putting an afn motor in my a4 2.5tdi avant, anyone know what i do to mate the car and engine harness

[andrew field]

hi guys, halfway through putting an afn engine in my a4 b5 2.5 tdi Quattro.(v6 engine). old motor had issues, afn engine sweet but from rusty car. donor car had no air con, Quattro does, clearly cant mount ac pump to engine, thats ok, ive got windows. but, with the wiring plugs under the engine fusebox, do i have to swap out the loom behind the dash as well. the immobilser light doesnt go out, so the car wont work..

 

[aragorn]

The loom behind the dash is massive and snakes around the whole car.

Really you want an AFN loom that matches the year of your car, and then it will just plug right in.

If it plugs in, its probably correct.

Immobiliser requires the cluster to be paired with the engine ECU. Autolocksmith, or various tools are available on ebay etc if you know what your doing.

 

[aragorn]

If you want the AC working, you'll need the AC pump and pipes from a AFN car.

 

[jbh]

Have you got the donor car? you could try swapping the clocks over and the chip from the key to match the new ECU and clocks.

Im interested on how you get on as Ive played with the idea of doing an AFN swap on a facelift 2.5tdi quattro I prefer the AFN engine over the V6 2.5tdi and it would be nice to have a facelift car

 

[andrew field]

Have you got the donor car? you could try swapping the clocks over and the chip from the key to match the new ECU and clocks.

Im interested on how you get on as Ive played with the idea of doing an AFN swap on a facelift 2.5tdi quattro I prefer the AFN engine over the V6 2.5tdi and it would be nice to have a facelift car

HI, in theory, and according to rhe web,(which never lies). the engine loom is plug and play. it isnt, the wiring config on the plugs is different. so, junking the ac till i get the correct pump and pipes, unless i can swap the engine bracketry over tomorrow, will update o my failure with that.
with the loom, i have un plugged the donor loom from the cabin loom under the lhs kick panel in the car. from steering column and working my way along the firewall. time spent on wiring, 2 hrs so far. im using the clocks and key chips from donor car.. one thing ive done is use some of the v6 intercooler pipework and using two intercoolers.
ive no clue if theres a benefit to 2 intercoolers.
will update tomorrow night.

 

[Samuel c5 Q]

Hey, you stole my idea lol. I am very interested in this though as I have the bits to turn an AHU engine into a 250bhp motor, well motor would be good for 400bhp but the turbo I prefer is only good for 250bhp. The Cordoba has enough problems with wheel spin with 110 bhp at the minute so was toying of the idea of putting the engine in a Quattro car. Although I have enough to be getting on with at the minute.

The two intercoolers will give an extra pressure drop which may affect overall pressure ratio and air flow etc. The maths is for another day but my instincts will say that overall AIT will be lower than with a single intercooler aiding denser air and ability to make more power. At a guess a single efficient front mount, even a small 140mm*550mm*65mm intercooler would be better again.

 

[aragorn]

if your fitting a non-climatronic harness into a climate control car you do realise all the climate stuff will be wrong?

Your really going about this the wrong way.

Either splice the AFN loom into the 2.5 end plugs, or source an AFN harness from a car of the same year as yours.

What years are the two respective cars?

 

[andrew field]

if your fitting a non-climatronic harness into a climate control car you do realise all the climate stuff will be wrong?

Your really going about this the wrong way.

Either splice the AFN loom into the 2.5 end plugs, or source an AFN harness from a car of the same year as yours.

What years are the two respective cars?

Hi, both cars from 97 but yes,the afn didnt have climate, i didnt specifically choose each car for this job, it just panned out that way, when you say the climate stuff will be wrong, what do you mean?. i already suspect thats the reason for the plug incompatability. ive been away working for a month, offaain for 3 days, but then a few days to play. even cntemplating rbuilding the v6 and putting it back to stock

 

[aragorn]

climate cars have a heater box with full electronic control. non-climate cars have a completely different heater box with mechanical cables to move all the flaps.

I put a 1.8T into an S4 shell and the plugs were different. I just cut the plugs off the S4 harness and soldered them onto the end of the 1.8T harness, using a wiring diagram for each engine to match up the respective pins. It wasnt particularly difficult.

Stick a photo up of the connectors on each loom.

 

[Samuel c5 Q]

1.9 tuned for the win. Here's the mates alh which had more to get out of it. I believe this was with out a 130 pd intake manifold which would have allowed it go make 250 bhp on the turbo that was on it. Torque was mapped back to limit wheelspin.

 

[aragorn]

peak torque at 3k? Doesnt look very nice to me. You tend to sit around 2000rpm while crusing along in a diesel and its making nothing down there.

This is what happens when you take an engine beyond sensible levels, and why many OEM's are using twin turbo setups on 2L diesels to get past 200hp.

