Debating an s6 4.2L swap...

[JumboBlack1.8]

Yup. Straight from Greg. Each set will be made to order

[kaploww]

Yup the 99.5 had an AEB, which was DBC. Early 2000's also had the AEB which was DBC. The ATW engine is essentially a DBW AEB, then late 2000 had the AWM which was the 06A block and DBW.

If you install the appropriate wiriing DBC/DBW doesn't matter, however it's much easier to start with a DBW car and use a DBW engine.

All 40V v8's were DBW and it's impossible to convert them to DBC unless you go standalone, which adds $3-$4K to your build.

If you want a DBC engine then look for a 32V engine from an A8.

Definitely not impossible.

You just have two throttle bodies.

One doing the engine air management, the DBC TB.

And one sitting in the engine bay satisfying the ECU doing nothing, tucked away somewhere so it doesnt look like ass, and moving like the ECU tells it to.

[Scotty@Advanced]

Definitely not impossible.
You just have two throttle bodies.
One doing the engine air management, the DBC TB.
And one sitting in the engine bay satisfying the ECU doing nothing, tucked away somewhere so it doesnt look like ass, and moving like the ECU tells it to.

That doesn't sound like it would work too well. but it's worth a try.

[Mad Cow]

Definitely not impossible.

You just have two throttle bodies.

One doing the engine air management, the DBC TB.

And one sitting in the engine bay satisfying the ECU doing nothing, tucked away somewhere so it doesnt look like ass, and moving like the ECU tells it to.

The problem with that is the 32v tune would be different than the 40v tune, sure it would probably work but it's far from ideal.

EDIT: I misunderstood, for some reason I thought you were talking about a 32v ECU with a 40v motor. The problem I see with that method is you'll still get an error code for missing the throttle, which will likely put the ECU into limp mode. The electronics in these cars are complicated to the point where hack jobs and workarounds just aren't feasible because so much can go wrong.

[revolution337]

Did you get up getting that S8 engine jumbo, or are you still searching?

[JumboBlack1.8]

Not yet.....I was banking on getting one locally, but the guy's shop is swamped....so I haven't been able to swing up there to get it. At the moment, I'm focusing on getting a decent daily driver for my move down to CT. I think I'm going to take my time with this swap, get a low-ish mileage engine (at a reasonable price, if possible), and really get this thing installed without a hard deadline looming over my head.

It was unrealistic to think I could have gotten this done in 3 weeks.

On a positive note, I might be picking up an '05 1.8T 6spd w/ K04 and a bunch of other goods....only has a few needs.....slow, but it'll be a nice daily. Should be picking it up next week

[JumboBlack1.8]

Got some stuff done over the last few days.....

FINALLY installed some S4 skirts




and finally got this little pea shooter yanked out


Heartless B5...


Lastly.....upon visual inspection, it looks like I MAY run into a problem with the driver's side downpipe with the v8 motor. The passenger side has plenty of clearance, but the driver's side trans mount is definitely in the way...



Does anyone recall seeing any info in the other build threads about potentially switching the driver's side trans mount to a B5 2.8L mount?


Also, if anyone out there is interested in buying my stroker motor, PM me. I'm trying to sell it locally first tho

[biketsai]

If it comes down to it, you may have to swap your subframe to the 2.8L or automatic one. In my car, since it was originally auto, my drivers side is the 2.8 one.

[Capt. Obvious]

Your best bet is probably to get an S4 subframe. Not sure if they differ from a 2.8 subframe or not, so it might not matter.

[JumboBlack1.8]

Hmmm.....I'll continue to do some more research to see if there's a way around getting a new subframe.....I would rather not uninstall it.

[Capt. Obvious]

The subframe is probably fine, you'll want a tranny brace (or whatever it's called) from a V6 model though since they have two humps in them for the downpipes to go through.

[JumboBlack1.8]

Just did some more research......you're definitely right. I'll need either the drivetrain stabilizer brace, or an S4 or V6 subframe.......I THINK i may go the subframe route......Just ONE more thing I've gotta buy and install....damn

[revolution337]

It looks like when kaploww (I think that is his username) did the swap he used an AWE drivetrain stabilizer bar as the transmission mount. Not sure if he just completely eliminated the drivers side mount then or what.

[JumboBlack1.8]

I think that's what everyone who started out with a 1.8T has done.....I just don't feel comfortable eliminating the driver's side mount altogether. I'm looking into locating a V6 subframe and upper trans bracket locally

[revolution337]

I'd rather not have to modify/swap out my current subframe if at all possible. I wonder how stable the trans would be with just the stabilizer bar and the passenger side mount.

