AFPR 86 IROC - Third Generation F-Body Message Boards

woundupz · 09-22-2009, 06:24 PM

I just installed a BBK AFPR in my Camaro. Before I installed the AFPR the stock fuel pressure (with the vacuum line to the AFPR disconnected) was 42 psi. After the install I raised the psi to 52. I haven't really noticed a difference so I am wondering if I should try raising the psi some more or if the AFPR just doesn't add noticeable horsepower?

DJP87Z28 · 09-22-2009, 06:56 PM

Unless you want to wear out the Fuel pump with the higher PSI, I would keep it at 45. you are not going to feel that SOTP performance. I added fuel pressure gage just to check the PSI's.

woundupz · 09-23-2009, 02:08 PM

How does the AFPR affect the fuel pump? All the AFPR does is allow you to compress the internal spring inside the housing to increase fuel pressure to the injectors. The computer will then adjust the band width of the injectors. The whole benefit to the AFPR is it creates better fuel atomization.

DJP87Z28 · 09-23-2009, 05:07 PM

Quote:

Originally Posted by woundupz

How does the AFPR affect the fuel pump? All the AFPR does is allow you to compress the internal spring inside the housing to increase fuel pressure to the injectors. The computer will then adjust the band width of the injectors. The whole benefit to the AFPR is it creates better fuel atomization.

Yes, but the fuel pump will be working harder to supply the additional fuel.

woundupz · 09-23-2009, 05:18 PM

Yea but the fuel pressure increases because that internal spring is compressed not because the fuel pump is sending more fuel, right? Sorry, I don't mean to argue I'm just trying to figure things out.....

Theking · 09-23-2009, 05:48 PM

Highering the PSI at the rail, will higher the pressure/load on the pump
The stock pump is not built to work above 50PSI for longer periods of times.

If you want higher PSI then 50 you need a new pump, Walbro 255 HP pump (rated60+) can deliver it for you.

But going higher then 50PSI isnt needed on a pretty much stock engine..

woundupz · 09-23-2009, 05:56 PM

Your car is very nice. My car looks just like yours except that it is an 86. What is the IAC? Is there an advantage to replacing it?

Theking · 09-24-2009, 04:42 AM

Quote:

Originally Posted by woundupz

Your car is very nice. My car looks just like yours except that it is an 86. What is the IAC? Is there an advantage to replacing it?

Thanks

IAC is Idle Air Control
There is only an advantage to change it if its bad..
I thought mine was bad so I changed it when I cleaned out the whole Throttle Body.. It had 20 years on it , so I thought a new Delco one would be good..

DJP87Z28 · 09-24-2009, 08:31 AM

Quote:

Originally Posted by woundupz

Your car is very nice. My car looks just like yours except that it is an 86. What is the IAC? Is there an advantage to replacing it?

I thought you would know the IAC contolls the Idle Air and turns it into working air in the thottle body. Best reason to replace the IAC is to get that air working again and not letting it be Idle.

Fast355 · 09-24-2009, 11:37 PM

Quote:

Originally Posted by Theking

Highering the PSI at the rail, will higher the pressure/load on the pump
The stock pump is not built to work above 50PSI for longer periods of times.

If you want higher PSI then 50 you need a new pump, Walbro 255 HP pump (rated60+) can deliver it for you.

But going higher then 50PSI isnt needed on a pretty much stock engine..

You only need that pump for BIG HP applications.

A regular old CPI Astro pump works for me and I run 50 PSI constantly on LT1 injectors.

Theking · 09-25-2009, 02:13 AM

Fast355: I know

thats why I wrote that he only needs it if he wants pressure over 50psi and that a pretty much stock car runs fine on the old pump and pressure

thunder85 · 09-25-2009, 04:58 PM

if you are going to go through the trouble of replacing the pump, why put a lesser unit in? if you slap in a walbro you have a higher quality unit and if you decide to add no2 or a turbo in the future you won't have to buy another pump.

a good psi to run with these engines(especially mostly stock) is around 46. good atomization and it doesn't put too much stress on a stock pump