So before I DO actually ask, it must be made clear that I'm a total noob when it comes to Audis. I like them, but I just got my first one almost 2 months ago. I've got a B6 3.0 Quattro A/T. My question is simple to ask. How come the chosen route to go for forced induction is a supercharger? Why not a single turbo or TT? I've done endless hours of research and so far the closest thing I've come to is some obscure page with a 3.0 B6 TT that looks nice, but lacks some performance vids. Suspicious to say the least... Found another post about a possible TT setup, but that person was using a 2001 s4 motor, he was having it bored out to 3L's. Doesn't help me. I've seen that the earlier A6's have TT on them, but I haven't been to find an engine designation list to see if that's the same motor that's in the B6 3L's. I'm aware that there's almost no aftermarket support for the V6 versions and that room in the engine bay might be an issue, but I keep coming back to the late 90's early 2000's A6's. Is there a place I can find forged internals for my block? I'm sure I can come across a turbo or two. Will the work be ALL custom? Is it possible that the price of this project has made people choose not to take on this kind of project? I've been into cars since before I could drive, I've seen the craziest mods ever. This one has to be possible. Another possibility that just kinda popped in my head one day was actually using a 4.2 from an B7 S4. I understand that's a HUGE engine, but the S4 seems pretty small to be holding a V8. I'll be in Germany in about 5 months and there are most likely many more options, but for now I just want to pick everyone's brains and see what all of you can come with. Also, the only version I could find at a decent price for the car I have was A/T... I hate automatics... Can a manual trans. be directly swapped? Obviously I'd have to install a clutch pedal and such and rework the gear selector to accommodate the manual version, but will there be any issues mating it to the block? Sorry for the novel, but all these questions have been bugging the hell out of me, and I haven't been able to find the answers I need. Thanks in advance.

 

The A6 that used a twin turbo V6 had the same engine as the B5 S4, the 2.7TT. Stock, it's good for 250HP. (3.0 non-turbo is 220HP.) You could, in theory, go single or twin turbo on the 3.0 V6, but as you speculated, it would be all custom, and therefore VERY expensive. Most likely you'd need custom pistons to lower the compression ratio, probably custom engine management software, and I'm sure tons of other stuff I don't even know about. It's *probably* cheaper to swap in a 2.7TT, especially given that you'd be able to sell the 3.0 V6 to offset some of the cost. Also, the 2.7TT motor, given the right (well known, readily available) mods, can make BIG power. The supercharger route, given that it doesn't require an engine swap and is a pre-developed solution, is probably the cheapest option.

The B6 S4 and B7 S4 should have the same size engine bay as your B6 A4, so theoretically either of their V8s should fit, but that's probably a VERY expensive swap. You might also want to source an S4 transmission in order to safely handle the additional power. Of course, with enough money, just about anything can be done, but in that scenario, you really have to ask yourself if it'd be a better deal, given the S4's bigger brakes, better suspension, etc, whether it'd be more cost-effective to just sell the A4 and buy an S4.

As far as the manual swap goes, a lot of people would probably tell you that it'd have been better to just buy a car with a manual in the first place, but it can and has been done. There are several people over on audizine that have done it - I'd do a quick search over there for their threads documenting the process if I were you.

I think your best course of action would be to carefully assess which options appeal to you the most, research their cost (and then add some extra $$$ for labor and the random crap that will go wrong), and then compare that to the cost of selling your car and buying an S4.

Hopefully that helps...

 

That makes sense, except for one little drawback... I've seen the back seats on the B5 S4... not gonna happen. The mrs. wants children someday, I'm not trying to make a track or a show car, but I can't have a car and not do something to show that it's mine, and it's unique. I'll be sure to update this site with anything I decide upon, but I really want to stay in the A4 camp. Thanks for the info, it really helped me out.

 

Happy to help.

A4 and S4 have the same back seat, unless I'm horribly mistaken (S4 is basically a factory hod rod A4 - more power, better suspension & brakes, etc), but perhaps I didn't clearly state my train of thought - I was suggesting that you look at a B6 or B7 S4, not a B5.

Also, I'm 6 feet tall and I fit in the back seat of an A4/S4 just fine (B5 or B6, haven't sat in a B7), so I really don't see what the issue is.

For that matter, though, why do people always think you need a gigantic back seat for kids? Kids come sized for small seats. You won't need a big back seat until they hit puberty and really start to grow. You can have a car with a tiny back seat for the next 10 years, even if your wife gives birth tomorrow!

 

The other big reason for a supercharger is relative ease of installation. It requires only service position. Fitting turbos and manifold would require an engine pull...