 

[Samuel c5 Q]

Check the values out though. It is making 240 ft lb at 2000 rpm, 20 ft lb more than my asv tdi mk1 Leon which was tuned to 159 bhp. The leon got off side rather well. The alh engine also makes 325 ft lb at 2500 which is 50 ft lb more than my leon. Check out dark side developments powergraphs for what seems to be mainly 1.9 pd engines using gtb turbos and you can see that Des's engine makes more power and torque earlier and more power later in the rev range. Des's was a ve engine using pd internals.

 

[aragorn]

Torque is nothing without RPM. The result of torque x RPM is power. Which is why folk going on about torque alone is meaningless. Diesels are "torquey" but what that means in the real world, is they have lots of power low down in the rev range. This makes them nice to drive, as unlike a petrol the power is accessible easily.

By fitting a huge turbo, which takes eons to spool and moves the peak torque waay up the revs, you've ruined the diesel characteristics that make them nice to drive.

At 2000rpm that car is making about 75 horsepower. That means when you sink the boot, you've only got 75hp available to actually accellerate the car.

My petrol car is making about 65horsepower at 2000rpm, and its a complete slug down there. But unlike the derv, that part of the rev range isnt really used, as your cruising at 3000rpm in a petrol, where it has about 160hp available due to the much wider rev range on a petrol.

As a comparison a stock 330d is making about 120hp at 2000rpm...

I've driven a Bora with a hybrid, and it was horrible below 2500rpm, compared with the 330d which pulled cleanly and strongly from probably 1500rpm. Despite both on paper having the same power.

I think any engine has a point at which tuning them further starts to become a bit silly, and the correct answer is a larger engine. For diesels, that point is around 100hp/L. For petrols, its around 175hp/L. Now ofcourse there are exceptions, but i'm talking road cars here, rather than race/track cars where things can be wilder and you get away with it. To get round those limits you end up doing stuff like BMW has done with the 335d or 123d. BMW even have a triple turbo engine in some of their larger cars. But those are worlds apart from nailing a huge turbo onto a 1.9VE engine and claiming an amazing 250hp.

 

[Samuel c5 Q]

Torque is a measure of work done. It's a turning force and what overcomes a load. That's why diesels pull up hills at lower revs better than most petrol engined cars. His makes 240 ft lb where as yours is only making 170 ft lb at 2000 rpm.

His turbo wasn't that huge, a 2.5v6tdi hydrid and his torque was mapped back to stop wheel spin. There are some pd with gtb1756 that will make as much if not a bit more power and torque as early but they can't make the power on up the rev range and the ones with a gtb2260 can make almost the same power at the upper end but still tail off some 500 rpm earlier which is significant. They also are woeful in the lower range than Des's . I believe it's the fuelling that is important in making the ve engines rev. Contrary to popular belief diesels can rev and make power at the higher revs increasing your top end speed for the same gearing and allowing 60mph in second gear instead of say 48mph etc. The fuel pump is key here as well as the turbos ability to flow.

My 50-70 mph time in the leon in 4th and 5th was 4.5 and 5.6 sec which is isn't to shabby. Engine speed range from 1700rpm to 2400 rpm for 5th. Des's engine was in a mk2 golf with a kerbweight of 1100kg. 0-60mph of 5.7sec and 0-100mph of 12sec in the dry and 13.25 in the wet and 157 mph top end.

It's hammered a few top end Subaru impreza, sierra cosworth (sapphire rwd, 300 BHP I think) and one I definitely remember was he sat right with a 03 e46 m3 from 70mph until 135 mph when it started to pull out the legs on him. They are 343 bhp albeit some 300-400 kg heavier from memory. I haven't been on carfolio specifications to check.

Your 330d engine is awesome, had a go in one and the pull is unreal from the get go, can't quite remember how the top end was and where it revved out to. That is my Leon seemed to run out of puff at 4250 rpm. The 2.5 v6 tdi engine is rubbish unless someone has poof otherwise. I had a go in a 180 bhp Quattro a4 and my leon with less power made it feel like a one litre fiesta. They are dead below 1500 rpm same as the 1.9 pd where as with the ve engines you can feel the pull straight from the idle with reasonable pull from 1300 rpm, good and strong from 1500 rpm, pull whack from 2000 rpm. The 2.0 pd engines seem to be a lot more flexible than the 1.9s before them.

 

[Gazwould]

I wouldn't say a 1.9 PD is dead below 1500 rpm ,
( remapped ) mine makes 175 ftlb at 1550 and 230 ftlb at 2K .

It pulls everywhere , I forgot to go down in 3rd and in 4th it pulled slowly but cleanly up a hill from less than 1K .

