Fuel Pressure Regulator

[rooster]

St Louis SHO tells me that if I want to up my boost, I should get a good FPR. Which one do you guys use?

 

[Sho-Driver]

Josh at SHONUT has a great FPR kit that has everything already worked out. It's well worth the money. At 12 PSI, you really ought to be using one already. You can start out with the standard kit and upgrade to the HI-PO setup later if you think you need it. In most cases, the standard one is all you need. What fuel pump do you have?

 

[rooster]

I just flipped through my receipts. I couldn't find anything for a new fuel pump. It does have a SHO SHOP Boost-A-Pump

 

[Lupo]

The stock FPR can handle boost no problem. It's at low speed which it can't handle the high pressure 255lph pumps required for 12psi. It can't drop enough fuel pressure at idle/cuise, which creates problems with idle and driveability.

 

[St Louis SHO]

And thats the problem it already has....

 

[Sho-Driver]

Personally, I would get into the tank and see what fuel pump you have and work from there. I don't know that I'd keep the boost-a-pump. If I were that worried, I'd sell the boost-a-pump and get the HI-PO FPR kit from Josh and just make sure you have a sufficient fuel pump.

 

[St Louis SHO]

It has a 255lph pump. If you have or have driven a S/C SHO, you'll know that a stock fuel pressure regulator makes it idle like shit and on decel its fat as a f'n pig and will do all sorts of funny stuff like die, foul plugs and all that. After driving Jeff's car for a couple of days, it in my eyes is useless for driving, unless you wanna 2 foot it, which is why I suggested upgrading FPR before upping the boost, just to make it more driveable. The OP likes to drive his car, not have it sitting at my house while I change the plugs and figure out whats going on Thanks for the help so far guys, as I have almost zero experience with a supercharged/turbo car.

- James

 

[St Louis SHO]

Also, to add to what I posted above, the car is still running on the SHOShop tune, will anything need to be done with that right away with the FPR change?

Thanks

- James

 

[SinisterSHO]

Also, to add to what I posted above, the car is still running on the SHOShop tune, will anything need to be done with that right away with the FPR change?

Thanks

- James

I made zero changes to my car when I added my FPR. Just set the pressure and went. I guess potentially on a SHOShop blower tune it could probably be leaner, but it will probably be fine out of the box.

 

[BlackonBlack89]

Is it still using the SS LPM tune?? Is that what it has or is it a tweecer??? I've read the SS tune just dumps fuel by the boatloads. I know the FPR will help alot more in this issue but I would bet a better tune could help with the drivabilty/idle too.

 

[St Louis SHO]

LPM 100% sure on that.

 

[Lupo]

I made zero changes to my car when I added my FPR. Just set the pressure and went. I guess potentially on a SHOShop blower tune it could probably be leaner, but it will probably be fine out of the box.

Having the correct fuel pressure throughout the entire vac and boost range is going to do nothing but help ANY tune if you ask me!
The ECU is constantly doing the lean/rich dance trying to compensate for the overpressure at idle, and then the normal pressure at partial throttle.
Once I fixed the FPR problem, the car idled way better, and didn't run ultra rich in idle/cruise. This is with an original SS tune.

 

[Sho-Driver]

If the car is trying to lean out at idle due to over-pressure, it will apply these tables to WOT meaning it will try and lean that out too. You're going to do nothing but good if you have an FPR that can keep u with all the vac/atmos/boost needs.

 

[rooster]

Thanks for all the help. I'll get in contact with SHONUT for the FPR, and I'll order me a new pulley.

Hey James... You ready to get f'n crazy?

 

[St Louis SHO]

Oh, you know it.

 

[1995SHO9]

Just to let you know Rooster, I ordered a fpr kit for my turbo project from SHONUT, they are back ordered for close to a month. It sucks becuase that is the only thing holding me up from doing my project. I'm about to just get one off of ebay in the mean time...hmm I might have to.

 

[Toolman]

As others have stated, you will not need to make any changes to the LPM tune once you install the FPR. From what I can tell, SHOSHOP made the following changes: MAF settings, timing advance, rev limiter, secondaries opening, idle settings, and adjusted the WOT fuel multiplier. There were no changes made to the stabilized fuel settings. The LPM's needed to be removed and the battery unhooked so as to 'clear' the computer, as it was doing it's best to adjust the fuel trim, but could only do so much.

Adding a good FPR should make a world of difference for a SS LPM car with a big fuel pump.

TT

 

[BlackonBlack89]

That is good news. Thanks tim for the info.

Kinda of related... what is the rev limiter on the SS lmp tunes. and doesnt the ecu cut the fuel when u hit the rev limiter. isn't that a bad thing when boost is added??? what do you boosted guys have for a rev limit