Yesterday I finally got to do a bit of tuning and was able to get the boost up to 15 psi and the RPM's to 9000 ........... , all I can say is WHOA!!!! , she pulls so hard that I get scared and back off before I even get to 7000rpm (not to the delight of my tuner!!) , the acceleration is like nothing I ever felt before (My friend with his turboed HONDA found out the hard way https://www.nopistons.com/forums/pub... ) . The sound of the bridges when the start to "work" is soooo beautiful to say the least , I am quite pleased with the results of all my efforts , thus far https://www.nopistons.com/forums/pub...#>/biggrin.png .

Now a new problem , not enough fuel !!!! , the A1000 seems to be almost out of capacity , I run 4 - 850cc's and 2- 1300 cc's and they are hitting 88% duty cycle !! at 15psi and 9000rpm , I am looking into swappin in a pair of BOSCH 044 pumps , anyone know anything about them ? , will they flow enough for 25-28 psi ? . https://www.nopistons.com/forums/pub...IR#>/bigok.gif https://www.nopistons.com/forums/pub...#>/biggrin.png https://www.nopistons.com/forums/pub...DIR#>/cool.png

What kind of pump are you running now and FPR/psi??

I am using the AEROMOTIVE A1000 pump and a PAXTON 1:1 FPR , my static fuel pressure is 37psi . As boost builds , so does the fuel pressure , until a max of a little more than 50 (its supposed to go to 52psi with 15 psi boost) , then it starts to fall off to about 45psi as I go up in the rpm's.

Isn't your base pressure a little low? I don't know but I thought most people ran higher then that?

my base is about 35psi. I run 2 550's and 2 1600's with a walbro pump and had PLENTY of fuel on the dyno https://www.nopistons.com/forums/pub...IR#>/smile.png

If you check this fuel calculator out and input your mods and you are hitting 88% then you are making some crazy ******* power, AT 15 PSI. Something doesn't seem right?



fuel calculator

Yes, but if you account for the pressure drop, it only comes out to around 500rwhp which is very doable on the bridge and that turbo at 15psi.

I would suggest turning your static fuel pressure up to 45 psi.

Not if he is already having pump problems. That would just make the pump flow less.

I think KSP Engineering ran a couple of those and they're making around 700rwhp, so I think they would work https://www.nopistons.com/forums/pub...#>/biggrin.png

Yeah, I missed the second post on this thread... https://www.nopistons.com/forums/pub...1047683664.gif ...



DuMaurier7, something's sounds wrong with your pump/pump wiring. I'm using 2 FD pumps at 45 psi static fuel pressure and it hold thru 9000 rpms/15 psi boost. What gauge wire are you using for your pumps? Are you sure your getting the right voltage to them?

I am using 8 gauge amp. wire from the battery streight to the pump , my battery is at the back so the distance is short , the ground wire is also connected at the batterys grounding point in the hatch and is switched via the HALTECHS pump control system which I wired to switch an additional relay. I found that the supply voltage from the HALTECHS's system (the orange coloured wires) wasnt capable of supplying enough power when the battery is placed at the back , although I used 0 gauge oxygen free audio wire (expensive stuff) to connect the battery to the +ve connection point up front , before switching around the voltage supply , the fuel pressure would keep falling off at as little as 10 psi boost.

A bit more info , at WOT in third gear my max . exhaust temp. was about 1440 deg . F (782.2 C ) , max intake temp without W.I active was 95deg F ( GOOD ol' large NPR) and coolant temps was at 180 F max.

Good numbers!

Yeah you should be seeing around 40psi fuel pressure at idle, and add 1psi per pound of boost. Nothing wrong with 88% duty cycle, just keep it out of the 90's.

You shouldn't be having any pressure problems with that pump, yet. You might want to check the fuel filter. Even if you were very careful assembling your fuel system, sometimes there is still a little bit of crap that gets in the system, and takes a little while to catch in the filter. I would try pulling the filter out of the system and backflushing the filter to see if there is anything in it. What size line are you using out of the pump to the rail?

i am using -8AN all the way up to the engine then it splits int two -6AH hoses to feed the rails.

Where do you have the pump mounted? Is it lower than the gas tank?

Not it isn't lower , but it is in line with the suction point which is at the rear of a sump that I had attached to the underside of the tank. I have the pump mounted on to the black, metal piece of sub-frame that goes between th tank and the Diff , I bolted the pump on to a flat rectangular piece of aluminum , then mounted that on to the sub-frame.

I am running 50 PSI base with this pump and My pressure holds all the way to redline, but at 24 PSI I checked the peak injector duty and it was about 98%. The 24 was insane compared to the 18 PSI I normally ran. I wanted to try 25 but wont even think of it untill I get some room on the injector duty.



I am using 10 AN to the pump and 8 AN feeds to each rail. My pump is lower then the sump. I wonder if some crud did not get cought in the filters? What filters are You using (micron size)? I used teflon steel braided lines and the fittings are a bit restrictive so I am changing to rubber stainless lines and Earls fittings as the bends flow better. I am not sure if it will help but I am going to change them out.

I am using the AEROMOTIVE filter with the 10 micron stainless steel element . What turbo and porting are you running (sub-Zero) ?.

The 10 micron filter will not work before the pump.

It's too restrictive according to Aeromotive and also after finding out the hard way!:( You need to use the 100 micron filter before the pump and the 10 micron after the pump. The 10 micron gets clooged too easily making it useless before the pump.

Fuel pumps (any kind of pump for that matter) do not take well to restriction on the suction side, do what crispeed said.

Sounds like a good start

OK I checked it back and found that I have the 100 micron ,stainless steel mesh filter on the suction of the pump .I havn't pulled it yet to see if its clogged though but I doubt it , but a while ago I posted something similar to this that had been happening to a local racer . He was using an SX pump and four 1600cc injectors and was running out of fuel up top (90% duty cycle) , He eventually put a SUPRA pump in-tank and "T -eed" it into the discharge of the SX pump , this solved all his problems !! , I think I'll try that before putting out for the twin 044 pumps, although the BOSCH set-up would be better , the other set-up would be cheaper. https://www.nopistons.com/forums/pub...#>/biggrin.png

I am using an HKS EVC 111 , boost controller and I'm having a hard time getting "it UP" , (the boost that is https://www.nopistons.com/forums/pub... ) in the manual mode , I still haven"t programmed it yet in auto , the lower I go with the offset the less boost I get , am I missing something ?.