Boost Spike on Homemade Ball/Spring MBC - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

caall99 · 10-10-2005, 07:40 PM

i built my own simple adjustable boost controller from parts that i found at true value and home depot. I connected the MBC inlet with a vacuum hose to the throttle body and the outlet to the wastegate. The MBC itself is closer to the wastegate than the throttle body. In all gears it goes to 13 psi and then drops to 10 psi by 5500rpm. i haven't yet drilled a bleed to compensate for signal lock that can occur when the ball bearing comes down again. would this even affect the spiking i am experiencing? would putting a nipple on the hotpipe and connecting the MBC inlet to it help at all?

on a side note, i also noticed when i did a fourth gear pull today that the car hesistated at 6000 rpm. like it cut ignition. could this be due to the spark plug gap being too large (.043 inch)? these are BKR7EIX iridiums.

thanks guys

caall99 · 10-11-2005, 12:31 AM

i am bumping my thread cause i am an impatient bitch...

Maeda · 10-11-2005, 02:18 AM

I'll give you an impatient answer. Get a real boost controller(profec B spec 1), you won't regret it.

drift into a curb · 10-11-2005, 04:21 AM

That gap is too large for turbo cars. Around .032 - 0.035 or so. Re-gap and try again.

caall99 · 10-12-2005, 12:00 AM

maeda, that wasn't helpful, if i had the money i would have bought one by now. thanks, drift into a curb, i am gonna gap them down tomorrow. anyone else have any comments or suggestions on reducing boost spiking with a manual boost controller?

caall99 · 10-12-2005, 11:19 AM

and i guess this thread is dead now...

10-10-2005, 07:40 PM	#1
caall99 Zilvia Member Join Date: Apr 2005 Location: Wellesley, MA Age: 40 Posts: 267 Trader Rating: (0) Feedback Score: 0 reviews	Boost Spike on Homemade Ball/Spring MBC i built my own simple adjustable boost controller from parts that i found at true value and home depot. I connected the MBC inlet with a vacuum hose to the throttle body and the outlet to the wastegate. The MBC itself is closer to the wastegate than the throttle body. In all gears it goes to 13 psi and then drops to 10 psi by 5500rpm. i haven't yet drilled a bleed to compensate for signal lock that can occur when the ball bearing comes down again. would this even affect the spiking i am experiencing? would putting a nipple on the hotpipe and connecting the MBC inlet to it help at all? on a side note, i also noticed when i did a fourth gear pull today that the car hesistated at 6000 rpm. like it cut ignition. could this be due to the spark plug gap being too large (.043 inch)? these are BKR7EIX iridiums. thanks guys __________________ Signature over limits http://www.zilvia.net/f/showthread.php?t=21036 Last edited by caall99; 10-10-2005 at 09:16 PM..

10-11-2005, 12:31 AM	#2
caall99 Zilvia Member Join Date: Apr 2005 Location: Wellesley, MA Age: 40 Posts: 267 Trader Rating: (0) Feedback Score: 0 reviews	i am bumping my thread cause i am an impatient bitch... __________________ Signature over limits http://www.zilvia.net/f/showthread.php?t=21036

10-11-2005, 02:18 AM	#3
Maeda Nissanaholic! Join Date: Dec 2002 Location: Camp Snake Bite, CA RIP Posts: 2,356 Trader Rating: (0) Rides Gallery: Maeda Feedback Score: 0 reviews	I'll give you an impatient answer. Get a real boost controller(profec B spec 1), you won't regret it. __________________

10-11-2005, 04:21 AM	#4
drift into a curb Post Whore! Join Date: Mar 2002 Location: Seoul, South Korea Posts: 2,870 Trader Rating: (5) Feedback Score: 5 reviews	That gap is too large for turbo cars. Around .032 - 0.035 or so. Re-gap and try again. __________________ Go big or go home!

10-12-2005, 12:00 AM	#5
caall99 Zilvia Member Join Date: Apr 2005 Location: Wellesley, MA Age: 40 Posts: 267 Trader Rating: (0) Feedback Score: 0 reviews	maeda, that wasn't helpful, if i had the money i would have bought one by now. thanks, drift into a curb, i am gonna gap them down tomorrow. anyone else have any comments or suggestions on reducing boost spiking with a manual boost controller? __________________ Signature over limits http://www.zilvia.net/f/showthread.php?t=21036

10-12-2005, 11:19 AM	#6
caall99 Zilvia Member Join Date: Apr 2005 Location: Wellesley, MA Age: 40 Posts: 267 Trader Rating: (0) Feedback Score: 0 reviews	and i guess this thread is dead now... __________________ Signature over limits http://www.zilvia.net/f/showthread.php?t=21036