fuel preasure questions????

[andrew N.]

how do you install a fuel preasure guage under the hood??

and i have a kenne bell boost a pump, whats normal fuel preasure and whats a good number for using notrous?

thanks

[John_D.]

<blockquote>quote:</font><hr>Originally posted by andrew N.:
how do you install a fuel preasure guage under the hood??<hr></blockquote>

It will tie in to the schrader valve on the fuel rail. This is a valve that looks a little like an oversize tire valve stem, on the passenger side of the engine.

As far as mounting it, you can bolt it just about anywhere under the hood, as long as the line reaches from the schrader valve to the gauge. Or spring for the $180 and up electrical gauges to mount it in the car. Then you put the sending unit on the schrader valve and run a wire inside the car.

Also you will need to unscrew the valve core from the scrader valve. The easiest way to do this is get one of those little tools to unscrew the valve core from a tire valve stem.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by andrew N.:
whats normal fuel preasure and whats a good number for using nitrous?<hr></blockquote>

Normal is around 40 psi, which is maintained by the fuel pressure regulator on the fuel rail on the driver side of the engine.

My 85 shot NOS-5175 is supposed to kick it up around 70 psi when the nitrous is flowing. I'm still hooking everything up, including an electrical gauge, so we'll see...

[ June 17, 2002: Message edited by: John_D. ]</p>

[12secondv6]

First, do you really want one under the hood?
It's kinda hard to see when you are cruising down the road w/ the hood shut :D
I have an electric one mounted in one of my vents on the inside of the car.
With an electric guage you need a sender unit, I have one mounted to my afpr but you could have it right off your shrader valve on the fuel rail.
With a mechanical guage you can not have fuel go from the engine compartment to passenger compartment (tech rules and safety too) so they use something similar to anti freeze to run from the guage to the sender unit.

As for kenne bell boost a pump, it does not boost fuel pressure, it just can boost voltage to your stock fuel pump. I set mine to about 10-15% n/a and 50% for nitrous runs.

My stock fuel psi was 32.5 psi.
With my dry kit I used to run 42 psi on the street and 46 psi on the track.
With the wet, I dunno yet, my guage stopped working :(

[John_D.]

I got the fuel pressure gauge hooked up today.

I get 50psi at initial key on, 42 psi at idle,
about 44psi going down the road, and about 40 psi when coasting or slowing down...

I wired the nitrous kit, installed the fuel pressure gauge, the boost gauge, rocker switches, traced down instrument lamp wiring for the gauges so they'll dim too, and finally finished the line for the nitrous. Man I'm tired... It's been a long day. Tomorrow, getting the bottle filled!!

[12secondv6]

Dang, that's better fuel psi than I had stock
Good luck and let us know how nitrousing

[John_D.]

Ok, I hit it about 4 times yesterday. It pulls strong. Not like hitting a lower gear, but more like going from 1/2 throttle to full throttle. When I normally would be going 70 or so, it was already doing 90. I'm very pleased with it so far.

Fuel pressure is only going up to 60psi though. The paperwork said it should go up to 70. Haven't autotapped it yet, so not sure what the o2 readings are with the 60psi. I may have to experiment with that jet in the line to the regulator.

And I have a pinhole leak at the pipe fitting going into the first solenoid, so I need to fix that. Does the fitting need to be screwed in as tight as possible, or does the teflon paste do all the sealing?

[12secondv6]

Teflon paste and tighten it down.
I had several leaks initially but once we played around with it we took care of the leaks.
The first couple sprays will feel kinda weak.
You will notice a HUGE amount of black smoke from the exhaust under full throttle and juicing. That is normal. Nitrous is a detergent, it will completely clean out that engine from all carbon build up.
The first couple times I juiced I thought nitrous was a waste.
I was extremely dissappointed.
I'm quite satisfied now though :D
Give it 1-2 bottles.
I would have thought your fuel psi might be a bit higher.
With my 120 shot I saw around 80+- psi (although I do have the kenne bell boost a pump).
Yeah auto tap it

[John_D.]

Fixed my leak. Re-tefloned the pipe fitting going into the first solenoid, also had a leak at the AN t-fitting going to that pipe fitting, just had to tighten it down some more.

Haven't taken it out on the road yet to test out again. Probably will tomorrow morning.

How much $ is a nitrous refill, usually? The place I went charged right at $50 including tax! $4.60 per pound. (plus he put a "little extra" in there, he said...)

[12secondv6]

Nitrous refils can be between $2 and $5 per pound
There are 2 ways of filling the tank, freezing the bottle or cryo pump.
10 lbs is 10 lbs.
that is what is meant to go in there.
Weigh it and see how much is in there just for the hell of it.
A local crappy speed shop claimed they stuffed I think 15 lbs in a 10 lb bottle, guess what, you can't do that.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by 12secondv6:
You will notice a HUGE amount of black smoke from the exhaust under full throttle and juicing...
Give it 1-2 bottles.
I would have thought your fuel psi might be a bit higher.
With my 120 shot I saw around 80+- psi (although I do have the kenne bell boost a pump).
Yeah auto tap it<hr></blockquote>

Thanks for all the info. [img]smile.gif[/img]

I'll post more (and probably start a new topic, since we kinda took over the original fuel pressure one) after I autotap and play with the maft if needed.

I am wondering about the fuel pressure (just 60psi). We'll see where the o2's fall and go from there.

Where did you get the boost-a-pump? There are some psuedo kenne bell sites, but nothing orderable on them. Is this something that Jegs, Summit, tbyrne, etc. regularly carry? I've never noticed, but never really looked before.

I need to get some pictures up, somewhere. I mounted the bottle in the spare tire well, in a way that I can turn the valve by just taking the rear speaker grille off. Thought it was kinda cool. :D

[12secondv6]

Try www.google.com
Put in kenne bell boost a pump
Wroks quite well