a couple questions about fpr setting, 510cc capabilites

[khartley]

Ok, I have 2 quick questions:

I have my car set at 17psi...what should my FPR be sitting at? I have it at 60psi right now, which I think is a little high, but I don't want to end up lean, I'd rather run too rich than too lean.

At what point would my 510cc injectors be maxed out at? Like I said, I am set at 17psi on a stock 14b. With better tuning I might shoot for 19psi later on...and even further down the road I'll probably go for 16psi on a 16g. When should I plan on upgrading the injectors?

 

[Loewen21]

Take the vaccuum line off of the fpr, and set it for 34 psi.

 

[Loewen21]

My bad false info there. Mixed the numbers off. Take the line off and set it for 43 psi. Sorry bout that. Thats standard setting, and then if your having problems with that you can adjust it.

 

[chicagoavenger]

^ 36-38 is the base for a 1g

 

[GVR4592]

36 psi for a 1g with a manual transmission 43 psi for a 1g with an auto tranny.

If you don't have some sort of tuning device to compensate for the larger injectors you should take them out and install the stock injectors. You should also have a datalogger if you're going to perform modifications like this.

 

[khartley]

I have a datalogger, but I'm still kinda understanding how to use it (its old, and has an old program on it) I just wanted to get a good base of what the fpr should be at, so I'm not starting off blind when I do the tune. So are you saying 36-38psi for stock, 43psi for 17lbs of boost?

 

[GVR4592]

No, I'm saying fuel pressure is 36 psi. If you set it higher and don't compensate for it somehow, the car is going to run like crap and not make any power. Same thing with adding larger injectors, you have to have a tuning device(SAFC,DSMLINK, etc) to make it work correctly.

 

[CanadianTSi]

Stock FPR for a 1G is 37psi with the vacuum hose off regardless of what boost you run.

 

[khartley]

Ok, then what if I put my stock injectors back in until I can get an SAFC, what boost on a 14b will max out the 450's?

 

[jking29]

Instead of pulling the injectors back out, you could upgrade to a 2g mas and set your base fuel @ 45lbs. That should put you in the ballpark, but you will definitely need to log it to be sure.

 

[My91TalonTSi]

Ok, then what if I put my stock injectors back in until I can get an SAFC, what boost on a 14b will max out the 450's?

It all depends. Monitor your logger and it will tell you where your at as far IDC and knock. I wouldn't push too far past 90% IDC and you obviously want 0 knock or close to it.

 

[khartley]

Ok I finally logged today! All I monitored was knock, what else should I be monitoring?

As for knock, I turned my fpr to about 53, and knock stayed at 0 the whole time, except once when it said 224 for a split second and then went back to 0....not sure what that was about. I'm going to mess with it a little more tonight to try and get the fpr down just a little more.

 

[GVR4592]

You shouldn't be adjusting your fuel pressure if you don't have a tuning device. Log your fuel trims bet there all over the place.

 

[pballer]

you should log: knock, rpm, IDC, timing, o2 volts. thats a start. Deffinatly lower that fuel pressure as well.

 

[zippyshoe]

In most cases, there is no reason to set your base fuel pressure to any value other than the factory setting (regardless of your boost pressure.) There are some instances where some people will raise their base fuel pressure a bit to increase their injector flow rates. This is sometimes used as a "band-aid" fix for injectors that are too small for their application. The long-term solution to this problem is to upgrade to larger injectors (and return to factory base fuel pressure) in order to keep a reasonable IDC and ensure that they are operating at their rated fuel pressure.