Is there any thing that I could have done wrong installing my fuel pump that would give me readings that are not exactly the same every day?
I just intalled my A&A procharger kit and got it tuned. I made really good power. It is a used kit Andy put together for me when I was trying to get in of the special he advertised a while back on three of his used Vortech kits. I must have been caller number four! So he hooked me up with this kit. It is a P1SC, original style intercooler and duct work. New bracket and 60# injectors, with a new Lingenfelter 255 pump. When I first intalled it and was running it on Andy's base tune the pressure always stayed at 62 lbs. But after a hundred miles of testing and working out any bugs (none ever showed up)before making the long trip to the tuner it started to drop occasionally to about 60lbs and on the trip from Tucson to Tempe I even saw it down to about 59 lbs. I assumed it was due to less fuel in the tank and or temperature. The only reason I am asking is my tuner told me he was losing fuel pressure at the top end limiting the power at the high end. Although I think it made really good power (480hp,429tq) through stock manifolds and catts with the only edition being a LG BIG 3 catback. The amount of boost that it sees because of the restrictive exhaust is a little scary at 11 lbs. At least that is what the tuner said he saw on the guage during one of the last pulls. I was busy keeping my five year old from touching anythingShe is my future gearhead.
Is this normal for what I have?

 

Sounds normal, anything in the high 50s or above is great especially just at idle and cruise, even mid 50s should be fine. You need to worry when the pressure drops into the low 50s and especially into the 40s during a WOT pull. Now your tuner can compensate for this as well but a good fuel system should be able to keep the pressure up

I have a boost regulated system now so the pressure fluctuates greatly. Back when I was off the stock regulator I seem to recall it being higher pressure on colder days (58-60) and lower on warmer days (54-56).

 

Thank you for your response. It gives me peice of mind to know that this is normal. I wish I know how much it dropped off on the dyno.
Is surging a normal part of the beast too? It did not do it until a day after my tune was done. But I don't think it is tune related though. I think my blow off valve may stick a little bit or something because the vacume guage moves with the surge. It only does it when trying to maintain a steady speed. I have not noticed it with the cruise control on.

 

Thats normal just monitor the gauge when your in the upper rpm range did it drop while on the dyno?

 

My tuner said that fuel pressure was dropping off at the top end and he had to tune around it to smooth out the curves. He suggested a hot wire or a boost a pump. But I think that maybe next year I will be doing headers, cam, rockers, springs, and methanol injection. I am going to be a textralia clutch pretty soon. I have all the parts just don't have time right now. Work and family are taking up all my wrenching time.

 

Do think about a BAP or something for more fuel. The meth will help but should not be used as a substitute, rather to work with your fuel to make the tune even safer. Adding headers and a cam will create the need for more fuel even though you may loose a bit of boost.

 

Thank you. I will be doing the boost a pump at the same time. I have a problem with surging right now that I want to get worked out before doing any thing else. I have another thread started asking for input on that issue. I have today off so i will be trying to sort that one out. I appreciate all the help that you guys have given me. I hope it helps some one else too.

 

What cam are you running?

 

Its stock right now.

 

What BOV do you have? If I had to take a guess I would think since its a stock cam the surge would be tune related.

 

That's what I was getting at. I would think there should be NO surge with a stock cam