1.7 turbo conversion
WHAT ENGINE?
Instead of buying those awful 1.7 renault engines and trying to put a turbo on them you should resort to something else - VOLVO 1.7 turbo engine commonly found in Volvo 440/460/480. Contrary to popular belief, stated on various R5GTT boards, this is a RENAULT engine, you can actually find Renault markings on the block, which is absolutely identical to any F type engine Renault makes (those are 1.7 L in R5 GTE/GTX or other renaults, as a mater of fact 1.8/2.0 16V is also a F block). What was added in Volvo is some low compression pistons, Garrett T2 (yes a T2!) turbo, and a complete set of trick Bosch LH jetronic fuel/ignition management. What is trick about it is the fact that it incorporates boost control but more about it later.
The engine develops only 120 HP, but that is with very little boost, probably 0.4 bar, and with a very restrictive cat/exhaust.
BUYING
Ok, the engines in 440/460/480 turbos are identical, and I suggest you find the best you can. If you are in a position to buy a good one from a 440 then I suggest you buy the gearbox too. The reason is simple, 440, in contrary to other 4xx volvos, and R5GTT, has a different gearing, which will not give you any more top speed, but the gears are stacked together a bit more, and 5th is a direct 1:1, which is much better if you like to drive fast somewhere else than on the motorway.
I actually bought both a gearbox and the engine from a 440 and can say that the box is a straight swap for a GTT one, while I somehow find the changing action much better, more precise.
Electronics
When buying make SURE that you get all the electronics, since there are two boxes, one for the fuel, other for the ignition. The ignition box has a small pipe to which vacuum/pressure from the intake manifold is connected.
The wiring loom usually looks like a a big tangled bunch of wires, something that no one can manage, but in reality it consists of 3 sets of wires, which are connected together by some plastic clips:
1. Wires for the lights and indicators - to be separated and thrown away
2. Bosch fuel/ignition wiring loom. Can be identified by two big connectors for the ECU's. Take it out carefully. It also has a bunch of relays which control the fuel pump and ignition.
3. Special wiring loom which is used for the turbo/injector cooling. Now, like GTT, a Volvo turbo engine also has a fan which blows air onto the fuel injectors, but it also has a water pump that circulates water through the turbo, even when the engine is shut off (similar pump can be found on R19/Clio 16V). Those are controlled by two (or is it three?) sensors, which you can find under the turbo (on the water line), and screwed to the intake manifold. I took this off and threw it away, did the same thing with the water pump. The pump gives you an added bit of protection, but only if you are stupid enough to shut the engine off immediately after a hard run.
Exhaust
Apart from the exhaust manifold with the turbo attached, which I presume you will take with the engine, you should also take the turbo downpipe, which fits neatly in the GTT with no modifications, and is made to a much higher standard than anything you (or any "tuner") can make. It is also pretty hefty in diameter. If you want you can also take the catalytic converter, which hosts the lambda sensor.
I took the cat, but used a drill to take out the ceramic catalytic converter inside, so I ended with a empty box.
Intake
Make SURE, and I can not stress this enough, to get the airflow sensor. It is a hot wire type, and probably costs more new than you will pay for the whole engine. It is worth checking if the wire is broken, since it can happen, especially if the car was damaged in an frontal accident. Also worth checking is the rubber flexible pipe going from the sensor to the turbo, if broken it will give you headache. Mine was completely destroyed and I had to improvise. It also houses an recirculating type dump valve.
Misc
It is highly unusual to find an engine complete with the intercooler, since it will probably be damaged in the accident, but try to get as many coolant/intercooler hoses as possible, since you will find them useful later.
Ok, you just bought the engine, what is next?
Checking it out
First, open the cam belt cover and examine it or replace. F type engines have, besides the cam, oil pump driven from the belt also. Just above the pump drive you will find a 1/4 inch oil line going under the exhaust manifold to the turbo. This can sometimes crack also. I had to replace mine and did so with the engine in the car which was a pain. Do not buy the original item, but have it made out of a braided flexible teflon hose... much better.
WHAT TO MODIFY
Tuning
Ok, I guess you are not satisfied with 120 horses, so do something about it.
First of all, you do not need the CAT. You can just bolt it off or do what I did and drill the ceramic core out of it. The CAT also houses the lambda sensor, which you can just plug out (it will increase the consumption somewhat but will improve power/driveability). I kept the sensor, but just plug it in when I need to go to MOT.
Volvo engine has a very weak wastegate, which is connected to the turbo housing by a little silicone line. On it, you will also find a little electromagnetic valve. This valve is used by ECU to control the boost. I did the following and am suggesting you to do the same: remove the boost control, and change the wastegate. You can not use the one found on the GTT, since there the turbo is turned the other way round, but should buy a normal T25 wastegate. I took mine from a big T25/32 turbo that I am using for my 1.8 16V. I have mine adjusted to 0.6 - 0.8 bar, which might not sound like much but is plenty.
