Profec B Spec II

[subieboy]

So been toying with an idea and need some info from electrical engineers and the like on whether this will work.

This is to use on a 99 BH5 TT.

Seeing as I run the Greddy Profec B SPec II with remote switch, I wanted to as an alternative just use the eLabtronics Voltage Switch to trigger the Profec "HI/LO Function" at the point in the rev range where the change over between the primary & secondary occur. Thus it would negate having to trigger the profec remote manually.

However the RPM signal is PWM... Too hard basket.

A few knowledgeable persons suggested I use the trigger signal from either a control signal to one of the solenoids that controls the secondary bov closing and the intercooler valve opening...

I basically want the Profec II to trigger while accelerating at 5250RPM(ish) into "high boost", and when decelerating I want it to trigger back into "low boost"... The "HI/LO Function"

AS most know, before 4200RPM it has to be at 10Psi (& through VOD). I know from experimenting that if you trigger higher than 10Psi before the secondary stage at 5200RPM(ish) the ECU opens the BOV and it will dump all boost and you loose all power... Stupid VOD... So all I will need is a way to intercept (take-off) the signal from either the control signal from the secondary bov closing or the intercooler valve opening or similar reliable signal for triggering...

Additional to the hardware below I am going to use the eLabtronics Voltage Switch (from autospeed):

http://autospeed.com.au/cms/A_110548/article.html

The eLabtronics Voltage Switch will be set to: "Output Switches on as Voltage RISES ABOVE Set-point"

It switches on as voltage rises above set-point, then on-board LED illuminates and output stays fully on. the LED and output switch off when input voltage falls below set-point.

Also in the below the bloke uses a momentary switch to change the boost map over. I want to use something else instead of the switch (i.e. electronically) So I will replace the momentary switch with something that will trigger automatically...

 

Part List:

1x 3.5mm Stereo METAL Plug WITH SPRING (CAT. NO. PP0135) = $1.35 (can

use alternative but needs to be a stereo one). The 3.5mm audio jack and lead

from JAYCAR which is the 'springy type’ - the black is the ground, the white is

the 5volt and the red is the 12volt.

1x PUSHBUTTON PUSH-ON MOMENTARY SPST RED ACTUATOR (CAT. NO. SP0716) =

$1.50 - Make sure that the momentary switch is of the Normally Open type

- or -

Small Black SPST N/O Momentary Action (CAT. NO. SP0700) = $2.80

(can use alternative but needs to be momentary "ON" type)

- or -

SPST Momontary Toggle Switch 20A 12V (CAT.

NO. ST0577) = $6.50

(Suits ST-0578 Missile Switch Cover)

1m or so of 3-4 core wire depend where switch is to the unit = $2-3

- or - quite possibly (should work)

AUDIO LEAD 3.5MM - 3.5MM PLUG STEREO 5M (CAT. NO. WA7005) = $8.95

If you buy pre-made skip to step 2.

Step 1:

Strip your wire and solder 3 different wires on different pins of the 3.5mm

plug.

Step 2:

Strip the wires on the opposite end of the wire to the plug(if using a premade

one cut one plug side off). Check with your multimeter on resistance (ohms)

between all 3 wires eg; between wire 1 & 2 , 1 & 3 and 2 & 3. You

want to make sure that all readings have no resistance value as this means

there is a short (dont hold the wires with your fingers as you are a conductor

and will create a circuit)

If you get a reading make sure that no wires are joining at the plug.

Step 3:

If step 2 is all good, plug the jack into the back of the profec and turn your

ignition on(make sure the side with no plugs wires arent touching). With your

multimeter on Volts DC find the ground and 5V wire, touch these wires for a

second and make sure it switches modes. If good turn off your ignition and with

the last wire(12VDC) cut the stripped part off, i taped it to the insulation of

the wire as later on i plan to get a switch with an LED and this will come in handy.

Step 4:

Solder up the 5VDC wire and ground across the switch, Plug in and test with car

ignition on. If doesnt work check all your connections, possibility of bad

solder joint or short circuit.

Step 5:

Drill and mount the switch where ever you like. I put mine in the spare switch

slot next to the steering wheel on my r33, then just run the wire with plug

back to the Profec head unit and enjoy

So the $64 Question is: will this Relay work or function as a momentary switch when wired up to the Autospeed kit??? Remember I will be using the constant output for the Voltage Switch...

Constant to Momentary Output

Positive Input/Positive Output

The capacitor allows the coil of the relay to be energized until the

capacitor stores a charge, thus de-energizing the coil. The resistor

bleeds off the charge of the capacitor when positive voltage is removed

from the other side of the coil. You can increase the output time by

simply changing the value of the capacitor. This one will give you about

a 1/2 second output.

right heave away me mateys of knowledge!

[kamineko]

disregarding the 2nd half of your post, you would like a small adjustable RPM switch with display that hooks straight to your profec? if there is demand for that i will build some

[subieboy]

 kamineko said:

you would like a small adjustable RPM switch with display that hooks straight to your profec? if there is demand for that i will build some

Yep I would be interested, that would be waaay easier than what I ma trying to do. How much and would it be adjustable with some pots etc...

But as my knowledge is limited on this subject, I was advised that the RPM signal is a PWM one and therefore not that reliable for something like running boost control with... Or have I got that a bit wrong??

[kamineko]

probably $50 worth of parts. bit more if you wanted a cute backlit lcd screen like what the profec2b already has. it would take some time to prototype so not really worthwhile unless i was making say 5+ units.

yeah its possible to interpret the RPM signal accurately, so any setting would be precise

personally before going down that road, i would check for a solenoid/valve/? output that is naturally switched by the ecu at the secondary changeover point, and tap into that

[subieboy]

Lets see if a few people are interested.

[subieboy]

Could someone with a TT BH5/BE5 do some quick probing for me?

Please probe the control signal to the TT system solenoid(s) (2nd dary BOV/intercooler valve) and see whether it will switch between 5V and ground during both acceleration and deceleration...

thank you

[subieboy]

BUMP

[kamineko]

i could look to make a prototype after MM. might sell better if its shown to work, lol

[subieboy]

 kamineko said:

i could look to make a prototype after MM. might sell better if its shown to work, lol

That would be sweet!