[JumboBlack1.8]

A subframe swap is easy. I'm not too worried about it anymore, especially now that the motor is out. Here's the Bentley DIY
http://www.dj-sures.com/GraphicFiles...%20install.pdf

[revolution337]

Just so I'm clear, what exactly is the difference between the two subframes? If you use a 2.8 you can run both PS and DS trans mounts?

[JumboBlack1.8]

Exactly....The 1.8T subframe and trans mounts only leave room for a downpipe on the PS. The 2.8/s4 subframe will allow proper spacing for both downpipes. .....Hopefully everything will go together without a hitch

[revolution337]

I see. Another topic, I'm not exactly sure what flywheel I can use for this swap. Obviously I need something that will allow the trigger wheel to line up correctly with the sensor, as well has have the 8 bolt pattern. And whats the deal with the trans spacer? When is this necessary? I'm getting some mixed signals as to if this is needed or not.

edit: pilot bearing? I haven't figured out what to do there yet either. The more I dive into this project, the more I realize how much work this is going to require lol

[JumboBlack1.8]

Yea, it's certainly not nearly as easy as I was anticipating, but fortunately, I'm picking up a DD next week, so this project will be done at a more reasonable pace. As for the flywheel, I got a spec b5 S4 LWFW, because it was available at a great price. If it doesn't work, I'll get rid of it. But, from what I understand, the transmission spacer will aid in getting the trigger wheel to line up properly......There are definitely a few things that I need to iron out as well

[SeekB00st]

I see your running a AME tru boost controller.

[JumboBlack1.8]

I was......ya want it? $225 shipped

[walky_talky20]

Just to add some more info (or confusion) to the subframe issue, I'll add that (AFAIK) all B5 subframes are effectively the same, other than 1.8T *5-speed* subframes. So a 1.8T automatic, or V6 automatic, or V6 5-speed, or any B5 S4 subframe would work to fix your issue there. The only one that *won't* work (and requires that chunky mount) is the 1.8T 5-speed subframe, which happens to be the one you have.

[JumboBlack1.8]

Yea.....working on hunting down one that is V8 friendly....Thanks for the info

[beemercer]

once you get going if you want a hand with some work lemme know, I could stop by some weekend day and help out. I'm actually starting to consider doing this swap as well, my A6is too big to be fun but I love the 4.2/S8 cams/S8 IM/LWCP/LWFW stg4 clutch/longtube headers powerplant. I think in a gutted out B5 it could be some good fun.

[JumboBlack1.8]

Yea, I cannot WAIT to get this done.....it think the B5 chassis will be a great match for a S8 powerplant.....Once I get rolling on this, I may be shooting you a PM.....However, I have no timetable for when that might be....Will keep all of you posted

[kaploww]

as far as mounts go. I have eliminated both trans mounts, and will be running the DTS bar as transmission support. In addition to that, I installed a set of stern mounts. Between the near solid engine mounts, and the beefy stabilizer bar, I'm not even worried about it. those components are so strong. If the drivers side transmount still fits when all is said and done, I migh pop it back in, but as if now. Im not worried about it.

[ZimbutheMonkey]

Wow, good on 'ya for pulling the trigger. Best of luck, I'll be watching.

PS: subframe is easy to pull with the motor out. My guess is that you'll be changing out the uprights anyway, so it's not much more work at all.

[JumboBlack1.8]

The parts are starting to pour in!

For those that're interested, here's what I've got so far:

C5 A6 4.2 upper motor mount brackets (including oil cooler)
Stern C5 Motor Mounts
B5 S4 Transmission spacer
Dual 12" push radiator fans
SPAL 185-degree Harness
A6 4.2 Coolant Expansion tank
SPEC LWFW for B5 S4
034 SAI Blockoff plate
2.5" Milltek Downpipes (currently being made)
Other misc. items needed for the swap

NEED to buy:
S4 front subframe
S4 DS trans mount and upper bracket
Flywheel bolts
That's it so far.....still searching for a set of a6 4.2 lower motor mount brackets....I THOUGHT I'd located a set (through a supplier known here on AZ), but my payment was just refunded earlier today, and I've received no explanation for it.....SO, the hunt resumes......I'm buying a daily within the next few days, so I'm not in a huge rush to get this done. Hopefully my patience will pay off.

And, for my exhaust....I THINK I'm gonna try to mate the downpipes to a 2.5" B5 S4 true dual exhaust (I think techtonics and milltek make a 2.5" version....but they're rare).

And, lastly.....I'm regrettably STILL looking for an engine. I thought I had one locally, but I have yet to hear back from that shop, as they are constantly swamped with work, and they haven't gotten around to returning my phone calls or responding to my emails. SO, I'm moving on for now......

