I use an EAT chip in my 95 540i and love it. It is by far the cheapest power upgrade you can do. Johan
I have the Dinan tune which is just enough power/torque for me, however there are plenty of other options (most of which you can find on e90post). Dinan and GIAC are 2 of the ECU flashes, while the piggybacks include JuiceBox (JB+, etc), Procede, SSTT, and others. I had a Procede when it first came out and it was kind of a hassle to install/remove; however, its a lot easier now with the plug-and-play harnesses (although still not totally plug-and-play). If I had to do it all over again, I would have upgrade to the latest Procede since it has so much more tune-ability (is that a word?) with different maps that can be changed on the fly.
Get the Dinan Stage II software, nothing else comes close IMO. Not to mention not having to worry about the warranty conflicts. BMW can ID cars that have had piggyback/plug and play/software applications installed very easily now. They will know that you have or had something installed, and if it's not Dinan then it could be a PITA to get some things covered under warranty if there's ever an issue. Believe me, it is a big priority at BMW to be able to ID these cars as they really don't know what the future will hold reliability wise in the long term. Say you buy a 335 with 60k miles on it from an private owner, no CPO warranty on the car. Then the turbo fails and you call BMW screaming fire stating this is BS and should be covered under warranty. BMW then scans the car and finds that the original owner was running aftermarket software/piggyback unit. You just bought yourself a turbo and assurance that you will not get any warranty love at all regarless of the problem. They have numerous ways to tell what was installed in the car, how it was being told to run, and how it was being driven. Don't believe the venders that state "undectable" by dealers. They lie/don't know any better.
KaBOOM! You can do what you want and I am a Dinan dealer so I may be biased but do you really want to trust your engine to the cheapest software? These software add-ons have the capability to overboost and cause engine failure. In our area several 335's and 135's have had engines replaced that have piggy-back and re-flashed computers. SOME have been covered under warranty and SOME have not, if you know what I mean. If you can't afford the Dinan, I'd leave it alone. If you can the stage II or III package with the exhaust will rock your world for sure. Enjoy,
While I agree that BMW wants to know if a piggyback was used, they can't always tell. There are tools/equipment out there that can clear codes and any evidence of a piggyback.
merci thanks everyone for informed opinions---going to go with the Dinan upgrade, so as not to worry about the warranty, and sleep at night...
there is a the bt scan tool you can get to clear the codes the new chips are much better than they were before i like the dinan stage 2 and giac stage 1 but no matter what you get remember more boost means more heat so it will be a good idea to get supporting mods fmic oil cooler etc
The last time I had my M3 at our local dealer, just for kicks I asked them to see if their computer could detect the Dinan software (and SMG software installed). They could not....
