For my next car i am considering an B5 A4, B5 S4, B6 A4, or B6 S4. All are avant, quattro, manual. Which one of these engines would be the most realiable DD while still making 400chp? All I am trying to determine which would require the least maint. and least likely to fail. Obviously there would be other supporting mods (clutch, tranny, suspension, brakes) but I am only concerned with the engines at this point.

 

As far as A4's go id get the B6 just because its newer, i am assuming your talking the turbo 4cylinder if you want 400chp. youll need a turbo kit though

A B6 S4 is only going to make over 400 crank HP with a supercharger or nitrous. exhaust and a chip will make it a little perkier than stock while still being very relyable, gas is just expensive because mpg's suck

A Stage 3 B5 S4 would make 400 crank HP on ultra low boost, much more if you set it up good. Replacing the turbos takes away the main failure point on an S4. If you do the preventitive maintaince at the same time you wont have as many problems. OTS kit $5500 + clutch + intercooler and your really all set. Manual transmissions on B5's are a pain in the *** and will probably need to be rebuilt eventually

In conclusion B6 s4 wont make the HP you want without an additional $11,000 (not that bad), and I prefer the 2.7 in the S4 to the A4 because it has more cylinders and a larger displacemnt than the A4, twin turbos running less boost compared to a single large turbo running a higher boost.

 

HP Addict summed it up, there isn't much more that can be said. While they do have their share of maintenance issues, the B5 S4 will easily produce (and exceed) your power requirements for the best price. Once you swap turbos (which will be necessary for 400chp) most other maintenance issues are related to other crap like control arms, 1-2 tranny synchros and some other smaller issues.

 

to be honest the JHM transmission rebuild is only a little over $1000 and comes with a great step by step DVD and will solve the transmission issues, and when your going stage 3 you can get a complete front suspension kit for under $500

As long as you make sure the car it sorted it should be plenty reliable, and with new turbos and the transmission rebuilt its better than a stock S4! I had a 2000 Saab 95 that left me stranded everywhere, some people would say a stage 2 S4 isnt relyable but mine starts every day and has never broken down.

 

B5 S4's are the most relibable cars ever made

B6 you could also easily get 400 hp aswell but its going to cost quite a bit more from what i have seen even for just full exhaust, intake and chip your looking at more then getting 400hp out of a B5 its nice to drive a v8 though haha

 

Chip, intake, and exhaust isnt going to net you 60 crank hp in a B6 or B7. Its just not gonna happen. You need a supercharger or Nitrous.

A B5 might be around 400 crank as stage 3 minus... but figureing about 25% driveline loss with AWD that like 300HP at the wheels and i have NEVER seen a stage 2 put that down.