MGF Trophy 160 Turbo

[paulbeecham]

Many times the question is asked whether you can turbo charge a MGF, well yes you can as I've just done it. This is not a concise "how to" but a general guide of what I did. Sorry no pics as I lost my phone with them on.
I wanted to use OE part's where possible without resulting to any thing special.
The easiest route was to purchased a Rover 75 1.8t engine as most every thing needed is there.
Using the Rover turbo engine takes care of thing's such as turbo oil and water supply and compression ratio etc. This engine differs mainly from a normally aspirated one as it has slightly shorter connecting rod's and uses the 160 TF pistons. The block also has a turbo oil return port.
The donor engine was bought from a local scrap yard with 80k miles but I wanted to rebuild the engine for reliability using new liners, rings, bearings, oil and and water pump.
The new liner's were installed and sealed with hylomar, I also stuck them in with anaerobic adhesive to stop liner lift during assembly which would break the hylomar seal. You can clamp the liners but I find this method easier.
I wanted to fit a MLS head gasket but it's very important to have some liner protrusion with even liner heights to allow for a correct seal. I measured 2-3 tho across the deck, some more would of been better but decided to go with it but take some additional precaution's with a .5mm stainless steel shim.
The shim is stuck to the head with some Stag jointing compound and the gasket is sprayed on both sides with a copper sealer. This helps to guard against any coolant weep which can happen with a metal gasket. The shim help's to reduce the liner digging in to the face of the head as they often soften causing HGF in time.
New head bolts, upgraded oil ladder rail and turbo core were also fitted.

Fitting it in.
This is where it gets interesting as I reckoned it was possible with out too much trouble.
The MGF engine bay is slightly too small to accommodate the turbo engine as it fouls the bulkhead but I did not want to cut the bulkhead or remove the fuel tank.This is the usual method when using the OE exhaust manifold as the tank is behind the bulkhead and it doesn't always come out easily without a load of grief as it "grows" in service.
How I did it.
The standard 2052 LS turbo has an integral dump valve on the compressor housing which interferes with the the bulkhead just above the two heater pipes where they enter the car. To counter this I removed the dump valve with a chop saw and repaired the modified housing with Milliput epoxy filler. The DV was to be replaced with a remote piston type plumbed in to the intercooler circuit. This made the turbo much more likely to fit in the space available.
A few trial fittings later and with some slight modification to the bulkhead with a ball hammer it went in.
The area above the heater pipes "was knocked in " to form a groove about 35mm wide to allow the radius of the compressor to sit. (It helped to tuck the heater pipes into the pipe recess to get them out the way when fitting the subframe) I also relieved the bulkhead slightly around the turbo inlet area to give the inlet hose some more room.
The bulkhead was easy to shape and there is enough "give" for it to be successful bearing in mind the plastic fuel tank is behind. The removal of the dump valve really makes it achievable.
Because the turbo is very close to the bulkhead heat is an issue. To mitigate this I applied heat resistant tape to the bulkhead behind the turbo area and refitted the standard heat shield duly modified to fit the new profile. The manifold and down pipe were wrapped in heat resistant bandage and a turbo "nappy" fitted on the hot end of the turbo. The alternator and manifold also had heat shields fitted.
The exhaust was formed by a cut and shut of the existing exhaust and a Rover 75 turbo down pipe. Both lined up perfectly and another reason to go with the OE manifold.
To make it run I used the original 160 VVC inlet manifold but the throttle body, cam cover non return valve, and map sensor came over from the turbo engine. I would not usually fit a VVC manifold to a standard head as port size is different but careful fitting of gaskets and forced induction overcomes potential problems. I did not want to fit the plastic manifold as I prefer not to have the trouble some green gasket.
The MGF crank position sensor is also required.