One of the major problems with this Volvo engine is that the ignition controler also has an overboost switch. Unlike the GTT, on which it was possible just to plug it out, on the volvo you can not tamper with it. The result is that with this ECU it is not possible to go above 0.9-1 bar.
T2 turbo on 1.7 engine is a bit small, I admit. It is actually a bit bigger than your standard T2 turbo found on the GTT. Tuners would probably call it a STAGE 1 hybrid . If you like your power immediately, and available from low on the rev range, the standard turbo is your best bet. I could see a bigger (T25) one... but I would have to change the electronics to cope with the increased boost. I am not thinking of that, since I have a 1.8 16V turbo waiting to go in.
PUTTING IT IN
Engine mounts
Ok folks, it might say VOLVO on the intake manifold but it is a normal Renault F type engine. So, the gearbox engine mounts fit, you just need to change the one engine mount that is found on the block. You need the complete mount, not just the rubber, since the metal part that bolts onto the block has a different bolt pattern.
If you want to use your old GTT gearbox you will have no problems, bolting pattern between the GTT engine and a F type one are very similar, and the GTT box has holes for both types. The only thing to chnage is a little metal guide, usually found pressed in the gearbox, around the bolt, near the right driveshaft. You just need to pull it out and place it in the hole nearby. Do not worry, you will see it.
Exhaust
As I said before. Make sure you get the downpipe. You can use it with or without the CAT body, you just need to have someone connect the exhaust. You can use your old GTT one or make a new one. Modifying the GTT one is a 10 minute job at your exhaust specialist nearby.
Do not use an restrictive exhaust. Standard R5GTT one is no good and will rob you of power. Aftermarket ones are ok for the most part.
I first made a side exit one, no silencers, and that one was FUN FUN FUN, but just too loud. Now I use a straight through pipe, 2 inch dia. with no silencers, which exits in the normal position. It is also a bit loud but much better than the side exit one.
Oil cooler
Volvo engine uses a sandwich type oil cooler, with the engine coolant water passing trough. This is no good for two reasons: First, it does not do a very good job, and more importantly, the filter sits too high on the block and interferes with the radiator fan. For a while I actually could not install the fan...
I did the following: Use the block that is used on the standard GTT 1400 engine, mounted under the oil filter. It will fit the volvo engine perfectly. Either run the oil through the radiator like on the standard car, or install an external cooler (what I did). I like the cooler found on Opel (vauxhall) Kadett/Astra.
Engine cooling
First of all, remove that stupid electric water pump that you will find on the volvo engine. I is a nice idea but just complicates things. Also remove its wiring loom.
Connect the turbo to one of the water jackets coming out of the head. Water exiting the turbo should run directly to the pump. There is a large metal pipe running around the block in front. It also collects the water from the cabin heater. Do not worry about this, there are plenty of places to connect this.
Top cooling hose, going from the head to the cooler is not a problem, it is straight and not a problem to connect. The hose going to the pump is another story...
F type engines have their water pump positioned lower down on the block, and the pump intake is facing toward the gearbox, instead down as found on the standard 1.4 turbo engine (C type engine).
Additional complication for me, was the fact that I was using a R5 Diesel radiator which itself is much bigger than the standard item, and together with the intercooler covers the whole cars' front.
What I did is find a Renault 25 radiator, which has both intake and radiator exit positioned on the same side. I had to modify it, so that I can turn it upside down, so that the intake/exit sits closer to the gearbox. This gave me a direct line from the head to rad, and a nice, almost straight line, with only one L bend for the lower line. This was by far the biggest modification I had to make to make this engine work.
Intercooler
Now, I have not seen the original volvo intercooler, since it was damaged too much, so I can not speculate, but I used a normal GTT intercooler. I removed the thermo flap long before. Connecting the turbo and engine intake with the intercooler is best left to your creativity, I used a combination of Volvo and Renault hoses, and some pipes I made myself. One thing to watch out for is the first little silicone elbow used by Volvo on the turbine exit. It is a "samco" type rubber, and should definitely be used. Just make sure, with the engine out, that it is properly connected and use a strong clip so that it will not fall off. It is a pain to mount later on, and is difficult to identify a leak there.
This is about it... If you haven't taken your engine out before, let me remind you that this is best done by removing the front subframe. I actually changed the whole engine myself, with basic tools and some improvised lifting jack used lift the engine off the subframe. It took me a two days to exchange the engine, two more weeks to connect everything.... Not a big job if you have time.
What to expect
Ok, let me put it in this way: 0.6-0.7 bar boost, straight through exhaust, no air filter yet, The car spins its wheels through 1, 2, and if the roads are dirty, even 3rd. This is on A520 Yokohamas, 195/45 15. I did some acceleration tests, and while spinning wheels prevent me from posting a good 0-60 time, in high speed acceleration (50-70 and above) it is faster than Civic Type R (old 190 HP one) I can outrun Accord Type R's without problems. Even on standard gearbox, it will do 140 mph, and will get there VERY quickly. On one occasion, at that speed my rear spoiler flew off.
Best of all, I must have spent 600 pounds at most for the whole conversion. I admit the car does not look like much, but it is fast...
