afpr psi on a 255pump and stock injectors???

[Sbeing1]

I have a 255 pump and i just bought a afpr (comming in mail soon) what psi should i set the fpr to with my stock injectors? also, my car is running SUPER rich right now, on a 255 pump what psi do u think its running right now? thanks

 

[FORMONTOYA]

set the new one at 43.5psi with the vacuum hose OFF. you should be at 43.5psi with a factory fpr. you are correct that the factory has the car running fairly rich.


jim

 

[CorvetteBoy]

Run your stock 43psi w/ vacuum line off.

I wouldn't change the pressure until you have something to monitor your rich/lean conditions with. Its hard to say what your really running for PSI if your over-running it. It really varies from car to car, i've seen some guys run a 255lph on stock FPRs and not overrun them..

Hope that helps you out a bit.

 

[sweet97]

I have a 255 pump and i just bought a afpr (comming in mail soon) what psi should i set the fpr to with my stock injectors? also, my car is running SUPER rich right now, on a 255 pump what psi do u think its running right now? thanks

What pressure it's running now is irrelevant, it's also supplying a lot of volume which is more important than pressure and that's what the Walbro's and such are for, the additional volume so there is always plenty of fuel available. When I added a Walbro 255 I idled Ok but once I hit boost black smoke and sputtered like mad!! AFPR rectified that. good luck. Mark

 

[UncleBens]

Yea when I put an aftermarket aeromotive fpr on, the dsm IE-fpr kit from Importevolution.com and it fixed a lot of rich conditions, especially at idle. Better gas mileage now too!

 

[Sbeing1]

great thanks guys, i know im def running way to rich, my car bogs out and goes really slow, i have tons of mods and im slow, has to be it. thanks alot guys hope it works

 

[uvbneclipsed]

i did the evo3 swap and the car was bogging down bad at idle. I have an afpr by buschur racing on the car now but the only way i can get the car to idle decent it to turn it way up kinda scared to tell u what im at but its 70 psi on 450cc injectors whats goin on here? hit me back


Derek

 

[sweet97]

If you have an EVO big 16G you may need 70psi of fuel pressure to run 20PSI of boost on 450's. What psi do you have the base set for? Mark

 

[uvbneclipsed]

the 70 is at idle im not quite sure what it is under full boost i know the car needs a new iac motor so the idle is rough maybe the car needs a good tuning.

 

[sweet97]

something is WRONG!! You should have 43 psi at idle with the line off. Turn your BISS screw all the way in and see what happens because at 70psi your motor probably should not run, that's why it's rough. You must have a major leak to allow 70psi to let your motor run. Are you familiar with the ISS screw? It can adjust your idle and is located on the throttle body facing the front of the car, hood up. Turn it in until the car shuts off or the motor wiill idle with 43 psi base pressure. Mark

 

[Diplomat]

"great thanks guys, i know im def running way to rich, my car bogs out and goes really slow, i have tons of mods and im slow, has to be it. thanks alot guys hope it works "

While I'm sure things will improve after you install and adjust the AFPR, I wouldn't go racing for pinks just yet. You're heading in the right direction with your current setup, but it looks like a couple key ingredients are missing from the "tons of mods" list.

In order, the next upgrades you'll want to buy are a fuel controller/stand alone unit, and larger fuel injectors. Your turbo is capable of maxing out 550cc injectors and you're running stock 450's. However, throwing on different sized injectors with no way of compensating for the additional fuel would really screw things up. Therefore, I'd suggest getting a piggy-back style controller like a SAFC or a stand alone like DSMlink or the AEM EMS before buying much else. In fact, you'd probably be able to tune a few horses out of your current set up before you get the injectors as well as push back or [hopefully] eliminate fuel cut (depending on what type of fuel tuning device you go with). Meanwhile, you won't be able to completely unleash your turbo until you get some more fuel going, but at least you already have most of what you'll need.

 

[badas93tsi]

I dont want to hijack a thread, but I'm also getting an afpr in the mail today. Should the base psi be set at 43 even though I have 770cc injectors?

 

[EclipseTrbo420A]

i did the evo3 swap and the car was bogging down bad at idle. I have an afpr by buschur racing on the car now but the only way i can get the car to idle decent it to turn it way up kinda scared to tell u what im at but its 70 psi on 450cc injectors whats goin on here? hit me back


Derek

Your gauge is broken , probably. get another and chech your Fuel pressure. thats too high .

 

[snox135]

I dont want to hijack a thread, but I'm also getting an afpr in the mail today. Should the base psi be set at 43 even though I have 770cc injectors?

