Okay as previously discussed in this post we have established that the St's turbo has an oil supply to lubricate and cool the turbo bearings. It also has a water supply from the cooling system that flows through cooling passages in the turbo to cool it down. When this water leaves the turbo after cooling it this water is very hot, however because the water is under pressure the water temperature can reach over 100°C and it doesn't boil. This water is then said to be super heated. The super heated water is then returned to the cooling systems expansion tank to be cooled via the radiator.
As previously stated you can fit an oil cooler to your car which will lower lube oil temps and in turn reduce the load on the cooling system this will help keep temps down, or you can fit a up rated radiator. These are good ways of keeping temps down but they are expensive. A good way of helping to get the cooling system temps down is to cool the super heated water after it leaves the turbo and before it goes back into the expansion tank. This is what a turbo cooler does. I have managed to fit one to the ST and this is how I did it. However you should note that my car has the Radtec intercooler fitted so your mountings that you make will be different from mine depending on where you decide to mount your cooler. It will also depend on the type and size of the cooler you use. I have used a turbo cooler from a Series Two Escort RS turbo. I chose this as it was the right size for where I wanted to fit it. It cost £80 and it also came with 2 new silicone hoses and Hose clips.
WARNING DO NOT ATTEMPT THIS IF YOU ARE IN ANY DOUBT AS TO YOUR OWN ABILITY TO DO THIS JOB SAFELY
The tools you will need are
Prerequisites
Ensure that the engine is cooled down before you start. Open the bonnet and remove the cap from the cooling system expansion tank to release any pressure then refit it again.
1. Use the Philips screwdriver to remove the six screws that hold the plastic air duct cover over the bonnet catch as shown if Fig1
2. Next you need to relocate the horn. When the plastic air duct is removed you will see the horn mounted on top of the intercooler on the right hand side. Use the 10mm spanner and remove the horn as shown if Fig 2.
3. When the horn is removed use the pliers and cut the wire that goes to the horn as shown in Fig 3 don't cut it to close to the multi plug at the horn end as you will need to leave some wire to crimp your new section of wire to.
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4. Use the crimping pliers and crimp two new section's of wire onto the original wires as shown in Fig 4. You are looking to extend this wire so it will be long
enough to reach to where you relocate the horn too.
5. Next run some insulating tape round the new wires to protect them and feed them along the top of the intercooler and over to the N/S inner wing. When you have done this, mount the horn on the inner wing behind the ECU. Use the earth strap securing bolt on the inner wing. As shown in Fig 5 Then reconnect your multi plug to the horn and check that the horn works, better to check that your wiring is okay now rather than when the cooler is fitted. Remember to put the ignition on.
6. The next thing to do is to fit the cooler. Sit it in place and make some templates for your securing brackets. Use some cardboard for this. When you are happy that you have got the shape of your brackets and that they will fit make them from some mild steel/ aluminium. I used aluminium it is easy to work with. Remember to check that the plastic air duct will fit over your cooler without fouling your brackets. A picture of the brackets I made are in Fig 6
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7. I fitted the main bracket and then marked and drilled a hole for the securing bolt for my second bracket as shown in fig 7. When I secured this bracket in place I put the bracket under the panel I had drilled to secure it. This was so that it isn't seen when it is bolted on.
8. When you are happy that your brackets are done, connect the hoses to the cooler and tighten them up it is easyer to fit the hoses now than when it is in place. Don't secure the cooler yet leave it in place and feed the outlet hose along the top of the intercooler under the plastic slam panel and run it up to the expansion tank.
9. Next feed the cooler inlet hose through the gap between the radiator and the plastic slam panel. Use the screwdriver and remove the airflow sensor as shown in Fig 8. When this is out of the way you will see the outlet pipe from the turbo that the super heated water flows through as shown in Fig 9. Press the green plastic tabs on the hose connector and pull it off. Because you took the cap off the expansion tank and depresurised the cooling system and then refitted the cap there will be some water that escapes from the system but it will not be much.
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10. Next remove the plastic connector from the hose as shown in Fig 10. If it still has the original hose fitted then you will have to cut the securing clip so be careful not to damage it.
11. When it is removed cut the hose from the cooler to the right length and fit the plastic connector to it. Tighten it up und refit as shown in Fig 11
12. Remove the hose from the expansion tank as shown in Fig 12 and then fit the new hose from the cooler outlet to it. Don't cut it to length just yet though.
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13. Refit your airflow sensor and hoses then start the car up. As the outlet pipe on the cooler is not at the top of it you could get some air trapped in it so I tilted the cooler with the outlet higher up to ensure that I got all the air out. When I was happy that I had achieved this I stopped the engine and then secured the cooler to my brackets. Make sure that the securing bolt doesn't foul the cooler as shown in Fig 13.
14. When it's secured and in place you can then trim the outlet pipe from the cooler to the expansion tank to the right length. Start the car up and check for any leaks and check your water level. When you are happy that everything is okay then refit your plastic air duct cover.
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15. When the cooler was fitted and the engine warmed up I measured the temperature of the water entering the cooler at 3000 RPM and it was 109°C. The car was stationary and I had a fan blowing air at the cooler. It was a good sized fan and was supplying a good flow of air to it. The ambient air temperature was 4°C. When the water left the cooler it was 84°C The temperature drop was 25°C. The leads on my multi meter are not long enough to reach inside the car so I was unable to drive the car and get some readings. It is cold just now and therefore a better cooling effect will have been seen than if it was done on a hot day. The real test would be on a hot day and giving it some on a track. So was my little project worth it? Time will tell but for £80 and a few hours of my time I'm happy with it as it's a lot cheaper than oil cooler or radiator upgrades.
