OK, I'm looking to gather a few extra horses from my MK3 Genesis AAV.

I would prefer to keep most of the existing engine, which lead me to an idea...

What if I grabbed the GT injection bits and fitted them to the AAV...?

(The reason to keep the AAV is that it's low milage (53k) and there is also a certain sentinmental attachment).

By my best research I would need:

ECU & loom

Inlet manifold

Injectors

In-line fuel pump

Air box?

Throttle body

Cam

(Possibly fit the different GT head valve springs).

I realise it won't be a GT. Compression ratio being down and gearbox/rear beam/exhaust not to GT spec, but it would be a conversion I could achieve...

So, what do you think? Crazy, stupid, possible, ill-advised etc? Anyone offer a guess at a bhp figure? (I'll start the ball rolling at 68bhp!)

very possible, i did this to my 1.3 spi AAV lump and it was QUICK. I stole them from a mates GT which was a very fruity engine and it ran very well, you dont need the fuel pump, the stock item is more than up to it, but you will need all inlet/throttlebody and mpi fuelling items and loom, ecu, airbox, afm, etc. The GT head isnt necessary with the double valve springs but if you fancy revving to 8k it is advised!

Will probs make about 65-70bhp with stock GT items but if you replace the lump with a 1.4 ABD then you'll be looking at 80bhp with much more torque and much more fun even with the 8P g'box. I highly recommend the 1.4 lump but if you use the 1.3 AAV item its a huge amount more fun than standard!

you'd need the GT thermostat housing but it is possible to pikey the existing spi housing also need the GT AFM

ooooooh excellent! The cogs are turning! Would I need the GT distributer too?

How hard is it to adjust the SPI thermostat housing?

Thanks for your help chaps

Just get a GT thermostat housing, GSF do them for about £16. Will save alot of time and messing around.

Yes you will need the GT dizzy too, you will be around 2 - 3bhp down on power as the GT has a higher compression but it means you dont have to take the engine out which isnt really worth the hassel for the gain.

You will most likely find it will be better on fuel as well, my 1.6 GT is better on fuel then my old AAV was!

Edited 10 March, 200917 yr by carver

you dont neeeed the gt thermostat housing, you can just shove a pipe inbetween the two tubes that are blocked on the gt one :p

and it should definitely be better on fuel. dont forget you can use the poloace chip and gti afm for slightly more power!

This was the first mod I did to my CL 8 years ago! Without the GT cam it's like an AAV that revs, but needs the cam to feel any more powerful. The 8P long-legged gearbox on the CL dulls things down a bit too.

Make sure you get the ECU and engine bay wiring looms - and I agree, GT thermostat housing is a nice-to-have, not essential. Use GT spark plugs too.

This was the first mod I did to my CL 8 years ago! Without the GT cam it's like an AAV that revs, but needs the cam to feel any more powerful. The 8P long-legged gearbox on the CL dulls things down a bit too.

Make sure you get the ECU and engine bay wiring looms - and I agree, GT thermostat housing is a nice-to-have, not essential. Use GT spark plugs too.

Joeshaw's right, just get a length of hose and use it to block off the 2 outlets not used with the clamps too that should be all good. sounds like a nice little project!

With all the parts it will only take a few hours to change it all over, the 8P gearbox is a bit long for the 1.3 engines though so you might want to change that for a GT box at a later date.

To be honest, if you're going to the hassle of swapping the 'box to a GT item as well as the GT injection system, you may as well do a full-on GT conversion in the first place. I always regretted not doing that - and stuck a G40 in instead after a few months.

Ooooooh is the GT coil required too?

For the gearbox think I will stay with the 8p, really need that high 5th for moterways!

So far I have the list to be:

ECU

Loom

Inlet manifold

Injectors and rail

Dizzy

AFM

Airbox and tubes

Throttle body

Cam

GT plugs

Coil?

Is this the lot?

Some great info and feedback so far, very much appreciated.

Pretty sure the coil is the same on all mk3's.

I'd definitely get a RR printout before and after though

edit: I have an injector rail and injectors. Pm me if you need them!

Edited 10 March, 200917 yr by martinb

martinb - thanks for the offer of injectors but have sourced a set with the rest of the parts. Will let you know if do need them though.

