I am building a 13B autocross car. The car has a turbonetics turbo which blows through a Weber carb. I took the from another car that ran great. All kinds of power across all ranges. I took the entire drive train to avoid problems, but now I am having problems.

The car runs very well if the turbo plumbing is disconnected. The moment the turbo is put back in front of the carb, it falls flat on its face the moment boost starts to build. My assumption is that I should have taken the fuel pump and pressure regulator from the donor car before it went down the road. My problem now is that I do not know what I should be looking for as far as specs for the fuel pump and pressure regulator. Do you agree with my analysis? I believe that I have inadequate pressure in the carb to compensate for the boost. How should these systems work and what contols the fuel pressure as the boost builds? Plese help me get this solved. The car is set up to run approx. 10 psi boost, dynoed at 350 hp.

Thanks in advance! I greatly appreciate the help

 

Do a Search on the forum for a RRFPR.

Rising
Rate
Fuel
Pressure
Regulator.

As an aside, why don't you just find out what was on the Donor car and replicate it?

 

The guy who bought the car (1000 miles away) scrapped the fuel system to put a V8 in the car. I did not build the original system and therefore I don't know what parts to replace them with.

 

I dont think they make a rising rate fuel pressure regulators for cars running a carb. Since they run very low fuel presser as compared to fuel injected cars. Is you carb tuned to run boost. I would try the first gen section on the forum since they are pretty much the only ones running carbs. I've seen v8s with a blower and carbs, and when tuned they run very strong.

 

I had the same problem when I hooked a hairdryer up to a small engine. The engine dies at the first sign of boost because it stops getting fuel. I am not sure of the details of your carb, but you typically have to modify carbs to work with a blow-thru system so that the float bowl (or equivalent) gets manifold pressure. I am pretty sure I read that in a turbo book somewhere, so you might seek guidance at a bookstore.

I am sure you'll need to do something for fuel pressure, too. You just need to figure out how to raise the fuel pressure at a 1:1 ratio with the boost pressure.

-Max