You should always start out at the manufactures base fuel pressure setting, regardless of what size injectors you are running. The reason for buying a afpr is to maintain a constant fuel pressure curve with higher volume pumps. This is because the outlet on the stock fuel pressure regulator is too small. When used with higher volume pumps you lose your linear fuel curve. In my opinion you should only adjust your fuel pressure as a last resort when trying to tune your engine.

 

[badas93tsi]

I dont know if youre talking to me, but I'm not trying to tune, just trying to set my new afpr. Thanks for the info.

Donnie

 

[oldman]

I dont want to hijack a thread, but I'm also getting an afpr in the mail today. Should the base psi be set at 43 even though I have 770cc injectors?

No, it should be set at 37psi without vacuum for 1g regardless what injectors you have. With that said, you will have hard time tuning 770s with just a safc.

 

[badas93tsi]

No, it should be set at 37psi without vacuum for 1g regardless what injectors you have. With that said, you will have hard time tuning 770s with just a safc.

Actually, I had the car dyno tuned at Extreme Motorsports and it held good afr at 21 psi. Im only adding an afpr because Im also adding a N.O.S wet kit and the tech at Summit suggested I get one. Thanks for the base pressure info though. You guys are a big help working on my p.o.s. Sorry for junking up your thread.

Donnie

 

[oldman]

Actually, I had the car dyno tuned at Extreme Motorsports and it held good afr at 21 psi.

21psi of fuel or boost pressure? I don't see how you can tune 770s with just a safc unless you're decreasing the fuel pressure via the afpr to lower the flow rate of the injectors, 680s are about the maximum adjustment range of a safc. Have you done a log yourself since the dyno tune?

 

[badas93tsi]

When I first built the car I had the ECU chipped for 550's. It was dyno tuned at 21 pounds of boost. stock fpr. I havent done a log, now way to do it. I only wanted to know what the factory setting was. Sorry for the confusion.

 

[oldman]

When I first built the car I had the ECU chipped for 550's. It was dyno tuned at 21 pounds of boost. stock fpr. I havent done a log, now way to do it. I only wanted to know what the factory setting was. Sorry for the confusion.

If the ecu is chipped for 550s, then 770s should still be within range of the safc, just looking out for you and nothing more.

 

[badas93tsi]

I apprecitate your help, I should have clarified the ecu thing at the start, I forget about it most of the time, its been so long. Thanks for the help.

 

[oldman]

You're welcome.

 

[snox135]

I dont know if youre talking to me, but I'm not trying to tune, just trying to set my new afpr. Thanks for the info.

Donnie

No I wasn't directing that completely at you. I was answering your question plus giving you and others some helpfull info. I have seen others buy a afpr to try to tune there engine with fuel pressure.

 

[Sbeing1]

alright, so a safc1 is probably gioing to be my next mod, then injectors. Sorry to ask, but what are the max injectors allowed by safc? 600? thanks alot guys you have been really great help. i got the fpr installed but i still havent bought new keys (i lost them a week ago, in another topic) otherwise id test it out. thanks


ps- also, you guys said to run the fpr without the air hose connected. why is this so? is this so the ecu doesnt read it and pump more fuel or something?

 

[oldman]

alright, so a safc1 is probably gioing to be my next mod, then injectors. Sorry to ask, but what are the max injectors allowed by safc? 600? thanks alot guys you have been really great help. i got the fpr installed but i still havent bought new keys (i lost them a week ago, in another topic) otherwise id test it out. thanks

I strongly suggest that you get the car up and running correctly before you start to think about next upgrade. An afpr should take care of your rich conditions during idle and part throttle but should not contribute to bogging during hard acceleration, you probably have other issues like boost leaks and such which will reveal itself once the afpr is set to 43psi. There is no need for a safc unless you have larger injector so do them both at the same time.

ps- also, you guys said to run the fpr without the air hose connected. why is this so? is this so the ecu doesnt read it and pump more fuel or something?

Because our system is set up for 1:1 ratio between intake pressure and fuel pressure so the idea is to set the base pressure without the influence of the intake pressure, the 1:1 ratio will take effect once the vacuum line is reconnected. For example, a 18hg vacuum will result in -9psi of pressure so you should read 43psi-9psi=34psi at idle.

i did the evo3 swap and the car was bogging down bad at idle. I have an afpr by buschur racing on the car now but the only way i can get the car to idle decent it to turn it way up kinda scared to tell u what im at but its 70 psi on 450cc injectors whats goin on here? hit me back

First check and make sure the fuel gauge is functioning properly. Like I have posted above, you should be running at about 34psi of fuel pressure with the vacuum line hooked up at idle. If the gauge is good, you have some serious problems and you're using the afpr to cover it up. I suggest setting the afpr to 43psi base so you can troubleshoot your problem properly. Start with the basics like checking IPS, TPS, ignition timing...etc.