So, parts sourced now it's simply a case of picking them up and putting it all together!

I'm currently reading all past forum topics with this kind of thing done, the FAQs etc. and the Haynes manaul as this is a bit of a stretch for me technically.

Will be sure to take photos as I go and write it up so that it can be of use in the future.

Sure I'll be back with questions before too long!

Many thanks for all your help so far :-)

Quick update and further questions :-)

Picked up the GT bits on Sunday from Aron (aroncmc22). He and the broken car owner are both thoroughly great blokes - really helped me by taking the time to label the loom and keeping every single nut and bolt (and an engine mount - see other thread!) - even giving me some carpet samples to protect the boot from the bits :-D Many many thanks chaps!!

OK, so bits are now here. While it's all in bits I'll take the time to clean everything up - carb clean the throttle body etc.

Amunst my 'useful saved webpages' I found a repost in a Sweedish forum of a post that looks to have originated here. For the life of me I cannot find the original however will paste it here (all credit to the original writer for a very informative, excellent piece!!) Andy - I wonder did you write this post? (as you have done this conversion in the past and the post appears to have been written by an Andrew?)

"VW Polo CL to GT Conversion

Those of you who got the recent Club Polo newsletter (2003 newsletter) will be well aware of Keith Lee's twin carbed Polo GT. Well, Keith's decision to modify his car enabled me to give mine a little more poke, as it was me that bought Keith's old injection system. My main reason for doing this was that my '92 Polo CL (engine code AAV) was only single point injection, so the plan was to use the bits I'd bought from Keith to convert it to multipoint. Armed with a load of enthusiasm, and knowing that as ever the E-Group would be at hand with advice I launched into it!

Essential Parts from GT

• ECU - ensure that you get the mounting brackets for this too as they are different to the CL.

• ECU relay - this is the 5-pin relay mounted next to the ECU. The other is for the fuel pump, and is not needed as the original CL one can be re-used.

• Engine wiring loom

• Inlet manifold, including bolts.

• Throttle body

• Induction system

• Airflow meter

• Distributor

• Spark plugs

• Oil breather system - the GT oil breather system is different to the CL. The CL lacks the crankcase breather pressure valve. See diagrams further on.

Also

• A large range of jubilee clips from ¼" to over 1½"

• Gasket sealant

Other parts

• Main wiring loom - I managed without this, but for sake of neatness and originality I would recommend using it.

• Replacement inlet manifold gasket - should really be an essential, but having forgotten to order in time for my conversion I managed to salvage and bodge the old one.

• Coolant expansion tank - the GT's tank has coolant level sensors on it, use in conjunction with the GT main wiring loom. Not essential by any means, and pointless if you don't use the GT main loom.

Getting stuck in!

First of all disconnect the battery - this is important seeing as you'll be messing around with the car's wiring! I would also recommend that you read the Haynes manual for the car thoroughly at this point and try to get clear in your head how you're going to approach the task.

Dismantling the existing injection system is fairly easy if you approach it in a systematic manner. I started off by removing the airbox and worked my way from there. You need to remove everything from the inlet manifold upwards - I found labelling wiring you disconnect to be an invaluable safety net later on.

Before you remove the inlet manifold you need to drain the coolant from the car, as the inlet manifold is connected to the cooling system. Follow the procedure in Haynes to do this. Also be aware that when you remove the fuel lines from the injection module they'll have a fair bit of fuel pressure in them, so be prepared for a bit of spraying fuel - so make sure that the engine's cold!

Once I'd removed the inlet manifold and airbox I set about removing the engine wiring loom and ECU. I started by unplugging the ECU and pulling the wiring loom through the bulkhead to the engine bay. It was then a case of tracing where the wires went, then labelling them up and unplugging them.

At this stage you would also remove the CL distributor and spark plugs, replacing these with GT items. I didn't do this at first and when I'd finished the car ran like a bag of nails, but at least it ran so that I could take it to get the GT distributor fitted and the ignition timing sorted!

