Newb Questions regarding Fuel pressure regulator

[mitsumafia]

Hey all, I have a 91 525i with the m20 engine, I've ordered a TMS chip that hopefully should be arriving next week but in the mean time I'm trying to do some homework regarding switching my injectors to the m50 ones. So far I've learned that they are a direct fit, and I should use the green top injectors, design style 3. However the answer to my next question is avoiding me, the question is that according to information I've read you need to decrease the flow to 2.5 bar for a bit so that the ecu can deal with the change. After which you can turn it back up to 3 bar, however if I just used a portable fuel pressure regulator (some cheap ebay job like autoteq) ran the car at 2.5 and after a bit hooked up the factory one (which from what I can tell runs at 3 bar) would everything be good or do I need to keep the adjustable unit in ? Hopefully someone can guide me straight regarding this. Thanks, Derek

[Binjammin]

Please show me where you found this bad info.

[mitsumafia]

h**p://www.davelength.net/car/bigsix.html
h**p://www.nmia.com/~dgnrg/page_17.htm
h**p://www.maxbimmer.com/forums/showthread.php?t=55842
h**p://www.euroasians.net/2007/11/09/my-pre-v12-e34/
h**p://www.dtmpower.net/forum/archived-threads/15617-installed-m50-injectors-extrude-manifold-bored-tb-etc-but-car-runs-like-shit.html

h**p://forums.bimmerforums.com/forum/showthread.php?p=15323267#post15323267&highlight=m50+m20+injector

and so on, ive got another 10 or so.

[uk525td]

if the ecu eventually learns you may as well run stock fuel pressure surely?
but sounds fishy, normally the ecu will only trim on cruise conditions ??? i can understand fitting larger injectors then decreasing fuel pressure to "break even" but htat would result in worse atomization.... surely stock inkjectors are well within duty cycle to make a few extra hp?

ok i read up :)
one particular thread actually mentioned that the guy was running on 5 cylinders
the rest of the threads suggest that running m50 injectors on stock m20 fuel pressure is close enough to thee original (nearly maxed injectors) to run ok, and suggests that tweaking the base fuel can be done via adjusting a wheel on an m30 afm....(maybe same on m20)