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Boosted guys: Our road race fuel pump kit uses a Walbro 255 to feed the engine. This pump cannot be upgraded or replaced (except with the identical model). If you want to run it how it was designed and tested, this pump *must* remain the primary pump in the system (see final note below). It is not a normal 255, it is a special model and has features we do not want to lose. However, there is an additional pump holder that can hold another 255, 300, 340, or 400lph pump. Anything with the typical Walbro diameter.

Costs to add a secondary pump:

1: cost of pump itself ($80-250)
2: cost of hoses/fittings to integrate it ($30-50 minimum)
3: cost of an activation system for the secondary pump, such as a hobbs pressure switch
4: optional; cost of upgrading OEM sending unit pump, to make sure the road race pump gets enough fuel (will be needed for larger output setups, or when running a secondary pump full time)

Example 1: If your HP were just BARELY beyond the single 255s reach, we would just add another 255 and splice into the line to the fuel filter, and you would be set. Thats like $125-150 plus a hobbs switch. You might not need a hobbs switch if you already have a 255 in your OEM sending unit... but I really must say that it is better if the secondary pump is not full time running. The stock regulator will not be able to handle that type of fuel volume, and you would need to add one of our return systems with external regulator. Even then it sounds troublesome.

Example 2: Moving to the other extreme, you wanted to make 1200HP... then we would run a 255/485 combo in the road race pump. You would run probably a 340 in the OEM sending unit. We would complete bypass the OEM filter and regulator setup, integrate a full return solution and billet external filter.

So this can swing around all over the place. It really just depends on the power of the car. If the HP is within the realm of flowing through the stock filter and fuel lines, then we are talking about the first example.

I know this is frustrating to try and figure out... but there are probably 100 different combinations we can go on a fuel system in these cars... and I cant possibly test all of them to make nothing but guarentees on all of them... I can only tell you what has been done/tested already, what I think would work, and what I think isnt the best idea. Due to this, a private phone conversation is probably in order for anyone exceeding 500rwhp or using E85 with boost at any HP. Built engine HP numbers will need like an entire consultation LOL... basically the higher the power you are running, the better I will want to make sure you understand how the system is working so that you can make educated decisions on what you want to do.

note: testing of the unit with an Aeromotive 340lph as the primary pump instead of the designed-in 255 would be OK, but I cannot guarantee 100% flawless function of the unit configured that way. If it did work flawlessly, than it would only mean I over-killed the initial design of the product. I am skeptical of it working out alright.

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