Difference engine fwd vs quattro and engine codes in general

[tommyf]

Hi all

I would like to know if there is such a thing as a quattro engine or fwd engine. Can anyone help out?

Reason I am asking is because I am thinking of converting my fwd in a quattro, but not in the usual way. I want to put my engine (comes out of a fwd car) in a quattro. I will buy another car with awd and manual gearbox as mine is manual as well, and change the engines.

Why do I want to use my engine to do this I hear you ask, well at the moment I am rebuilding my engine and from top to bottom it's being forged and strengthened where possible. Along the way, I wrestled with the idea of getting the amount of power efficiently on the ground with fwd. Logically, quatro started to sound like a better idea. I am trying to find out how much of a hassle it would be to get this done.

So I did find the following. All of these are from an a4 B7 and are manual gearboxes.

This one is taken from a QUATTRO - Gearbox code = GVE (Engine BWE)
334592

This one is taken off a FWD - Gearbox code = GVD (Engine = BWE)
334593

This one is taken off a QUATTRO - Gearbox code = GVE (Engine = BGB)
334594

And last but not least we have this one, taken off a FWD - Gearbox code GVC (Engine code not sure, but it states bgb and bwe). This btw is not manual so it's not an option anyway.
334595

Unfortunately the last 2 pictures aren't that great for comparison but the GVE and GVD gearboxes in the first 2 pictures, both from BWE engines, seem to have matching mounting holes. The BGB engine also uses the same gearboxes.


if anyone could help out with the following questions, that would be awesome:

- were quattros produced with specific engine codes or the same as fwd? ( So I think I answered this one already as I found that bwe/bgb are used both in quattro and fwd )

- my engine code is bwe, if I find a quattro with bwe engine, will the transmission be an issue when transferring the engines if both are manual? ( This one is partially answered, but perhaps someone has more insight)

- what if I find a quattro with another engine code than mine, what issues should I look out for. In other words, what are the differences in the engines between the various engine codes?

-What should I do with the Ecu from both cars? My own ecu has a custom tune already (car will get another custom tune after having driven in the engine) and I would need it to make my parts work on the quattro, at least until the second custom tune.

- any other tips (besides getting rid of the car and engine and buying a new one) are all welcome.​


Hope someone can help out.

[Cyrik]

were quattros produced with specific engine codes or the same as fwd? ( So I think I answered this one already as I found that bwe/bgb are used both in quattro and fwd

I can't remember exactly off the top of my head but back in the day I was looking into options for my Tiptronic Quattro to convert to manual, only to find out it wasn't worth it at all since the gear ratios in the rear diff are different between manual/automatic and the crankshaft splines on the engine going to the transmission are different between CVT/Manual and the Automatic Tiptronic engines. With me having a Tiptronic Quattro I would essentially be replacing EVERYTHING.

If I am not mistaken, you can use A CVT/Manual engine with a Tiptronic (Automatic) transmission but you CANNOT use a Tiptronic engine w/ a Manual/CVT transmission. Weird, I know...


my engine code is bwe, if I find a quattro with bwe engine, will the transmission be an issue when transferring the engines if both are manual? ( This one is partially answered, but perhaps someone has more insight)

As I stated above, as long as the engine came out of a CVT or manual you're fine. There is no difference on the engine side as far as mounting goes.


what if I find a quattro with another engine code than mine, what issues should I look out for. In other words, what are the differences in the engines between the various engine codes?

There is quite a few engine codes and they are all slightly different in some way (some literally have a slightly different compression ratio at certain RPM's). For simplicity, I'd recommend just sticking with the same engine code to prevent any other incompatibility (make sure you get the correct config for the PCV, as it differs between early and late model engines split in the 2006 year. One model has the check valve in the PCV and the other has the check valve located in the breather hose going to the turbo). For a bit more info on this, refer to this post: https://www.audizine.com/forum/showthread.php/123431-Which-2-0T-FSI-Engine-do-you-have


What should I do with the Ecu from both cars? My own ecu has a custom tune already (car will get another custom tune after having driven in the engine) and I would need it to make my parts work on the quattro, at least until the second custom tune.

