HELP ME- how do i control my boost??? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

clv5045 · 06-08-2009, 03:50 PM

when i got my redtop sr in i had no boost controller or gauge so i over boosted and blew my pistons. i just replaced 'em with new stock pistons and rings, and have had it running for 3 days now...i have a boost guage and a manual controller hooked up (and set as low as it goes) to the internal wastegate on a new stock t25. before i reach 5000rpm's it reaches maximum boost for stock internals (14psi) and if i were to keep accellerating it would over boost again!!! how do i get this thing to maintain 12-14psi throughout the rpm's without over boosting???? my ebay boost controller does seem to do jack sh*t!!!

Leo-kun · 06-08-2009, 03:52 PM

Your first mistake was buying an ebay boost controller.

Temple240 · 06-08-2009, 04:02 PM

Are you sure you hooked it up correctly? Did it come with instructions? I'd make sure that your internal wastegate is setup and working properly.

*DALAZ_68* · 06-08-2009, 04:03 PM

Quote:

Originally Posted by driftgodleo

Your first mistake was buying an ebay boost controller.

pretty much sums it all up

homermartinez1 · 06-08-2009, 04:03 PM

remove the mbc out of the picture...check your vacuums and your wastegate actuator and if its still doing it might be your actuator

j87w · 06-08-2009, 10:27 PM

So even after blowing you motor due to poor boost control you still went and bought an ebay boost controller? I would suggest running your car on wastegate pressure (eliminating the MBC as homer said) and seeing what happens. You may have another issue besides your MBC or vacuum routing.

soreballz · 06-08-2009, 11:58 PM

You know, you can build your own highly effective MBC with parts from Home Depot for super cheap.

*fliprayzin240sx* · 06-09-2009, 06:51 AM

So you were overboosting WITHOUT a boost controller, so you went ahead and bought one in hopes that it will LOWER the boost?!?! DO YOU EVEN KNOW HOW A FUCKING BOOST CONTROLLER WORK ON AN INTERNAL WASTEGATED TURBO?!?!

I suggest you stop driving the car, take the boost controller off and figure out why its overboosting to begin with. Keep driving and you'll be rebuilding that shit...AGAIN

midnight_rex · 06-09-2009, 10:55 AM

just put everything to factory setup. delete the mbc and just run off the actuator. running off the actuator should put u at stock boost (7psi).

guitaraholic · 06-09-2009, 01:07 PM

Well, if your WGA is shot (like mine was), not matter what you do, you are going to get maximum boost even if you hook the vacuum line straight from a source to the WGA. Diaphram leaks on WGA are more common than you might think. If it leaks you are not going to be able to build up enough pressure in the WGA to open the wastegate. Try hooking an air compressor straight up to the WGA and see if it moves, it should start to move at 5psi or so, if not, you need a new WGA (try HKS it's only a little more and its adjustable)

06-08-2009, 03:50 PM	#1
clv5045 Join Date: May 2008 Location: State College PA Age: 36 Posts: 34 Trader Rating: (1) Feedback Score: 1 reviews	HELP ME- how do i control my boost??? when i got my redtop sr in i had no boost controller or gauge so i over boosted and blew my pistons. i just replaced 'em with new stock pistons and rings, and have had it running for 3 days now...i have a boost guage and a manual controller hooked up (and set as low as it goes) to the internal wastegate on a new stock t25. before i reach 5000rpm's it reaches maximum boost for stock internals (14psi) and if i were to keep accellerating it would over boost again!!! how do i get this thing to maintain 12-14psi throughout the rpm's without over boosting???? my ebay boost controller does seem to do jack sh*t!!! __________________ 91 240 cpe w/ sr SOLD 96 240 w/ sr

06-09-2009, 06:51 AM	#8
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	So you were overboosting WITHOUT a boost controller, so you went ahead and bought one in hopes that it will LOWER the boost?!?! DO YOU EVEN KNOW HOW A FUCKING BOOST CONTROLLER WORK ON AN INTERNAL WASTEGATED TURBO?!?! I suggest you stop driving the car, take the boost controller off and figure out why its overboosting to begin with. Keep driving and you'll be rebuilding that shit...AGAIN __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

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06-08-2009, 03:52 PM	#2
Leo-kun Zilvia Member Join Date: Sep 2008 Location: Yokota jp, Bay Area CA Age: 32 Posts: 184 Trader Rating: (1) Feedback Score: 1 reviews	Your first mistake was buying an ebay boost controller.

06-08-2009, 04:02 PM	#3
Temple240 Leaky Injector Join Date: Feb 2007 Location: philly/ collegeville Age: 36 Posts: 101 Trader Rating: (1) Feedback Score: 1 reviews	Are you sure you hooked it up correctly? Did it come with instructions? I'd make sure that your internal wastegate is setup and working properly.

06-08-2009, 04:03 PM	#5
homermartinez1 Leaky Injector Join Date: Feb 2007 Location: Killeen Age: 38 Posts: 83 Trader Rating: (3) Feedback Score: 3 reviews	remove the mbc out of the picture...check your vacuums and your wastegate actuator and if its still doing it might be your actuator

06-08-2009, 10:27 PM	#6
j87w Leaky Injector Join Date: Feb 2006 Location: nm Posts: 122 Trader Rating: (2) Feedback Score: 2 reviews	So even after blowing you motor due to poor boost control you still went and bought an ebay boost controller? I would suggest running your car on wastegate pressure (eliminating the MBC as homer said) and seeing what happens. You may have another issue besides your MBC or vacuum routing.

06-09-2009, 10:55 AM	#9
midnight_rex Zilvia Member Join Date: Jul 2008 Location: houston, tx Age: 38 Posts: 239 Trader Rating: (1) Feedback Score: 1 reviews	just put everything to factory setup. delete the mbc and just run off the actuator. running off the actuator should put u at stock boost (7psi).

06-09-2009, 01:07 PM	#10
guitaraholic Zilvia Junkie Join Date: Jun 2006 Location: Spanish Fort, AL Posts: 430 Trader Rating: (0) Feedback Score: 0 reviews	Well, if your WGA is shot (like mine was), not matter what you do, you are going to get maximum boost even if you hook the vacuum line straight from a source to the WGA. Diaphram leaks on WGA are more common than you might think. If it leaks you are not going to be able to build up enough pressure in the WGA to open the wastegate. Try hooking an air compressor straight up to the WGA and see if it moves, it should start to move at 5psi or so, if not, you need a new WGA (try HKS it's only a little more and its adjustable)