Stock B7 (new S4 off the lot) vs. a stock Z, the S would win by a bit. But who cares about straitline speed? With the S your getting a far superior overall car. Just as fast as the Z, wonderful handling in the corners, good looking car, practical 4 door sedan, so far a very reliable V8 (excluding early build date B6ers). For me the switch to the S4 would be a nobrainer. I may be biased considering i drive an S, but i have riden (not a word) in a friends Z and wasnt too impressesd.

 

If start line performance is all you care about an Evolution is a better bet. Mods are cheaper and typically produce more hp gains. S4's do offer more luxury, refinement, and etc however. Like Sooks said there are several S4's running in the 11's, many of them full interior daily drivers. There is even one (like Sooks mentioned) that is running low 11s/high 10s with a standard stage 3 set-up and weight reduction.


as for comparision to a 350Z...a B5 S4 (2000-2002 bi-turbo) will typically be faster with a simple software upgrade. The B6/B7 S4 (2004+ with V8) are similar to a stage 2 B5 S4 (software upgrade and exhaust). However the cars are apples and oranges....350Z are a two-seat sports car, the S4 is a performance sedan. While the S4's are (or can be) faster, the 350Z seems like it would be more fun to drive.

 

If it helps.. I sold my 03 6sp Track Edition Z for a stock Tip 01.5 S4. The Z was fun, handled great, but the ride was harsh and it was much less practical in CT. I had to have a winter vehicle which meant 2 insurances, car payments, etc. I was worried the change would be depressing but I would do it again in a heartbeat! I love the S4... it's a different animal...much smoother across the board. Very refined interior, classier exterior, and overall feel is just better quality (paint, amentities, rattles..etc). Love the AWD and extra two passenger capability.

S4 all the way! Can't imagine how I'd feel once I added a few mods to this car!

Best of luck...holler if you have any questions.

Mike

 

if you go with a B6/B7 S4 you get that amazing exhaust note as while. Not to mention the best interior out of all of them.