As far as ECU goes on the engine side of things you won't have to do anything at all since it's a swap-in-swap-out situation. According to other sources, because everything is mechanical with the gen 4 quattro systems in our cars you shouldn't need to do anything with the ECU. Source: https://www.audizine.com/forum/showthread.php/381996-FWD-to-AWD-Conversion



- any other tips (besides getting rid of the car and engine and buying a new one) are all welcome.​

Make sure you get EVERYTHING first before starting the swap. There's no bigger headache than finding out you're missing bolts or other small parts cause you didn't double check. there's A LOT OF PARTS.

I know it sounds like you're set on doing this but if I may give my two cents... With how extensive the labor is when doing this conversion, these days I personally think it's not worth it. I just looked at FB Marketplace for Quattro B7 A4's and I found multiple for $4000 or less (I live in Denver where AWD comes at a slight premium too out here). None of the cars I looked at there were in particularly great condition, but the amount of time you'd spend fixing one of those instead of spending WAY more time on this swap is what makes it not worth it. As an Automatic Tiptronic owner of 7 years... If I want a manual, I'm switching cars (remember as I stated at the beginning of this post I'd have to replace literally everything to get a manual). With that said, your car is not my car, so do as you please.


Hope this info helps!

[tommyf]

I can't remember exactly off the top of my head but back in the day I was looking into options for my Tiptronic Quattro to convert to manual, only to find out it wasn't worth it at all since the gear ratios in the rear diff are different between manual/automatic and the crankshaft splines on the engine going to the transmission are different between CVT/Manual and the Automatic Tiptronic engines. With me having a Tiptronic Quattro I would essentially be replacing EVERYTHING.

If I am not mistaken, you can use A CVT/Manual engine with a Tiptronic (Automatic) transmission but you CANNOT use a Tiptronic engine w/ a Manual/CVT transmission. Weird, I know...



As I stated above, as long as the engine came out of a CVT or manual you're fine. There is no difference on the engine side as far as mounting goes.



There is quite a few engine codes and they are all slightly different in some way (some literally have a slightly different compression ratio at certain RPM's). For simplicity, I'd recommend just sticking with the same engine code to prevent any other incompatibility (make sure you get the correct config for the PCV, as it differs between early and late model engines split in the 2006 year. One model has the check valve in the PCV and the other has the check valve located in the breather hose going to the turbo). For a bit more info on this, refer to this post: https://www.audizine.com/forum/showthread.php/123431-Which-2-0T-FSI-Engine-do-you-have



As far as ECU goes on the engine side of things you won't have to do anything at all since it's a swap-in-swap-out situation. According to other sources, because everything is mechanical with the gen 4 quattro systems in our cars you shouldn't need to do anything with the ECU. Source: https://www.audizine.com/forum/showthread.php/381996-FWD-to-AWD-Conversion




Make sure you get EVERYTHING first before starting the swap. There's no bigger headache than finding out you're missing bolts or other small parts cause you didn't double check. there's A LOT OF PARTS.

I know it sounds like you're set on doing this but if I may give my two cents... With how extensive the labor is when doing this conversion, these days I personally think it's not worth it. I just looked at FB Marketplace for Quattro B7 A4's and I found multiple for $4000 or less (I live in Denver where AWD comes at a slight premium too out here). None of the cars I looked at there were in particularly great condition, but the amount of time you'd spend fixing one of those instead of spending WAY more time on this swap is what makes it not worth it. As an Automatic Tiptronic owner of 7 years... If I want a manual, I'm switching cars (remember as I stated at the beginning of this post I'd have to replace literally everything to get a manual). With that said, your car is not my car, so do as you please.


Hope this info helps!

Hi Cyrik,

First of all, thank you for all the information.

I hear your advise but I am to far in, financially, to pull out now haha. The idea to go from fwd to awd got more traction (dont mind the puns) when I was halfway through rebuilding the fwd engine. Basically, it's not so much of a conversion but rather an exchange of similar engines. I have found an a4 b7 quattro sline with manual transmission and bwe engine, same as mine. I think a lot of issues will be prevented with this choice. I still have to go and check out the car and buy it, but once that is done, it's just a matter of switching engines and ecu's.