 

[aragorn]

Torque is NOT work done. Its a force, and nothing more. You can have 1000lbft of torque and achieve no work at all if there is no speed (ie 0rpm). Work done is THE definition of Power. A large torque value simply means that your capable of doing more work at lower rpm. The work is still what makes you accellerate. Diesels also tend to have longer gearing, which means they climb thru the rev range much slower for a given speed range, and thus spend longer in the lower ranges where power is less. Stock diesels often have quite flat power curves, which is why they are so tractable.

There is simply no way you will convince me that a small 4 cylinder diesel is a performance engine. its not. They're fine in a daily driver, and tuned sensibly with stock sized turbo (GT1749 or the BV43 etc) will produce a decent daily due to the excellent low down delivery. My mates remapped PD130 was a great everyday car, and felt quicker than it was due to the low down punch. Once the hybrid went on? Not so much. It was laggy, and at cruising speed you were a few hundred rpm below where the torque really came in, so it was flat and limp. Sure, floor it up the revs and it went pretty well, but thats 1 or 2% of the time spent driving the car, and for the remaining 98% it was worse than before. Comparing VE and PD is largely pointless, they just squirt fuel in, and any differences between them is simply down to mapping. Theres no reason a PD engine cant hose fuel in at the low part of the rev range. Its likely that they're simply tuned better with tighter smoke limiters low down, which results in less torque off boost and probably a slightly slower spooling engine. The PD engine actually has far better control over the fuelling, and personally i'd prefer that system (after common rail).

If you want a fast car with 250 or 300hp, then you either need more cubes, or petrol. Trying to achieve those numbers from a 2L diesel is just hopeless. The 330d shows what happens when you do it properly. Audis 3.0 TDI is similar. Stick to what its good for and you'll have a great result. Go chasing silly numbers, and you'll ruin it.

 

[andrew field]

climate cars have a heater box with full electronic control. non-climate cars have a completely different heater box with mechanical cables to move all the flaps.

I put a 1.8T into an S4 shell and the plugs were different. I just cut the plugs off the S4 harness and soldered them onto the end of the 1.8T harness, using a wiring diagram for each engine to match up the respective pins. It wasnt particularly difficult.

Stick a photo up of the connectors on each loom.

Cheers,apologies for the late reply, ill post the pics tomorrow, i wonder how well the heating system will actually work

 

[andrew field]

Hi, Ive not forgotten, just been busy with forest fires, varous other distractions i can do without, but im guessing the theory is that i can mix and match to create a climatronic loom of sorts, which sounds easier than replacing a complete loom and the heater box and controls, which i dont think im masochistic enough to do given the finished products low value

 

[Samuel c5 Q]

Are the climate control looms and engine bay looms not separate? I know the compressor and clutch pulley is part of the engine bay but are they not a generic part fitted to all models that have the aircon? The difference between aircon models and non aircon being the larger radiator and the twin fans. From what I can tell the engine harness and climatronic system are separate.

 

[Samuel c5 Q]

If your a4 has climate control then it will run and regulate the cabin temperature as usual. What you need to do is fit a bracket to your AFN engine and a air con pump. Then the connect the pipes to it to pump the refrigerant. The final bit being changing the connector to attach the loom that tells the clutch mechanism to engage/disengage. That is if the end connector needs changed. Obviously you'll need the correct length of drive belt. Don't forget to fit the old turbo from your v6 tdi while your at it. The 150bhp hot side with 180bhp cold side works best.

 

[aragorn]

Its all one combined loom, that does EVERYTHING in the car, its really not a quick DIY job to convert from one to the other.

 

[Samuel c5 Q]

Trim the afn loom down then making the aircon part of the loom redundant whilst leaving the v6 part in place to manage the air con.

 

[aragorn]

Why does he need to touch the loom at all? I really dont get it.

I put a 1.8T into an S4 shell, and it too came from a non-climate car. There was no issue with the climate control, it was all just left as it was from the S4.

Your somehow thinking that stripping half the car apart, and trying to mess with a seriously massive wiring harness, is somehow easier than just snipping off and replacing 4 electrical plugs on the engine harness?

I've done it. I removed the whole harness from the S4, and stripped out every unneeded wire to save weight. It was a stupendous amount of work, and i'd never do it again. It certainly isnt needed here.

 

[Samuel c5 Q]

We must be on different wavelengths. The fella wants his aircon to work. I am suggesting that it fits the bracket pump etc and plug his v6 aircon loom to it which will tell the clutch to engage. The rest of the v6 loom in the cabin will control that part of it. The afn must have an engine harness like the 1.8ts but you said it is all one loom or were you referring to the cabin loom?

 

[aragorn]

Mechanically thats fine.

But hes talking about the harness INSIDE the car, that runs the heater/climate unit, as well as everything else in the dashboard and the rest of the car.

 

[Samuel c5 Q]

That can be left in place. It'll still work.

