Plumbing… Super Mario Bros. wanted!!
Plumbing took a couple of days to finally achieve an acceptable result. The intercooler pipes, at between 60 and 70mm diameter, occupy significant space and do not like bends, other than those designed into them. I ended up using modified 620Ti pipes, which with the recessed intercooler allowed the retention of the original nearside gearbox mounting and clutch cable anchor point. On the first Montego we fitted out, these areas had to be changed.
Of vital importance to any engine, but more so to a turbo engine is a high quality air filter, and for performance preferably one that can flow, and filter, sufficient air to supply the engines needs. I was hoping to use a proper airbox with integral performance filter, to eliminate the characteristic Turbo 'whooshing' sounds. Lack of space beat me into accepting a large K&N cone filter mounted above the gearbox. Sometime I will eventually achieve my goal, together with a cold air feed pipe from the front of the car, but as it isn't that loud this may be a 'round tuit' job.
Water hoses and pipes are predominantly 220 Turbo with the exception of the 820 top hose. Of course there were other minor little hoses used, such as those to connect up the water cooling to the turbo housing, and the odds and sods for the heater and expansion tank connections.
Power steering was also quite simple to pipe up, largely down to the convenience factor that the unions into the rack are the same for both 220 and Maestro. This is a real bonus as the fluid pressures can reach up to 1500 psi on the pressure side, which is guaranteed to find any weaknesses! A remote 214 reservoir, modified Maestro coolers pipe and a couple of other minor Rover/Maestro PAS hoses connects all the loose ends.
Exhaust..ed
From this stage the only plumbing left was the exhaust, fuel pipes, and to add a fuel filter. The Turbo tank and pump are the same as the EFi so only the engine bay positions are different for the feed and return. The exhaust is a simple combination of original 220 Turbo down pipe cut and shut, then mated to a 2.25" bore twin box Maestro Turbo sports system. With such a bore clearance is always a problem where the pipe passes between the front subframe and underside of the engine bulkhead. Here time and many minor adjustments and trial fits are needed to optimise the clearance before attacking it with the MIG welder. The job wasn't made any easier by the rear section having the wrong run, which fouled on underside of the rear.
The last installation task involved the wiring, which puts many off doing similar conversions. It isn't quite as easy as earlier M16 conversions where the management system for both the 8 and 16 valve engines is from Lucas. Now Rovers own MEMS system is almost universal and whilst some sensors and minor components are common, the rest is totally different. On the plus side though, is the fact that now only one ECU is employed and this is mounted in the engine compartment and attaches to the engine by the same separate wiring harness.
You can see that by using the proper engine harness nearly all of the wiring is done for you. You only have to connect to the original cars power supply, to an earth, and about half a dozen other connections, for control of coil, fuel pump, starter, and feeds to rev counter, temp gauge and oil warning light.
Fuse box
As the new wiring harness has pre moulded plugs I found it easiest to introduce a 214/220 engine compartment fuse box, as these plugs simply slot in. Not only is this a fuse box, but it also carries relays for starter, oxygen sensor main and fuel pump, as well as acting as a distribution board. Obtaining one from a wreck, along with all of the other pre-formed plugs, still with wire attached, made for light work mating the new and old systems. This may have simplified the work, but come start time I found that there was no provision for an earth for the starter relay, so turning the key initiated the 2 second fuel pump buzz, followed by earth shattering silence!!
Once the starter relay circuit was complete the engine was cranked with no fuel or spark until the oil light extinguished. Reconnecting the circuits and cranking once more was rewarded with an almost instant start and settlement to a slightly lumpy idle, even if it sounded like a skeleton in a tin! This horrible sound is normal with hydraulic tappets that haven't had time to fill with oil, and after a couple of minutes the noise had settled to a more acceptable level. Once the engine had fully warmed (on a fast idle) it had become almost silent.
Servo, what servo?
Only a couple of hose clips needed a tweak before the contemplation of a first drive, well it was until I found no servo effect on the brakes. The problem was easy to identify as whilst 'muggins' had gone to considerable trouble to cut and line up that plastic servo pipe, before using very hot water to reform the joints, he had forgot to check the arrows!