The next step is to fit the new inlet manifold gasket and the GT inlet manifold. I think the Haynes manual has the correct torque settings for the bolts, but being as I don't have a torque wrench I just did them up tightly! You'll see where the brake servo vacuum connection goes, but you'll notice that the coolant pipes have nowhere to connect to. Remove one of the pipes completely, and connect the loose end of the other to the now vacant connector on the engine. All you're doing is blocking that part of the cooling system off, as the GT manifold does not form part of the cooling system.

I fitted the GT manifold with the injector rail and idle stabiliser valve still attached to it, which makes things easier. It's worth giving the idle stabiliser valve a blast with carb cleaner to get rid of any crap that's accumulated. I noticed that by this stage I had some wires to connect, so I decided to connect up the GT ECU and engine wiring loom. There are two relays by the ECU on both the CL and GT versions. However, one of the relays is different on the GT to the CL, so you need to ensure that you get the 5-pin ECU relay from the GT to fit. The other relay is a fuel pump relay, and the CL and GT share the same part.

The next step was to mount the throttle body on the inlet manifold, which is a fairly easy job. Once you've connected that the induction piping can be connected, and you'll notice that you have vacuum hoses to connect as well as a hose from the oil breather system. The vacuum hoses are connected up as per the ETKA diagrams shown here - it's easier than explaining where they all go!

(pic at http://img524.imageshack.us/my.php?image=g...ersion1adi8.jpg and other I (cheys03) don't have)

The oil breather system on the GT is different to the CL one, as it includes some sort of a pressure regulating valve. Be aware that this valve is essential, as without it your car will develop an oil drinking problem along associated running problems.

(pic at http://img518.imageshack.us/my.php?image=g...ersion2jx4.jpg)

I tried using a setup like the LHD GTs use, but for some reason I found that too much pressure was being built up in the oil breather system. This meant that I got oil leaks everywhere - oil filler cap, dipstick and the oil breather pod at the back of the block. It was somewhat alarming to find the car smoking, as oil was dripping onto the hot CAT - ooops! Anyway, the setup on the far right of the diagram is what I found worked best. It sorted out the oil use problem, which meant that the car ran a lot better.

At this stage you should now have the mechanical side of things sorted - you've just got to finish connecting up the engine wiring loom. It was at this stage I realised that you can't just connect the GT engine wiring loom straight up to the main CL one. Panic set in as I needed the car for work, but thanks to advice from Mark Hunter I got the wire cutters and solder iron out to set about mating the two looms. For simplicity's sake I would suggest that you try to get the GT main wiring loom - I think this just plugs straight into the fuse box, so it's fairly easy to do."

Now my questions are:

1. How easy is it to change the main wiring loom? Will I have to take the dash to bits etc...?

2. Does anyone know how to splice the AAV and GT loom together as above? How difficult is it?

3. Has anyone experince of the oil breather issues and solutions listed above?

As always, all info is greatly appreciated

Lol at the carpet samples!.. still got more if you want them dude!

I'll make we salvage the main loom before the shell goes to car heaven dude, if you cant be arsed with another road trip I can get it posted (if u pay the postage) if thats any help?

Good luck with this project dude, like I said before you have an ideal motor there for a project like this

Get the photo thread started!! :-D

Lol - I did write that 'How To', that was back in the Yahoo E-group days. Brings back a few memories.

Lol - I did write that 'How To', that was back in the Yahoo E-group days. Brings back a few memories.

Ah sweet! It's still out there giving guidence to all! You don't happen to remember the loom modification / splicing at all do you :-D ?

Afraid not - it was 8 years ago after all! No loom splicing if you get all of the engine bay side of the GT loom though.

I only had the GT ECU loom, so had to splice that into the rest of the engine bay loom from the AAV. It was only a few wires from memory, some cables by the coil (think one was earthing part of the GT loom) and another in the plenum chamber to get the fuel pumps working.

**loom may differ if its early or late spec **

its a differance in 3 wires on the gt loom and 2 on the spi i believe. on a plug down near the coil

basically you connect 2 of the 3 to the 2 of the other loom, and earth the last wire.

run all the loom, take a pic of the 2 plugs that dont connect and post it on here, ill edit it and all will become clear

get the pics of the plugs you cant match up and itll become easy.

you dont need to tough the interior of the car at all.

