Few 20vturbo questions

Well since I've not got the time to do it, my mk1 is going into the garage next week for the conversion doing. I've bought the mounts from crazyquiffs along with 02j gearbox mount as I fancy a nice hydro clutch. Also got conversion for pedal box. Plan on using mk4 cable change aswell.

I've got a few questions, firstly driveshafts. Everyone keeps saying use 100mm late cabby shafts, then others say 90mm ones have been used? Where is this measurement taken from? Is it the diameter of the joint at the gearbox end? What will a standard 1.1 have? Also there is talk of changing drive flanges on the box? Are these too big? What do they need changing too?

Next up is fuel pump. As my car was originally a 1.1 il need to fit a proper pump. Now I have the pump from my mk4 donor, has anyone ever retrofitted one to a mk1 tank? Just seems logical as it only requires the one pump, is obviously up to job and is easily replaceable

Thanks in advance, I'm sure there'll be more as it progresses

Mat

you need 100mm shafts, as i dont think there are 90mm flanges that fit the 02a/j boxes? if there are then you can fit those and use 90mm shafts. the measurement is taken across the inner cv from the outside edge. 1.1 will be 90mm and wrong length for 020/02a/j anyway so either way they'll want replacing for cab/rocco 100mm ones. post 84 gti and post 88 1.8carb are what you are looking for

mk4 pump will never fit its way too big. you need either mk1 gti tank, or late cab/rocco injection or any g40 shape polo lifter pump + under car fuel reservoir with your old tank.

main pump use a std mk1 gti with an M12x1.5 banjo adaptor, then you can use push fit rubber fuel lines, or plastic ones from mk2/3 golf or g40 polo might work.

Ok so assumIng I source some cabby shafts what drive flanges do I need to mate them to an o2j box? Obviously 100mm ones but from what car?

And thanks for the info about tank, could I not mod the tank and have something like a facet external pump mounted underneath?

there are 2 types of flange, bolt in and clip in. check if yours have bolts in the middle, if you do then you need 02a bolt type flanges. but measure first, pretty sure 02j will have 100mm flanges anyway so direct fit.

if you can find a facet pump with enough capacity for a 20v then fine, but i thought they were more for carby? basically your tank only has outlets in the level sender on the top, and no swirl pot so you will suffer from fuel starvation when cornering plus most pumps wont like having to drag fuel out the top and some will die quickly if they run dry.

hence the need for a late lift pump plus under car fuel reservoir.  you'll probably find a std k-jet main pump is cheaper and easier to find than some kind of aftermarket pump, and the k-jet pump is pretty much the best you can get except for a bosch 44 motorsport pump

Do you mean the shafts either bolt or clip to the flanges? if so my box has bolts holding them together, so il just need to double check there 100mm dia when i get in tonight. Ive been offered some late cabby shafts with hubs for £100, does this sound reasonable?

Fuel pump wise my idea was to get the tank modified so there was a large feed from the bottom to an external inline pump. ive seen a facet red top that claims to be ok for 250bhp, but if the bosch would be better could that be used in the way i suggested?

thanks for taking the time, im still new to these funy german boxes and the garage thats doin it havent done it before

mat

no the flanges either clip of bolt to  the gearbox. if you look in the middle and it has a big allen bolt, then its bolt type. if not they're clippy type.  £100 is ok if they're in good nick i.e. fit and forget, if ropey looking cvs/boots you'll want to pay less than that. late cabbies are starting to pop up in the scrappies now, if you find one take the shafts with the bearing carriers still attached as its 1 less hassle plus some combo of 100mm outer cv + 90mm bearing carrier results in lock up as the later carriers have more clearance machined into them

adding a feed to the bottom of the tank would be very difficult to do safely as weld/brase + fuel vapour = bang. far easier to just drop a left pump in the tank and fit a swirl pot. if you could get an outlet on the bottom that would help, but you still wouldnt have a swirl pot so it'll still have fuel starvation on cornering. the reservoir fits easily under there where the accumulator would go if it was k-jet, just make sure you get a bracket to go with it

Agh I get you now, either way aslong as there 100mm theyl work.

The shafts I've been offered still have hubs attached, but need one cv boot changing, il have a look in scrappies.

So just to clear it up if I got the complete fuel system from what car would be alright? Ive been looking at gti tanks and pumps but they seem to fetch silly money

you only really need the lifter pump and reservoir from late cab, rocco or g40 polo, plus the lines between the lifter and the reservoir to make your life easier. can just make em up tho if not.

if you can get a proper GTI tintop tank then all of the above is not needed, apparently the diesel tanks have the internal swirl pot too. the internal swirl pot will keep the main pump happy and no fuel starvation issues to worry about.

Then fit some kind of main pump that can cope with your projected power, facet, bosch 44, oem mk1 whatever you like. if you get a k-jet type pump you can convert it to push fit rubber fuel lines using m12x1.5 barbed adaptor off ebay, will cost like £3

then its a case of run up some fuel lines either plastic ones of later mk2/3/polo if they fit ok, or run your own rubber fuel injection stuff. try to get braided stuff for a bit more protection. you could use 8mm copper pipe as well for a more oem mk1 feel. the old metal pipes are probably past their best now but if ok you might be able to reuse.

Well I figured I'd have to get new 8mm copper feed lines run, and since I'm pretty much only paying for parts then that shouldn't cost too much. So that's that problem sorted.

The ideal solution would be a caddy in a scrap yard, then take everything I need from that. It's shed some light on it tho so thanks

Mat

John i maybe wrong but i think some 02j boxes have 108mm but im sure can be changed to 100mm…

apologies if im wrong….

Late 02j do have the 108mm flanges. Not sure of the cross over year

Mines a year 2000. Il measure later and see

minimat said

Mines a year 2000. Il measure later and see

I think its 2003/4

I should be ok then. Apparently a swirl pot is only 13 quid from vw so I just need a lift pump and I'm nearly there

Mat

cool noted, im not really a mk4 expert, I just cut up their wiring

John to most of us on here your VW god…
I have a few questions for you concerning wiring original mk4 1.8t ecu and series 1 & 2 fuse boards but im trying to work it out mysef with the help of your many write ups before I resort to bothering you….

Keep up the good work John alot of us rely on you

Cheers

this thread is very helpfull, near the end ive gone thru all the pins for the blade type mk1 fusebox:
http://www.clubgti.co.uk/forum/showthread.php?t=205887

if its on the ceramic fusebox i strongly recommend you replace the wiring for later, though you could add the mk4 fusebox next to it I suppose. not the way I like to do them but its your call

Cheers John already using that thread ill have to look when I finish work (on construction site at mo ) but my issues were with changing early board to later blade one as this must be better than keeping original but idealy dont want to start cutting in to wires would rather use the plugs unless you think cutting and joining would be safe enough
As I said earlier I have 2 or 3 questions so I get back over the weekend if you dont mind…its more of a case of confirming im right

Many thanks John (lagger)

when you convert an early fusebox to late its a case of gettign the right complete car loom.  there are a few things you need to think about before you buy your donor loom:
1. what dash is it
2. what rear lights has it got
3. do you want the rear washer/wiper to work

What woud your advice be on keeping the early board in and wiring the mk4 agu ecu in
Good idea bad idea…..