1.8T Conversion Thread I know the 1.8T conversion has been spoken about in many threads covering several topics , which makes it a long process finding what you are looking for. I think it would be a good idea to have all the info in one thread, with help from members who have undertaken the conversion, to help people like me. Since having a go in my mates MK2 1.8T and seeing many at Inters, Frennos for instance, im totally sold to the idea and want to gather as much info as possible. Ive got so many questions to ask, as its a bit more involved compared to my old conversion (Driver to GTI), so will start off with a few basic questions, then hopefully get as much info gathered to cover the whole conversion, top to bottom, with part numbers included. 1. What would be the best engine code to use, an early NDBW (agu) or a DBW engine (Aum ). Im hopefully going to use a whole doner car, either a MK4 or a Leon. Can all the OEM parts be used like the Intercooler, ecu ect Im not looking to run big power, just want to keep it as OEM as possible, with just a custom code remap. 2. Can you use the MK4 gearbox in the MK2 ? If not what does everyone else use ? Also does the gear linkage ect need changing ? 3. Engine looms. Ive heard that AndyOut can convert a MK4 loom to fit in with the CE2 electrics. Is this the easiest way? 4. Fuel pumps and level senders. Do you use the MK4 one, or can the MK2 or others be used ? 5. Engine mounts. What ones are needed. Ive heard so many different things im not too sure what mounts are used ? 6. Brake upgrades. Ill definitely be converting my rear drums to discs. Would front G60s and standard GTI rear discs be an ideal upgrade ? If not what would you recommend ? I know there is so much more to ask, which I will in time, but any info regarding the questions above will be much appreciated. Cheers, Rich
Yes it is about time i know qpeng guide covers the basics. I am on the verge of swaping my Vr6 build to 1.8 20vt. a guy from bristol started a good build thread and seems to have disappeared.
That Qpeng guide is quite useful Never seen it before. Didn't know you could use an 8v box on the 1.8T either ? Not sure if it would be strong enough though.
Its easy when you know how! So in reality its quite difficult,although help is at hand lol. (all this is just my opinion mind) 1-Yes a whole donor car is the way to go,leon cupra is WAY better than an AGU mk4 in a few ways; Much better management,better turbo,better injectors,upgraded/more parts to sell etc... Forget about the standard intercooler though,FMI it is. Both the donor cars above can be bought for the price of a Qpeng P&P ECU too. 2-Yes the mk4 shifter mech can beu used.Bin all the mk2 parts and fab up the mk4 shifter. You can use mk3 shifters but the change is cr@p (early mk4's are like mk3's so beware and ask 1st if not sure) 3- Yes Andy or others can convert the loom to be a very easy "plug & play" with CE2 & its very easy. It does depend on which clocks you want to run mind? mk2 16v is easy or mk4 style etc... both have pro's & con's so its up to you. 4- yes mk2 or mk3 tanks can be used. again it depends on the clocks,management and power you want to run (mk4 pump needs to go in a mk3 tank which needs at least 1 x mk3 strap) 5-mounts are VERY important to line things up. many seperate threads on here for this with all the part numbers listed. One thing is linked for this and thats the brake master cylinder,as it hits the head. i reccomend the Ford focus/ibiza cupra item. 6- G60 fronts with STD rear discs will be fine. (worth noting) K03s is a great little turbo and will transform a mk2 into a monster (compared to what it was before) K03 turbo is diesel like in its rev range & delivery and not worth fitting in the 1st place IMHO 1st step is a hydro pedalbox/clutch conversion. Cost hikes are on the little things or tools for a job needed to be done,it all mounts up though. Have a 100% plan to stick to regarding the install BEFORE you start. (it will save you money) Feel free to PM me if you have any quiries etc...
Thanks for the detailed reply I have a KO3s on my MK4 1.8T (AUM) and it is a great little unit. Plenty of power just from a custom code remap!! Regarding the clocks, i'd like to keep the Mk2 ones in there, but would Mk4 clocks fit and work easier than converting the Mk2 clocks? I might try and find a damaged leon cupra or similar. Iirc they are 180 standard, and come with the 6 speed box. So i suppose the 6 speed box can be used. Also driveshafts. Can the existing ones be used or would i need to use the old Mk2 ones ?
