My B6 2.7t swap

[Heckas]

Hi there, I'm in the process of a B6 2.7 turbo swap like so many others and figured I'd create a thread about it. I have not been on the forum long and I'm kind of a returning Audi enthusiast.

I see people on here selling their toys due to babies on the way etc. I'm approaching 40 and although I wouldn't say that I am through that kid-phase of my life … I now have an opportunity to return to my hobbies. Back in the days I had a couple of Audi S2's, yes I lived in Europe back then. If the old S2's were available here in the states I would've probably bought one of those for nostalgic reasons. But since they're not readily available I picked up a ‘04 A4 3.0 Quattro 6-speed with a bad motor. The car came with two bad 3.0 engines (long story but it involves one failed timing belt and one failed attempt at replacing timing belt without cam lock tools by previous owner...). Once I figured out that the 3.0 wasn't all that fun I decided that if I’m going to spend the time fixing something I might as well spend it on what will in the end be something I will enjoy. That is when ‘the swap’ started intriguing me. So, I also bought an '00 Audi A6 2.7t Quattro tiptronic.

If I could have figured out how to insert a picture of the two I would have here

Why am I saying all this? Well, I figured it might give you an idea of what I'm looking to get out of the project. I'm doing this as a fun project and I'm not in a hurry. Projects are not (as) fun when adding pressure or anxiety. I'm planning on doing things right and not skimp on parts but I'm also not going to throw good money away. I'm cheap by nature

What do I want the end result to be? I want a car that is fun to drive. I've been driving around in automatic cars too long!! I'm not aiming for 500 hp but if there are easy horses to be found I don't want to miss the opportunity to let them run free. I'd like to be somewhere in the 300+ hp range without giving my std K03's too rough of a life. If I do find the turbos are not in as good shape as I think I will definitely replace them with something other than standard, probably K04's. I'm planning on making this a daily driver if all goes well.

I drove the A6 the roughly 80 miles home no problem (smooth shifting tiptronic, working AC and all) but I could tell it was in limp mode. Turns out it had a bad MAF that prevented it from really even trying. Once I disconnected it I found a boost leak in the wastegate control lines. Still have to fix that part but it will be easier once engine is out. It also has a bad ABS module, which from what I read, seems to be standard on that model.

The current status is that the engine is out of A4 and prep work has been done to get engine out of A6 (bumper etc. off, front in service position) but it is still drivable. Hoping to get the free time to take the engine out shortly, but free time is something I have very little of...

As part of the swap I'm planning to:

- Give engine a good cleaning
- Fix boost leak
- Do a complete timing belt including crank seals etc.
- New gaskets all around. Well, maybe not head gaskets. More on this below.
- Decide on which ECU tune I want to go with.
- Replace vacuum lines etc.
- Replace temp sensors in the back of the engine and associated o-rings etc.
- What other things are a must to replace once engine is out?

Exhaust
My goal is a car that sounds nice but not like a dragster or anger my neighbors too bad. Remember, I'm approaching 40.... So relatively standard until you step on it would be ideal. At least as a starting point I think I'll put something together with what I have. So I'm thinking stock 3.0 catback with piggie pipes, or is there a big difference between 3.0 and the B5 S4 catback? If so maybe I'll pick up an S4 exhaust.

Downpipes
I've read the other swap threads and there seems to be some conflicting information on downpipes. I like the idea to keep the main cats. My plan is to attempt to make piggies from my A6 tiptronic pipes but I haven't really looked at it close enough myself to determine if it is possible with some minor mods, cuts and welds. Has anyone tried what I'm planning to do (i.e. A6 tip pipes on B6 man)?

Engine Rebuild?
Now to my main dilemma. Well, it is not really a dilemma, just trying to decide which route to take. The 2.7t has 155k on it, but it seems sound and solid, no noises. Not smoking and turbos seems good as far as I can tell. Really the only bad things are oil and boost leaks. The question is what to do as part of swap.

Option 1: Do a compression test and if all appears well just move engine over (after replacing seals etc. as described above).

