20v Conversion thread

Hi guys

just completed the 20v conversion and i know there are people who want to do this so i thought it would be a good idea to start a thread listing all parts and mods needed to do the conversion

first of considerations

1,
which engine 150bhp  180bhp 225bhp in all honesty i would go with the 150bhp as this is all you need the mk1 golf is an old car and front wheel drive so anymore than 200bhp would be wasted due to lack of traction drivability

2,gearbox this is a important part of the conversion which can cause major headaches and expense the 020 gearbox will fit on the 20v engine no problems the downfall is that you may get through them like desposable razors
the 20v cable change gearbox more expensive to buy they fit ok with the correct mounts which can be a nightmare to make or buy and then you have the cables i prefer the rod change box as thats what im used to and they are stronger than people think  

3, drivetrain 020 box you can use the gti cab driveshafts as they have bigger cv joints and gearbox flanges remeber when fitting driveshafts to the gearbox use plenty of locktight

4, Brakes mk2 16v servo and master cylinder seem to be the way to go with bigger discs and calipers me personaly will be getting a autocavan peddle box and do away with the servo and bars ect ect

5,im getting coilovers and i dont want the back sqauting at every opportunity stronger springs on the back are a must with all the power your going to lay down you dont want the car feeling like a sponge

6,cooling system 16v golf gti rad and fan renault laguna top hose mk2 golf bottom hose mk1 header tank and conncting pipes theres lots of little pipes like the heater pipes which you will need to play about with cut and join to get them right

7, intercooler front fitting custom ones are the way to go measure the gap between you grill and rad and bingo get on ebay jobs a good one DO NOT USE A MERC SPRINTER ONE these do not fit as people suggest without cutting bits of the front panel ect ect plus they are plastic ended

8, downpipe can be made if your good with a welder or qpeng sell them for ?250 im going to buy a pre made one once mines on the road for peice of mind

9,engine management the oem stuff is good but you will need the keys clocks ecu ignition barrel i personaly think a mk4 dash in a mk1 looks pants standalone is just as easy to fit theres lots of different variants you can but as follows

emerald = expensive but excellent support plus loads of people using it so maps would be easy ish to get hold off

dta= similar to emerald expensive loads of people using it theres also a good forum for support

megasquirt= cheap cheap chaep good forum BUT im the only person using this on a 20v but you wouldnt need a rolling rd to tune just a wideband wiring this seems the most difficult thing in the world to some peolple including me but have no fear get a haynes manual for the engine you are using ie mk2 golf manual and then a mk1 mk2 manual

you dont need all that much of the 20v loom so you can strip the loom right down and use the bits you want

for now thats all i will add to this with photos and awnser question you may have

Ben

Good man :y:

Once this threads up and running i'll FAQ it  :wink:

right time for part 2 if i miss anything or you have somthing to add please feel free

let get onto the engine choice we have basically 2 options

transverse and longitude

lets start with the transverse

this engine will be found in golf mk4 and audi A3 to name a couple this in my opinion is the best to get ok theres different bhp variants but thats not for disussion yet

so if you get this engine you will need to make the offside engine mount as the mk1 mount will bolt up but on its side so you need to cut the mount and reposition it no easy task i spent a few days researching this and found the following diagram which helped loads they are not my pictures but ones i found on the net




so anyway now you see what you need also you will require a 16v cambelt tensioner as the mk1 mount will foul the 20v tensioner the 16v one fits on nicely you still use the 20v cambelt you will possilby need to space the tensioner maybe a max of 5mm its your preference just check the belt runs in the middle without rubbing the sides to much

next the longitude engine these are mainly from passats and audi a4s
these engine are good if you dont want the hassle of making the offside mount the mk1 mount will bolt straight on  BUT yes theres a but because its a longitude engine the inlet manifold and turbo point in the wrong direction for a mk1 so you would then need to get a transverse inlet manifold and turbo and manifold

stock engines the 20v engines seem to be bullet proof as far as im aware ive read that its possible to squeeze 300bhp out of a 20v before internals like pistons and the crank need replacing and other bits that may break

youll have to excuse my spelling and gramma as im thick

in our next lesson we will talk about the mods need for the gearbox and mounts  

Are the longditudinal engines front wheel drive, or are they from 4wd variants of the passat and A4?

the a4 engines are front wheel drive there are some 4wd drive but mainly the audi s3

Hi all

lets talk about the gearbox situation

020 or cable change

the 020 is the easiest box to use and i think theresa bit of a miff going on about how strong they are ive known 020 boxes be very good with this conversion despite what people say there are ways of making the box stronger if you feel the need the 020 type box can come from mk1 golf gti mk2 16v gti seat ibiza 16v and mk3 diesel the chioces are endless but do remember you never know what your getting until you fit it it may last forever or a day thats the risk you take

i expect there are plenty off people who wouldnt use this box but this decision is yours and yours alone

mods to fit the 020 box you need the clutch that goes with the box you select it will bolt straight onto the 20v engine you can use all the mk1 mounts for this i however did upgrade the front and rear mount to poly uthane as they are stronger

on the gearchange side you will need to bend down the long flat bar so it misses the turbo this will cause the the rod with the clips holding it in either end to run very close to the gearbox but this mod also creates a shorter shift i did mine and i get every gear with no problems

the cable change box is a completly different animal considerations you need to think off

1.where do i get the mounts can i make them
2. how do i run the cable change from the cockpit without drilling holes in your lovely bulkhead
3. how do you fit the peddle box and hydralic system

ok so the box will be stronger because it was made with the 20v in mind but is it worth the hassle you will have to fit it and the cost of the mounts

i will be doing this cable change conversion at a later date for now i have the 8v gti box which is most entertaining wheel spin in 4th gear yeah   baby  

later i will bore you with the intercooler and coolant options  

your like a fountian of knowlege . keep it coming .  

