Mini Spares - 8-Port Project Min

If you refer back to the October 1993 edition of Mini Tech News, we were about to embark on modifying the suspension.

As luck would or would not have it, we had the advantage of setting up and sorting out the Monte Carlo Mini, which would help us in some directions. After checking the ride height of the car, it was higher on the left hand side by 1 Vs' at the front and W' at the back.

An adjustable suspension was fitted and all four corners of the car lowered to the same height. The first thing to do is set the castor angle which is different on either side. The Rover workshop states 3' for castor and that is exactly the best position we find for handling. Yet both Monte Cars and our project Mini were set at around 4' by the factory. By fitting our 21 A 1091 adjustable tie rods, it was set at 3°.

By decreasing the castor angle it increases negative camber, so you should always check castor first. The negative camber on the project car was also very inconsistent with 2° positive on the right side and 1h' positive on the left hand side. This was our first major problem and we were not sure which way to tackle it, bearing in mind other Mini owners might wish to follow our findings (at their own risk!). By taking off the original standard lower arms and fitting our C-AJJ3364 negative camber arms, we ended up with l ' negative on the left hand, front, and 0' positive on the right, which suggests standard arms are not too exacting.

To make life easy, a blank arm could have been drilled to give the extra l ' negative camber required. This seemed the only logical way to get the required l ' negative, but we knew it would prove difficult for the general public to follow, so plan B was put into operation.

Plan B, was to sort the subframe out as mentioned in the last edition of Mini Tech News.

We knew by the different wheel base lengths, ie. the right hand 1/2" longer than left, meant that the front subframe needed looking at.

The top tower bolts were removed and by looking down the hole it could be seen that the subframe was not in its correct position. The right hand side needed pushing back so the tower bolt would align perfectly when refitting. To do this the other mountings had to be loosened off; the front pear drop type mounting actually fell off broken after less than 1000 miles. The top bolts were correctly lined up and replaced. We elongated the holes in the rear lower mountings so they would line up with the bolt holes in the floor. The front/rubber mountings were replaced and padded out correctly between the front panel and subframe.

Now the front subframe was properly located it still moved when the steering wheel was turned (you can see the top tower rubbers twitching), so top alloy blocks from our C-STR 640 Kit were fitted which eliminated this problem. Fitting the lower alloy blocks between the bulk head cross member and subframe caused so much road noise on this car that we removed them.

All this seems straight forward and easy, but when you do not know where the problem lies, you have to start isolating different areas that could be causing the problem; it took nearly eight hours to straighten up this misaligned subframe. The car handled fairly well on standard shock absorbers and the only addition to the story is, before buying these wonderful Road Handling packages available, sort out the ride heights, castor angles, and camber angles which are more beneficial. All these things were done to my son's car which has standard shock absorbers, our Minilife 5x 12 wheels with standard Pirelli 145x 12 tyres and it handles better than most Minis I or my staff have ever driven.

Our car was originally fitted with our own 5x 12 Minilife wheel and Dunlop 165x60x 12 tyres which do not require spacers. This gave an improvement, but because of the extra torque produced by the engine, it made the car feel like it was on tram lines and under hard acceleration tramping became intense. By changing the front shock absorbers and different settings we later cured these problems, but if a softer ride is required, we overcome some of this by using more toe out just as ERA did on their Turbo cars with 13" wheels, however, tyres do wear out quicker. On the subject of tyres, for all-round performance, especially in the damp, this area has been improved by the fitting of the new A510 Yokohama 165x60x t 2 tyres, which are directionally fitted, (ie. they have to be fitted on a certain way with an arrow showing rotational direction and tyre valve side is marked by a dot). These were fitted after shock absorber testing.

With the car now lowered it was reset at 3112° castor and ended up with a negative camber of to on the right hand side and W on the left hand side. The car had settled further and while testing different shock absorbers, the front wheels were rubbing on the arches so the car was raised slightly, and by fitting Koni adjustables at full hard setting, all the problems created by the extra engine torque were erased. Note: we had increased the power of the Mini Sprite from 49 to 104 BHP. The Konis were the last shock absorbers out of all the wellknown brands to be tried and were the first to actually work on our particular car. As the Konis seemed to be the best, we then fitted Koni Sports front shock absorbers, which are only made for standard ride height. These did not appear to make very much difference, but as they are expensive and meant to work better, we fitted rear shocks to compliment the front. The suspension has become much firmer and a decision has been made to stay with them, but play about with the castor/camber angles; i.e. we will try and increase the negative camber on the front and decrease the negative on the rear to 1/4° or neutral (it is sitting at about 1/2° at the moment). We will try 3° castor again with the front wheels at 1/16 " toe out and the rear 1/8" toe in.

We are fitting Monte type special Konis to the front for evaluation, to help cope with the extra power and torque. On our particular car we found that none of the other makes we tried were as good as standard Konis.

We will be supplying the 4 tyres, our 5x t 2 wheels and Konis or alternative shock absorbers as a complete package for £496.00, which makes everybody elses handling kit look expensive (considering we supply 4 wheels as well). If you want the special sports Konis on the front add an extra £35. The engine, once off the dyno, was stripped down. Pistons replaced, bore honed. Crankshaft was cross drilled and wedged and the full assembly balanced and a Turbo clutch fitted. (See article: 8-PORT EFI, Completion of the first stage, for Dyno report on engine - page 29).

First impressions were with mixed feelings. The car was only OK up to 2500-3000 rpm and from there up to 7,000 rpm it went Like stink, but needed different gear ratios, which in helical form (for quietness) are not available.

The five speed gearbox incorporated a 22G 1040 laygear, making it close ratio, the same as the original Cooper S 4 synchromesh gearbox with a 3.3 1st gear. The fifth gear is 0.805, which on the 3.4 final drive gives 2.76 overall gearing. This gearbox is designed for fast motorway use and is a special for analysis, with our own special cross pin road differential similar, but downgraded to the one on the Monte Carlo Mini.

Pull away power was OK, but the camshaft might be changed to MG Metro profile, or it's back to the dyno to get the better low speed pick up power. The other area to look at will be the plenum and cylinder head port sizes and shapes. After the first few weeks of testing this ratio, we feel the fifth gear is not particularly beneficial with the traffic around London, as it does not accelerate very well in fifth gear. However it would be good for Autobahn driving where, believe it or not, this car will cruise at around 1oomph. This really is a fun car, but more testing and trials will be taking place.

Fast Car magazine are testing the car as it stands on April 12th, along with the Monte Carlo Mini, before the Monte goes to a Japanese exhibition for PR work. Mini World will be testing the 8-PORT car after that.

Keith Dodd