Vortech Recalibration Disk?
#2
Boost Czar
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with your pump you'll probably want to go as far as a 8:1 disc. Speaking of I need to pick one up soon. Or you can spend the $5-10 extra bucks and get the complete set of discs and see what works best.
#6
Originally Posted by Snowsurfer03
12:1 comes with the kit right?
I am running really rich, so rich that everything bogs down at WOT.
My question is would a 10:1 Vortech Recalibration Disk do the trick?
OR sould I get the 8:1 & 10:1 and see what works best?
I am running really rich, so rich that everything bogs down at WOT.
My question is would a 10:1 Vortech Recalibration Disk do the trick?
OR sould I get the 8:1 & 10:1 and see what works best?
#7
Originally Posted by olderguy
Does anybody have the specs on JR Pump?
http://forum.miata.net/vb/showthread.php?t=20858
#10
8:1 with a 255 at 8psi is gonna fry your injectors. I was on the limit with the 8:1 when I was running 7psi. As soon as I upped my boost to 8psi, one of my injectors failed closed (leaned out one cylinder). My fuel was 100+ psi with the Pierburg and the 8:1 disk (I have a fuel pressure guage with sender). I would go for the 6:1 disk until you can muster some cash for an emanage and some injectors, or go with an adjustable Begi FPR.
#15
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Ok from what I understand -
To calculate your needed fuel:
PR²x(idle_psi) + Boost = Fuel Needed
PR= 14.7 (atm. pressure) + boost / 14.7
So lets calculate 9psi
9psi = 1.61 PR
(1.61*1.61)x36+9=101.7psi of fuel needed
To calculate to amout of fuel given by your FMU:
Ratio x boost + idle_psi = Fuel Pressure
9psi with a 12:1 on the stock pump would supply
12 x 9 + 36 = 144psi about 30 more psi than required
so
9psi with a 8:1 disc would be
8 x 9 + 36 = 108 psi - 6 more psi than required, Corky recommends around 10, so this is close.
Checking Pump Pressures:
If you do this test you should be able to see how much boost you can safely run.
As far as figuring at when the injectors reach 85-90% duty and what the oem fuel pump can deliver is where I'm stuck. And make sure you calculate using your base idle pressure, I'm sure the 255 lb/h idles with more base pressure.
To calculate your needed fuel:
PR²x(idle_psi) + Boost = Fuel Needed
PR= 14.7 (atm. pressure) + boost / 14.7
So lets calculate 9psi
9psi = 1.61 PR
(1.61*1.61)x36+9=101.7psi of fuel needed
To calculate to amout of fuel given by your FMU:
Ratio x boost + idle_psi = Fuel Pressure
9psi with a 12:1 on the stock pump would supply
12 x 9 + 36 = 144psi about 30 more psi than required
so
9psi with a 8:1 disc would be
8 x 9 + 36 = 108 psi - 6 more psi than required, Corky recommends around 10, so this is close.
Checking Pump Pressures:
Originally Posted by Corky Bell
A brief check of the maximum fuel pressure available should also be done at idle. This is essentially determining the pump’s pressure capability. None of the regulators can force a pump past it maximum pressure potential. With a pair of pliers, squeeze the fuel line shut that connects the FPR to the original fuel pressure regulator. When squeezed shut, the pump will be forced to maximum output. Make sure the pressure available is consistent with your intentions. In all cases, the pressure must show, in this idle test, to be about 10 psi higher than the desired fuel pressure, as the available pressure under real load conditions will be less than that measured at idle. This test does not actually prove the pump to be adequate under boost, but if it doesn’t pass this test, it is certainly a waste of time to continue with the same pump.
As far as figuring at when the injectors reach 85-90% duty and what the oem fuel pump can deliver is where I'm stuck. And make sure you calculate using your base idle pressure, I'm sure the 255 lb/h idles with more base pressure.
#16
With these calculations there is no mention of injectors. I would think that 25cc more per injector (about 12% larger) would change the amount of fuel pressure needed at specific level of boost.
Would 1.8 injectors @ 90PSI be the same as 1.6 injectors @ 100PSI?
Or I'm I talking out of my ***?
Would 1.8 injectors @ 90PSI be the same as 1.6 injectors @ 100PSI?
Or I'm I talking out of my ***?
#17
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From what I understand injectors just supply the fuel and can reach 100% duty cycle. You want them to run at 80% or so. But if they can only flow to a certain point. So 90psi of fuel on 1.8 injectors would be 90psi of fuel on 1.6 injectors. The reason you go to larger injectors is to supply more fuel for the higher boost levels. Where 1.6 injecotrs could supply enough fuel for 5-6psi 1.8 injectors can supply enough fuel for 7-8psi....I'm still trying to read and learn more about fueling, but so far this is what I understand.
#18
Are you saying that at 100PSI the 1.6 and the 1.8 are flowing the same amount of fuel?
When I said:
I meant flow the same amount of fuel. At least that would be my assumption given that at the same fuel pressure a 1.8 injector will support higher boost levels than a 1.6 injector.
I wasn't saying that changing from a 1.6 injector to a 1.8 injector would lower fuel pressure.
I think we are saying the same thing
Going back to my original point. Which injector is being used with the calculation you posted? I assume that it is stock injectors on a stock motor, and that it is a pretty safe calculation, even more so if the injectors are larger.
Jay
When I said:
Would 1.8 injectors @ 90PSI be the same as 1.6 injectors @ 100PSI?
I wasn't saying that changing from a 1.6 injector to a 1.8 injector would lower fuel pressure.
I think we are saying the same thing
Going back to my original point. Which injector is being used with the calculation you posted? I assume that it is stock injectors on a stock motor, and that it is a pretty safe calculation, even more so if the injectors are larger.
Jay
#19
Originally Posted by braineack
From what I understand injectors just supply the fuel and can reach 100% duty cycle. You want them to run at 80% or so. But if they can only flow to a certain point. So 90psi of fuel on 1.8 injectors would be 90psi of fuel on 1.6 injectors. The reason you go to larger injectors is to supply more fuel for the higher boost levels. Where 1.6 injecotrs could supply enough fuel for 5-6psi 1.8 injectors can supply enough fuel for 7-8psi....I'm still trying to read and learn more about fueling, but so far this is what I understand.
8:1 disc in my setup is just a little lean in some spots and rich in others when I bypass the Emanage. I'm running a 190lph HP. With the slightly larger pump I would expect the 8:1 disc will compensate for the lean spots based on a higher flow at specific pressures.
If it's too rich, I have a 7:1 disc available