Ok, this is my week for beating dead horses, so bear with me....

I have read more than I can contain in my head about wastegates & mbc's.... My question is, with just a wastegate (PTP in particular) with a 16lb. spring and no boost controller, will I be spiking and holding around 16lbs of boost? i am trying to determine if I actually need a mbc at this point, for I have read you can just adjust the wastegate. However, nothing I have read is exactly clear at this point, or at least not to me. If all the mbc will do is make it spike 1-2 lbs higher (for I don't have any fuel mods), then at this point I would rather not bother. Any input would be greatly appreciated! Thanks

 

I'v looked into the same type of thing, and what i have read you really shouldnt go past 17psi with the stock injectors. but i am a newbie, so dont take me completly serious. ha....

 

ok ...first of all, the stock fuel system can't handle more than 16 or 17 psi. With that being said, if you want to swap your wga ... what you'll do is install the wga and set it so the car will only push about 11 or 12 psi. Once that's set, what you do is insert the mbc and turn the boost up using that.

You'll probably see spikes of 17 psi and holding close to 16 psi at redline (if you set it right).

 

ok to clarify...you don't NEED a mbc, but without one you'll get massive ptb.

 

Thanks! That is exactly what I needed to know... I've seen a couple local guys with an in-line Perrin boost controller that seem to work pretty good. Anyone have some knowledge on these?

 

I have no bc, just wga and holding 15 or 16(2nd gear)3rd and 4th usually holds 19 or 20.Is this dangerous?....I'm still running stock fuel sys.

 

simply, yes. turn it down.

any mbc is pretty much going to do the job. all it is is a spring and a ball in there lol. the kinetic and the turbo xs are the most common that are seen, but most are good. just stay away from the in-cabin ones, those are pretty innacurate and often times don't work too well (too far from the turbo)

 

Word! Thanks for the help. Going home after work and installing Stg1, mbc, & a wastegate.... Can't wait! It will be even better when my O2 housing finally arrives and I can put my 3inch S.E.E. on! Also have dogbones, AEM UEGO, oil pressure gauge, and a gauge pillar arriving hopefully by Friday! You may see a couple posts for all of these will be a first for me....

 

what is bad about partial throttle boost? can someone explain?

 

ptb is bad for two basic reasons.

first, what's happening is that you're hitting full spool at only part throttle technically the name for this condition is part throttle overboost. when this happens then you are running extremly lean due to full boost at part throttle, and the ecu is not compensating by adding more fuel.

secondly, you're creating back pressure on the turbo. that's why you get the flutter noise when you get into this condition. this will reduce the life expectancy of the turbo over time.