I'll post more updates as I continue to compile parts and install stuff


*EDIT*
Torn between which of these two cars to choose for my new daily:

Stock-ish IMOLA B5 S4 w/ alcantara, euro S4 rear, and oem RS4 front ** no extensive records, clean cosmetically, recent(ish) T-belt and turbo replacement
http://www.audizine.com/classifieds/...dy-mods&cat=67




or an '05 B6 1.8T 6sp w/ K04, RNS-E, and a bunch of other mods ** good mechanical shape, full maintenance history, but somewhat rough cosmetic shape




I'm leaning more towards the B6......but that Imola is hard to pass up.....I'm gonna be test driving both this weekend.

[Capt. Obvious]

Having had both a 1.8T B6 and an Imola B5, that's a tough decision.

The interior on the B6s are nicer and they're a bit larger/more luxurious feeling, and the 1.8T tends to be lower maintenance. However, 2.7Ts are just plain fun to drive, but they're a bit of a pain in the ass to work on.

Between those two specific cars there, I think I'd go with the B6.

[ColinAndrews]

I'll second the B6 with a 1.8T as a daily. The torque of the 2.7T is fun, but working on it sucks. The 1.8T with a K04 will still be plenty of fun on a daily basis and A LOT nicer to sit in.

[JumboBlack1.8]

Yea, I'm leaning more towards the B6 as well....I know the engines inside and out, so it'd be an easy fix, if need be.

I was just drawn to the B5 cuz it just looks so damn good....and I'd keep the bumpers for THIS b5.....But, I'd hate to have to work on the 2.7 when any problems pop up

[biketsai]

1.8t w/k04 and bigger interior seems like DD material to me.

[revolution337]

You have a link to the fans/harness that you're using? I'm still browsing around for electric fans and haven't decided on a brand yet.

[JumboBlack1.8]

I got some Champion Cooling 12" radiator fans on Ebay. I was originally looking for SPAL fans only, but I couldn't find a set of 12" fans at the time. I found some good reviews on them, and they have a pretty high flow rating. From what I've seen, they appear to be pretty good quality. Not flimsy or cheap at all. And comes with a full money-back guarantee!
http://www.ebay.com/itm/200660850548...84.m1439.l2649

As for the harness, I got this:
http://www.ebay.com/itm/200662473537...84.m1423.l2649

It's for one single fan. I'm thinking I may always run one fan (like a viscous fan) and use the other to kick in at higher temps (i.e. the stock auxilary fan).....still not sure

[JumboBlack1.8]

Btw, here's the mod list on the B6......think I'm def gonna go with this, if the test drive goes well

KO4 turbo giac x+ tune, tt 225 injectors
Forge 007 Diverter Valve
Custom FMIC
H-sport front and rear sway bars.
Koni sport shocks
H&R sport springs
B5 s4 engine mounts
Stern Solid trans mount.
Stainless Steel Brake Lines
B5 S4 Front Brakes, with Hawk Hps Pads
CM FX300 240mm Clutch Kit
034 motorsports high flow cat.
Auto Speed USA 2.5in stainless catback
JHM short shift kit
OEM RNS-E
raw carbon fiber interior trim
OEM V10 R8 oil and coolant caps.
OEM ECODE Xenon HID's
Diesel Geek Skid Plate

[revolution337]

Will you be able to fit 2 12" fans on the radiator? From my (rough, mind you) measurements I found that dual 12" fans won't fit, so I was planning on running dual 10"

[JumboBlack1.8]

Will let you know by the weekend. I thought I'd read somewhere that dual 12s would fit. If not, I'll go with 10s

[Crispy222]

I got some Champion Cooling 12" radiator fans on Ebay. I was originally looking for SPAL fans only, but I couldn't find a set of 12" fans at the time. I found some good reviews on them, and they have a pretty high flow rating. From what I've seen, they appear to be pretty good quality. Not flimsy or cheap at all. And comes with a full money-back guarantee!
http://www.ebay.com/itm/200660850548...84.m1439.l2649

As for the harness, I got this:
http://www.ebay.com/itm/200662473537...84.m1423.l2649

It's for one single fan. I'm thinking I may always run one fan (like a viscous fan) and use the other to kick in at higher temps (i.e. the stock auxilary fan).....still not sure

I have one of these as my main cooling fan for my 1.8T. I deleted the clutch fan. I can't comment on life, but I've had no problems with it for almost 8k miles. (mostly highway 70mph+)

If you stagger the fans, you should be able to fit two 12".

[JumboBlack1.8]

How do you have that wired up?