For anyone who plans to add a fuel pressure gauge to your G8, you'll notice that there isn't much room for adapters at the front end of the factory fuel rail where the Shrader valve is.

The fuel rail is a -4 AN male, and most aftermarket fuel pressure gauges are 1/8" NPT male, so you'll need a -4 AN female to 1/8" NPT female adapter. Normally this adaptation would be done using two separate adapters, but on the G8 there isn't enough room for two pieces due to the location of the power steering reservoir.

It wasn't easy to find, and it's not cheap, but such an adapter does exist. It's made by NOS, and is part number 17982NOS.

Hope this information is helpful to someone at some point down the road. :)

This is good, Thanks

Doesn't Dashhawk tell you the fuel pressure anyway?

Doesn't Dashhawk tell you the fuel pressure anyway?

Nope, doesn't recognize our signal apparently. Reads as 0. I reported it to Dashhawk folks already.

Doesn't Dashhawk tell you the fuel pressure anyway?

I don't know about Dashhawk, but there is already a fuel pressure sensor in the car...

The factory sensor doesn't measure fuel pressure at the fuel rail, which becomes critical with power adders. ;)

Sorry to resurrect an ancient thread but I have a question: Are you certain the fuel rail takes an AN fitting? Aren't OEM flares usually 45 degree as opposed to 37 degree for AN?

Also, I assume the Schraeder valve needs to be removed for this, right?

Thanks much!

Sorry to resurrect an ancient thread but I have a question: Are you certain the fuel rail takes an AN fitting? Aren't OEM flares usually 45 degree as opposed to 37 degree for AN?

Also, I assume the Schraeder valve needs to be removed for this, right?

Thanks much!



The -4AN fitting works just fine. A -4AN fitting is what I used to get fuel for the wet nitrous system in my G8. The schrader will need to be removed.

The -4AN fitting works just fine. A -4AN fitting is what I used to get fuel for the wet nitrous system in my G8. The schrader will need to be removed.

Thank you Sir!

Thank you Sir!


That will be $5. I take Paypal. :wall:;)

For anyone looking for this, I grabbed one, then realized I couldn't use it because I needed a tap for another fuel line :facepalm:

Throwing it up in the for sale section.

For anyone looking for this, I grabbed one, then realized I couldn't use it because I needed a tap for another fuel line :facepalm:

Throwing it up in the for sale section.


What do you mean?

I'm looking for this fabled fitting (-4 AN female to 1/8" NPT female adapter). Where can I get one?

I'm looking for this fabled fitting (-4 AN female to 1/8" NPT female adapter). Where can I get one?



Here you go. It will give you the option to end up either running 1/8"NPT male or female and coming out of the front of your drivers side fuel rail with either a 90 degree bend or straight if you prefer. The straight one may hit your power steering fluid reservoir. I used a 90 in there when I ran fuel for my old nitrous system and it fit perfect. This should work for what you need and look clean as well even if it isn't technically a single fitting. Good luck.