Attention: TDR Forum Junkies 
My new AirDog 2 200GPH came factory set at about 25 psi. Initial test driving after the instal yielded 23-35 psi from idle through WOT. EGTs dropped from 1800s to 1600s at near sea level. Industrial Injection told me I should have a minimum of 45 psi and that 70 was an even better goal. Pureflow Technologies told me to turn the fuel pressure up and see what happens. It was turned in until pressure from the spring became more stiff, then backed out a few turns. Without the engine running, fuel pressure was 58 psi.
The next day during a test drive fuel pressure was spiking from 70-120 psi and a return line blew off, creating quite a mess, and the AirDog quit. An inline fuse to the AirDog had fried. The fuel pump was then turned out several more turns and pressure is now reading 58-63 psi just before the injector pump but the truck has since performed far worse. Maximum boost pressure dropped from over 49 psi when the AirDog was set at 25 psi down to 18 psi boost after the spiking and blowing a hose. No sign of boost, coolant, or fuel leaks.
Haven't taken anything apart yet but as of driving it home boost was low, power was extremely low, and there was no smoke except a small puff in neutral at an idle. We suspect the spring in the overflow valve could not handle that much pressure coming to it and broke. We'll find out tomorrow, hoping Dodge will have a new one in stock by then.
Industrial Injection told me that most aftermarket overflow valves are heavy duty. I bought mine from Piers less than two years ago and I. I. said it should be fine. What I'm now wondering is if there is an upgrade to eliminate the overflow valve and use some sort of remote regulator in the return line. I've read of Aeromotive regulated setups but none with a Fass or AirDog. Can anyone recommend what I can use or who to ask? Pureflow was closed by the time I tried to call today and I think they're closed all weekend.
Another thing I don't understand is that I thought the spring in the overflow valve is overcome at 20-30 psi. Is it only overcome partially, meaning it is still creating a lot of restriction at those pressures? If the overflow valve opens completely, it would seem the part is unnecessary with high fuel pressure. I don't think this is the case, it must need restriction in the injector pump no matter how strong the pressure being fed through the pump, is this correct?
Is there any possibility of damaging the injector pump with the pressure it has seen? Most folks tell me the Bosch P7100 runs better with high fuel pressure. Industrial Injection told me most trucks with stock mechanical lift pumps push 45-55 psi. So should a stock replacement overflow valve be safe seeing 60 psi all the time? Any other thoughts or ideas that can help me make this setup more reliable? This is my second overflow valve within a couple years and I'd like to put things back together more reliably.
Thanks,
Matt
The next day during a test drive fuel pressure was spiking from 70-120 psi and a return line blew off, creating quite a mess, and the AirDog quit. An inline fuse to the AirDog had fried. The fuel pump was then turned out several more turns and pressure is now reading 58-63 psi just before the injector pump but the truck has since performed far worse. Maximum boost pressure dropped from over 49 psi when the AirDog was set at 25 psi down to 18 psi boost after the spiking and blowing a hose. No sign of boost, coolant, or fuel leaks.
Haven't taken anything apart yet but as of driving it home boost was low, power was extremely low, and there was no smoke except a small puff in neutral at an idle. We suspect the spring in the overflow valve could not handle that much pressure coming to it and broke. We'll find out tomorrow, hoping Dodge will have a new one in stock by then.
Industrial Injection told me that most aftermarket overflow valves are heavy duty. I bought mine from Piers less than two years ago and I. I. said it should be fine. What I'm now wondering is if there is an upgrade to eliminate the overflow valve and use some sort of remote regulator in the return line. I've read of Aeromotive regulated setups but none with a Fass or AirDog. Can anyone recommend what I can use or who to ask? Pureflow was closed by the time I tried to call today and I think they're closed all weekend.
Another thing I don't understand is that I thought the spring in the overflow valve is overcome at 20-30 psi. Is it only overcome partially, meaning it is still creating a lot of restriction at those pressures? If the overflow valve opens completely, it would seem the part is unnecessary with high fuel pressure. I don't think this is the case, it must need restriction in the injector pump no matter how strong the pressure being fed through the pump, is this correct?
Is there any possibility of damaging the injector pump with the pressure it has seen? Most folks tell me the Bosch P7100 runs better with high fuel pressure. Industrial Injection told me most trucks with stock mechanical lift pumps push 45-55 psi. So should a stock replacement overflow valve be safe seeing 60 psi all the time? Any other thoughts or ideas that can help me make this setup more reliable? This is my second overflow valve within a couple years and I'd like to put things back together more reliably.
Thanks,
Matt
