you really dont need to spend that much money on a mbc. hallman mbc's run about half that and hold boost really well. get a boost gauge if you dont have one already, because you'll need one to see what boost your setting it at. you can leave it set down at 14psi if you want, but you'll still have an issue with partial throttle full boost and the boost may not taper off towards redline like the fbc. if you really want more boost and stock behavior, try the 3/16th mod or run a dual solenoid setup to switch between a mbc and fbc.

 

I would stay away from the 3/16th mod... not very safe or consistent with most cars. You will see a LOT more fluctuation than with an MBC/EBC. One of the guys at our local meet (SB^2) ran it and saw massive fluctuations and spikes. Shiv from Vishnu Performance Tuning also highly discourages it, and he's a whole hell of a lot more experienced at tuning matters than I am, so I readily take his advice .

MBC (and EBCs for that matter) ... PTHB is an occurrance, but not a big issue as long as you modify your driving habits a bit, and keep your eye on the boost gauge. Most PTHB situations happen in the mid-throttle range. If you notice high boost while in the mid-throttle range, go to WOT or let off the gas to reduce boost. It's not hard to stay out of PTHB situations as long as you have a good awareness of your boost. EBCs tend to be safer, since with most, you can set an upper limit afterwhich the EBC will dump the rest of the boost, keeping spikes more controlled and keeping the set boost ceiling more consistent. An MBC will require adjustments for temperature. It is not uncommon to set an MBC for 15psi on a warm day, only to see it spike to fuel cut (~17.5 psi) on a cold day.

A boost guage is MANDATORY if you are going to modify from the stock FBC. You need to keep an eye on your boost for PTHB situations, and to set the MBC if that is the route you choose. You may also want to run an EGT gauge to keep an eye on your EGTs, which will skyrocket if you run in the PTHB zone. Do yourself a favor and read a bit on what causes PTHB situations (air/fuel mixture, open/closed loop, etc) so you understand what you are getting into.

I used to run a home-made MBC (hybrid ball/spring with bleed, set the ball/spring to about 9psi, bleed to 15) and had fine performance with it, but I didn't want to have to reset the MBC setting every time it got colder or hotter so I switched to an EBC for the safety margin and the convenience of in-cabin adjustments. MBCs aren't very hard to make. Do a search in the forums and you will find the one I used for a while (hybrid ball/spring with bleed valve), which seemed to me to control spiking better than just a ball/spring while still maintaining a good boost response. Total construction cost and time will run you about.. oh... 30 minutes and maybe 20 bucks.

shadowcat

 

http://www.vishnutuning.com/loadcontrol.htm

Please go read.

Buy your MBC (Hallman or Joe Pa) install the EMI and be safe never having to worry about EGT's. not to mention a few other benefits.

Drew