Author Topic: Is my boost switch now calibrated??  (Read 2157 times)

Offline AdzCM

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Is my boost switch now calibrated??
« on: March 21, 2013, 10:04:16 pm »
Right, I've followed the instructions given by cheys03's FAQ and I'm wondering if anyone can confirm if I've done it correctly.

- pumped up bicycle tube to 6psi

- connected up boost switch to it via hose

- set my multi-meter to read resistance, and with the screw of the boost switch fully screwed in, unscrewed it until my multi-meter read 0.00 i.e. the switch contacts are now closed

Is this correct and is my switch now calibrated to 6psi???

Want to know for certain before I fit it inside my throttlebody

Adrian

Offline cheys03

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Re: Is my boost switch now calibrated??
« Reply #1 on: March 21, 2013, 10:14:10 pm »
Sounds good! So long as you can be sure the tube was at 6psi when the contacts were closed (I used a T piece to the switch and boost gauge).

Offline AdzCM

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Re: Is my boost switch now calibrated??
« Reply #2 on: March 22, 2013, 12:10:55 am »
Hmmm I read that you used one but I don't have one :( I pumped it up to 6psi using a standard air line hose with the wee built in gauge. Don't know how accurate it might be.

Ill try and get hold of a pressure gauge and try again.

Thanks for that mate. Hopefully have it running this weekend.

Offline AdzCM

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Re: Is my boost switch now calibrated??
« Reply #3 on: March 22, 2013, 12:42:26 am »
You mean a standard boost gauge? Never thought of that lol...

Offline dubstar

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Re: Is my boost switch now calibrated??
« Reply #4 on: March 24, 2013, 12:50:28 pm »
I like your method. The only snag is that mechanical gauges see the most inaccuracy at low pressure, as your standard air line gauge built to read up to 150psi or whatever. I think the suggestion of using a boost gauge is a good one, as they generally only read up to around 30psi so the chances of being accurate at a low pressure of 6psi on that gauge are 5 fold the 150psi gauge.
« Last Edit: March 24, 2013, 12:52:40 pm by dubstar »

Offline Etches

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Re: Is my boost switch now calibrated??
« Reply #5 on: March 24, 2013, 01:30:01 pm »
I tried this method but couldnt get the pump in the circuit. I always ended up losing pressure when i'd pump the tyre up to 6psi. I need to figure out a way to do this!

Offline dub-disaster

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Re: Is my boost switch now calibrated??
« Reply #6 on: March 24, 2013, 02:20:38 pm »
if anyone is desprate i have a little rig i made up at work to set them up with a regulator guage and a valve, i conneft this to the standard workshop air supply (10 bar) then use the regulator and guage to set it to 6psi, the pressure is set with the valve closed then it is opned and switch set up using a continuity meter from there.

If any one needs it done post it to me and pay for postage back id be happy to help!

Offline Etches

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Re: Is my boost switch now calibrated??
« Reply #7 on: March 24, 2013, 02:27:45 pm »
Mate that would be ideal, I asked around a few of my mates garages but no one would have a pop!

Offline AdzCM

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Re: Is my boost switch now calibrated??
« Reply #8 on: March 25, 2013, 03:28:01 pm »
I like your method. The only snag is that mechanical gauges see the most inaccuracy at low pressure, as your standard air line gauge built to read up to 150psi or whatever. I think the suggestion of using a boost gauge is a good one, as they generally only read up to around 30psi so the chances of being accurate at a low pressure of 6psi on that gauge are 5 fold the 150psi gauge.

Its cheys03's method :) would have been lost without it.

etches69 - I just pumped the tyre up to a random pressure, say 10psi. then like cheys03 says, used a t-piece with the main part going to the tyre, then the other 2 bits to the boost switch and boost gauge. I used ptfe tape on the boost switch and tightened it up as it was leaking being just hand tightened. Then cable tied everything else.

Then with it all connected, I let the pressure out of the tyre slowly, watching the gauge until it read 6psi. Then with the screw of the boost switch fully in, released it until it was on the border of reading the contacts as open/closed. Then did the minor adjustment so that they were closed at 6psi i.e. 0.00 on the multimeter.
 
Then tested it by pumping up the tyre again, and slowly releasing the pressure. As soon as it hit below 6psi, the switch opened again [i.e. 1 on the multimeter] as there wasn't enough pressure to close the contacts.

Correct me if I'm wrong??

Only problem I can see is, the boost gauge doesn't seem to sit exactly at '0' ?? nor does the new one in my car.

How accurate should the boost switch be calibrated? Would a chip not just be set to read a boost switch, and it just runs on a signal from the switch closing its contacts? I mean, is the chip set to fuel at 6psi or is the chip set to read a signal from the boost switch closing its contacts whether it be 6psi or 6.2psi for example?