thas gna help me loads in a couple of years...hope i can find it!

me again

right coolant side of things

the following is what i did but to be honest yuo may find better pipes rad ect ect

im using the mk2 16v golf radiator its alot smaller than the mk1 gti so it fits in nicely i have mk1 gti header tank and pipes that go with it

my top hose is from a renault laguna there all pretty much the same so just get one from a scrap yard the bottom hose is from a mk2 gti it fit ok with some slight trimming  

the 2 pipes that come from the heater matrix will need cutting quite a bit but once you trim them down you just need to get a couple of connecting tubes to join the mk1 pipes to the 20v engine ill be honest its not as easy as it sounds i spent a couple of days trying to work out the best way to do it and several trips to the scrappy later i managed to find the right type of pipes to use

the intercoole i have is a cuson made one that i got from evil bay but it fits really good between the front grill and radiator however the twin lap grill i have ive had to remove the inner spots to give me enough room to get the ic pipes in

the ic pipes are a pain in the butt to get right i used a load of different pipes from the scrappy to get all the boost pipes to fit how i wanted them i do intend on getting remade with ally now i have a working set

also with the ic pipes it does differ with different engines ie 225bhp audi tt engine the inlet is on the opposite side

try and use ally pipes if you can as these loose the heat quicker than stainless or steel and you dont want hot pipes as this defeats the the use of a inter cooler

ill dig out some pics of my cooler for you all later

just so i dont forget theres a couple of chnages i made to the engine to make my life easier at a later date

the 20v oil coooler has the 2 water pipes in the standard posisiton these foul the rad fan i took the oilfilter of and adjust the position it sits at by loosening the centre nut and twisting it anti clockwise as far as it would go now my pipes are nowhere near the rad fan also you may want to put the mk1 oil senders in the 20v filter housing on the 20v housing theres a oil sender already there so swap that one and then theres what lloks like an alan key bolt counter sunk into the housing remove that and put the sender from the mk1 head into that position it will screw straight in    

think ill try and explain the megasquirt wiring next just to show how easy it can be

well as my conversion is using megasquirt ill show you a wiring diagram and how i did things

things needed are a haynes manual and the balls to chop large parts of your mk1 loom out

im using the msns extra code ms 1 v3 board this give you the capability of using a coil pack do not use ms2 it only has one spark output
heres the v3 wiring diagram this is a standard item that you can add stuff to



 the db37 plug which plugs into the ecu is where you would be wiring the engine harness too

theres loads that can be done to the megasquirt bits can be added so its your own preference i personly have the following

2 spark output
wideband output
tach output for dash
boost control output  

the 20v engine harness is a piece of cake to get you head round you will be better off stripping the loom for 2 reasons

1, to get it the correct lenght so you dont have wire hanging in the footwell
2, because you dont need most of it

i only used the following from the 20v loom

1,injector loom and plugs
2,throttle position sensor
3,vr sensor
4,manifold air temp
5,temp sensor loom

bear in mind i stripped the loom into its seperate parts

there are son many other parts of the loom that i didnt need

the mk1 gti loom was all but useless the only bits i used are

1, starter motor wires
2,alternator wires
3,oil sensor wires
4,header tank wires

the rest of the mk1 loom i pulled inside the car cut it down and marked each wire so i had a rough idea what it was for

i will go through my notes and post tommorow how i wired different things up

can we have some more info  :mrgreen:

Just completeness useful link to the Qpeng website:

vhttp://www.qpeng.com/

this is getting me really interested, i'd love to know how the megasquirt works out for you, management is the most expensive bit otherwise!

sorry about the delay had a busy week

i was talking about the engine management basicaly the wiring side of things isnt to bad once you have the engine harness how you want it then just follow the schematic above

although you will need to go through a haynes manual to find all the 12v feeds that you need

it realy isnt that hard i was supprised how easy it was and to date im yet to melt any of the wiring

although i do have some issues with my dash but they were there before i started the conversion

megasquirt is a great alternative for the ecu its cheap easy to install and theres a great website for help

all i will say is to start with the tuning software isnt that user friendly there are lots of parameters that need setting so it means lots of reading

i will try and get some photos for you today of the wiring and the tuning software

ill come back to this part later

ok guys the next part is where the headaches start the downpipe

as the conversion is what it is only a few people make a downpipe that will fit straight on so you have 2 choices buy one which could cost you ?250+ or make one

the downpipe sits realy close to the steering knuckle see in the below picture



not a great picture i know got you get the point

i made the downpipe which was an ass but it does the job idealy you will need some 2.5 to 3 inch pipe with bends so you can cut and tack where you want it you will also need a flexi joint as when the pipe goes under the car you have a little friend called the anti roll bar to that you need to miss

i will be buying a pre made downpipe when i get the funds but for now mine is good enough

also dont worry if the pipe sits less than a inch away from the steering knuckle boot trust me these boots do not melt mine sits about an inch away

as for the rest of the exhaust get a straight piece of pipe cut the centre silencer out and replace leaving only the back box

trust me the noise pollution doesnt change the turbo soaks up most of the noise from the exhaust so 1 box is enough  

Thats some amount of info there.  

I own a Ibiza Cupra 20v which Im looking at breaking and doing this conversion soon as I find a decent Mk1 Golf shell.

I take it from what you say the engine from the Ibiza would need a new inlet manifold due to the way it point?

i think the ibiza engie should be ok which way does the engine sit is it transverse or longitude or in english is the turbo down the back and does the throttle body come out the front or the side??

Yeah turbo is out the back, basically the same as the Golf Gti.

yeah that will indeed fit and even if it didnt id make it    

may just be some modding to the offside mount needed