Where to get pressure transducer (at a reasonable cost!)

[FordMuscle.com]

Just wondering where to get a 0-30 or 0-50 psi pressure transducer (0-5V linear) which is at a reasonable cost.
I contacted Kavlico who makes them (See link below)...they want $249 for 1 unit...

http://www.kavlico.com/library/pdf/p155.pdf


thanks

[nitrousdave]

I don't know what you consider reasonable but www.digikey.com has some for ~130 it looks like (http://dkc3.digikey.com/PDF/T043/1376-1377.pdf). Also I'm using the 0-100 psi sensor from this thread(http://www.innovatemotorsports.com/f...=&threadid=151) to measure my fuel pressure (6-7 psi) and it works good and still measures down to .1 psi. Hope this helps, Dave

[Andereck]

Autometer 2246

Pigtail

S619 Standard
EC89 Napa
PT375 Ac Delco

It takes a late model TPS sensor pigtail

0-100 psi guage linear 0-5 v

any speed shop can get it.

It is the Kavlico sender for a whole lot less money.

Mark

[FordMuscle.com]

thanks dudes. so the 0-100 provides enough resolution to accurately measure 0-30 psi? e.g a voltage range of onlyabout 0-2V ?

[FordMuscle.com]

also meant to ask, what are late model cars using to feed fuel pressure data to the EEC ? i'd imagine it is a similar sensor, no? if so, anyone just pull one from a wreck or dealer parts counter?

[Andereck]

I think that provides for a bit over 400 data points. I think the box digitizes 0-5 v to 1024 data points.

There are no 50 psi senders I'm aware of.

Mark

[Andereck]

Do they monitor fuel pressure? I they do it might be part of the pump assembly on returnless cars. Older efi cars don't monitor fuel pressure.
Regardless you'd still be back into that 0-100 psi range.

[FordMuscle.com]

Andereck,

Yes EEC-V monitors fuel pressure.

Kavlico sells pressure transducers in a variety of ranges, including 0-30 and 0-50psi !
only problem is they want $250 for one..haha

[porsche speed]

Originally posted by FordMuscle.com
Andereck,

Yes EEC-V monitors fuel pressure.

Lousy setup, but nice to get sensors cheap from. All the 'deadhead' (returnless) fuel systems have to monitor pressure, or they would not be able to correctly compensate for the overheated fuel, rapidly attempting to vaporize in the rails...

Someday, the ~$25 per car that it would cost to properly setup the return system and still meet emissions regs will be factored into Ford's pricing structure. Until then, just one more thing to replace when you start tuning.

Greg

[klatinn]

Hi Greg,

As an aside note:
The returnless systems are mandated by emissions regulations. They want to eliminate the fact that the fuel warms up when circulating through the engine compartment. The extra fuel vapours from the tank are typically vented into the intake system and can escape through the air filter after the car is shut down. That's what they want to avoid.

Regards,
Klaus

[porsche speed]

Klaus,

True enough, that's the party line excuse, but if you scratch the surface a bit I think you'll find that it is (as always) all about the money.

Unless I've been misinformed, returnless systems are not mandated per se - just the management of the vapors is mandated.

Deadhead rails are the cheapout solution set. One can quite easily manage those vapors in other ways - but it does cost money (the figure I've been given is ~$25 per car). In an environment where performance is a distant second to saving (literally) $.05 on any given part, it's no surprise that Ford (or anybody else using returnless) would choose to save the money.

But I do find it amusing that they use emissions as an excuse. There's already plenty of gasoline components flashing off, even at room temp. They have to manage those vapors already. Managing a little more volume is simple.

But, if you can save the money of a return line, the hardware to hang it on, the labor cost to install it, the overhead cost to ship and store it...


Cheers,

Greg

[FordMuscle.com]

Originally posted by porsche speed
Klaus,

True enough, that's the party line excuse, but if you scratch the surface a bit I think you'll find that it is (as always) all about the money.

Unless I've been misinformed, returnless systems are not mandated per se - just the management of the vapors is mandated.

Deadhead rails are the cheapout solution set. One can quite easily manage those vapors in other ways - but it does cost money (the figure I've been given is ~$25 per car). In an environment where performance is a distant second to saving (literally) $.05 on any given part, it's no surprise that Ford (or anybody else using returnless) would choose to save the money.

But I do find it amusing that they use emissions as an excuse. There's already plenty of gasoline components flashing off, even at room temp. They have to manage those vapors already. Managing a little more volume is simple.

But, if you can save the money of a return line, the hardware to hang it on, the labor cost to install it, the overhead cost to ship and store it...


Cheers,

Greg

Greg,
So you are saying in 1999 a bean counter at Ford decided, after 10 years of return-style fuel systems on EFI Mustangs, that NOW was the time to cut costs?

Seems to me there is likely an engineering driven decision more so than cost cutting.

cheers

[Andereck]

Hehe...to think this all started from a little pressure transducer post.

Say, what's your guys opinions on the middle east? just kidding

Mark

[FordMuscle.com]

speaking of pressure transducers...
so i installed a 0-100psi transducer. I am noticing with no pressure in the line (car and fuel pump off), the LM3 logs a steady .53V ... this would equate to 10psi. Since this is a carbed system, I know there is not 10psi when the system is off!

So that said, I am suspecting the .53V is noise from probably the 12V power source to the LM1. What is the best way to deal with this... do i just scale the voltage to psi table to subtract out the .53V (eg .53V = 0psi) or do I try to filter out the noise?

thanks

[Andereck]

uninstall the pressure transducer, or take the fuel bowl feed line off and check it. Depending on your regulator and needle and seat health it can retain pressure when you shut if off. I know what you're saying, you don't have 10 psi, but you might have something there trapped. You can set up logworks to subtract anything you want, though the guage will probably display a negative number (around the dial). You can create a new input file in the custom conversion.