As previously stated you can fit an oil cooler to your car which will lower lube oil temps and in turn reduce the load on the cooling system this will help keep temps down, or you can fit a up rated radiator. These are good ways of keeping temps down but they are expensive. A good way of helping to get the cooling system temps down is to cool the super heated water after it leaves the turbo and before it goes back into the expansion tank. This is what a turbo cooler does. I have managed to fit one to the ST and this is how I did it. However you should note that my car has the Radtec intercooler fitted so your mountings that you make will be different from mine depending on where you decide to mount your cooler. It will also depend on the type and size of the cooler you use. I have used a turbo cooler from a Series Two Escort RS turbo. I chose this as it was the right size for where I wanted to fit it. It cost £80 and it also came with 2 new silicone hoses and Hose clips.
WARNING DO NOT ATTEMPT THIS IF YOU ARE IN ANY DOUBT AS TO YOUR OWN ABILITY TO DO THIS JOB SAFELY
The tools you will need are
- Philips screwdriver
- Plain screwdriver
- 10mm spanner
- Crimping pliers
- Drill
- Knife
- Insulating tape
- 8 AMP single core cable
Prerequisites
Ensure that the engine is cooled down before you start. Open the bonnet and remove the cap from the cooling system expansion tank to release any pressure then refit it again.
1. Use the Philips screwdriver to remove the six screws that hold the plastic air duct cover over the bonnet catch as shown if Fig1
2. Next you need to relocate the horn. When the plastic air duct is removed you will see the horn mounted on top of the intercooler on the right hand side. Use the 10mm spanner and remove the horn as shown if Fig 2.
3. When the horn is removed use the pliers and cut the wire that goes to the horn as shown in Fig 3 don't cut it to close to the multi plug at the horn end as you will need to leave some wire to crimp your new section of wire to.
4. Use the crimping pliers and crimp two new section's of wire onto the original wires as shown in Fig 4. You are looking to extend this wire so it will be long
enough to reach to where you relocate the horn too.
5. Next run some insulating tape round the new wires to protect them and feed them along the top of the intercooler and over to the N/S inner wing. When you have done this, mount the horn on the inner wing behind the ECU. Use the earth strap securing bolt on the inner wing. As shown in Fig 5 Then reconnect your multi plug to the horn and check that the horn works, better to check that your wiring is okay now rather than when the cooler is fitted. Remember to put the ignition on.
6. The next thing to do is to fit the cooler. Sit it in place and make some templates for your securing brackets. Use some cardboard for this. When you are happy that you have got the shape of your brackets and that they will fit make them from some mild steel/ aluminium. I used aluminium it is easy to work with. Remember to check that the plastic air duct will fit over your cooler without fouling your brackets. A picture of the brackets I made are in Fig 6
7. I fitted the main bracket and then marked and drilled a hole for the securing bolt for my second bracket as shown in fig 7. When I secured this bracket in place I put the bracket under the panel I had drilled to secure it. This was so that it isn't seen when it is bolted on.
8. When you are happy that your brackets are done, connect the hoses to the cooler and tighten them up it is easyer to fit the hoses now than when it is in place. Don't secure the cooler yet leave it in place and feed the outlet hose along the top of the intercooler under the plastic slam panel and run it up to the expansion tank.
9. Next feed the cooler inlet hose through the gap between the radiator and the plastic slam panel. Use the screwdriver and remove the airflow sensor as shown in Fig 8. When this is out of the way you will see the outlet pipe from the turbo that the super heated water flows through as shown in Fig 9. Press the green plastic tabs on the hose connector and pull it off. Because you took the cap off the expansion tank and depresurised the cooling system and then refitted the cap there will be some water that escapes from the system but it will not be much.
10. Next remove the plastic connector from the hose as shown in Fig 10. If it still has the original hose fitted then you will have to cut the securing clip so be careful not to damage it.
11. When it is removed cut the hose from the cooler to the right length and fit the plastic connector to it. Tighten it up und refit as shown in Fig 11
12. Remove the hose from the expansion tank as shown in Fig 12 and then fit the new hose from the cooler outlet to it. Don't cut it to length just yet though.
13. Refit your airflow sensor and hoses then start the car up. As the outlet pipe on the cooler is not at the top of it you could get some air trapped in it so I tilted the cooler with the outlet higher up to ensure that I got all the air out. When I was happy that I had achieved this I stopped the engine and then secured the cooler to my brackets. Make sure that the securing bolt doesn't foul the cooler as shown in Fig 13.
14. When it's secured and in place you can then trim the outlet pipe from the cooler to the expansion tank to the right length. Start the car up and check for any leaks and check your water level. When you are happy that everything is okay then refit your plastic air duct cover.
15. When the cooler was fitted and the engine warmed up I measured the temperature of the water entering the cooler at 3000 RPM and it was 109°C. The car was stationary and I had a fan blowing air at the cooler. It was a good sized fan and was supplying a good flow of air to it. The ambient air temperature was 4°C. When the water left the cooler it was 84°C The temperature drop was 25°C. The leads on my multi meter are not long enough to reach inside the car so I was unable to drive the car and get some readings. It is cold just now and therefore a better cooling effect will have been seen than if it was done on a hot day. The real test would be on a hot day and giving it some on a track. So was my little project worth it? Time will tell but for £80 and a few hours of my time I'm happy with it as it's a lot cheaper than oil cooler or radiator upgrades.
