run4cvr and I were talking today about tuning the fuel system in my hi-CR motor. I know I need the fuel lines and the digital AF meter, but would someone's crappy cartech be good tool for me since I don't actually have to deal with boost? Just a thought. It would be interesting to see that they are good for something. I may even get me a fuel pump that sounds like a raped pig for the car too! :P

Thanks!

You would have the same "challenge" turbo guys face with the cartechs... your idle fuel pressure might fluctuate every time you started the car.

If you're not worried about all your fuel pressures varying +-10% then sure, it'd work for richening up a high compression engine if you really wanted to.

The problem with the Cartech unit is that it is not a fuel pressure regulator. It is a pressure riser. It is nothing more, nothing less. It is VERY good at rising the pressure with boost, with a multiplier even. The added benefit is that it does not require discs or springs to rise the pressure.

From Cartech's site... (http://www.cartech.net/fmu2020instruc.htm)

>>>1.) The rising rate regulators fit into the fuel system after the >>>stock regulator, and in series with it. The regulator becomes >>>the last item before the fuel returns to the tank. Do not remove >>>the stock regulator, as it still controls the fuel flow under >>>most manifold vacuum conditions.


So there is word from Corky Bell's company. It is NOT a regulator. I do not know why it is used as such. It is a pressure riser. The best way to make the Cartech work properly is to use a base pressure regulator, such as an Aeromotive. It will only rise 1 PSI with boost, but it will set a rock solid idle fuel pressure. It will hold a rock solid idle fuel pressure, by the way, because it is a REGULATOR.

The only reason that the Aeromotive rises fuel pressure 1:1 with boost is to overcome the pressure in the manifold. Injectors work with a pressure differential. In an extreme example, if you were to run 48 psi and you had 48 psi of fuel in the rail behind the injector, no fuel would be able to push out of the injector. I think that this may become a problem with the SRT-4, as it has a static fuel pressure regulator, just like ours, but it is set for 58 psi of boost.

-=B-=

I still have my shitty cartech in my car. I cant get the thing to run less than 95-100 psi of fuel pressure at full boost. So I run extremely rich with my 440cc injectors. But I only use 110 octane in my car and I run 15-17psi. I am going to upgrade to the sfmu and finally get some tuning done.

Originally posted by Dave_FL
I still have my shitty cartech in my car. I cant get the thing to run less than 95-100 psi of fuel pressure at full boost. So I run extremely rich with my 440cc injectors. But I only use 110 octane in my car and I run 15-17psi. I am going to upgrade to the sfmu and finally get some tuning done.

Go to a hardware or welding supply store.. get some a .025,.030 and 0.035 mig welding tips..

put them inline with the boost signal line to the fpr

Also.. open your needle valve..

-- WheatKing

Originally posted by The1Bill
The problem with the Cartech unit is that it is not a fuel pressure regulator. It is a pressure riser. It is nothing more, nothing less. It is VERY good at rising the pressure with boost, with a multiplier even. The added benefit is that it does not require discs or springs to rise the pressure. From Cartech's site... (http://www.cartech.net/fmu2020instruc.htm) >>>1.) The rising rate regulators fit into the fuel system after the >>>stock regulator, and in series with it. The regulator becomes >>>the last item before the fuel returns to the tank. Do not remove >>>the stock regulator, as it still controls the fuel flow under >>>most manifold vacuum conditions. So there is word from Corky Bell's company. It is NOT a regulator. I do not know why it is used as such. It is a pressure riser. The best way to make the Cartech work properly is to use a base pressure regulator, such as an Aeromotive. It will only rise 1 PSI with boost, but it will set a rock solid idle fuel pressure. It will hold a rock solid idle fuel pressure, by the way, because it is a REGULATOR. The only reason that the Aeromotive rises fuel pressure 1:1 with boost is to overcome the pressure in the manifold. Injectors work with a pressure differential. In an extreme example, if you were to run 48 psi and you had 48 psi of fuel in the rail behind the injector, no fuel would be able to push out of the injector. I think that this may become a problem with the SRT-4, as it has a static fuel pressure regulator, just like ours, but it is set for 58 psi of boost. -=B-=

Sorry to say Bill but you are slightly wrong on this matter...
You see if you look closely at the cartech site youll see that just like Voretch they have different models of FMU....
They have one like you describe that only acts as a rising rate regulator and cannot set base FPR, but they also have versions that do just that.... along with models that rise at 1:1....

Also, I've been using my cartech on my setup for the past 10000 miles since I rebuilt.... and I'm running it at 15psi, with 450CC injectors controlled by none other than the cartech.... ;)

Lee.