AHU into a 81 mk1 rabbit

So I have a 81 rabbit with the NA 1.6L and fixed the car up all nice and it looks great and shouldnt rust away anytime soon, plan on driving it a while. Turns out the injection pump started to leak and I always told myself since I bought this thing that if I have to many issues with this sissy engine I would just do a swap!
So I got a 98 jetta front clip, I've done tons of reading and research on here about this swap so I know what to expect what I can do what I shouldn't do and so on! One question I have so far for anyone that has done the swap or anyone that may have a solution is. The 81 rabbit controls the inside temp by a heater control valve that restricts coolant into the heater core, from what I can tell the 98 jetta uses a blend door and coolant always passes threw the heater core. So in order for my rabbit to still use all the original heater controls and such I need to be able to restrict coolant into the heater core or my ass is gonna burn up all the time! So my worry is that if I put a heater control valve like the mk1 has in the heater core line that I may screw something up by restricting coolant flow to or from the egr cooler that the engine was designed for? Im thinking that somehow I need to have a bypass hose to bypass the heater core when the heat is turned off that way the coolant can still flow properly and not harm the engine, I'm just unsure on how to make or do that with a single cable pull?

i haven't made a build thread (yet), but i swapped an ahu (+ lots of goodies) into my 82 rabbit. i love it. i could probably answer just about any question you got

first of all, you should delete the EGR (and get tuned).

and do a complete CE2 wiring swap (and delete everything you don't need).

and yes, you need to add a bypass before the mk1 heater control valve (and get a new one - they're like $5 on autohausaz, they wear out and then constantly flow enough coolant thru the heater core it stays hot all the time - real annoying in the summer). because you need the side coolant exit on the head to always have flow. it will still get the heater core plenty hot for when you open the valve.

pics of my build, mostly undocumented, in my sig...

burpod said:

pics of my build, mostly undocumented, in my sig...

Click to expand...

all i gotta say is "WOW!" all them pictures of ur swap are awesome!!! u did everything! i went threw and patched my floor board holes, fixed any rust underneath, i wanna put bedliner underneath to further prevent rust. but i did the whole body and everything interior and did it all up nice so i can drive it every day be comfortable and save on fuel.... or that was the intension. i didn’t plan on doing this swap anytime soon but when the injection pump started leaking i didn’t wanna spend the money on this super slow engine when i could spend a little more and get twice as much! i don’t plan on taking the engine apart like u did, and don’t plan on hoping it up I plan on keeping it mostly stock because its gonna be a daily driver to save on fuel. So I was just gonna put new crank seals, timing belt, water pump, oil cooler, and clutch in it and put it all back together and throw it in there.
so far what i have planed to do is, take the whole pedal assembly out of the jetta and fuse that part of the firewall to the rabbit so that way i have all the new stuff in it, new break booster and master cylinder (the rabbit needed to be replaced anyways) and then all the switches on the pedal and everything would hook right up. i think the steering column from the jetta should spline to my rack and that way i have all the jetta controls and stuff there as well. Also another thing i wanna upgrade is the breaks because the short time i drove the rabbit they SUCKED and i plan on pulling a very small trailer with my race ATV on it... gotta be able to stop it! I was gonna keep the EGR and cooler to keep it stock and from what I read ppl that take it off lose some milage, plus If I take it off I would have to do something to the ECM or it would throw a code right? It took me FOREVER to find an ecm that would work that was affordable because the one I got with the front clip was bad for sure and don’t wanna chance screwing that u… don’t wanna go threw the huge headache of that again. now one difference between your swap and mine is that im gonna run the rabbits factory A/C, so i was gonna put all the pulleys from the rabbit on the TDI including the A/C pump and alternator from the rabbit, that would also eliminate the power steering pump that i won’t need. so with me having a condenser in the front of the radiator there is NO room for a intercooler.... so i was considering just putting the stock jetta IC somewhere there was room and mount a fan on it that runs constant when the engine is running.

1) Not sure what else to do with the IC… got any suggestions?
2) What steering rack did you go with?
3) How did you go about making the trany mounts or did you buy them? I was hoping that I could mount the old rear trany mount on the new trany by extending the bolts adding spacers and bolting it up but then there would be only three bolts holding it instead of two so im guessing that’s a bad idea?
4) You have two different transmissions sitting there, what is the difference?
5) What axles did you end up using
6) I noticed you had rear disk, how did you go about that?
7) With that break setup do you have the proportioning valve or not?
8) What is that black bar/bracket that you have a pic of in front of the wood pile?
9) What sway bar is that? Gonna need something to help that thing handle!
10) Do all them bars that stiffen up the body really help and worth the money?
11) Noticed you installed a fuel lift pump, is that necessary? Mine is basically gonna be stock.
12) What did those seats come out of? Look sweet!
13) What kinda bypass are u talking about? im just not sure how to do it!
Any help and advice is greatly appreciated and will be put to good use!