 

[aragorn]

yes, but his AFN harness wont plug into the 2.5 harness as the connections/pinout is different.

But instead of changing the connectors, hes talking about changing the whole loom, which is why i've been trying to convince him thats a crazy idea.

 

[Samuel c5 Q]

Why does the AFN harness have to plug in to the v6 one? Is it not like the 1.8t were the engine bay side can come around the baulk head and in to where the ecu is? The other side of the loom goes to throttle pedal sensor and clocks etc.Yes/no.

 

[aragorn]

i'm not really sure i understand what your on about.

The engine harness runs into the ECU box, and then interfaces with the main car harness thru 5 plugs. Otherwise it'd not be connected to anything and wouldnt work...

Those 5 plugs differ between engines and generations of car, so the engine harness may or may not actually plug into the car harness depending on the specific combination of parts.

His car harness expects the connectors and pinouts of the V6 engine loom, and those happen to be different to his AFN loom, thus it wont plug in.

 

[Samuel c5 Q]

I was thinking exactly what you were thinking. He'll not know until he checks the pin out diagrams. More than likely the throttle pedal and crank position sensor parts of the loom will match up but having two cam shaft position sensor parts will need looking at. The power, earth and ignition on lines in should be the same. But he'll not know till he looks at the diagrams.

Yes, I forgot the AFN had no aircon. He'll have to draw a lead out to the aircon pulley wheel clutch to operate it if he can locate the pins out from the back of aircon unit in the cab then he could run a lead either from it or make up a lead to run from the five socket part under the ecu box.

 

[aragorn]

The cable for the aircon is seperate to the engine harness anyway, so that will all still work fine.

 

[andrew field]

Why does he need to touch the loom at all? I really dont get it.

I put a 1.8T into an S4 shell, and it too came from a non-climate car. There was no issue with the climate control, it was all just left as it was from the S4.

Your somehow thinking that stripping half the car apart, and trying to mess with a seriously massive wiring harness, is somehow easier than just snipping off and replacing 4 electrical plugs on the engine harness?

I've done it. I removed the whole harness from the S4, and stripped out every unneeded wire to save weight. It was a stupendous amount of work, and i'd never do it again. It certainly isnt needed here.

HI, no i wasnt really thinking that would be easier, of course. i just want to do something to make the car work, had complete brain fade with the damn thing, got three days off now so its out with the multi meter. ill post pics of plugs today,

 

[andrew field]

Torque is NOT work done. Its a force, and nothing more. You can have 1000lbft of torque and achieve no work at all if there is no speed (ie 0rpm). Work done is THE definition of Power. A large torque value simply means that your capable of doing more work at lower rpm. The work is still what makes you accellerate. Diesels also tend to have longer gearing, which means they climb thru the rev range much slower for a given speed range, and thus spend longer in the lower ranges where power is less. Stock diesels often have quite flat power curves, which is why they are so tractable.

There is simply no way you will convince me that a small 4 cylinder diesel is a performance engine. its not. They're fine in a daily driver, and tuned sensibly with stock sized turbo (GT1749 or the BV43 etc) will produce a decent daily due to the excellent low down delivery. My mates remapped PD130 was a great everyday car, and felt quicker than it was due to the low down punch. Once the hybrid went on? Not so much. It was laggy, and at cruising speed you were a few hundred rpm below where the torque really came in, so it was flat and limp. Sure, floor it up the revs and it went pretty well, but thats 1 or 2% of the time spent driving the car, and for the remaining 98% it was worse than before. Comparing VE and PD is largely pointless, they just squirt fuel in, and any differences between them is simply down to mapping. Theres no reason a PD engine cant hose fuel in at the low part of the rev range. Its likely that they're simply tuned better with tighter smoke limiters low down, which results in less torque off boost and probably a slightly slower spooling engine. The PD engine actually has far better control over the fuelling, and personally i'd prefer that system (after common rail).

If you want a fast car with 250 or 300hp, then you either need more cubes, or petrol. Trying to achieve those numbers from a 2L diesel is just hopeless. The 330d shows what happens when you do it properly. Audis 3.0 TDI is similar. Stick to what its good for and you'll have a great result. Go chasing silly numbers, and you'll ruin it.

I absolutely agree, a simple analagy is hp is how fast you hit the wall, torque is how far it pushes it afterwards. but yes, torque on its own is pointless. here in sweden people do amazing things with old merc diesels, but not the small 4 pots, ive driven a couple of reasonably high tune small diesels and honestly, not pleasant to drive.

 

[aragorn]

If you can tell me the years of the respective cars, i can try to sort you a wiring diagram for each.

Thats what i did with my 1.8T into S4. Sat with the wiring diagram and made up a table showing the 1.8 connections on one side and S4 connections on the other. Then i just soldered the S4 plugs onto the end of the 1.8T loom.