I figure since I have a TPI system (actually its Stealth Ram now) I should get a gauge that goes to 60 PSI. My main question is if I should get a digital one and mount it in the car, or just get one that rests on the fuel rails. I figure the only time I'll need it is when tuning/troubleshooting. Not really something that I'd have to check while driving, right? What are some good brand gauges too? I've heard alot of bad things about the cheaper gauges, especially cyberdyne.

I don't know if this is the same for FI gauges but the carb ones are really bad dealing with heat. After they get hot they'll bury the needle.

Mech. gauges are cheaper but you'll need to buy an isolator if you want to run them into the cabin. Then you still need to deal with running a line with a neutral fluid. Otherwize you could mount it on the inside a cowl.

Course you could go totally electric sender gauge, but those are more expensive.

One in the cabin would be nice if you ever plan on putting a poweradder on the car.

I've had good luck with the Autometer phantoms.

For in car mounting, I use an Autometer Z-series electric fuel psi gauge on my GN. It's dead nuts accurate and way easier to install than a mechanical with isolator.

I'm thinking I'll never need to know my FP while driving (hopefully I won't have any problems with the car), so I'm looking for a mechanical one on the fuel rails.

For four years I had the fuel pressure guage on the fuel rail and it was useful for tuning the adjustable fuel pressure regulator I have. However in the last two years I changed to the Autometer elec. 0-100 psi guage which I put on the A-pillar in my car. I changed because I've done a lot of work to the motor and intake over the years and I use the guage along with a snap-on scanner to help tune the car at WOT while driving to make sure the pressure doesn't fall off at any one point.

If you ask me it comes down this, if you just want to set your fuel pressure and maintain the setting then I would go with the one on the rail. If you are racing and have a lot of money in your engine, you'll want to make sure you have a good supply of fuel when you are pushing it, get the one in the car.

As a last note one nice thing about the one on the rail is if you ever think you have a leaky injector after shut-down the guage on the rail is very easy to watch.

I think I'm gonna be using a wideband O2 sensor for tuning, I'll know if its getting the right amount of fuel by the AFR, then I'll take it from there. Does that make sense?

I have an autometer electric gauge as well. Piece of cake to install and sits nicely in my a-pillar. I wouldnt do mechanical but thats just me.

When it comes down to it's your call whatever gauge you want to put in, I just gave you my opion on the pros and cons of each. It's easy to change later if you want. If you do put one inside the car do yourself a favor and use an elec. one from someone good like Auto-meter. Otherwise I would say it's your call I think I had an accel gauge under the hood when I had mine on the fuel rail, the readings were always accurate I believe, however the lens on the gauge fell off after a year or so.