While all those mods would logically seem to be easy and highly effective, it will not necessarily be so. Why? Well, first of all, the downpipe minuses:
1. cost (I sold a brand new one w/gasket for $120; most sell for far more)
2. Doing away with the cat *will* give you driveability issues
3. They almost *always* leak and require rework (more $$)
4. Alignment problems are almost guaranteed. (more $$, time)

Exhaust minuses:
1. cost (anywhere from $600 to $1600)
2. again, going cat less will result in CEL's and other driveability issues
3. Noise, any high flowing exhaust will make more noise than the stock exhaust
4. Possible vibration and drone at certain RPMs
5. Leaks again, more $$ and time

Now, both of these will definitely cause warranty issues if you have problems. At the very least you'll have to replace the stock units and then they'll know (believe me, they will know) that the exhaust has been altered and could refuse warranty coverage.

More importantly, the power gains from *just* adding these mods will most likely be miniscule. Regardless of what some folks claim, the bigger exhaust diameters will cause some sort of low end losses. Without a lot more work of tuning the car for fuel delivery and ignition timing, these modes are almost useless and could actually make losses of power under some conditions. The big kicker here is that the changes required to the ECU are not so easy to accomplish. For instance, those piggyback *chips* and other fuel or ignition signal modifiers are very difficult to adjust properly even with the use of a dyno and expert help. The reason is that the stock ECU will detect all the efforts of the piggy back devices and will reset all values to try to stay within the OEM parameters.

Now, some folks have achieved very impressive results by modifying their cars, but I believe that even the best tuners deal with driveability issues all the time but choose to ignore them or minimize them because that's the price to pay for great performance. Before I get lambasted for ignoring the replacement ECUs, just do some reading of the various threads that folks maintain just to discuss issues of driveability, reliability and tuning of all the various aftermarket ECUs.

I already went through a lot of time and money with my WRX. While I did realize some gains of power and performance, I must admit in retrospect that I spent a lot of money and time for very small results. My WRX cost me about $25K I spent probably in the order of $4K -$5K in parts and labor (that includes putting it back to stock as well). Did I get my moneys worth?? I think that's very debatable, while I enjoyed messing with the car and all, I did have a number of driveability issues to contend with, spent lots of $$ and the actual perf gains were very small. Compared with the $30K for my new EVO8 (or wait and get the new STi) the modified WRX was never even close. For performance, the only really (cost) effective mods to the WRX are good tires (the OEM suck) and drivers' school for the owner

Just my $.02

 

First of all, I apologize for highjacking the thread.... It was about FMIC comparos..... Anyway, allow me to explain myself a little more. I'm not opposed to modifying a car per se. I was only commenting on my experience and my feeling about the issue based on what I did.

I think that for me and many other people any type of CELs or backfires, vibrations, bad smells (for at least a while) or excessive noise will constitute driveability issues. Of course, for a number of folks those are not important issues at all, they are willing to ignore or minimize these problems because of their enthusiasm over the hobby.

The really hard issues to ignore are the excessive fuel consumption, hesitation, missfires and sometimes the car will run like crap in limp lode or ever fail to start! These are real, actual issues that've come up with me and a number of other guys that I know with their WRXs (and other cars as well).

As far as warranty issues go, it would be totally disingenuos to say that modifying the car will have no repercussions with warranty work. It's been my experience and that of many others who write to lots of car forums, that the majority of dealers and SOA (as well as other manufacturers) will do all they can to avoid paying for anything that they can. Any modication to the car will give them that excuse. Sure, you might in the end win the fight, but is the hassle really worrth it? Besides, most times they will win and you'll be stuck with the cost of the repairs.

Now, I'm fully aware that the above problems can be dealt with by the tuner. I also have read of many guys who are completely happy with all their mods. Still, it is very likely that for the average joe out there, the minuses will outweight the plusses when looked at disspassionately and objectively.

As far as bang for the buck, I still say the gains are miniscule for the effort and money spent. Specially in a car like the WRX. Please take a look at my website and see what I've done to some of my cars. www.tango-rio.com/evo8-1.htm Be sure to look at the links to WRX and Miatas. Another car (perhaps the fastest one) is not there. It was my Integra GSR to which I added a supercharger, all kinds of headers, exhaust, etc. Plus complete suspension upgrade including springs, coil overs, adj. shocks alignment and upgraded susp bushings, engine mounts, etc.
Anyway, I'm not trying to brag or anything like that, but I want peeps to know that I'm talking from experience and not from magazine articles, hype or marketing and advertising materials.

Peace,

Manuel