I have a 2006 325i, U.S. model. I am considering some minor performace upgrades. I talked to a BMW mechanic who works at a dealership, who told me I could upgrade the DISA valve with one from a 328i and have the computer reflashed. I was thinknig of doing this and installing a REMUS exhaust system and then perhaps having the car dynoed. What say you?
Without being familiar with the specifics of what expectations might be had from a disa-swap, I don't know that whatever bump in hp/torque you'd get from those mods would justify the expense of a dyno run. Whatever might be done that's 'easy' (vs. something like an engine teardown and performance rebuild) might slightly improve the butt-dyno response/fun-to-drive factor incrementally, but in the overall scope, probably not add up to really big numbers. If you want big hp numbers over stock, it'll take big mods, and big money. On the other hand, a dyno test isn't all that expensive, if you find it helpful to know you have 5, 10, 15, or 20 hp over whatever you should have had coming out of the factory, go for it. You'll avoid disappointment with realistic expectation over high hopes (picture yourself saying "I spent all this money and I only got what?!?!"). Rather than just throw money at the car with a general goal in mind, get specific about what you want or would hope to accomplish and why. Then formulate a well-researched plan how best to achieve what you want. Might save disappointment and money in the long run, or help to keep you from chasing an elusive and unspecific goal. Good to ask questions here and elsewhere, I certainly wouldn't throw money at something based on one person's opinion.
good point I hear what you're saying. I don't really want to throw a lot of money into the car, but I think it would be just a little quicker with say another 20-30 horsepower. Overall I am pretty happy with the car and realize that no matter what I do to the car or drive, I can never go faster than the car in front of me. I have also seen some cars that were so modified, I don't think they are really BMWs anymore. I really don't want that. I want the car to stay as close as possible as what it was. But I have seen some earlier model M3's that have around 250 hp which seem to run pretty good. Well thanks for your advice, I will continue to reseach and see what I can come up with. No matter what, my 325 is a really fine car and one of a few that is well optioned with a manual transmission. Jared
not that expensive either... The DISA valve is not that expensive... but could gain you some performance, but then again might not. Remember it is basically a intake port/run tuning device and gives a broader torque curve than without it. Even playing with the one you have via the software might get you a similar improvement. These things are pretty failure prone (at least on the e46) and should be checked regularly to make sure the butterfly valve is not loose. My son just replaced one on his e46 last week and I need to check the one in my wife's e46 because it is suspect.
