If you have played with blow through carbs you know that the power valves will drive you nuts. Mine was working pretty good and then I reoriented the carb hat. Now I have to change the power valve because it responds differently. I have seen some stuff on drilling out the carbs and making some weird kinds of power valves.... blah blah. I want something simple and do not want to carve up my carb. So what about doing this: Take any old nitrous kit, use the gas side of the nitrous kit to add gas instead of a power valve. You could set it in a couple of ways. One, trigger it with a simple vacuum switch. You say won't this be the same as a power valve? No, because it would be triggered with manifold pressure with no interference from carb hat pressure. Two, if you have a programmable ignition system like the new AL-2's you could use a MAF sensor system. With very little work could even have a two steps system. The third way would be make up a TPS sensor and trigger off of throttle position. Another advantage I can see is that as boost rises fuel pressure rises and you would add more fuel. Feel free to punch holes in this or refine the idea. I know very little about nitrous systems so anyone that has worked with these things please let me know if this is feasible.
have you seen this thread on theturboforums.com? http://www.theturboforums.com/threads/355679-The-quot-Crutch-quot-carburetor-tech-section It sounds like what you are wanting to do would be the same thing, which is to supply extra fuel under boost.
I would go fuel injected before I would do that. Most of those guys are dealing with more boost than I will go to and I think what I am proposing would be pretty simple.
Actually I do not have a problem with fuel under boost. It is more of a problem of controlling when the extra fuel comes in. I looked at Brent's crutch system more than once and it adds a new layer of complexity that I am not interested in. My idea is get rid of the problem and that is the location of the power valve. If the power valve opened as advertised would not have to worry about it. But putting the pressure in the hat really messes the whole thing up. My idea is to get the signal from different source. It would also be easy to tune. The switch would be easy to get to and be adjustable. You could even add fuel to the system without touching the carb. Could even add a switch for cold start. The one thing that I am concerned about is fuel atomization. There would be no air added to help atomize the fuel and do not know enough about how the spray bar will work without nitrous to atomize the fuel.
You might be on to something. Most plate setups have a pretty efficient spray pattern, so I don't think atomization would be an issue. I think the hardest part is going to be correlating the proper fuel jet size to replace the PV, and developing the best activation method for the solenoid. I'm not sure how it would work using one solenoid to replace both the primary and secondary PV's. It might be best to plug the secondary PV and just jet up, and use your method on the primary side.
Know one I know uses a power valve on the secondary side. I have now heard on blower sites that this has been done successfully. As far as jet size it would at least be easy to experiment with as it would only take a few seconds to change the jet out.
