New Member looking to convert MK3 8v to 1.8 20v Turbo

[GolfGTI8v]

Hi All,

I'm new here, my name is Andy.  I've got a MK3 8v GTI which ive owned for a couple of years now.  I've maintained the car to a high standard and imo its a good clean MK3 with low miles so im looking to keep what Ive got and go for more power.   I've got my heart set on the 1.8T 20v conversion and from what ive seen/read online its been done before without too much hassle.  Im not looking for mega power etc.

Apologies if this has been asked several times before but im after some specific answers regarding the conversion. 

Can this been done for around £2000?

Are the engine mounts in the same location i.e. just use uprated mounts? i.e bolt straight up? Any welding/fab required?

Which gearbox/flywheel/clutch/linkage... Im guessing my standard 020 box wont take the power hike? Will it even bolt up?

With regards to wiring is it a nightmare? Could this be done by a competent mechanically minded diyer?

Do I have to run aftermarket management and if so what happens with regards to the Speedo etc can I retain mk3 clocks?


Any information at all would be greatly appreciated 

Many thanks 

Andy

[Ess_Three]

Andy,

Not sure if you have, but read the first 2-3 pages of this thread...as we've been discussing it today:
http://www.golfgtiforum.co.uk/index.php?topic=166121.0
...before it went off topic. Sorry folks.

On top of all in that thread...you have the 'wrong' pedal box so you'll need to go to a hydraulic one to run a 16v/1.8T O2A/O2J gearbox as your O2O will go bang.
Can it be done for £2000...yes.
Can it be done properlyusing a good 1.8T, gearbox, pedal box, better brakes, better suspension...for £2000?
Not sure. Probably...if you do your homework.

[GolfGTI8v]

DOH  :embarassed: Sorry

yep just read through some great info!

ive just noticed this on qpeng http://www.qpeng.com/conversion_guide.html 

they used the mk2 gearbox?  020?  and suggesting a plug in and play wiring harness??  is this a good route to go?

Would it be possible/good idea to get a whole MK4 golf gti lump (with ancillaries) and box,  Fit the lump with my 020 box use their harness to sort the wring side and do the box change etc at a later date?   my box was recon'd about 2k mikes ago and id perfer to do the engine change as straight forward as possible and uprgrade box etc at a later date rater than in one hit if that makes sense ?? 

Many Thanks

Andy

[Dan_GTi8v]

I havn't read the linked thread, as tbh I cant be arsed but you dont need to use the 1.8t box, and you dont need to convert to a hydro clutch

what you need to do is get an 02a box from a 16v gti and use the seat ibiza clutch cable setup, (the reaon they use a mk2 box in the qpeng guide is because there putting it into a mk2!) this will allow you to keep a cable clucth and save messing about with pedal boxes. you cannot however use the 8v gti box as it is too weak and will break

In regards to the qpeng route, its been covered many many times, but general census seems to be qpeng is easier but more expensive and some people dont think its worth the risk of running the engine without a knock sensor (again info on this can be found using the search function, or for general info just google 'knock sensor')

The plug and play harness is handy to have and saves a bit of work but the engine management qpeng uses is far inferior to running oe management.

I'll be doing my conversion for around £2000, but im doing all the work myself and have also managed to get some good deals (AUM ecu plus remap for £300!)

First thing you really need to decide is which engine you want to run, as there are a fair few different 1.8t's that are compatable. Im using an AUM from a mk4 gti which runs a ko3s turbo, and is a fairly straight forward swap. I know others on the forums have used other engines though so it would be good to hunt around for info on all the variants and see which is right for what you want

[Ess_Three]

I havn't read the linked thread, as tbh I cant be arsed but you dont need to use the 1.8t box, and you dont need to convert to a hydro clutch

what you need to do is get an 02a box from a 16v gti and use the seat ibiza clutch cable setup, (the reaon they use a mk2 box in the qpeng guide is because there putting it into a mk2!) this will allow you to keep a cable clucth and save messing about with pedal boxes. you cannot however use the 8v gti box as it is too weak and will break

O2A from a Mk3 16v, or an O2J from a Mk4 will do.
You say you don't need to use the 1.8T 'box which is correct...but if the engine has one bolted on, why bother looking for a Mk3 16v 'box? They are the same (bar minor gearing changes).

The lashed up cable conversion on a Cupra Sport is awful...the cable soon gets sticky and the clutch gets heavy. Add an uprated clutch to the box, which may well be required when the boost gets turned up. Going to a hydraulic clutch is a better solution, in my view.
Certainly not essential, but a better solution.

It's only a 30 minute job to change the pedal box from a 8v cable type to a 16v/VR6 hydraulic type, if the engine is out anyway.

Either way will work...

[LazyLunatic]

OMG, why is everyone putting a 20VT into there Mk3 now!

Sorry bud, just your the millionth person to post up about. Having a read through my thread and have a look on clubgti, look at the setup people run and see whats what.

Cable clutch conversion is fine, I have no problems so far. O2J has different mountings to the O2J, although yes the internals are the same.

[dom]

OMG, why is everyone putting a 20VT into there Mk3 now!

Sorry bud, just your the millionth person to post up about. Having a read through my thread and have a look on clubgti, look at the setup people run and see whats what.

Cable clutch conversion is fine, I have no problems so far. O2J has different mountings to the O2J, although yes the internals are the same.

Someone needs to compile all of the info that has been passed around over the last few days and then sticky it! Then if people still ask the same question, we can send them that way before we shoot them 

[LazyLunatic]

I need to put something together really. They can ignore the QPeng stuff if they want go down another route but there would be lots of other useful info. Just can't be a$$ed

[GolfGTI8v]

  Sorry guys i didn't realise it was such a popular topic when i googled this i didn't get many results, however ive now acquainted myself with the search function some great info to be found!

Question though what's the best box to use with the 1.8 20v Turbo? and by that i mean i want to get away from crunching into second gear with fast changes i know its common on the MK 1, 2 & 3's but do the more modern boxes cure this? i was speaking to a friend who has a MK4 gti and still suffers the same crunch with fast changes up into 2nd,  i don't want to go to all that effort and still be crunching on fast changes.  I know there's allot of advise out there to change to thinner oil,  will this REALLY cure the crunch on any or more modern box?

If run the O2A from a Mk3 16v box, what's the limits this box will take?  as i understand its torque that kills boxes not hp?
is the hydraulic pedal box a straight swap or is there fab work involved?

Sorry for all the questions guys im continuing my research.   HOW many engine codes did VW use ffs 

Thanks

Andy

[LazyLunatic]

OK I will put something together.

O2A diesel box, code CTN or ASD, all the other O2A boxes are too short. I have a 16v box. I get no crunching, just gotta make sure you keep the clutch in when you shift! Gearbox can handle it.

I would stick a cable clutch conversion on the O2A, but up to you. Its very easy to do.

20VT bolts in using Mk3 16v engine mounts.