Stages of Tune - Classic Mini
Haynes Mini Performance Manual by Tim Mundy
Simply the best "must have" book for Classic Mini performance and modification info. Covers just about everything from engine mods to digital clocks. Disc brakes, steering, gearboxes, interior, suspension, body work, special editions-every mod you can think of. Haynes "Mini Perfomance" by Tim Mundy
The following excerpt helps define the various stages of performance tuning in a Classic Mini. Paddy was elevated to the Stage 4 tune in July 2010 by Mincomp Racing in Costa Mesa, CA.
Stage 1 kits
Stage 1 kits are available from just about every Mini specialist and are a very worthwhile fitment.
The kit consists of:
- an uprated exhaust manifold which can be either a Cooper freeflow or an LCB, depending upon the kit supplier and engine size,
- an uprated inlet manifold, a K&N airfilter or similar,
- plus a richer carburettor needle,
- and a decent exhaust system which is usually a Maniflow or an RC40.
Most kits claim around a 20 per cent improvement on a 998cc engine. In a MiniWorld/Keeping Your Mini Alive (KYMA) test we managed to get 51 bhp from a 998cc Mini which was standard apart from electronic ignition using a kit from the Mini Shop. The exercise certainly backed up the claims.
To go from Stage 1 to Stage 2 is a case of fitting a modified head. In the case of 1,275cc engines this will probably mean retaining standard valve sizes. A carburettor needle change will usually be required too.
Stage 3 involves fitting a larger-valve head and uprating the carburation.
Stage 4 and beyond will involve a cam upgrade. This requires the engine to be removed from the car and a full engine rebuild which should include strengthening the crankshaft and balancing all rotating components.
Book Source: Amazon.com - Haynes Mini Performance Manual
Below is Paddy's 7/29/2010 Stage 4 Engine Modification Invoice