Option 2: Rebuild engine. Hone cylinders, replace rings, main bearings etc. and redo cylinder heads. This would basically give me a new engine that hopefully lasts a long time. I'd do it all myself besides the cylinder heads so it shouldn't get ridiculously expensive.

Option 3: Well, this is maybe when my mind is going a little crazy. If I'm going to do option 2.... I have two 3.0 cranks in the garage... A set of pistons and some cylinder boring would be the only difference to me having a 2.9l-3.0l which would be a good starting point if I'd ever get the urge for some real power. I see people use the 2.8 heads for this but I'd imagine the 2.7 would do fine, right? I'm sure no one had gone through the effort of building a stroker and not putting on big turbos but how much difference would the volume difference really do for performance? I understand there are many variables but does adding about 10% volume equal about 10% gain in hp and torque?

To cover some of the other aspects required for a swap

Clutch - Will my 3.0 clutch and flywheel work or do I need to get a B5 S4 clutch?

Wiring –I’ve done my homework studying Bentley wiring diagrams and I think I have this fairly well under control. I’m an electrical engineer and have had some email conversations with Clint already. I got the B6 3.0 male plugs off of a U-pull-it car so I didn’t have to cut up my harness. Plan on taking the C5 female sockets off of my A6.

Fueling – My A4 has a single supply line (no return) so I’ll have to modify that. Seems pretty straight forward.

SMIC’s – Plan is to move over the IC’s from A6.

Fan wiring – Haven’t decided which way I’m going to go but it seems pretty straight forward either way.

Well that's a start. I'm sure I will have many questions along the way. If I could figure out how to include pictures (maybe a newbie like me don't have the privileges?) I would have. I know those posts are more fun and informative to read :)

Cheers,
Henrik

[Steve Bassen]

If the compression test is good, just reseal the motor. Keep the K03's until they blow, then throw the flavor of the month China K04 based tubos on. The APB is good for 300k+ with good maintenance without ever cracking into it, and will hold together (with good tuning) fine with a typical K04 setup on stock rods. Building the longblock can add significant time and hidden costs to your swap (first hand experience).

[JB5]

I did what Steve Bassen mentioned.

Downpipe
Because of the tranny subframe, I was not able to use piggies, I cut my 3.0 downpipes and welded the bottom part to the turbo downpipe. this was on the cheap side, if using the A6 downpipe, you'll definitely need to mod it. my advice is go custom downpipes from a local exhaust shop, in the long run it's better.

Exhaust
Im using my 3.0 catback.

This is what I did on my swap. it came from a 2001 A6 APB at 125k (motor was sound and turbo had minimal shaft play): change valve cover gasket, rear main seal (wish i didn't do this part, if it's not leaking don't touch it), lower oil pan seal, timing belt kit, ignition coil conversion, 710n DV and JHM LWFW with RS4 clutch and PP.
I'm running stage 2 and engine wiring was done by Mr Clint. I'm sure eventually I could have gotten the wiring but I literally had no time to work on it and Clint already knows what he's doing, definitely worth it for me.

when my turbos go, I may still stay with K03s or depending of funds I may move to Franken turbos. if going with the later i will need to update IC and fueling, tho Im pretty happy with Stage 2.

so the advice is, if you just want to get it running, clean up the engine and do all the maintenance stuff, like VC, timing belt and such, maybe get some rebuilt K03s or use yours until they blow. you will definitely need to get the fuel return line off a junked B6 or new lines. I personally love the stage 2, it's plenty fast (it's the fastest car I've owned[built]).

[Heckas]

Thanks for your input Steve, much appreciated. Would your answer be the same if you assumed all machining etc. was free and all you had to pay was for parts? I have a friend that used to build Nascar engines for a living and still builds race car engines on the side. He's promised to help me out.

From what I've read the 2.7 is very solid though so since I'm not looking to increase output drastically I think you're right.

[Heckas]

JB5, nice to hear from someone that has been through it and appears to have had about the same goal as myself in mind.

Are you suggesting custom downpipe keeping the 3.0 (or 2.7?) main cats?

Is there any benefit to doing the ignition coil conversion at the same time as swap? It is all easily accessible with engine in car, right?

