Boost On Vacuum Systems
- Nd4SpdSe
- Senior Member
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Boost On Vacuum Systems
I picked up and will shortly hook up a boost guage on the X and it got me thinking, when I tap into a vacuum line, it'll let me know if it's under negative and positive pressure, but what happens when it's under positive pressure, what happens to stuff like the cruise, brake booster, and even the VRIS system on an Mx-3 when it's under boost? Those devices function by using the vacuum of the motor, but if the guage is telling me there's a postive pressure, wouldn't that mean that they wouldn't work? Wouldn't the vacuum lines pop off from the pressure?
1992 Mazda Mx-3 GSR - 2.5L KLZE : Award Winning Show Car & Race Car ['02-'09] (Retired)
2004 Mazda RX-8 GT - Renesis Wankel : LS3 Coils, BHR Mid-Pipe + Falken RT-615K 245/40r18
2011 Mazda Mazda2 GS - 1.5L Manual : Yozora Edition (1 of 500)
2003 Nissan Xterra SE - 4x4 Supercharged : 2" Body Lift, 4" Suspension Lift & 33" MTR Kevlar
2001 Nissan Frontier SE - The Frontrailer : Expedition/Off-Road Trailer Project
2004 Mazda RX-8 GT - Renesis Wankel : LS3 Coils, BHR Mid-Pipe + Falken RT-615K 245/40r18
2011 Mazda Mazda2 GS - 1.5L Manual : Yozora Edition (1 of 500)
2003 Nissan Xterra SE - 4x4 Supercharged : 2" Body Lift, 4" Suspension Lift & 33" MTR Kevlar
2001 Nissan Frontier SE - The Frontrailer : Expedition/Off-Road Trailer Project
- cjthor
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Re: Boost On Vacuum Systems
Your brake booster should have an inline check valve and be ok. I put zip ties on all my vac hose connections to help them not pop off. Not sure on the cruise. I would guess that having the VRIS system close (as it would be with boost pressure pushing on the cam that activates it) would be of benifiet to keep the runners short under boost.
Jarid Perry
94 mx3 Turrrbooooo (not even close to stock) 302WHP
71 Chevy C20 (tow rig!!)
77 Jeep CJ5 (no way its stock)
06 MINI Cooper S JCW GP (few goodies) 210WHP
2008 MINI Cooper Clubman S
94 mx3 Turrrbooooo (not even close to stock) 302WHP
71 Chevy C20 (tow rig!!)
77 Jeep CJ5 (no way its stock)
06 MINI Cooper S JCW GP (few goodies) 210WHP
2008 MINI Cooper Clubman S
Re: Boost On Vacuum Systems
The VRIS system uses a check valve too. But yea I've wondered that too, wouldn't the cruise control not work then?
KLZE-ed '94 RS/'92 GS hybrid -- It's complicated
-- Now somebody's winter beater
1999 Audi A4 2.8Q -- New ride
![Laughing :lol:](./images/smilies/icon_lol.gif)
1999 Audi A4 2.8Q -- New ride
Re: Boost On Vacuum Systems
Check valves should cover most of the bases, and for cruise control it shouldn't matter since you'll never be WOT (so manifold pressure will always be negative relative to atmosphere).Nd4SpdSe wrote:I picked up and will shortly hook up a boost guage on the X and it got me thinking, when I tap into a vacuum line, it'll let me know if it's under negative and positive pressure, but what happens when it's under positive pressure, what happens to stuff like the cruise, brake booster, and even the VRIS system on an Mx-3 when it's under boost? Those devices function by using the vacuum of the motor, but if the guage is telling me there's a postive pressure, wouldn't that mean that they wouldn't work? Wouldn't the vacuum lines pop off from the pressure?
- Gord
1996 MX-3 GS-ZE 2.5L 5spd
KLZE+LSD / Headers / KL02 VAF / Clutchmasters stage-I / Fidanza 9lb flywheel / Eibach Pro Kit / Tokico HPs / Urethane bushings & mounts / SSR Comp-C 16x7 / General Exclaim UHP 205/45R16 / Wilwood 13" brakes / Whiteline rear swaybar / Carputer / Software Crossover / Infinity components+subs / 41hz Tripath Amp9 / Trunk SLA batt / Keyless entry
1996 MX-3 GS-ZE 2.5L 5spd
KLZE+LSD / Headers / KL02 VAF / Clutchmasters stage-I / Fidanza 9lb flywheel / Eibach Pro Kit / Tokico HPs / Urethane bushings & mounts / SSR Comp-C 16x7 / General Exclaim UHP 205/45R16 / Wilwood 13" brakes / Whiteline rear swaybar / Carputer / Software Crossover / Infinity components+subs / 41hz Tripath Amp9 / Trunk SLA batt / Keyless entry
Re: Boost On Vacuum Systems
True. So then pretty much everything vacuum related isn't meant to work at WOT, that's pretty cool.
KLZE-ed '94 RS/'92 GS hybrid -- It's complicated
-- Now somebody's winter beater
1999 Audi A4 2.8Q -- New ride
![Laughing :lol:](./images/smilies/icon_lol.gif)
1999 Audi A4 2.8Q -- New ride
Re: Boost On Vacuum Systems
Well, except VRIS, hence the vacuum chambers.
- Gord
1996 MX-3 GS-ZE 2.5L 5spd
KLZE+LSD / Headers / KL02 VAF / Clutchmasters stage-I / Fidanza 9lb flywheel / Eibach Pro Kit / Tokico HPs / Urethane bushings & mounts / SSR Comp-C 16x7 / General Exclaim UHP 205/45R16 / Wilwood 13" brakes / Whiteline rear swaybar / Carputer / Software Crossover / Infinity components+subs / 41hz Tripath Amp9 / Trunk SLA batt / Keyless entry
1996 MX-3 GS-ZE 2.5L 5spd
KLZE+LSD / Headers / KL02 VAF / Clutchmasters stage-I / Fidanza 9lb flywheel / Eibach Pro Kit / Tokico HPs / Urethane bushings & mounts / SSR Comp-C 16x7 / General Exclaim UHP 205/45R16 / Wilwood 13" brakes / Whiteline rear swaybar / Carputer / Software Crossover / Infinity components+subs / 41hz Tripath Amp9 / Trunk SLA batt / Keyless entry