For me, adjusting the screw clearly changes the pressure at both idle and full boost. I can hit 90 psi starting at 50 (with vacuum applied). When I start at 45, I can't get to 90 at full boost. Does more pressure automatically mean more fuel? I don't know but would think so. I was hoping to see a clear shift up or down in the air/fuel graph as I made adjustments, but it didn't happen. I did, however, put down consistently more horsepower at higher fuel pressures.
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Multiple CTSC dyno runs with fuel pressure adjustments between runs
- Thread starter gobble
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Base dyno tuning is best left to someone who has lots of experince, that is what I am doing. The AEM can give you all the information you need to do all the tuning yourself, but there are over 3000 data points which can be manipulated, lots of control, and lots of opprotunity for disaster.gobble said:
I have experince building motors, doing most types of upgrades, and a very good understanding of how cars work. With this background I am comfortable making small changes for drivability to a map set up by the experts. After a season playing with the AEM I will probably be comfortable doing more :smile:
My understanding is the RRFPR Comptech uses has a rising rate determined by the spring inside, specific fuel pressure for a specific amount of boost. There is a switch which inceases voltage to the fuel pump as soon as there is positive pressure in the intake manifold, which is why there is 90 PSI available. Changing the base pressure on the regulator 'should' only change where you start the pre determined rising rate of fuel pressure. With the CTSC, you should be seeing full boost at WOT around 2500 RPM, your fuel pressure should be close to 90 PSI and stay there until boost drops off, around 7200-7500 RPM(depending on your motor and set up) when it should start to creep down. I have always set my base rail pressure at 42-43 PSI and let the system contol it from there.gobble said:
I wonder if they changed it somehow. I took the paragraph below out of a private message I sent someone a couple of weeks ago. These were the numbers I saw with the settings that came from Comptech:
"I did some road testing last night and my numbers vary a bit from your suggested ranges. At idle, I'm at 45 PSI. Without the vacuum line I jump to 56. At WOT, the best I can get to is 86 PSI. Funny that I'm high on the low end but low on the high end."
I couldn't get close to 90 psi until I raised the base pressure to 50 psi. I wonder if my RRFPR defective?
"I did some road testing last night and my numbers vary a bit from your suggested ranges. At idle, I'm at 45 PSI. Without the vacuum line I jump to 56. At WOT, the best I can get to is 86 PSI. Funny that I'm high on the low end but low on the high end."
I couldn't get close to 90 psi until I raised the base pressure to 50 psi. I wonder if my RRFPR defective?
Might be worth a call to Shad the 'Comptech God' :biggrin: Phone: (916) 939-9118.gobble said:
I was just reading something that will help you understand the CT RRFPR a little better.
http://www.comptechusa.com/instructions/ins036.pdf
If this does not help then call Shad.
http://www.comptechusa.com/instructions/ins036.pdf
If this does not help then call Shad.
titaniumdave said:
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