There are lots of mods for the R170 but none of them are cheap.
cant help much, as I'm unfamiliar with R170's, but this is very well written and helpful. As you mentioned, i'm not sure what his goal is (HP gains or visual gains, etc), but you're write up is great!Pretty much agree, but I guess the OP should define what is "cheap" in his mind.
Some almost free "mods" are: Put you car on a weight reduction diet: get rid of spare tire, tools and any air compressor (and all other junk clanking around in your trunk) and use AAA or similar if you get a flat. Not everyone will like not having a spare, but since SLK32's dont come with a spare tire.... Buy a 14 lb battery for about $80 and save another 30 lbs.
I have seen ecu tunes for the AMG 32 motor as low as $400 now, not sure on pricing for SLK230 tunes and if the OP would consider that "cheap." Same comment on pulley kits to spin the supercharger faster and make more boost, some might think the $/HP gained is good for a mod like that and some might think it isn't cheap.
Bilstein shocks can probably improve your handling quite a bit if you have the standard suspension for not much more than $100 per corner plus installation. Again, not sure if that fits the OP's definition.
Also, unless you have done it recently, change your air filter! Don't want to restart the debate on OEM paper vs K&N or Greens, but a dirty air filter on a forced induction engine will cause a noticable loss of power. Make sure you have a fresh clean air filter.
Most power chips that claim huge HP gains for everything from Toyota Corollas to 500+ HP exotics, are really resistors that are piggy-backed into existing wiring to "fool" your ECU into thinking your air intake charge is cooler than it actually is. This might give some HP boost if your air intake charge is so hot that your ECU would otherwise detune your engine temporarily to prevent detonation. Probably some safety margin on when the ECU wants to detune due to high intake temps, but I don't really think this is a great strategy for ongoing HP gains. And I doubt these chips produce the full HP and MPG gains claimed under most driving conditions.Thanks for the info SantaMonica! I'll look into those ideas
Question what about these Power Chips I see advertised... they supposedly add some 100HP and increase MPGs... are they for real?
good tires. makes a world of difference in handling =)
as for cheap mods on a older slk, refreshing the car would be key. new plugs, air filter, oil change , etc. make it run tip top. to actually produce power, there is no such thing as cheap.