I have seen alot of posts by people asking how to convert to a gt and thought as I was converting mine i would get some piks and write up a little how to so everyone can see just how simple it really is. first of all it helps to have a good set of tools to hand.

You will need everything from the engine bay of a GT

-fuse box (just makes it a bit more simple but you can use the existing one)

-engine wiring harness

-lighting wiring harness (not esential but has a different plug by the coil)

-engine and everything attached to it!

-gt fuel pump located under the drivers side rear wheel and held in place either by the hose clips or 3 13mm nuts.

and thats about it

I was converting from a 1ltr spi but I'm sure this applies to the 1.3 aswell.

Rite to get started drain the engine of all of its fluids, oil & water. It makes everything that little bit easier.

Now you can start removing things I started by taking off the inlet elbox and disconecting the fuel lines be carful though as the fuel lines will still have pressure in them so a bit or paper towl around the banjo fitting is advised, then go ahead and get the throttle body and inlet manifold off. As a usefull tip i labled up the existing loom as i was taking things off because if the loom you are replacing it with is not labled you might think i recognise this plug but where the hell did it go!!

Then go ahead and take the exhaust manifold off for good measure soak the nuts in wd40 or penitrating oil the night before to help loosen them off a tad. By this point you engine bay should look a little like this>

Now i presume if you are doing this you have some way of getting the engine out ie a crane or somthing like it. this is a good point to get it hooked up as we now need to start undoing the engine mounts. After the weight of the engine is supported by the crane start loosening the two front mounts as they are the easiest when they are loose get under the car and undo the 2 13mm bolts that hold the rear engine mount to the car if possible you want to take the rear mount off as it makes getting the engine out alot easier. Dont forget to undo the gearbox linkage and driveshaft bolts while you are under there as it isnt coming out if you dont, the driveshaft bolts are a multi spline so you may need to get/borrow one from somone. Take the bolts out of the front two engine mounts and you are ready to get it out!!

At this point its a good idea to give the engine bay a good old clean i used a pressure washer and it took about 10mins and ended up looking like this

Now you can start to get all of the spi wiring out of the bay thred everything back thru to the fuse bod and then take the 2 or 3 screws out olding the fuse box out. When it is loose you should be able to unplug it from the interior loom and be left with somthing looking like this.

Next i decided to get the gt engine up on the crane and into the bay because it had nothing to get caught on.

Take the time and while it is on the crane put all the mounts back on drive shafts & gear linkage in place and bolt it back up make sure all the bolts are nice and tight then you wont need to get under the car again untill you change the pumps over.

As for wiring it back up it dosnt get much easier. the GT looms and fuse box just plug straight onto the multi blocks that were behind the spi fuse box. Saf (grungeisdead) being the nice guy he is labled up the gt loom so all i had to do was play connect the plugs to the appropriate things. But i cant see it being difficult as there is a difference in about 3-4 plugs between both looms and if you took the time to lable up the ones that came out then you can use it as a guide.

The next step is really just connect everything to the engine if it didnt go in with it on, inlet manifold throttle body exhaust manifold, thermostat housing, water pipe with the stab valve attatched. All of the water pipes bar the ones that go to the inlet manifold on the spi engine can be re-used if there not broken why get new ones. The thermostat housing i got with my GT engine was broken so i had to make up some blanking plugs for the spi 1 to block of the pipes that go to the inlet manifold.

They are just 2 bits of bar cut short and pushed into the ends of the pipe and clamped in, you could get a new thermostat housing from gsf or vw but i didnt have time to get one. When you have most of the bits attatched it should be starting to look like a proper engine.

Get all of the plugs connected and chances are you will have 1 or 2 left over a large 2 pin plug which is for the water level sensor in the header tank and another smaller 2 pin plug with a blue and yellow wire going into it. the level sensor if you didnt get a tank with a sensor in it can be bridged with a bit of wire and some terminals as it just senses a closed circuit. and the blue and yellow wires can be extended to reach the oil sensors on the back of the head.