Is the 710n a common problem? (yes, I'm a newbie).

So did you replace your clutch because you wanted it to be able to handle more power or does the 3.0 not even fit? I'll likely go a similar route to what you did.

Thanks,
Henrik

[JB5]

JB5, nice to hear from someone that has been through it and appears to have had about the same goal as myself in mind.

Are you suggesting custom downpipe keeping the 3.0 (or 2.7?) main cats?

Is there any benefit to doing the ignition coil conversion at the same time as swap? It is all easily accessible with engine in car, right?

Is the 710n a common problem? (yes, I'm a newbie).

So did you replace your clutch because you wanted it to be able to handle more power or does the 3.0 not even fit? I'll likely go a similar route to what you did.

Thanks,
Henrik

The "custom" downpipe I did, I consider it a hack job that personally Im not too happy about, spent too much in my opition. SSAC turbo down, right where the 2" part begins, i welded that section down from the 3.0. then you have the clamps to connect to the rest of the exhaust. In total I think I spent way too much money, custom downpipe would have been better (what i mean by this is i would have preferred turbo down to exhaust done by an exhaust shop, not the hack job i did). On the good side, it works. I'm not suggesting this by any means, I'm running catless. later on I can add a pair of cats by cutting the downpipes.

It was an option i had, i prefer to work on the bench and do all the work that needed to be done. you can certainly do it once the motor is in the car too. it just gave me better access to route the cables the way i wanted them.

if you're doing stage 2 you need 710n. the stock part doesn't hold the pressure, at least is what I've found in the forums.

about the clutch, i got a good deal buying it used.
Does the 3.0 flywheel fit? yes
Does it hold the power? I don't know, no one has tried using it. all I know is that the bolt patter is the same. guys running 3.0 cranks use the same 2.7 flywheel. i don't know if the "tone ring" (i think it's called that way) around the flywheel is the same between 2.7 and 3.0. so i don't know if it will crank.

[Pr1ce]

Central floridaaaaaaaaaa

Can't wait to see the progression of this build and how it goes. When you're done I want a ride please

[7speed]

Nice, another local.

[7speed]

Nice, another local.

[Heckas]

I might be wrong but I think we've spoken on the phone 7speed. Did you have a white A4 3.0 with bag motor for sale as well as an A6 a little while ago? If so, I called you :) if it wasn't you there's someone else in your area with a modded avant similar to yours. As you can tell I ended picking up another A6.

I put Orlando in my profile since it more would know where that is. I really live in Lake Mary area.

Pr1ce, sure no problem!

Great to connect with some locals.

[fernandj]

I just finished this swap into a b6 S4. Word of advice plan everything out on paper, sort of a checklist. I am still ironing stuff out on the car, it is my daily but i have another car to drive in case it fails on me. The wiring can be a pain, but everything else is pretty easy surprisingly bolts right in. If you want a cheap flywheel check out rock auto, and if you want an rs4 clutch check out ebay some vendors from the UK have them. My a/c is still not working, along with the coolant fans and reverse lights, but everything else works great. Downpipes and the snub mount is the really only custom work needed to be done, i just got some SSAC downpipes and had a friend extend them. The forum practiaclly has all the information needed to do the swap just take time to read the massive threads.

[AudiA4_20T]

good luck! It's not too expensive just keep looking out for parts.

[Steve Bassen]

Thanks for your input Steve, much appreciated. Would your answer be the same if you assumed all machining etc. was free and all you had to pay was for parts? I have a friend that used to build Nascar engines for a living and still builds race car engines on the side. He's promised to help me out.

From what I've read the 2.7 is very solid though so since I'm not looking to increase output drastically I think you're right.

The actual shortblock build is fairly simple... it's the rest of the longblock assembly that takes a while, especially when you're adding that into the overall mess of the engine swap and wiring. It also adds a lot of other variables that can kick you in the balls after you think you're close to done. I.e., realizing your rear main seal flange is pissing coolant/water after you finally get to the point that you can fill the cooling system. If I could do this again (instead of getting RS6 hybrids and doing rods), I'd have just resealed a stock longblock and doing regular K04's or F21's.

