We are continually asked, "What fuel pump should I use?" Naturally, there are many answers here in relationship to the vehicle weight, gearing, engine, its applications, and power output. As you can see, it is important to be dealing with people that know what you are using and what you need. Be clear this Technical Tip is to make you aware of this area and serves the people that are using our products and combinations (verification required) so we know what to recommend.
Almost all engines will use the stock VW mechanical pump. We ran the stock pump on our 1725 pound race car until it was running in the low 12's. This was possible in part because of the float bowl volume of the 48 IDA, our ball needle and seats and the short amount of time at full throttle opening. Street wise, it is rare that anything but the stock pump will be required unless long continuous speed runs are made or your car is capable of running in the mid 12's. Off-road and other types of racing will depend on power being used and for how long it is being sustained. Should you decide to go to an electric fuel pump, it is critical not to replace it with a unit that is less effective than the factory set-up. This is a common problem for people to make by installing an inexpensive, lesser volume output pump compared to what is removed.
The factory pump, when properly set up, is more than adequate for most applications, which is what lets some people get by with these lesser quality electric pumps. Where we continually see a problem is when at least factory volume is required and the new electric pump cannot supply even the stock volume. People have an overheating or a lean condition, spend forever and maybe even a couple of engine failures because they think they have the fuel problem handled, but do not. They knew they had an electric pump so it couldn't have been that, so they continued to have failures and looked elsewhere. If they get away with an inadequate electric pump, the engine was likely not even using the factory mechanical pump to its potential in the first place.