1.8T ATW

[Clewe]

So I just traded my 1.8t gti for this 2000 Audi a4 1.8t but it has an ATW motor, both of my other cars had the AMW with 180hp stock, I tried searching around for the good/bads on the ATW motor and couldn't find anything helpful or worth reading. All my friends want to slap me because my gti had a built bottom end, 6 speed swap out of a 20th ann., 3 bolt flange with ko3 swap from a TT, GIAC tune, etc.. anyways I have been desperate for a factory midnight blue a4 1.8tq so I could do everything myself. I finally found one, although a little beat up and a 3rd gear synchro problem I decided to do it. I'm planning on doing the transmission and putting in a stage 2 clutch first, I also have a ko4-22 laying around that I was thinking about putting on with the supporting mods, but before I do anything I was wondering, is this motor worth putting any money in as far as performance or is this kind of the 'dud' out of the 1.8t motors.. Sorry for the rambling and asking stupid questions I just couldn't find any threads that cover my questions, any input is helpful..

[Clewe]

Also since there's a synchro problem with 3rd, I was thinking about swapping transmission instead of rebuilding it, my buddy has an AMW transmission are they interchangeable with the ATW, both 5 speed 1.8t quattro.

[walky_talky20]

All the 5-speeds are interchangeable. Even the V6 ones, which just have longer gears.

There isn't anything bad about the ATW, physically speaking. The only downside may be the electronics. Tunes for the ECU are a little more limited, but I don't think it's a big deal. It is actually not too difficult to upgrade it to AWM spec as far as the ECU and harness. This adds the wideband o2 sensor and ability for newer tunes, mafless files and such. It is literally a couple wires and the wideband sensor and you're in business (haven't done this myself, but that is my understanding).

Actually, I've got an AWM and my brother has an ATW. Both 5-speed quattro cars with stage 1 chips. His ATW runs better than my car, by a mile. That's more to do with something being wrong with my car, but just goes to show.

[Seerlah]

All 01A transmissions are interchangeable. Just the gearing is different on the 2.8 versus the 1.8t (don't know engine codes). The B6 A4 uses the same tranny (5-speed, not the 6-speed), so you can use one from there. Simplest and cheapest thing to do is just find a used tranny and swap it in. Also, choose a clutch for your future goals so you don't need to replace it again later on. And when it comes to the engine, it is the same damn 1.8T engine found in all VAG cars, with slight differences between engine codes. Since you come from the Vag world, I am pretty sure you know what these cars are capable of. I'm at 145k and just installed my T3 GT2871R like 2 months ago. Internal upgrades coming along later with fresh hone/piston rings. Are these cars worth dumping money into? That is something you need to answer yourself.

Here is info on the engine codes of the B5 A4 and how they differ (1.8t content):

97-99.5 is the AEB engine with an 058 short block. You should already know about the AEB cylinder head, so not going into that. It is a drive by cable throttle system and has a narrow band primary o2 sensor. Stronger rods than the 06A block because of the larger wristpin (20mm vs 19mm). You have no SAI, no MAP sensor, and you have an ICM for your ignition coils. All the specs of an 058 block apply. This is the pre-face lift (minus 99.5) as far as the body goes when it comes to the B5 A4.

00 is the ATW engine with an 058 short block. People call this the bastard child because it is DBW throttle system, still has the o58 block, and the primary o2 sensor is still a narrow band. Other than it being DBW, same thing as above. Basically a DBW 058 block with smaller cylinder head found on the later model A4s (00+ is when they made the smaller port units). As for body goes, this is the facelift version of the B5 A4.

01-01.5 is the AWM engine with 06A block. Has all that emission crap, including SAI. Has small port cylinder head, is a DBW throttle system, has MAP sensor, has wideband primary o2 sensor, no ICM (4 wire coils with ICM built into them), came with slightly larger injectors from the factory, came with more HP (more boost) from the factory, has vented valve cover, and all the stuff that comes along with an 06A block. This is the facelift version of the B5 A4.

[SS92]

There isn't anything bad about the ATW, physically speaking. The only downside may be the electronics. Tunes for the ECU are a little more limited, but I don't think it's a big deal. It is actually not too difficult to upgrade it to AWM spec as far as the ECU and harness. This adds the wideband o2 sensor and ability for newer tunes, mafless files and such. It is literally a couple wires and the wideband sensor and you're in business (haven't done this myself, but that is my understanding).

This is happening to my car next weekend, Maestro gets delivered to my door this coming Tuesday. Hopefully I have a write-up by Sunday if it goes well.

My ATW hasn't posed any problems to me that any other 1.8T would. Only downside is small port vs large port if you have a BAT. But my 2871r wont outflow my head so I'm not concerned.

[Clewe]

Thanks guys all of my questions have been answered right on the spot... it's good to back on these forums, vwvortex mkiv forums were such a joke. Anyways I got some decent plans for the new car, I'll keep it posted.