Next the cam position sensor plug needed changing as the original VVC one is different, it also needed + ve supply taken from the engine loom socket.
The ECU was replaced with a remapped unit which also controlled a boost control solenoid again robbed from a Rover 75t which controls the wastegate. The VVC solenoid plugs etc are now redundant.
The fuel pump was upgraded to a Welbro 255 unit and a Malpassi adjustable 1.1 fuel pressure regulator fitted. I removed the rail mounted FPR and fitted an adapter that supplied return fuel to the new regulator.
Some OE fuel line connectors from the scrappy make's a nice job going in and out of the FPR and marries up with the existing lines with out any cutting.
Intercooler set up.
I was not sure of the best way to go here as space is at a premimum and heat is an issue.
Ultimately a charge cooler with a front mounted radiator, pump and tank is probably the best route. Smart Brabus do a nice unit which I will prob fit later.
On this occasion to keep it simple I went for a standard air to air intercooler sourced from an Audi S3 at the scrap yard.
I then fitted a fan to the intercooler that came from a smart car intercooler. The fan was connected in to the fuel pump supply and draws air through the intercooler from the nearside wheel arch. Additional cooling is provided by a 100mm ali pipe routed from the side air vent into the intercooler and cone filter area.
The intercooler pipe work is a combination of Rover 75 Turbo and SAAB Turbo. The SAAB pipe was chosen as it would fit and had a nice port to fit the Dump valve on. Additional silicone turbo pipes were fitted to connect throttle body and intercooler.
Turbo inlet pipe is standard 75t with a K&N cone filter.
Whilst in bits it was a good time to fit a remote 75t PRV thermostat, (original removed) at the rad end and additional bracing bars front and back from a TF.
How's it drive ?
It drives great with a lot of torque but being careful as it's very new. It also sounds the part with lot's of turbo noises.
Going to Monte Carlo in it next week so will see how it get's on.

[nigelandjo]

Look forward to seeing it in the flesh Paul

[talkingcars]

Sounds like an interesting project, got any photos.

[paulbeecham]

Just Returned from Monaco after a 2000 plus mile adventure via France, Switzerland and Italy. The car went well except for a slight exhaust leak which turned out to be coming from the turbo to manifold flange.

I took some pics whilst investigating the problem which turned out to be lose flange nut's that tightened up OK curing the fault.

Turbo and manifold with heats shields removed revealing flange nut's

I was concerned about cooling as the original air vents seem ineffectual so I made up an air scoop to ram some more air in to the engine bay. I used some fibre glass matting and resin for this.

Home made air scoop for intercooler

The scoop will hopefully give the intercooler and induction system some cold air as the fit is quite compact and temp's can get high.

intercooler etc

The modified compressor housing with internal dump valve removed. The airway was sealed with Epoxy putty.(Milliput)

Modified compressor housing with DV chopped off.

Twin piston dump valve mounted on SAAB turbo intercooler pipe to replace OE unit.

Replacement dump valve

We went with friends who took a MGF MK2 Steppy that developed a serious cooling issue which made crossing the Alp's challenging. We managed to fix it in Cuneo Italy using a modified Rover 100 radiator which cured it completely without any further issue.

[talkingcars]

The alps are hard on the cooling system, last year we had issue last year on the way up to the San Bernardino Tunnel and again a few hours later in Liechtenstein. Car was fine for the whole rest of the trip.

[Peter_B]

Hello Paul,

very interesting Turbo conversion you have built with your Trophy. May I ask if you still drive the car or in other words, is it still on the road?
I ask, because currently I'm also planning a conversion with an engine from R75 1,8T to be used, but problem is to get a manifold which will place the Turbo in a location in the engine compartment so it doesn't hit the bulkhead.
With your solution of modifying the Turbo housing itself and reuse the standard manifold from R75 this would solve my problems to get a custom build of a new manifold.
But was this modification of the Turbo housing in a longer term without issues? This is my question.

[nigelandjo]

The original poster hasn't been on the Forum since 2016, so you might not get a response.