Mk4 AUM would be a much better option than an AGU yes. mk2 clocks are easier but will not have fault code lights on the dash,but you don't have to wire the whole lot in then mount them too.(pro's & cons) Leon cupra's are 180bhp with 6 speed std. sell box & shafts for more money as its not worth the bother (trust me) buy a mk4 box & clutch M/C + slave with g60 fly-clutch with GTI shafts (or corrado/ibiza if you dont have them) mk4 shafts 5 or 6 speed are no good (100mm inner cups are required but are available) 6 speed needs custom shafts so out of price range for most budgets & not worth the bother.
There's another fairly obvious source of wiring looms that people seem to miss. Rubjonny can make 20vT looms aswell.
I think that an AUM would be the best bet. Regarding the clocks, i'd rather stick with the original MK2 ones, as the MK4s, imo, wouldn't look good behind a MK2 dash. If i was doing a dash swap then i would, but i want it kept as OEM ass possible. Also, do you mean using the MK2 gti shafts with the Mk4 box ? Thats good to know mate Need to find a doner car over the next few months and get this project going.
MK4 02J gearboxs work with Mk2 axleshafts, once you swap the flanges back to 100mm units. This is what I have done on mine.
So im guessing they bolt on then Regarding the twin fan setup and rad, could the Mk4 one be used and made to fit ? I'll more than likely have a Fmic installed, as suggested above, but will there be enough room behind the MK2 slam panel ?
Rich you have a perfectly good donor car buy yourself a mk5 or 6 gti and use the mk4 Joking aside i would use same engine as in your mk4 as you have something to refer to!! The stupid thing is i have seen complete cars that are a bit rough go for less than the engine especialy 4 motion engines. This site is intresting if i had more space i would get one from here but my Mrs would kill me i stripped another car on the road[:^(] http://www.salvagesparefinder.co.uk/search.php?search=golf gti I think i need to get a lookup up anyone know one near devizes let me know.
I couldnt bring myself to break the MK4, its way too mint for that. I really do want to use the AUM engine from a MK4. Its true what you say, there are some dogs out there for less than 1500, which is good.
Rich if you want I've got an AGU, some bits and pieces and an ECU. Come and have a look at it when you've got some time free. Or you could use the donor car you have there... He only seems to charge what he'd be willing to pay. Which isn't much because he's cheap
Standard intercooler doesn't fit, and is useless anyway. If you want an OEM fit, find a Rallye intercooler with a Corrado VR6 rad. Bolt in job with some pipe work. I have these on my current 16vt track car. The engine model depends on what you want from it. AUM is easier for what you want to do. Are you going to run a throttle cable, or DBW? You can use the 5 speed Mk4 gearbox with standard mounts and driveshafts. You will need to change the output flanges, but they are bolt in. I have the part numbers somewhere if you need them. I didn't use a hydraulic clutch, I'm using the Seat set up as I didn't fancy bashing the bulkhead flat. The only problem with this is that you have to cut the reverse light switch off the gearbox. It's not needed for MOT, but if you're driving the car around a lot, it might be a pain. Mk4 shifter fits, but requires some fabbing (I think). Not sure if the rod change bits fit the O2J box. The 6 speed box requires custom mounts and driveshafts. Looms answered above. Standard Mk2 is good enough for what you need. I ran my TurboTechnics 16vt on it just fine, and it had 235bhp. Stick with the Mk2 tank, or fit a Mk3. I don't believe you need to change anything else. Engine mounts covered above. 280mm brakes are fine. I ran them on the TT Mk2 at track days, and they were fine. HTH
Thanks for the info sparrow, much appreciated I may be able to get my hands on a AGU so its either that or the AUM. Iirc, the k03s will bolt straight onto the k03 manifold ? If i was to run a throttle cable, could i still use my MK2 pedal setup ? I know people change the pedal box when going DBW but what about NDBW. Good to know that the Digi fuel pump, housing and tank can stay intact, which will make it easier. Is there any direct fit shifter units i could use when using the Mk4 gearbox? Im guessing the MK2 one is out of the question!
