right i have my suspicions about the accuracy of the boost controller.

 

i check by using a mechanical boost gauge,stock boost gauge and the controller itself.

 

 

under boost the boost controller max's out at 5.6 psi the stock gauge goes up to where 9 psi should be......

 

this is really starting to piss me off as i dont know what to believe!

You sure youve not got any boost leaks in the lines your boost controller is hooked up to?

You sure youve not got any boost leaks in the lines your boost controller is hooked up to?

the boost controller takes the reading direct from the balance bar the same as wiring in a boost guage so i have checked the line that runs from the balance bar to the boost controller but cannot find any leaks :(

the boost controller takes the reading direct from the balance bar the same as wiring in a boost guage so i have checked the line that runs from the balance bar to the boost controller but cannot find any leaks :(

 

is the boost controller sharing the vac line from the BB with anything?

yes as per the installation diagrams its t'd off the boost sensor for the stock gauge. i tried to eliminate that by blanking off the pipe that leads to it. no change on the boost controller :(

try taking it off somewhere else, mine takes its reading from the vac line for the fuel pressure reg

what i dont get tho is that its still taking the reading via the balance bar, its all linked up to the plenum. im not dismissing the idea but the way i see it if they T into the same line and were effecting each other the stock gauge would be reading low too wouldn't it??

I'm sure I read somewhere that you need to make sure that the vac line to the controller is only used by it, not shared with anything else. Also might sound daft but the SBC is in PSI mode not something else?

I'm sure I read somewhere that you need to make sure that the vac line to the controller is only used by it, not shared with anything else. Also might sound daft but the SBC is in PSI mode not something else?

the controller has a t piece as standard to plumb it in, and i have checked and it is set to psi. i will take some more pics.

you didn't say what your mechanical gauge reads under boost

the controller has a t piece as standard to plumb it in, and i have checked and it is set to psi. i will take some more pics.

 

so it does, what the hell am I thinking of then?? lol

 

I've got the same sbc but It's been ages since I installed it. I'll have a look and see how I've done mine, as I just installed it and left it, haven't set it up yet but it does read -12 on idle.

you didn't say what your mechanical gauge reads under boost

im yet to test it under boost as i only plumbed it in today to check vacuum at idle to compare against the other two readings.

 

it just seems odd that the boost gauge is reading approx -4 psi higher at vacuum which would equate to a 4 psi lower reading under boost compared to the other gauge. which would mean 9psi on the stock gauge would read 5ish psi on the boost controller which seems to make sense.

 

im going to double check the pipe that leads to the controller ecu, there has to be a leak there some where......

From them pictures your stock gauge and sbc show the same reading sbc is in inHg when in vacuum and psi when in boost

the boost controller takes the reading direct from the balance bar the same as wiring in a boost guage so i have checked the line that runs from the balance bar to the boost controller but cannot find any leaks :(

 

get yourself a good known mechanical gauge and check it against another reliable gauge.. air compresser would do and go from there Gary...the elec boost controler is only as good as the reading it recieves and it could have goosed components in the unit or solenoid

From them pictures your stock gauge and sbc show the same reading sbc is in inHg when in vacuum and psi when in boost

ah ha!! right so -19inhg = -9.33psi

 

so only when the pressure becomes positive it shows in psi!! ffs could they make it any more confusing lol

 

so a blitz controller

you set it up in a boost percentage ratio

 

 

if set up to read psi

in vacuum it shows vac pressure in inhg and boost pressure in psi

always wanted to know what all this inhg stuff meant and ive just checked wikiinfofordumbpeople and found this

 

It is defined as the pressure exerted by a 1 inch circular column of mercury of 1 inch in height at 32 °F (0 °C) at the standard acceleration of gravity.

ah ha!! right so -19inhg = -9.33psi

 

so only when the pressure becomes positive it shows in psi!! ffs could they make it any more confusing lol

 

so a blitz controller

you set it up in a boost percentage ratio

 

 

if set up to read psi

in vacuum it shows vac pressure in inhg and boost pressure in psi

 

Yes ... when on 0 boost your blitz controler and stock gauge should show 0 :)

Im going to do or pay zed world to do a boost leak check for me, when i get the z back from the painters.

I have a boost leak checker if you want to borrow it?

I have a boost leak checker if you want to borrow it?

that would be great but not sure when im getting it back yet, i will contact you when i do ... thanks matey :)

right i have been playing about with this a bit today, myself ans z32bolt thought we should try sticking a stock restrictor jet into the output line to the actuators.

 

took it out for a run boost controller set at

 

15 ratio boost 5 gain and got 6 psi

 

30 ratio boost 5 gain and got 6.6 psi

 

40 ratio boost 5 gain and got 7.6 psi

 

50 ratio boost 5 gain and got 9.3 psi

 

55 ratio boost 5 gain and got 10.2 psi

 

the readout is via the boost controller which when i checked it with a mechanical gauge before was right,

 

my question is : is it uncommon to have to put a restrictor inline with the actuators and for the boost controller to be set so high on the boost?

Edited February 3, 201312 yr by hellraiser

any boost leaks, with the stock boost actuators off and boost controller on zero you should still hit 7psi ...

just looked at previous page and remembered I'd offered you the leak checker, sounds like you need it!

any boost leaks, with the stock boost actuators off and boost controller on zero you should still hit 7psi ...

i thought stock actuator spring pressure was 6psi?

 

even so if the actuators are original they might be a bit weakened over the years and only holding 6 psi.

 

what do you reckon jaffa?

i thought stock actuator spring pressure was 6psi?

 

even so if the actuators are original they might be a bit weakened over the years and only holding 6 psi.

 

what do you reckon jaffa?

 

sounds a massive boost leak there Gary...get your self a cheap adjustable manual boost controler (bleed valve type) you can get them for £15 on ebay and get that plumbed into the actu lines...2-1 going in and 1- 2 coming out down to the boost solenoids,that then should give you a truthfull mechanical way of obtaining boost and also give you the facility of increasing boost to see iff it holds.

sounds a massive boost leak there Gary...get your self a cheap adjustable manual boost controler (bleed valve type) you can get them for £15 on ebay and get that plumbed into the actu lines...2-1 going in and 1- 2 coming out down to the boost solenoids,that then should give you a truthfull mechanical way of obtaining boost and also give you the facility of increasing boost to see iff it holds.

the stock boost solenoids have been removed from my car.