[7speed]

I might be wrong but I think we've spoken on the phone 7speed. Did you have a white A4 3.0 with bag motor for sale as well as an A6 a little while ago? If so, I called you :) if it wasn't you there's someone else in your area with a modded avant similar to yours. As you can tell I ended picking up another A6.

I put Orlando in my profile since it more would know where that is. I really live in Lake Mary area.

Pr1ce, sure no problem!

Great to connect with some locals.

Yep, that was me. I sold it and moved onto the next one.

[JB5]

The actual shortblock build is fairly simple... it's the rest of the longblock assembly that takes a while, especially when you're adding that into the overall mess of the engine swap and wiring. It also adds a lot of other variables that can kick you in the balls after you think you're close to done. I.e., realizing your rear main seal flange is pissing coolant/water after you finally get to the point that you can fill the cooling system. If I could do this again (instead of getting RS6 hybrids and doing rods), I'd have just resealed a stock longblock and doing regular K04's or F21's.

I had to put down my Tranny after putting everything in because of the stupid RMS. This is the wisest advice I've read in the forums, "if it's not leaking, do not touch it....."

[Ephry73]

Used to live in Melbourne here. On my B6 conversion, the exhaust is a mismatch of parts. Finally decided to get correct piping and will eventually tackle a full 3' DP to 2.5" all the way back. For me its different, since I have an 01E trannny.

The 3.0 Mufflers are restrictive as hell, but they do the job. If you can find a decent pair of 2.5" straight through magnaflows, go for them. Spend the money on decent high flow 3" cats and build your system with them, or get the 3" Xs piping that comes with them. Once the motor is in the car the benefits will be cooler motor and better flow/spooling, which means better power and in my case almost 800 RPM drop.

As others have mentioned, if the motor specs out alright with the leak-down(a must really) leave it be. Do the timing belt and new AL water pump and clean it up. New motor mounts help, specially if you don't know the mileage of the current ones. The 2.7 is very much like a bigger 1.8t, so similar maintenance and oil etc...

Make sure you go over the cooling of the motor and plan it well(EFK, fan upgrades, sensors etc...) as these already run on the hot side from the factory and FL gets hot.

Any boost hoses that look long on the tooth, replace, or better yet, get a full hose kit and replace them all. Good clamps are a must for these motors as well.

[Heckas]

Thanks for the input Ephry73. I agree they do run on the hot side and especially in Florida I'd like the cooling to be overkill if anything. What fan upgrades are available? Or does the standard 3.0 fans do the job and just need to use switches that engages them a little earlier?

[Ephry73]

I was just told that the standard 3.0 fans should do the job correctly. The conversion is still new to me. I would love to find out if the fans with a lower threshold thermostat will be a good combo. I'm very tempted to do the thermostat swap, but will research further.

Perhaps even a better/ or new fan for peace of mind for the main fan will be the ultimate


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[GeneriX]

Im attempting the swap as well into my 02 a4. My engine was delivered last week but was damaged during shipment. Now i have to wait to resolve the damage issues with the company i purchased it from. I still have to decide on what i want to do with it as far as HP wise and keep it as a DD.

[Heckas]

Sounds like you and I are at the same stage, GeneriX. I finally got around to get the engine out of donor car. It is now sitting on the engine stand in my garage ready for a good cleaning, new gaskets, timing belt etc. This is when the fun begins!

As I got the engine out I found quite a bit of oil in drivers side intercooler. Early signs of turbo failure from what I read. I don't detect much play, maybe just the seals. But I'm now trying to decide myself where to set the bar power wise. Tempted to go with K04's but rebuilding my K03's is a quite a bit cheaper route.

So being that my donor car is tiptronic my ECU is an L-box (with Bosch MAF). Will it know what to do or be very unhappy mated to my a4 manual 01E transmission? Or do I need a new ECU? Maybe this can all be taken care of by buying the manual software version when chipping it?

If anyone needs a tiptronic transmission I have one for sale cheap. I don't know much about it but it shifted really smooth while I drove it home.

[Steve Bassen]

Whoever is doing your tune will just flash it with the appropriate base bin, whether that ends up being an A box or M box.