**loom may differ if its early or late spec **

its a differance in 3 wires on the gt loom and 2 on the spi i believe. on a plug down near the coil

basically you connect 2 of the 3 to the 2 of the other loom, and earth the last wire.

run all the loom, take a pic of the 2 plugs that dont connect and post it on here, ill edit it and all will become clear

get the pics of the plugs you cant match up and itll become easy.

you dont need to tough the interior of the car at all.

That's sweet - many thanks. Will be sure to post the pics!

Not wired it up yet...but...

It's a late SPI loom (M reg) to an old GT ECU loom (H reg) if that helps/makes a difference?

Cheers :-)

Wise oracles I request thy knowledge again....!

- The Idle Stabisation Valve... where does this physically bolt onto? Andy's guide mentions the inlet manifod but I cannot figure out where! Also, is this wired up to the ECU or just provided with power? Also where do the hoses connect? Logically I'm thinking somewhere before and after the throttle body?

- The oil pressure sensor. The AAV has one (blue) but I understand the GT has two? So far as I can work out though, these are not part of the GT ECU loom? But on the AAV the oil pressure sendor wire is fed from a plastic cable tidy mounted on top of the inlet manifold and shares a multi-plug with three cables that plug into the throttle body via a multi-way plug (pics below)

So what needs to be done to get this oil pressure sensor working?

As always, many thanks for all help!

on the back left of your head have you got 1 sensor then not 2 ?

is the other one welded shut or got a blank in it with a 5mm allen key in it ?

the isv bolts to the metal waterpipe on a gt that runs along the back of the block. your AAV wont have one. just cable tie it securly to the waterpipe or the bottom of the inlet manifold.

The second oil sensor hole has an allen-key blank in it.... remove plug, buy sensor, plug in? Which sensor to buy? Does this then plug into the GT ECU loom or into the instrument panel?

Thanks for the ISF info :-) Is this too controlled by the GT ECU? Edit: Found it as 'Auxillary Air Valve' in the Haynes manual wiring diagrams - it is controlled by the ECU.

Many thanks John!

Edit: The car is a late (M reg) Genesis with late GT clocks. Is this the reason for the single oil sensor?

Edited 31 March, 200917 yr by cheys03

OK, time for an update!

The conversion got off to a typically terrible start - head gasket went. It began steam-cleaning cylinder 1 and the exhaust. Not so bad though - old oil and coolant so could have been worse.

Stripped the head on Sunday and finally got around to fitting another gasket, water pump and cambelt yesterday (many thanks to my work-mate Rob for great knowledge and assistance!).

The GT cam is now in as well so starting to feel the conversion making some progress...

Currently the wiring is my main concern...

I have decided to splice the GT ECU loom into my AAV engine bay loom, primarily because it doesn't upset a proven, reliable engine bay loom with one of unknown history or functionality.

I've managed to work out some of the connections using the trusty multi-meter...

(Pic of the fusebox and nearby connectors)

On the AAV it turns out the oil sensor connects via the connector pictured below (yellow) to a 3-way connection mouted beside the fusebox which then plugs into the engine loom and from there the left-hand connector (white, pin 16) in the fusebox into the instrument panel.

On the AAV this 3-way connection takes the diagnostic cable, fuel pumps power and the oil sensor.

On the GT this 3-way takes the diagnostic cable, fuel pumps power and a red and black cable that goes from the ignition switch (I think) to the ECU connector, PIN 1.

So... this will require some cut 'n solder, but now know where the connect the oil sender!

The AAV 2pins Vs GT 3pins connector I think is this one (found next to the coil on GT, next to fusebox on my late AAV). It connects the the 2nd connector (black) at the fusebox:

(AAV)

(GT)

Common to both these connectors is a black and a black&red wire. The third on the GT is earth-brown. I assume it's black-black, red&black-red&black and just earth the brown?

Where I'm really struggling is the ISV. The looms I have don't appear to have the relavent connector. Aron is kindly looking at the donor car tomorrow to see if anything's obvious... but as an additional help, if anyone knows where it connects to then please post the info here!

Aside from the connections/splices listed above is there anything else I should be looking for?

Many thanks as always

Edited 4 April, 200917 yr by cheys03