Much cussing and hot water later, off we go. Throttle response is good even at low speeds and gentle operation, a tempting squeeze invokes a purposeful, yet unobtrusive intake rush. A very firm hand pressing you into the seat accompanies this. A silly grin starts to form! Then as the torque starts to take hold there is the unmistakable sound and feel of the exhaust catching underneath. Back track, jack up, further adjustments and were off again. This time the exhaust plays fair and keeps quiet, the open section of road arrives… bigger silly grin!!! A couple of miles is enough for now so it is back for checking of levels, for leaks and anything else untoward. Nothing found so a very satisfying way to end the day.
Next day sees further shakedown runs with longer but steady runs. No problem other than the exhaust is settling with the heat and touching again. No matter, the contact is only minor, let it settle some more and then readjust. At this time the idle is becoming obviously smoother, which is due to the ECU 'learning' the needs of this engine. It shows how much these have progressed, since the ECU learns the parameters of the engine it controls and constantly adjusts to obtain the best idle. This takes about 200 miles to fully achieve from the first time the ECU is connected to the engine.
One thing is abundantly clear, and that is the eagerness of the engine to respond to the throttle. It is easily the match of the EFi in this respect, but is backed by a wonderfully progressive and enormously powerful power delivery, far in excess of what was expected. This is also better than a couple of 420 GSi Turbo's on hand during this time. This is the first inkling that the extra power that was found with the M16 conversions, through use of a non-restrictive exhaust, was being mirrored with the T16 Turbo.
Clean exhaust, plenty power!
The T16 exhaust is normally fitted with a catalyst, yet for this application there is no cat, but the Lambda sensor is retained in working order. An exhaust gas analysis check shows excellent combustion with the important MOT gasses being 0.7%CO and 175-PPM Hydrocarbons. CO2 and O2 were also at excellent levels, indicating both good cylinder sealing and complete combustion. The first full tank fuel consumption also reflected the efficiency with 31mpg, remember 26 mpg with the 8 valve Turbo.
Over the next 1200 miles only the exhaust needed a further tweak, before the opportunity arose to use Peter Burgess's rolling road. In deference to the mileage, only a couple of runs were done, resulting in 198 bhp at the front wheels at just under 6000 rpm, which is within 7 bhp of Roger Bunford's identically engined M.G. Montego, whose engine has done more miles. Full power mixture was also ideal; indicating that the free flow exhaust wasn't causing the mixture to lean off.
198 bhp at the wheels is 63 bhp up on what a ballpark standard Maestro/Montego Turbo produces, and just over 100 bhp more than the average EFi. Quite clearly the performance associated with this level of power can be nothing other than awesome. Quantifying such performance requires specialist test track facilities and as yet I have not had the inclination or opportunity to pursue. At least maths provides a very reasonable guesstimate as to the new maximum speed, as we know the actual power and measured performance for standard models. (Many previous rolling road tests for power and Autocar performance test data)
150 mph Maestro…
Using 115 mph for the EFi and 130 mph for the Turbo, as mean average top speeds, the calculated top speed moves to 146.9 or 147.7 mph, each so close as to make no real difference. This is also realistic, as maximum power is just short of 6000 rpm, and with the Turbo gearing of 25 mph per 1000 rpm giving a theoretical 150 mph, the two dovetail almost perfectly. Comparison with the measured maximums of other Rover cars fitted with the same engine also tends to confirm the predicted figures. Acceleration is a totally different ball game as too many variables are involved, suffice to describe this facet as being 'adequate'.
And not forgetting the other bits!
It will have been noticed by many that I have indicated how I have fitted an engine which increased the power of the standard Maestro Turbo by a very significant 46.6%. This increase demands considerable additional preparation of the car to safely cope with such power. Needless to say there was an extensive programme of changes well prior to any power increases and these were enhanced further in anticipation of the T16 Turbo fit.
Brakes…
Any Maestro Turbo owner, and many EFi owners, will tell you about the weakness of the brakes. The usual path of harder front pads and specially prepared discs provides some improvement, but the effect is limited due to the front discs being only 240mm in diameter. Remember most of the braking is done on the front. Most current 2 litre family cars operate with front discs of around 260mm diameter, and performance models of the same ranges often have even larger discs.