The immobilizer might be an issue with the ecu's but that should be a quick fix. I cant quite figure out how to go about the tune once the engines are swapped.
At the moment:
Fwd engine: lots of modification in fueling and turbo and runs on a custom tune
Quattro: nearly standard, has a stage one tune.

I have to run in the engine first and actually want to do that with the custom tune (as the engine will stay like it is for about 1000km or so before I want to bring it to another level). After having run in the engine properly, other injectors and perhaps even a bigger turbo have to make room for the current ones.

Not sure exactly what is a smart way to bridge these 1000 kms run in time as I dont want to run my fwd hardware setup with the quattro software.

Option 1: run in engine in the fwd car for now and later swap the engine to the quattro and get a custom tune for the quattro and a reset to factory or just stage one for the fwd.

Option 2: swap only the engines not ecu and run in the engine with fwd hardware setup but quattro tune. After a 1000kms or so, time for a custom tune(My least favourite option)

Option 3: run in the forged engine with the quattro hardware and quattro software and afterwards, swap hardware and get a custom tune on the quattro (and also on the fwd as that one needs to keep driving as well).

Option 4: on another forum, someone presented an idea to copy the fwd tune by using MPPS and flash the quattro tune with it. This is also a viable option, but still have to do some research on MPPS as I have no clue how that would go.

Option 5: run in forged engine in the quattro but together with the ecu of the fwd. Immobiliser might be an issue but that again, that might be a quick fix.

For now, first just get the quattro. Btw, the quattro is an avant my fwd isnt.

[Cyrik]

I hear your advise but I am to far in, financially, to pull out now haha.

I was in the same boat when I swapped engines a few years ago after I wiped my bearings. I hear you loud and clear hahahaha


The immobilizer might be an issue with the ecu's but that should be a quick fix. I cant quite figure out how to go about the tune once the engines are swapped.
At the moment:
Fwd engine: lots of modification in fueling and turbo and runs on a custom tune
Quattro: nearly standard, has a stage one tune.

I have to run in the engine first and actually want to do that with the custom tune (as the engine will stay like it is for about 1000km or so before I want to bring it to another level). After having run in the engine properly, other injectors and perhaps even a bigger turbo have to make room for the current ones.

Not sure exactly what is a smart way to bridge these 1000 kms run in time as I dont want to run my fwd hardware setup with the quattro software.

Option 1: run in engine in the fwd car for now and later swap the engine to the quattro and get a custom tune for the quattro and a reset to factory or just stage one for the fwd.

Option 2: swap only the engines not ecu and run in the engine with fwd hardware setup but quattro tune. After a 1000kms or so, time for a custom tune(My least favourite option)

Option 3: run in the forged engine with the quattro hardware and quattro software and afterwards, swap hardware and get a custom tune on the quattro (and also on the fwd as that one needs to keep driving as well).

Option 4: on another forum, someone presented an idea to copy the fwd tune by using MPPS and flash the quattro tune with it. This is also a viable option, but still have to do some research on MPPS as I have no clue how that would go.

Option 5: run in forged engine in the quattro but together with the ecu of the fwd. Immobiliser might be an issue but that again, that might be a quick fix.

For now, first just get the quattro. Btw, the quattro is an avant my fwd isnt.

Avant and sedan quattro systems should be identical in every way so no worries there. Like I said in my post above since everything is mechanical with the Quattro system you shouldn't have to do ANYTHING to the ECU to get quattro to work correctly. (I'm not certain but I imagine when the ECU reads all the modules in the car it will read the new transmission and "load" the AWD module). If you swap ECU's you'll absolutely have to get the immobilizer to pair with the new one but that SHOULD be the extent of it.