Excuse me for jumping in, CJ and Burpod. Burpod, do you have any warm up problems in your beautiful Rabbit with the EGR deleted? Or did you completely remove it? I'm in CT collecting parts and info for my 1z to fiero build. Any more advice in cold climate areas? I will be looking through you build soon.
thnx,
wes

a few more questions i thought of,
what engine upgrades did you do? and
what kinda fuel milage do you get with it?

well, for starters, "hopping" it up, isn't going to affect mileage at all for normal driving.

- i got a meyle manual rack from autohausaz. it seems fine so far. but i probably would stay away from meyle next time. i got it a while ago when i was planning my swap before i realized how crappy a lot of their parts are

- i used the stock rabbit pedal cluster, just modifying the clutch pedal slightly to fit a 1980 honda civic clutch cable, using the "02b" eurovan mechanical clutch "actuator" (1stvwparts.com has these for $125), and making a little bracket to fit it on the transmission. i absolutely love the feel and simplicity of this setup.

- i used a brake booster from a 2nd gen 16v rocco, and modified stock rabbit brake pedal to fit the connection. full scirocco disk brakes with the prop valves, but used mk4 style rear calipers, made my own lines. you can use a master cylinder from a corrado, they're ~$45 new from autohausaz (PEX brand). or a 16v MC.

- if you delete the egr cooler and get a tune, you'll have more power, and likely more mpg as long as you're not driving like a maniac it's completely worth it.

- i used an 02a transmission, but put in a taller 5th gear (.681 is perfect). those two transmissions in that pic are the same, i was just cleaning them.

- used axles from a 2nd gen scirocco 16v

- rear sway bar is an autotech one. front is an h&r.

- a lift pump isn't necessary.

- i think the extra chassis/stress bars are well worth the money

- the rear and driver side tranny mounts i bought from NLS on vortex. the passenger side one you just have to cut, use front one as it is. i actually have a homemade rear mount i'm selling for cheap

- that big bar in front of the wood pile is an mk3 trailer hitch, lol. not sure how that snuck into my rabbit album

- those particular seats are recaros that came out of a non-running mk2 gli i have

i personally don't think the egr cooler has any noticeable effect on warm-up time. i actually recently deleted the coolant glow plugs in the rabbit, too. lol, i'm not very concerned. it's got a block heater to use on those real cold days (if i'm at home, of course).

i haven't kept track of my mileage all that well, but the *worst* i could get was about 40 mpg with my heavy 15" rims with grippy tires and lots of 85+ highway and generally driving like a maniac with my mk2 monterey 14" rims driving somewhat normal (75ish and not beating on it too much ) i've been getting ~50 mpg. i'm hoping i should get 55-60 mpg if i drove 65ish, but haven't managed to do that yet for a whole tank.

engine "power" upgrades are titan 764 nozzles, vnt 17/22 turbo, fmic, pd130 intake manifold. vwmikel tuned to 26 psi might be forgetting some things, but those are the basics.

OK so i finally have the engine setting in the rabbit! used the original engine mounts and made some new trany mounts using the old ones, hooked up some 1988 v16 rocco axles and everything seems to be setting in there just fine!

so the things im trying to figure out now is how to wire the old AC system from the rabbit into the new jetta harness? im kinda lost in that aspect. i think i can just supply a 25A fused power wire to the original harness under the dash to make the AC/heater/blower motor controls to work but how do i wire in the old single wire compressor?
also im using the old original alternator and so im unsure how to hook up the old rabbit alternator connector to the new jetta harness?
and then the cooling can from the rabbit has a 2 wire connector where as the jetta harness has a 3 wire connector? suggestions?
i think i can figure out the lights and radio and such.... the simple stuff lol.

then last of all im still lost when it comes to the intercooler... im considering just not running one at all since its gonna basicly be a stock engine but the stock engine has one so i feel like i should have one too. the problem is as i stated above im keeping the rabbit AC so there is vertually no room for the intercooler infront of the radiator, there isnt enought room to space the radiator back to fit one so my only option i can think of is to run a top mount right infront of the brake master cylider area... any advice on how to mount and effencent intercooler would be much appretiated!

Well I got an Saab 900 intercooler to use as a top mount and that thing sets in there like a glove!
Ordered some hoses to connect the intercooler to the engine so I'm waiting for them before I start making brackets to mount it. But I'm not going to be able to hook up the sensor in the original intake tube... Is that a Intake air temp sensor? Whatever it is, is it needed?
Also if anyone has any wirin experience with my above post it would be helpful!