My buddy just bought a dry kit, and he's decided that he wants it completely hidden. Not a problem - except for the fuel pressure safety switch!

How in the world can you hide the FPSS since this is a DRY kit?

 

get a fuel pressure guage and tell anyone who asks that it's part of the sending unit

btw anyone who knows what a fpss is will pick up on it in a second - you can bullshit the others

 

simple... take the fuel line anywhere on the chassis... cut it, flare the ends and put a T fitting in. (not as hard as it sounds...)

later on, if he ever decides to remove it, he can replace the FPSS with a pipe plug.


also with this mod, you can run a hidden wet shot... just tap the fuel off of the T fitting..

 

Can you give an actual part # for the fitting. The line is 3/8, so I assume I need a 3/8 NPT female fitting on both sides with a 1/8 NPT port in the middle to screw the fpss to, along with two 3/8 NPT nuts. I'm not sure if the fpss is 1/8 either, anyone know.

 

Use a Wide band commander instead

 

No flare tool is need if you use the following.


From AreoQuip
1) fcm2183 -6 x -6 x 1/8 female
2) fcm2497 compression nut
2) fcm2492 compression flare

Now this one of many ways to hide the FPSS.

Ricky

 

ok,
heres a rough step by step.

goto the hardware/parts store.. any decent one should have the following:

• (2) 3/8" tube nuts
  
• a Tee fitting that has two 3/8" flares and one pipe thread fitting
  OR
  a T fitting that has 3 pipe thread fittings. and then adapters to goto flare.
  (of course the preferred one is the first one, but either will work)
  
• if the FPSS went to the fuel rail directly it is -4AN.. however some use a -4AN to pipe adapter.
  if its 4AN get a -4an to pipe adapter to go into the T.. if its pipe thread, it should screw into the T.
• if anything uses pipe thread, get teflon thread PASTE (not tape)

you'll need a tubing flare tool. you can rent one from autozone.
now, we need to know for SURE that the line is 3/8" and not metric

• relieve the pressure from the fuel line.you will want to have the gascap off
• mark the line where you want the T put in. mark the cut and some orientation lines so you know what way is up and whats down...
• disconnect the line and remove it. its not too hard to get off.. plug the lines on the car at both ends... have something to catch the fuel that will spill.
• now that you have your fuel line off (not too hard to do) cut it where the T goes.
• slip a tube nut on first... on both ends. so you dont forget.
• debur the end of the tube
• put the flare tool on, the line and put a double flare on it.'
• assemble the T if it uses adapters... use teflon PASTE but no tape (tape could clog the injectors) anywhere theres pipe threads.. do NOT use it on the tube nuts or the flare fittings just pipe thread fittings.
• attach the FPSS to the T.. loosely assemble the T to the line using the "up" marks to have it lined up roughly correctly
• reattach the lines
• now that you can perfectly adjust its position, tighten the T.
• have someone under the car (but not under the line, watch your eyes.. lol) and turn the key to on.. and back off after the pump primes, and on again.. keep watching for leaks.
• check for leaks again.
• you should be done.

yes, its a bit involved, but even if you've never flared a line before, its not a difficult project..
if you want to practice, you can buy a piece of line that has the tube nuts on it already... then use the nuts for your car and practice flares on the tube...

 

ricky, how well do thoes compression nuts work on the steel OEM line? ive heard bad things, but i have no first hand experiance with them... ive always done the "extra work" of flaring it.

 

Put it at the end of the fuel rail w/90º fitting and cover up w/fuel rail covers...

 

Thanks, I like the compression fitting Idea best. The line with a dial caliper measures .370-.375", so I'm pretty sure its 3/8". I've done a few double flares, but if the compression fitting is safe and works it will be much easier.

 

I think they work fine as long as you get a good tight compression. Now there are some the earl's sells for aluminum, tubing, but the numbers I posted are for steel... I would even go as far as to use a little locktite on the threads so once your done, you never have to worry about the nuts lossing up.

Ricky

 

1. Loosen the fitting.
2. Remove the wires.
3. Install FPSS in nearest dumpster and use the narrow band O2s or better yet a wideband.

Thats my method.

 

just my thoughts on that....

nitrous setups are designed to run rich on the spray... with a narrowband, it will peg rich. with a wideband, it will read really rich.

when you start to have a fuel supply problem, the pressure, drops.
now, you cant set your pressure switch too close to the actual pressure, since you do get fluctuations..
however, normally regulated systems tend to run within 5psi or so of its actual normal regulated pressure. its safe to say, anything more then a 5psi drop is a fuel supply problem.
this 5psi drop is not enough to go lean. a normal nitrous setup should still be waay in the safe range. of course, the narrowband and the wideband still read rich. the engine isnt in any danger.
the FPSS set for 5psi less then the actual normal pressure however.. kills the nitrous.

id prefer that.
why?
because it just killed it when you have a supply problem, BEFORE engine damage.. you never went lean, but you're at the ragged edge of your fuel system... maybe that last gas station pumped rust in your tank.. maybe your fuel pump is dying.. whatever.
point is, BEFORE engine damage, it killed the nitrous system...

now lets look at what has to happen for those narrowbands to read lean:
the switch point of the narrowbands is 14.7..
14.7 is stoch..normal for cruising... but lean for WOT n/a...
and thats WAAAY lean for the hotter burn of nitrous.

in otherwords, by the time your narrowband unpegs and sees its not rich as heck, its too late. you're probably peppering the plugs with alum already.


one is measuring INPUT to the engine.. the fuel pressure.
one is measuring the current RESULT... the O2s.

id like to see the problem BEFORE it gets to the motor.. not just measure the end result, after its been thru the motor...


just my opinion of course.... really, if i was into it, id run a nitrous computer that looked at both the wideband, and the FPSS.... but if you only get one, get the FPSS.

 

the ace hardware type compression fittings work awesome, i use them on my 1800+ psi power steering steel lines w/o problems

dave

 

Sorry it doesnt work that way....A simple clogging fuel filter could cause a 20psi drop and torch the engine. Guess what the FPSS will never see it. You cant set them tight the deadband on these switches sucks. Ask anyone who has tried to set them say +/- 10 psi. I once had a fuel noid fail the narrow band O2 dropped out IMMEDIATELY. It acually went to zero. Got home found the bad noid and also pulled the plugs. All looked perfect. A FPSS would have done absolutely nothing in this instance as well. Thats my opinion on the matter. Over and out.