[fR3ZNO]

Exhaust
My goal is a car that sounds nice but not like a dragster or anger my neighbors too bad. Remember, I'm approaching 40.... So relatively standard until you step on it would be ideal. At least as a starting point I think I'll put something together with what I have. So I'm thinking stock 3.0 catback with piggie pipes, or is there a big difference between 3.0 and the B5 S4 catback? If so maybe I'll pick up an S4 exhaust.

I don't think this was answered, at least not directly.

B5 S4 has a single rear muffler, whereas the B6 has two rear mufflers for a dual exit exhaust. So the B5 S4 catback would not work. A B6 S4 catback is usually recommended, they're dirt cheap or free since people often upgrade the exhaust and have the stock one laying around.

Check out Clint's 2.7T swap thread, if you haven't already, tons of good info there. Clicky Click

[blitz2190]

if you plan on going with bigger turbos, or you think you might do yourself a favor and go with a 2.5" dual exhaust so you have room for upgrades. there are aftermarket b6 s4's that are 2.5 if you can find one used for a good deal that would be be the way to go.

[Steve Bassen]

Yeah, minimum of a stock S4 exhaust, but an aftermarket one would be preferred (one that's 2.5" all the way).

[bigab24]

Nice to see people from central Florida attempting the 2.7t swap. I am also originally from Europe and continue to carry that love for particularly Audis.

Yes I currently too have a A4 3.0 Quattro convertible but wish to swap it to a 2.7t yet I haven't found time for it.
Gonna keep an eye on this thread maybe we could potentially help each other out.

[Heckas]

Nice to see people from central Florida attempting the 2.7t swap. I am also originally from Europe and continue to carry that love for particularly Audis.

Yes I currently too have a A4 3.0 Quattro convertible but wish to swap it to a 2.7t yet I haven't found time for it.
Gonna keep an eye on this thread maybe we could potentially help each other out.

If you decide to stick with the 3.0 for a while I have some parts for you :) among other things a two engines and a complete timing belt kit.

[bigab24]

If you decide to stick with the 3.0 for a while I have some parts for you :) among other things a two engines and a complete timing belt kit.

That would be amazing! Car now has 170k miles on it, but there is no statement if the timing belt has ever been done. Also have I noticed that my variable intake/ vacuum lines aren't working resulting in sluggish low end torque and less optimal shifts.

Looking at your planned build I would not go with a stroker set-up. Rather rebuild the engine and get a tune. Depending on what your main purpose of this build is, I'd focus on handling prior to going K04 turbos.

[Heckas]

That would be amazing! Car now has 170k miles on it, but there is no statement if the timing belt has ever been done. Also have I noticed that my variable intake/ vacuum lines aren't working resulting in sluggish low end torque and less optimal shifts.

Looking at your planned build I would not go with a stroker set-up. Rather rebuild the engine and get a tune. Depending on what your main purpose of this build is, I'd focus on handling prior to going K04 turbos.

Bigab24, You've got a PM

[Heckas]

It has been a while since I updated this thread. They engine has now been cleaned up, has a new timing belt kit and valve cover gaskets from Blauparts. I discovered my engine already have 710n valves so no need to buy those. I picked up an M-box with ABT tune to have something to start out with. I figured I could use my L-box for tuning later.

I also picked up an AMD flywheel + clutch setup as well as the first half of used AWE 3" to 2.5" downpipes. I figured I only needed the first half since they will have to be modded anyway and they were cheap. A silicone hose kit (cheap eBay) is on its way.

I'm still debating whether to stick with my k03's or buying k04's. In some ways I'd like to make sure all swap related things works right with k03's. Also, for all I know my tranny could be bad since I've never driven the car. At the same time I'd prefer to not have to take the engine out later to install k04's if I didn't have to. If k04's and good clutch are already in the rest of tuning (fuel) can easily be done with engine in car.

Still to do is to before putting engine in is to seal up oil pan, replace vacuum hoses, fix aux water pump and install SAI delete brackets. The spider hose will also need some TLC. My boost leak turned out to be the wastegate control line by the way.

