Mike Brocks..MG Maestro Turbo..web site! Under construction!!

Modifications

The engine has been treated to the usual go-faster treatment, with re-boost to max 18psi (adjustable in/car bleed off valve). Scorpion exhaust/3" tail pipe, Strapped std intercooler with temp flap removed. Also, special three angle cut inlet valves with stage one gas flowed head. The std (dust bin) air box has been removed in favour of Motobuilds air filter kit. This consists of pipercross cone filter and mounting bracket.There's also an uprated carburettor needle and, finally Magnicore racing HT leads, high platinum spark plugs.

The car has not been back on road since this last outing. However, there is on going developments.

Strapped intercooler img close up. This modification is very easy to do, and will allow over 14PSI of boost, without plastic end caps blowin off. If you look closer at this Jpeg, you will notice the plastic end caps are simply held to gether with jubilee clips. Before this little mod was done, I removed the end cap, then remmoved the temp flap for better flow of air though the intercooler. Plastic moulding was also removed within end cap for flow. On reassebly, I used Silicon sealent, for a better air tite seal.

Below the picture shows an all alloy MG Maestro Turbo intercooler. This will alow much higher boost over the standerd intercooler.

FEATURES:

Core area 55% larger than standard intercooler.

Utilises all original hoses and mounts.

All alloy construction pressure tested to 30 psi.

It will cost you though, about £ 195.00.

The DIY high air flow intercooler below, belongs to Stephen Murphy. This impressive intercooler is actually two Maestro turbo units TiG welded together. This means, there is a massive 100% increase in capacity. Ideal if you are running turbo boost pressures in excess of 18PSI. Note, how it's inlet/outlet is constructed in such a way, that air only needs to flow in one direction for better cooling/less restriction. To add to this, the boost pipe that exits the intercooler, is further cooled, as it is situated in high flow area, in front of the car. The cost of making your own intercooler mod, like Stephen's one seen here, will be much cheaper than any one sold in the go-faster shops, and much more efficient!

The distance the boost pressure travels from the turbo outlet in the intake track on the MG Maestro Turbo must be over 5 feet long! not good for throttle response I bet?. Why not remove your air/air intercooler, in favor of the much more efficient water/air chargecooler kit. The benefits are, much shorter intake track and less restrictive flow, also more efficient. The only problem with them is, there very expensive!

(This one pictured above is AUXILLIARY type only)

The cost is over £ 509.25 !WoW!

Why not have a go at building your own chargecooler. This can be done for less than £120 or so.

Some pictures below are from Fast Car Magazine, this DIY chargecooler article, can be found in issue October 1994. Some text has also been taken from the magazine, written by Julian Edger, however I have added some of my own experiences, after building this kit myself, in December 1994. The kit was fitted to my MG Montego Turbo I owned at the time, of course this car has the same O series turbo engine as the MG Maestro Turbo.

Turbochargers can produce huge increases in power, but they're not without problems. One of the main snags is that induction temperatures soar, partly because air heats up as it is compressed and partly because the turbocharger is not 100% efficient, so some energy used to drive the turbo is lost into the air, heating it further. As hot air is less dense, less hot air will be drawn in by the engine than if the pressurized air were cool. Also, if the air is cool, a higher compression ratio, lower octane fuel or higher boost can be run - or the safety margin before detonation occurs is improved. Finally, lower intake temperature will reduce exhaust temperature. improving reliability. An air/air intercooler passes charge air through the tubes of a radiator. Ambient air cools the core, so the intercooler must be mounted where airflow can be directed through it. The core is uselly mounted at the front of the car, before the radiator or to one side of it (as is for the MG Maestro Turbo). Air/air intercoolers need large pipes - often 2 or 2.5 inches in diameter - connecting the core to the turbo and then to the inlet plenum. To reduce pressure drop and turbo lag, tube runs need to be short (not the case for MG Maestro Turbo). Ducts also need a smooth inner surface if the flow is to be least restricted. Water/air charecoolers transfer the charge air heat to water which circulated to a cooling radiator by an electric pump. They have substantial advantages. They're much more flexible in their packaging. The small radiator needed, must be located in a flow of cooling air, but pipes connecting it to the heat exchanger (within chargecooler) and pump can be threaded through tortuos routs without problems. And because the specific heat value of water is much higher than thet of air, even a compact water/air chargecooler can be very efficient.

