boost controllers...what they do

Fred

Leaving Skid Marks
Location
Orange N.S.W 2800
First Name
Fred
Drive
1998 Legnum VR-4 & 1999 Legnum VR-4 w. Recaros
hi all, just a quick question....boost controllers, you plug them in, dail in the boost you want, i.e 12psi, and wala, 12psi instead of factory boost...??? is that what they do???

also , what boost do legnums put out from factory...???

Cheers. Fred.
 

SLY-031

Leaving Skid Marks
Location
South Australia
First Name
Joel
Drive
VR-4 Legnum
Hi mate. They use a single or dual solenoid system to regulate the air pressure signal being read by the wastegate diaphragm. Essentially, all they do is "trick" the wastegate in to thinking that it is at its set pressure, ie 8psi, whereas what has happened, is that the boost controller has blocked the flow to the wastegate until the controller gets a manifold pressure of XX psi, then feeds air to the wastegate. Thus opening the gate and holding that pressure.

They also regulate the air being received by the wastegate to maintain a very smooth boost line.

Many also have a gain control, which will bleed air to the wastegate to creep it open slowly or have it fully shut a slam open at the set pressure.

Legnums from the factory run at 8 psi, though I believe there is already a factory style boost solenoid to allow boost to ramp up to 10-11psi.

Someone may correct me on some things, but that is what I know.
 

Fred

Leaving Skid Marks
Location
Orange N.S.W 2800
First Name
Fred
Drive
1998 Legnum VR-4 & 1999 Legnum VR-4 w. Recaros
cool , so they basically" trick" the wastegate, to open at a different psi than set....
 
G

Guest

Unregistered
I assume they risk engine damage the higher you boost an otherwise unmodified engine.
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
Depends on the Engine, but basically yes - you're running more power through the same components, so more wear and more stress, and if they're not up to the task then... However people have been running standard engine VR4s on up to 15psi for years, reportedly with no problems. Make of that what you will :)
 

snickells

Leaving Skid Marks
Lifetime Member
Location
Australia
First Name
Anon
Drive
Car
I installed a boost gauge today and I'm pulling about 10PSI when I slam it hard and about 5PSI when I'm slightly flooring it so I'm confused as hell now.
 
G

Guest

Unregistered
The prefacelifts usually boost around 6psi and the facelifts around 8 if you have an auto. My one in standard form was boosting to 6 before I installed the boost controller.
 
G

Guest

Unregistered
The prefacelifts usually boost around 6psi and the facelifts around 8 if you have an auto. My one in standard form was boosting to 6 before I installed the boost controller.

Thats good news, does that mean the prefacelift autos (rated at 260hp) were only down on boost? Sounds like a simple "fix" :D
 

MPBVr4

Crunching Gears
Location
UK
First Name
Malc
Drive
1997 Vr4 Galant Type S
Thats good news, does that mean the prefacelift autos (rated at 260hp) were only down on boost? Sounds like a simple "fix" :D

As far as know a facelift ECU in your car will give you 280 bhp. Wack in a
boost controller as well plus a decent exhaust and your up to 300 +:D
 

leebutts

1 AYC Bar
Location
New Zealand
First Name
Lee
Drive
2001 Golf GTI
Geez - I just bought one...

Getting one off FleaBay from the states with peak hold and warning lights. Came to about 100US delivered.

Lee
 

RaZZa137

Leaving Skid Marks
Location
NSW
First Name
Rowan
Drive
1998 PFL Legnum VR4 2012 Skoda Superb 1990 Suzuki GSF250
I installed a boost gauge today and I'm pulling about 10PSI when I slam it hard and about 5PSI when I'm slightly flooring it so I'm confused as hell now.

the harder the engine works, the more exhaust gases it produces, the more ehxaust=more pressure aka boost!
 
G

Guest

Unregistered
LOL group buy on boost guages. Just buy one, cheap as.

I don't want a cheap assed one that works some of the time ...
Not to mention I'm on a cheap budget for my car, I have to factor in all the new games for the PS3 and the Wii ...
I hate paying top dollar for everything.
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
I hate paying top dollar for everything.
Completely agree Paul, which is why I hardly ever do. Having said that, though, sometimes its worth paying top dollar if the value is there. But I agree that I resent paying hundreds of dollars more for things just because there are one or two extra people in the chain of distribution. Those people aren't adding value, they're f@#$ing me over a barrel... or trying to, at least.
 
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