car is extensively road tested. Only then is the car fitted with its individual model number plate.

*Dennis Adams designed the Marcos sports cars and the Probe conccept car.

The ERA modifications were major: the bulkhead needed intensive reshaping to allow the turbo and accillaries to fit under the bonnet. "That was the least of the problems", comments Sankey. After a long term testing around the track at Bruntingthorpe and MIRA, ERA found that the power was a bit much for the gearbox. "The synchros would die a death after 2,000 miles and the engine would lose compression in the middle cilinders - a common fault on the metro turbo, too.

The engine was de-tuned slightly and the mapping adjusted so there was less torque at low revs and more torque higher up the rev band. The gearboxes stopped blowing up with such regularity, but it was never a ideal solution. They experimented with a number of gearboxes on the two prototypes. The poor cars were well trashed, using a number of four, five, and even a six - speed box, som with synchro, while others were dog engaged, and made by Jack Night, of course. However, the fitting of an exotic box deemed too high, and all of the production cars were fitted with a standard four speed unit.

The ERA turbo has centre mounted auxiliary gauges and lower centre console hide usual heater eyesore. Note: five VDO and one smiths gauge! Japanese export models (most of the ERA`s production) had full airconditioning.

Line of sight speedo and tacho to conform with modern construction and use requirements. No red line on tacho. Small 1.5Bar turbo boost gauge at bottom right of auxiliary gauge cluster in centre of dash.

Engine bay looks amateurish and the turbo creates high under bonnet temperatures.

Special bonnet vent designed not as intake but to let hot air out of the engine bay. A hard pushed turbo unit can glow red hot so a through-flow of hot air is essential to avoid damage to non-metal components.
ERA Specifications:

It took ERA around 50 hours to carry out the following modifications to the cars, wich were almost always painted red or green.

  • Fitted with MG Metro turbo engine, clutch gearbox and modified exhaust.
  • Re-mapped ECU and turbo control.
  • Spill system fuel pipe layout with modified fuel tank and up-rated fuel pump and filter.
  • Dump valve in carburettor float chamber to drain on shut down and improve hot start.
  • Fuel pressure regulator to increase pressure on hot start.
  • Increased waterpump drive pulley diameter.
  • Rubber shroud fitted around radiator for improved airflow and reduced fan noise.
  • Secondary water radiator, front mounted.
  • Oil cooler front mounted.
  • 64 modifications to the shell, including bulkhead clearance for turbo, stiffeners, wheel- arch modifications to allow clearance for the 13" wheels, various brackets and fixings for body kit and interior trim.
  • And, and, and, and.
Only 480 cars (and possible up to four pre-production models) were produced between 1988 and 1991. Over 300 ERAs went to Japan, 110 to the UK, the remainder were mainly bought by western Europeans.

Vehicle Specification:

VEHICLE CATEGORY:

 
  • M1

MODEL DESCRIPTION:

 
  • 2 door saloon - right hand drive passenger car. ERA/MINI 1275cc Turbo engine front wheel drive.

ENGINE:

 

 

 

 
  • 4 cylinder in line OHV: Petrol, transversely mounted
  • Displacement: 1275cc
  • Bore Diam.: 70.61mm (2.78ins)
  • Stroke: 81.28mm (3.2ins)
  • Comp Ratio: 9.4:1
  • Max Power: 70.1 kW @ 6130 R.P.M.; 94 B.H.P @ 6130 R.P.M.
  • Max Torque: 118.0 NM/87 lbs/ft @ 3600 R.P.M.
  • 33mm intake, 29mm exhaust valves (exh. sodium cooled)

CLUTCH:

 
  • Single dry plate hydraulic.

GEARBOX:

 

 

 
  • 4 speed manual: transverse
  • front wheel drive
  • Ratios: 1st 3.647:1; 2nd 2.185:1; 3rd 1.425:1; 4th 1:1
  • Reverse 3.666:1
  • Final Drive Ratio: 3.21:1.

FUEL SYSTEM:

 

 
  • Carburettor: SU HIF 44
  • Turbo Charger: Garrett T3 with ECU controlled boost pressure. Max boost pressure 8psi @ 6000 R.P.M.
  • Air cleaner: ERA design and manufacture.

BRAKING SYSTEM:

 

 
  • FRONT: Ventilated disc 213mm: twin pot calipers ´H.I.' split dual circuit, servo assisted, hydraulic.
  • REAR: Drum: servo assisted hydraulic
  • Handbrake: cable operation to rear wheels.

WHEELS AND TYRES:

 

 
  • Wheels: 6 x 13 alloys
  • Tyres: 165/60 13 HR
  • Spare: std 12 x 41/2 J Steel Wheel and 145/70, SR12.

CAPACITIES:

 

 
  • Engine/Trans Oil: complete fill including filter and cooler 9 pints (5.11ltr.)
  • Cooling System: 8.5 pints (4.81tr)
  • Fuel Tank: 71/2 galls (35ltr.).

DIMENSIONS:

 

 

 
  • overall length: 10ft 1/2ins (3.05m)
  • Overall width: 5ft 11/4ins (1.56m)
  • Overall height: 4ft 5ins (1.331m)
  • Ground clearance minimum: 6ins (152.4mm)
  • Kerbside weight:141/2cwt (737.29Kg).

PERFORMANCE:

 

 

 

 
  • Max Speed: 115 M.P.H.
  • 0-60 M.PH. 7.80 secs
  • 30-50 M.P.H. in 2nd gear 3.40 secs
  • 50-70 M.P.H. in 3rd gear 6.30 secs
  • Standing ¼ mile 16.60 secs.
  • Fuel consumption: Urban 34.3 M.P.G.
  • 56 M.P.H. - 53.5 M.P.G.
  • 75 M.P.H. - 39.7 M.P.G.
   
  All claims result from manufacturer's tests.
   
   

 

Layout of the ERA turbo feulsystem with pressure regulator and fuel pipes.

  1. Fuel pipe
  2. petrol pump
  3. Fuel pipe
  4. pressure regulator (Malpassi Seregno)
  5. fuel pipe to carburator
  6. petrol filter
  7. fuel pipe back to tank
  8. pressure pipe to pressure regulator
  9. E.C.U. electronic control unit (regulates pressure up to 3500 rpm max. 0,25bar, above max. 0,57bar)

 

one of the prototypes.
The ERA turbos braking system had split system at the front, the very same as the MG metro turbo.
Layout of the ERAs engine bay and carburettor.
  1. Turbo unit.
  2. oil intake.
  3. oil drain.
  4. waste gate actuator.
  5. waste gate.
  6. intake manifold.
  7. plenum chamber.
  8. hose.
  9. hose.
  10. turbo boost solenoid.
  11. fuel pressure regulator.
  12. E.C.U.
  13. Carburettor.
  14. Carb. vent valve.
  15. Crank case vent.
  16. hose mixture screw.
another 2 ERAs
This is the layout of the box, if you want to install a turbo in youre Mini, the measurements are approx.(as I made it in my Mini)
most of this side is taken out of an 1988 broshure, some stuff taken from Marx ERA Page.