only boosting 15psi
#1
11-10-2010, 06:22 PM
only boosting 15psi
i recently did the diode mod and used a turboxs hpbc. i can set my boost any where between 0-14psi and it will be fine but no matter how much i adjust the mbc it wont go past 15psi. everyonce in a while it will come close to 16psi but thats it. i dont believe i have any boost leaks from a visual inspection and i get 20hg of vaccum. could the mbc be the problem or is the turbo just too old? any help is appreciated.
#5
11-11-2010, 10:34 AM
Is the MBC a bleed or block type valve?
Also, do you have the N75 harness plugged in still?
Did you follow their exact instructions when installing their MBC for the very first time?
http://www.turboxs.com/faq/turboxshigh.htm
They even have instruction if you plan on running 15+psi.
Also, do you have the N75 harness plugged in still?
Did you follow their exact instructions when installing their MBC for the very first time?
http://www.turboxs.com/faq/turboxshigh.htm
They even have instruction if you plan on running 15+psi.
Performance Tip
When increasing the boost pressure to higher levels (15 psi or higher), you will get more accurate, responsive and stable boost pressure by using a pressure supply line directly from the engine inlet manifold after the throttle body housing instead of the pressure line from the pressure side of the turbo as stated in step 3 above. By supplying the pressure directly from the engine inlet manifold, pressure effects due to air being forced through the connecting pipes and intercooler are eliminated from the operation of the wastegate actuator system. Ensure any previous pressure supply lines after the turbo are appropriately blocked.
When increasing the boost pressure to higher levels (15 psi or higher), you will get more accurate, responsive and stable boost pressure by using a pressure supply line directly from the engine inlet manifold after the throttle body housing instead of the pressure line from the pressure side of the turbo as stated in step 3 above. By supplying the pressure directly from the engine inlet manifold, pressure effects due to air being forced through the connecting pipes and intercooler are eliminated from the operation of the wastegate actuator system. Ensure any previous pressure supply lines after the turbo are appropriately blocked.
Last edited by Mike-2ptzero; 11-11-2010 at 10:39 AM.
#6
11-11-2010, 06:46 PM
^ its a combo bleed/ball and spring type mbc (turboxs hpbc). i took the hoses off the N75 and connected it to the mbc. from what i understand of the instructions, could i put a T fitting on the hose on the front part of the intake mani (where people usually tap to instal a boost gauge) and connect it to the mbc?
#8
11-12-2010, 12:38 PM
hey man im just curious on how it runs after the Diode and MBC? im getting ready to do the Diode mod as well. just waiting for the money to get the MBC. but is there a good bit of diffrence? what should i exspect? i dont wanna get my hopes up lol
#9
11-13-2010, 04:49 AM
i like it a lot over stock, it pulls a lot nicer and in my case spools up smoother. however, the only reason i did this mod was because im upgrading to either a gtrs or a 71r elim (havent decided yet) pretty soon. otherwise i would've got a chip. as for my problem, im going to connect the mbc the way mike pointed out, and wait to install my fmic. hopefully that will get rid of my problem.
#10
12-18-2010, 09:11 PM
Update: I just had my exhaust done today, 3 inch atp test pipe to 3 inch mandrel bent exhaust to a magnaflow 3 inch inlet to a dual outlet. I got on the freeway and my boost gauge went straight to 20psi. I guess it wasnt a boost leak problem, the turbo was just getting choked. now i have to set my mbc back to 17psi until i install my gt2871r.