comptech fuel pressure

[rcove]

What should the fuel pressure be at idle with the comtech supercharger on a 3 liter engine.

 

[jmp]

Are you running the base CTSC setup (ie CT fuel regulator and stock ecu) or are you running aem standalone, 255 walbro fuel pump, bigger injectors, etc?

Base CTSC setup - zaps the fuel pump with additional voltage and if I am not mistaken the fuel pump runs as high as 90 lbs. I cannot recall if at idle it is closer to 40 and progrssively rises. Others wll need to chime in???

If you have an aem, etc. (scenario 2 above), it starts at 40 lbs at idle and increase to 60.

 

[rcove]

I am running the standard boost comtech unit with no other changes to the system. The FRP was adjusted by a mechanic to get the car to pass an emmision test and I want to get it back close to the right setting before getting a dyno run.

 

[Paul]

With the "standard" CTSC kit, it should be somewhere between 40 to 43 psi at idle. At 6 lbs boost you should be seeing 90 psi or better.

If you are going to adjust the Fuel Pressure Regulator yourself, be sure not to bottom out the spring to prevent possible damage to the FPR.

 

[DDozier]

I am running the standard boost comtech unit with no other changes to the system. The FRP was adjusted by a mechanic to get the car to pass an emmision test and I want to get it back close to the right setting before getting a dyno run.

It is best to adjust the FPR while on the dyno, this is really the only mechanical adjustment you can make to the standard setup to adjust AFR. Make sure you tell the dyno operator that you need to make these adjustments after each run; the adjustments are simple and take less than 5 min. so they should not care about the added time between runs. Make sure you and the operator knows what the target AFR you are trying to achieve and make sure they know to abort any run that is going too lean under load. Your mechanic that adjusted the FPR would have most likely leaned the car out to lower emissions levels so stay out of boost until you know for sure what the AFR are. Also make sure the engine and blower are up to temp before you start your pulls on the dyno, the heat in the intake will cause the ECU to add fuel and pull timing this will change the AFR.

When you get done post you dyno sheets with AFR and I am sure if there is an issue many will chime in and let you know. Do not be surprised to see the AFR move around a bit, the CTSC Fuel system in its stock form is not going to yield a flat AFR across the RPM range.


Dave