Base fuel presure for s/c with brown tops????? - Boost Forum

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Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 8:59 AM
Many of you should know buy now what my setup consists of. S/c 7or 8 psi, safc2,cartech fmu,rk fuel rail,brown top injectors, blah blah blah. Im curious as to what I should start out as a base fuel pressure? Orange-Z suggested 35 psi. Just wondering if thats about right, he has steered me in the right direction many of times just want to make sure cause I dont want to fauk up my lil sweet heart of a motor. Thanks in advance this forum has been great!!!

Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 9:08 AM
35 sounds about right, otherwise it'll be pig rich at idle and will run like a diesel.

Start high, like 40 and pull it down till you get an idle that you can live with, don't go too low though.





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Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 9:24 AM
Hey Shifted where are you located at? I know you dont use an safc (your an E-manage guy) (netscape) lol but I need to know what In and Outs I should be running 5in 5out? Let me know thanks.
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 9:48 AM
I am idling my brown tops at 35 psi.... from my calculations Brown tops are rated at 35# at 38 psi...

Injectors for our engine are rated at 43.5 PSI, so if you do the math, the injectors are really 37.44 lbs, or 393.5 cc/min...

SO you're sporting 37.5 injectors in the car, roughly.... at our base pressure....

I didn't like bringing my brown tops down to 30 psi at idle, so I'm running them at 35 psi... basically now they're idling at 33.59 lb/hr.....

STOCK is 24 lb/hr injectors, and that's what the computer likes to compensate for... so at idle I needed to figure out how much fuel to pull with my S-AFC to get it down to stock specs.... I did a few calculations duty cycle wise...

33.5 - 24 = 9.5 lbs over stock.... now I need to know what % over stock they are

9.5 / 24 = 0.3958.... basiscally 39.58 or 40% over stock...

So these injectors are 40% over stock size, so I need to pull about 40 % at idle to get them down to 24 lbs at 35 psi at idle.... now I don't feel the need to pull THAT much, as I know the ECU Can compensate for a bit more fuel, so I have mine set to 30% - 35% which means I'm running about 25.1 lbs/hr at idle, which I think is more than acceptable for the car.

So - as you can see - fuel is ALL math. Smart math, always calculate it to be generous towards the engine for your fuel, you don't want to pull too much. The S-AFC can take an engine down if you're not smart about it.

So - that's my answer. 35psi fuel pressure at idle and -30% to -35% on the S-AFC with brown tops on the LD9.

Good luck!

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 10:03 AM
Adam Malinski wrote:Hey Shifted where are you located at? I know you dont use an safc (your an E-manage guy) (netscape) lol but I need to know what In and Outs I should be running 5in 5out? Let me know thanks.


I'm in northern wisconsin. I believe Chris (SunfighterGT), who is running the SAFC, is using 5in 5out. I will also be going the SAFC route for the time being, I won't be able to afford all the e-manage stuff right now, but for the small amount of boost I will be using I will be just fine.





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Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 10:41 AM
You da man but Im sure you already knew that. Do you have your pcm flashed? See I dont have the car on the road yet and cant exactly take it to the dealer. Let me know should I have it flashed no matter what. I want to hear it from someone with experience and a ld9. I need the wiring diagram for the pcm like a picture of the pcm with a label this wire here this wire there. Im no noob to the safc but on my old car (91 integra) i had a vafc, I know how to wire it but in posts ive read they say plug something is black and the other is blue. I took my pcm out of the protective shell under the fender and saw no blue plug or anything that resembled one. So if at all possible can you get me a pic of the pcm with the wires showing me at least colors. Thanks in advance so this is so long but your the only one who seems to know a lil something.
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 10:47 AM
Who're you talkin to? *laughs*

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 10:50 AM
both lol sorry didnt specify you's are da men, lol
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 10:56 AM
My PCM is a 1998 PCM Reflashed to a 1999 with a 2 wire knock sensor added. Works great.

As for the ECM, There should be one BLUE connector, and one BLACK connector.

Here are the pinouts courtesy of NY-Jbodies: LD9 Pinouts

As for the S-AFC install instructions on a 1999 pinout, refer to my install guide in my S-AFC post from 3 weeks ago.

Good luck.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 11:10 AM
http://www.ny-jbodies.org

Click the library link at the top, there are instructions for installing an SAFC on the LD9 on that page.





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Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 11:11 AM
HELLL NO Ron! Those are for a 2.3!!!!

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...

Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 11:12 AM
Well at least the pin outs are on that page





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Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 11:14 AM
Stupid n00b.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 11:57 AM
hey adam listen to what sunfire gt has to say about them injectors, its pretty much what ive already told you but he has already done the safc thing as i have not i just knew the info, so i hope you can figuer out the pin outs and how to hook the safc to the car, cant wait to see you get it going

if you got any questions hit me up with an email as im not going anywhere now lol




Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 2:32 PM
Holy @!#$ O's back, lol good to hear from ya
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 2:58 PM
I need to know where to get the 90 elbow that comes off the t/b and connects to the piping its 2 3/4 i/d to 2 1/2 i/d please let me know where I can get it over nited.
Re: Base fuel presure for s/c with brown tops?????
Sunday, March 06, 2005 5:28 PM
you can get them on ebay i think go check it out




Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 1:15 PM
nope cant find it anywhere
Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 3:06 PM
I do not have a regular fpr just the stock one. The cartech fmu says it only starts to work from 0 to whatever psi your running, but my ? is if you cant adjust the base (stock fuel pressure) with the fmu how the hell can you with the stcok one? It says in the paperwork diconnect the signal line to the fmu adjust the pressure to lets say 50 psi then reconnect the line and watch the pressure drop to stock. WTF? Help me out thanks.
Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 4:46 PM
Think about it and you'll understand why you can't adjust the base pressure with the FMU...

The fuel flow goes like this:

Fuel Pump -> Fuel Rail -> FPR -> FMU -> Fuel Tank

Now, the FPR is a restriction in the line to increase the pressure in the fuel rail. So lets say its restricting it to 50 PSI, and you want 30, so you adjust the FMU real low so you think it goes to 30, but you still get 50. Its because the FPR is first in the flow, so thats where the first restriction is. The FMU can raise the pressure above what the FPR is set at, but it can't go below that (how can it create less of a restriction in the line?).

The reason you take the signal line off the FMU is to adjust the fuel pressure at the FMU at WOT. Obviously its hard to adjust WOT fuel pressure with the screw on your FMU when you are barrelling down the road with the pedal wide open. Removing the vac line causes the FPR to hit its max PSI (1 atmosphere), so from there the FMU allows you to RAISE the fuel pressure, again, you cannot lower it below the FPR. The Cartech instructions assume that you only want to raise the fuel pressure, not lower it.





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Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 4:49 PM
Oh, and you can't adjust the base fuel pressure with the stock FPR either, you have to buy an adjustable one, like the Accell 74565 I think the number is.





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Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 4:51 PM
Duh my dumb ass fault. I feel like a total newb. I need to go swimming with the other squids!! LOL So the stock fr is 35 right?
Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 4:55 PM
I'm not totally sure, I could tell you in about 2 weeks when I get my pressure gauge put on





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Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 4:57 PM
ok this is how it goes

your gonna need to get an adjustable fuel pressure regulator you stock fpr cant be adjusted at all

you will also need a way to read the fuel pressure, i my self have a gauge taped into my fuel rail, but you can also tap into the lines going to the rail

you then will have to set the afpr to 35psi like i said before which will make a somewhat liveable idle

now to work on your fmu, this is what you need to do

you need to take the boost signial line off and you should read a higher psi then 35psi, but you wanna get it to only like 5psi over this and then hook it back up and it should go back to 35psi what this does it illiminate the lean spot before boost which some people run into with fmu's


also for more information for ya the stock pump can only pump up to 65-70psi cuz i know you where probley wondering that


also if you have any more questions let me know







Re: Base fuel presure for s/c with brown tops?????
Monday, March 07, 2005 6:44 PM
Ok thanks Z im only running 7 or 8 psi can the pump hold that amount with brown tops? So its a must that I need a afpr I cant run the stock one at 35 psi and adjust it down with the safc like sunfiregt said? Let me start this over again.

What should I do for my setup tell me everything even if you have to write for days j/p lol.
Heres my setup: 01 z24 5 speed
Vortech s/c
Cartech FMU
Safc2
Brown Tops
RK Sport Rail
Innovate Wideband Kit
Magnaflow Exhaust
Please tell me everything. Here's my list of ?'s sorry so long.
1. What psi should the fmu be at with the line disconnected?
2. What afpr should I get and where?
3. When I hook up the wideband where should the a/f be?
4. What psi should the base line psi be?
5. Where the hell can i get the damn hose coupler from?
6 When can you two come over and supervise me? LOL
THANKS GUYS FOR EVERYTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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