sc vs turbo: beating a dead horse? [Archive] - Bimmerfest - BMW Forums

: sc vs turbo: beating a dead horse?

02-16-2008, 10:12 AM
OK guys I know this has been discussed before many times, but this isn't just a general "what's better" question. Because of circumstances I won't go into (f-ing Norwegian govt.) I am going to be selling my 335 and I want to get an e36 M3 and go the forced induction route. I am now completely addicted to force inducted power and I don't see how i can ever go back again :D

I have narrowed down the FI options on the S50 to a twin screw supercharger or a single turbo setup, but I am having trouble figuring out what would be the best for what I am looking to get out of the motor. Coming from the 335, I am used to nearly lag free performance. There are situations where you notice a little lag, but the way the car pulls from below 2000rpm is unbelievable. I would like the FI S50 to have a similar torque curve, and I really don't want much more lag than I have to deal with now on the 335. The FI S50 I have planned will see the majority of it's duty on the street with the ocassional track outing, but definitly more street oriented. This car will also see a lot of rainy days and even some snow. My plan is to run around 8-10psi and get roughly 330whp and 350wtq. That being said, what do you guys think is the best solution?

My pros and cons list:

TS supercharger pros (compared to tubo)- great low end power, instant throttle response, insane sound, linear power delivery, decreased chance of detonation (although I will not be in a hot climate so...)
cons- fuel economy suffers, more required maint, insane sound (remember this is a daily driver)

Turbo pros- more torque, better efficiency, less maint., more sublte sound, and power band can be tweaked more
cons- lag!, throttle sensitivity suffers, higher chance of knocking, boost spikes (remember this car will see a lot of rainy days and I don't want to be climbing out of ditches all the time)

I feel I'm really close to making a decision, just wanted some expert advice. See my only FI experience is the 335, and while I am leaning towards a turbo system, I am afraid I will be dissapointed with the lag and low end power of an aftermarket system. What does the power delivery of the good turbo systems like AA, TT, HPF ect. feel like? Is it nothing until 3000and then a rush? And what about a twin screw, is the low end power and linear delivery really worth the decreased economy and more maint? As you can see guys I am torn here...and the more I research the more I realize how incredible the 335 is, but I just can't keep her, so I want the next best thing. If anyone with experience on this subject could give me some input, it would be much appreciated.

Thanks fellas,