In regards to Option 4, I have no experience in cloning ECU's and not sure how extensive this is with our platform. I have no doubt someone has done it however. Personally I would be using an ECU as stock as possible to prevent any issues that might be caused by the ECU being modified and simply start from scratch again with a new tune (example, timing codes popping up because the range set in the ECU is different from stock, I hope that makes sense)

Option 5 looks like the easiest solution IMO, along with a hint of Option 1 in regards to starting out stock and building up from there to prevent any weird issues. You're going to have the entire drivetrain out of the car anyway, might as well do the engine too since you're going to have a different block in the car later down the line anyways. Why bother putting in all that work only to have to get under the hood again in the future?

Good luck and looking forward to what you end up doing!

[Gunnarrrrr]

To clear things up:

quattro tiptronic is the only crankshaft that’s different. Unless you’re converting to a tiptronic, you have the right crank already.

should be obvious but you will need basically a whole rear subframe(including axles, spindles, diff), and gas tank(with the matching lpfp, driver side sender, and heat shields), and exhaust & prop shaft. shorter e brake cables, I think that’s about it. ECU is already good to go, even less to do there since you already have a 6 speed. a couple minor coding changes to do but nothing that will keep you from driving the car without them.

not sure why this guy is enabling you to go down the rabbit hole of swapping or cloning ecu’s or even commenting at all really, considering he’s offering absolutely nothing but confusion and has no experience swapping engines or transmissions in these cars let alone any understanding of it. You aren’t doing an engine swap, you aren’t swapping a haldex awd system, literally no reason to mess with your ECU aside from a few ESP adaptations, which is ABS related and once again has nothing to do with the ECU.

I know this guy looked into a tip to manual conversion awhile ago but that process is completely streamlined now and tons of people including me have done it with a pilot bearing adapter that a forum user on here machines. again, not relevant though, because that tip quattro crank is the only one that’s different. Your. Engine. Will. Bolt. Right. Up. You DO NOT need to source a different engine so stop shopping.


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[tommyf]

To clear things up:

quattro tiptronic is the only crankshaft that’s different. Unless you’re converting to a tiptronic, you have the right crank already.

should be obvious but you will need basically a whole rear subframe(including axles, spindles, diff), and gas tank(with the matching lpfp, driver side sender, and heat shields), and exhaust & prop shaft. shorter e brake cables, I think that’s about it. ECU is already good to go, even less to do there since you already have a 6 speed. a couple minor coding changes to do but nothing that will keep you from driving the car without them.

not sure why this guy is enabling you to go down the rabbit hole of swapping or cloning ecu’s or even commenting at all really, considering he’s offering absolutely nothing but confusion and has no experience swapping engines or transmissions in these cars let alone any understanding of it. You aren’t doing an engine swap, you aren’t swapping a haldex awd system, literally no reason to mess with your ECU aside from a few ESP adaptations, which is ABS related and once again has nothing to do with the ECU.

I know this guy looked into a tip to manual conversion awhile ago but that process is completely streamlined now and tons of people including me have done it with a pilot bearing adapter that a forum user on here machines. again, not relevant though, because that tip quattro crank is the only one that’s different. Your. Engine. Will. Bolt. Right. Up. You DO NOT need to source a different engine so stop shopping.


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Haha thanks for the reply.
It's not an engine I am shopping for. I think you misunderstood.

I have nearly finished rebuilding my engine, but don't want to put it back in my fwd car but rather a quattro. So I am looking for a quattro avant manual with either bgb or bwe engine as they use the same parts and transmission. Those two I have 98% confirmed are exchangeable. I would love to know if the BUL for example would fall under the same category as well. I have seen a few of those for sale but been skipping over them because I am not sure about compatibility (yet).

I brought my crankshaft, flywheel, pressure plate to the shop last week to be balanced. When that is back, I can finish the engine. At the moment, I am opting to just rebuild it in the fwd as I haven't found a suitable quattro that I like yet. I will run in the engine as it was and whenever a viable option presents itself, I am going to swap engines and ecu.

The quattros I like, have shitty salesmen as they dont react. So super annoying but I try to see it as it not being the quattro destined for me.

I will keep updating soon with pictures as well. Now that the holiday has started, I will have some more time to get busy with it.