As far as the A4 I today went to junk yard and picked up an OEM fuel return line from engine bay to fuel filter joint. I didn't have enough time to take the 'lid' where it connects to tank. I also didn't know exactly what I needed since I hadn't looked at my car before going. So I might have to return. While I was there I passed by a Touareg and snagged the ignition coil adapter plates. I also removed the power steering line off of my A6 but have not installed it in the A4 yet.

Engine adapter harness is 80% complete and I have an idea of what I want to do for the fan control. I'm planning on using the FCM from A6 since it controls the aux pump also.

So I'm checking off the to-do list I have little by little. Would be nice to install engine over Christmas break but I doubt that will happen.

All for now.

[ADCS]

In my opinion, go with new turbos (K04 or whatever you decide on) right from the get go. Leave the stock tune and injectors for your first start that way it won't really be any difference from rebuilt KO3s. Once you get it fired up without issues/codes swap the injectors, load your tune and carry on. It would be a lot easier to add larger inlets with the engine out as well since they may need massaging.

You don't need the V6 fuel tank cover but it makes it more OEM. Most people just cap off the vent line on the 1.8t tank cap but I would get the V6 cap if you can. That way there will be one less potential leak point.

[Heckas]

In my opinion, go with new turbos (K04 or whatever you decide on) right from the get go. Leave the stock tune and injectors for your first start that way it won't really be any difference from rebuilt KO3s. Once you get it fired up without issues/codes swap the injectors, load your tune and carry on. It would be a lot easier to add larger inlets with the engine out as well since they may need massaging.

You don't need the V6 fuel tank cover but it makes it more OEM. Most people just cap off the vent line on the 1.8t tank cap but I would get the V6 cap if you can. That way there will be one less potential leak point.

Thanks ADCS. My car starts out as a 3.0 return less. Don't know if that affects the fuel tank cover answer. I would imaging they are the same between 1.8t and 3.0?

[ADCS]

Correct, your 3.0 return less fuel system has the tank cap with the extra vent that you will need to cap off when converting to the 2.7 return system. Or install a 3.0 return style fuel tank cap that doesn't have that vent port in the cap (what i did).

Edit: The cap you want is on the feed side of the tank (hatch on the passenger side). This is the side the returnless system (Quattro) has an extra vent line that you won't need.

[Ephry73]

Correct, your 3.0 return less fuel system has the tank cap with the extra vent that you will need to cap off when converting to the 2.7 return system. Or install a 3.0 return style fuel tank cap that doesn't have that vent port in the cap (what i did).

I believe I have this setup as well on my 3.0 concerted to 2.7


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[Heckas]

Correct, your 3.0 return less fuel system has the tank cap with the extra vent that you will need to cap off when converting to the 2.7 return system. Or install a 3.0 return style fuel tank cap that doesn't have that vent port in the cap (what i did).

Edit: The cap you want is on the feed side of the tank (hatch on the passenger side). This is the side the returnless system (Quattro) has an extra vent line that you won't need.

Do you happen to know what my c5 A6 fuel tank cap looks like? Would it be interchangeable with the B6? If so, I have what I need in my driveway already. I guess I could go look but it's dark so I figured I'd ask instead :)

[ADCS]

No I don't but browsing ECS tuning is great for checking things like that.

[Heckas]

So about 143 undocumented steps later I started my car up Wednesday night! Still some buttoning up to do but so far so good!!

[AudiA4_20T]

awesome

[Bob Marley]

Correct, your 3.0 return less fuel system has the tank cap with the extra vent that you will need to cap off when converting to the 2.7 return system. Or install a 3.0 return style fuel tank cap that doesn't have that vent port in the cap (what i did).

Edit: The cap you want is on the feed side of the tank (hatch on the passenger side). This is the side the returnless system (Quattro) has an extra vent line that you won't need.

Sorry to resurrect this... not familiar with an extra vent line... I went from 3.0 ReturnLESS to Return. Did I miss something?

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[blitz2190]

Only if you didn't swap the fuel tank cap with it. If you did no need to worry if not there is an unused port/line depending on if you left the vent line connected.