I suppose the next logical step would be connecting the fuel lines. The pipes on the 1ltr had arrows on the as to which one was feed and return so you can cut and adapt them to suit. the inlet goes on the plastic bit of the injector rail and the return goes off the metal bit on the bottom of the regulator.

Lots of people dont know which vacume pipes you can get rid of and which to keep so i will attempt to show you.

And this is all you really need

Now really all that is left to connect up is the fuel pump make sure you got a multi point injection pump that runs at 3bar otherwise you will not have enough pressure to fire the injectors. the pump should be a straight swap for the old spi one undo the pipe clips and pull the old pump off be carfull fuel will come out if you clamp the pipes with some mole grips is should reduce the amount that comes out dramatically. If possible replace the vw clips for jubilee clips if they haven't been changed already. you can also change the filters while your at it all depends on time and budget.

When you have finished plumbing in the pump get a friend over to give you a hand to bleed the fuel system undo the tiny bolt on the end of the injector rail and put a pipe on in going into a jar and get a mate to turn the key to prime the pump an few times till the same amount of fuel comes out each time replace the bolt and you are ready to go!!

do a final check of the engine like oil plugs leads water and so on and then turn her over and see what happens. If you are lucky it will turn over and fire up. you may need to set the timing and base idle "que link to helpful thread on forum) http://www.clubpolo.co.uk/forum/index.php?showtopic=109802

There might be somthing i missed out but I'm fairly sure its all there hope it helps you guys in the ultimate quest for more power!!!

Good work dude

Top points! I am mid-conversion myself and this will prove very usefyl, thankyou!

Very useful indeed

Pinned by me.

Sweet looking engine too.

Top points! I am mid-conversion myself and this will prove very usefyl, thankyou!

Same here, answered my question about the fuel pipes and where the fuel return is, also usefull info on bleeding the fuel system.

Cheers buddy :-)

damn it!

wish i pressure washed my engine bay while the engine was out. owell, i got the worst parts.

this will be usefully aswell and thanks

Is the process that much harder for Mk.2 polos? I have a 1.3 coupé S, so could I even keep my existing bottom end and just transplant the head (is the GT head really any different to other 1272 heads, apart from the cam?) and induction system across? obviously no existing electric fuel pump on a mk.2

tejG40, see http://www.clubpolo.co.uk/forum/index.php?showtopic=12473

tejG40, see http://www.clubpolo.co.uk/forum/index.php?showtopic=12473

perfect, cheers. Might be just about to buy a GT conversion too!

Is the ignition still the same? or has that gotta come out of the gt aswell?

Lots of people dont know which vacume pipes you can get rid of and which to keep so i will attempt to show you.

And this is all you really need

Has anyone got the full diagrams here with labels?

I'm having a bitch of a time trying to work out exactly where the different vac pipes go.

Can any GT owners shed some light on this for me?

Cheers.

Steve

Get back to my PM about the gearbox! I'll come with my Polo and we'll setup your VAC pipes correctly.

Great info cheers!

anyone got any idea how this is done without changing the fuse box?I've done pretty much everything else

confused as to where the fuel return line goes, also on my injector rail, where the inlet is i have something missing :/ sposed to be healed on with two m6 bolts :/ and as the gt i have is on bike carbs i want it back on injection, unsure where all the pipes off the inlet mani etc all go! tried to work it out but struggling a little, bit of a noob lol! wondered if you could help me out? cheers

any diagrams of how all the water tubes go also which is flow and which is return on the injector rail? cheers in advance

need to read things more slowly I've answered my own question

inlet goes on the plastic bit of the injector rail and the return goes off the metal bit on the bottom of the regulator.

Edited 1 December, 201114 yr by 01mlacey

What extra do you have to do if the car has a 4 speed box to get it to a 5 speed? Cheers

Just a quick on going from an NZ to a GT can I use the exsisting fuel pump? Also can I use my inlet manifold as I'm trying to buy the GT lump but it's running a carb .

Thank you!!!

Cheers bud will need this for my new loon