[Jayz691]

So basically, CVT/manual engines(crank) differ from auto Tiptronic. But you can run either configuration, with mild modification.
To run a manual gearbox on tip engine, can just buy the crank adapter from "gearbox" on here($80).
To run tip trans with manual engines, some just slap it in. Better way is to buy a new Tiptronic bushing(end of crank) and have like 1mm milled off the outside. This will help keep the TC centered. There is a write-up on here about this also.
Far as mounting, if it's a b7 2.0t trans, mounting(bell housing) should be the same.

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[tommyf]

So basically, CVT/manual engines(crank) differ from auto Tiptronic. But you can run either configuration, with mild modification.
To run a manual gearbox on tip engine, can just buy the crank adapter from "gearbox" on here($80).
To run tip trans with manual engines, some just slap it in. Better way is to buy a new Tiptronic bushing(end of crank) and have like 1mm milled off the outside. This will help keep the TC centered. There is a write-up on here about this also.
Far as mounting, if it's a b7 2.0t trans, mounting(bell housing) should be the same.

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Thanks but this isn't really the issue or the question at the moment.

[Jayz691]

Thanks but this isn't really the issue or the question at the moment.Ok. Didn't read everything, just skimmed over it..
What exactly are you asking? All blocks are interchangable, even from transverse cars. Just need to swap a few things over.
Sorry, was just way too much to read, lol.

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[AudiB720TS]

Haha thanks for the reply.
It's not an engine I am shopping for. I think you misunderstood.

I have nearly finished rebuilding my engine, but don't want to put it back in my fwd car but rather a quattro. So I am looking for a quattro avant manual with either bgb or bwe engine as they use the same parts and transmission. Those two I have 98% confirmed are exchangeable. I would love to know if the BUL for example would fall under the same category as well. I have seen a few of those for sale but been skipping over them because I am not sure about compatibility (yet).

I brought my crankshaft, flywheel, pressure plate to the shop last week to be balanced. When that is back, I can finish the engine. At the moment, I am opting to just rebuild it in the fwd as I haven't found a suitable quattro that I like yet. I will run in the engine as it was and whenever a viable option presents itself, I am going to swap engines and ecu.

The quattros I like, have shitty salesmen as they dont react. So super annoying but I try to see it as it not being the quattro destined for me.

I will keep updating soon with pictures as well. Now that the holiday has started, I will have some more time to get busy with it.


The BUL will typically be a better spec:d car, and built at a ”better” factory so don’t exclude it. For what it’s worth I use an S3 BHZ engine in a BUL Quattro Avant. Can’t recall any issues.

[tommyf]

Ok. Didn't read everything, just skimmed over it..
What exactly are you asking? All blocks are interchangable, even from transverse cars. Just need to swap a few things over.
Sorry, was just way too much to read, lol.

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Exactly, what I want(ed) to know was whether bwe/bgb/bul are interchangeable. I am about 99% sure bwe and bgb are as long as they are both manually driven. I compared the list of parts on both engines and wherever a part is mentioned to be compatiable with bwe, the bgb is mentioned as well. The BUL engine, not so sure about yet. Still trying to find some reliable info.

[tommyf]

The BUL will typically be a better spec:d car, and built at a ”better” factory so don’t exclude it. For what it’s worth I use an S3 BHZ engine in a BUL Quattro Avant. Can’t recall any issues.
Hi, I know. Have been following your build and even had some contact about a 175b prv a few weeks ago.

The thing is, I have already started with my own engine, otherwise I would have just bought another quattro with whatever engine, and used that one.

While rebuilding and forging my own engine from my fwd car, the idea of a quattro started playing in my mind. So, my search for a nice quattro manual preferably avant started. I know they are around with the bwe engine, but currently most advertised are bgb (which I now know will fit as well). I found a few in Germany, "close" to the Netherlands, but the owner is really slow or doesn't react at all. There are a few closer to Switzerland, but I am really not looking to drive 9 or 10 hours to find out I made the drive for nothing.

So at the moment, engine is nearly finished, will probably put it back in my own fwd to run in the engine with the current tune and will continue the search for a nice quattro and later swap engines.