There are additional problems for the Turbo models in that the frontal body changes do seem to reduce the airflow around the wheels, so the brakes suffer as a consequence. Not only this but the 15" lattice style alloy wheels doesn't encourage through airflow so the brakes suffer some more.
With all these negative points I decided to tackle the problems head on about two years ago and create a braking system that really worked, yet be as simple as possible. The result is to fit 280mm diameter discs from the Golf G60. The other dimensions almost match those of the Maestro discs and require only minor work, along with some engineered spacers for the original caliper, to fit. The results are tremendous, with power and reserve previously way out of reach of the standard set up. Fifteen months and about eight thousand miles has not changed this opinion. It must be the right direction since I see that very similar conversions are now commercially available.
Wheels…
The change of discs was not the only modification to improve braking. Many years ago when my MGB V8 EFi sported uprated wire wheels, the brakes were nearly standard, yet provided wonderful braking. When the wheels became tired and flexible I changed them to 'knock on' Minilite alloys of the same diameter. Immediately the brakes became weak and easy to overheat. The result of reducing the airflow through the wheel.
Using this experience I decided to change the wheels to take advantage of this increased airflow. With the arrival of the MGF came a source of five and six spoke alloy wheels with the bonus of the same PCD (stud spacing) as the Maestro. These wheels are sized at 6" X 15" and will fit a standard Maestro hub, with just the addition of thin spacers at the front. (With the big brakes the VVC wheel fits without spacers.)
As can be seen from the photos I chose to use the VVC five spoke wheel, as I feel that it is a better looking wheel. Rover may well intend this, to add to the higher market position in which the VVC sits. I also note that the VVC wheel is made in Italy, by Speedline, a company with a very high quality image. Image is a personal thing but these wheels certainly add to the effect of the brakes when directly compared with the original cross spoke alloys. They also display the same characteristic as wire wheels do in heavy rain, in that it takes a second to clear water before full braking is felt. I have carried over the use of 195/50 X 15" Goodyear Eagle tyres.
Suspension…
The suspension has benefited from the usual reduction in ride height. This has been restricted to a 35mm drop rather than the more popular 50mm, quite simply to allow for the times when the car carries a load or has to negotiate speed humps and multi storey car parks, without having to worry about the sump and exhaust! Spring and damper rates are significantly increased, the dampers now being a gas type all round.
As the engine change occurred after the car had done just short of ninety thousand miles, all of the suspension and steering joints and bushes were replaced en-bloc, many for uprated components. With these changes, and with the brakes, the car maintains the principle of Safety Fast. Another benefit of these suspension changes is that this controls torque steer to levels below that of the standard car, even with the extra power.
Driver security and comfort…
Driver comfort is not often associated with safety, but it should be, as a comfortable and secure driver exerts firm control over the car. The original steering wheel, which was the standard three spoke leather item, had become quite polished on the rim and worn excessively in the 2 o-clock position. I did want to replace this with the visually identical M.G. Metro one that is about one inch smaller in diameter, but these are apparently no longer available. I ended up with a new standard wheel that is much more comfortable than the old one.
Also in the comfort zone I changed the front seats for a pair out of a 1987 Montego Turbo. These have much firmer cushions and are much more supportive than the post 1988 M.G. saloons. Not all the earlier cars had the harder cushions, there were several suppliers of foams, so you have to try the seats individually.
The future?
I now have a very exiting and pleasurable car that is far more practical and cheaper to run than it was previously. I can clearly see that 13 years of unbroken ownership of M.G. Maestro's should now extend into the next millennium. What comes next is impossible to say, but at the end of the feature I did on the M16 conversion, I said, "how about a Maestro with a 16 valve Turbo engine?" Well seven years on and we now stand next to such a beast.
I have a number of ideas still in the melting pot. One of those previous ideas was a 'K' engined Midget, but that has been beautifully done, so lets go one stage further and replace the 'K' series in an MGF with a 'T' series turbo. Trouble is that there is likely to be a V6 with 175 bhp (ish) and a supercharged 200 bhp (ish) available long before I can get to it. Perhaps I will have to be satisfied with altering something older with 4WD, ABS and other toys!
In reality, my main hope for the future is that in seven years time, we, as individuals, still have the right to actually create such machines, otherwise the world will be a duller place, and I will end up gardening!