I have put together this diagram to explain the workings of this DIY chargcooler, hopefully you should be able to relate to it.

End view of heat exchanger enclsure, minus end plates and plumbing attachments. Air enters and leaves via the two inlet/oulets manifolds at the top, and passes through the core twice. thin aluminium sheet is used for the walls, stiffness provided by the folds. End plates are thicker material. You can set a MiG welder up so you can weld aluminium, but it doesent look to good though, but it will do the job. TiG welding is the normal method!

This picture shows a larger industrial core in this application. This is ideal as a heat exchanger capability is very high. I used the heater metrix from an old car, in my monty turbo, but this burst within my DIY chargecooler at over 13PSI boost!! Best to use an old air condition metrix, with maching radiator from a some air conditioned car. I got a new air condition unit from a secound hand car parts dealer, for £40, it came from a Ford I beleive, I dont know what model though.

Water plumbing connections need to pass through the wall of the chargecooler. Connections were made by using male and female barbed fittings. You will find them at most big DIY superstores for £6 or something. Just use jubilees clips, to hold coolent tubes to them. Note, small water flow bores, you can use other methods, but these connections are ideal.

....Which look like this when in place. Hose clamp's threads were fixed using loctite. Remember, the chargecooler must be air tight, if it's not, then you will have boost leak problems. The same can be said with water connecting tubs within chargecooler unit, make sure you have no water leaks, before you weld the unit up! This happend to my one, but it was the MiG welder that melted one of the coolent pipes, with chargecooler.

Making the heat exchanger is the most difficult part of building a water/air intercooler. Obviously the heat exchanger must be able to efficiently transfer the induction air's heat to the fluid. It must also pose the least restriction possible to the turbo@s airflow. And finally it must be rugged anough to contain the boost pressures acting within it. Efficient cores are available in the form of automotive air-conditioner evaporators, generally compact and constructed to take high pressures. Car heater corse cane be used, but only up to pressures of about 10PSI, because they aren't built to withstand the rapidly fluctuating pressures found in the turbo system. The heat exchanger seen here uses an air-conditioner evaporator core (about 8x9x2.5 inches in size) costing less than £40 new. The core was mounted in an airtight enclosure - 2mm aluminium sheet was used for the vertical walls of the enclosure, with 3mm sheet for the end plates. Thinner material was used for most of the heat exchanger because care was taken to keep large flat surfaces to a minimum. Folds in the material help to stiffen it, giving less deflection under the high internal forces. The end plates, however, needed to be flat - and so the thicker material was used to ensure rigidity. Folding of the sheet was done at home using lengths of angle iron and a vice. The chargecooler was MiG welded using a hobby type welder.

It's easiest to use an electric pump, which is how the OE manufactures do it. Because of the high specific heat value of water a large flow isn't needed. The Subaru Legacy uses 15 litre/minute pump, run at 40% power until more than 80% throttle is used, where it switches to full power. The pump Julain Edgar used in his Daihatsu is the whale GP9955, made by Munster Simms in Northern Ireland. It cost about £18 in Australia, so should be much less over here! It's rated at 11.4 litres/minute, and is cylinder-shaped, measuring about 5.5"x1.5". It's seald, so can be mounted in where it may be splashed with water (like in the wheel-arch). 3/4" hose was used on the Daihatsu, though 1/2" can be used. Cooling is needed as soon as the car is boosting. Boost may be used for only a few seconds at a time in a charge up through the gears, so it's no use if efficient charge cooling takes 5 seconds to come on line. On car testing revealed that the pump should also operate after the boost has gone, otherwise the heated water would not be passed through the radiator and cooled. The pump is triggered by a micro switch mounted on the throttle butterfly shaft. It's adjustable for operating point, and is currently set up so that the pump is triggered at over abought 50% throttle opening. Getting rid of the charge air heat is a front mounted air con condenser. The core can be located in front of the engine rad. Using an air-con evaporator as the heat exchanger and the condenser core from the same air-con system as the radiator ensures a good match of the system components.