I need to know the limit of the TPI fuel line...Im going carb and I dont know if the line size is enough.ITs going to be a carb with a mechanical Carter pump

Daz

 

A 3/8" inside dia line and a big mechanical pump is good for about 500hp and about 6500rpm.
But for dragracing you may want to add a pusher pump in the back of the car to overcome acceleration G force and avoid
pressure drops causes by heat (vapourlock). 1 or 2 carter electric pump(s) added to the back is good for this. No regulator required.
All fittings must be 3/8 inside dia too.
Beyond 500hp go to 1/2" lines and fittings or double 3/8" fuel lines.

 

Running 2 pumps in series is a micky mouse way of doing it, I wouldn't recommend doing that. I wouldn't run a mechanical pump anywhere near 500hp either. A good mechanical is fine for say, under 300. After that I'd upgrade to a good electric to be safe.

Line size, I'd upgrade from 3/8 to 1/2 at about the 400hp mark.

 

There is nothing mickey mouse about running a mechanical hi volume pump or adding a pusherpump to avoid heatsoak problems. Hi volume mechanical pumps are good for 700hp on gas
and 550hp on alcohol with good freeflow plumbing.
Mechanical pumps cost less, are more reliable, quieter and most do not need a regulator. The carter electric pumps would be connected in parallel, not series if two are required. They cost less, draw less current and are more reliable than other electric pumps. The "pusher pumps" would only be needed at the track to help avoid vapourlock problems from heat soak on the inlet side of the system. Anyone who has spent time at the track on a hot summer day knows how a cars fuel lines can heat up while waiting in the staging lanes.
A system like this will serve your street performance needs
for well into the 10sec bracket with moderate cost and good reliability.

 

Please explain the parallel connection..

Daz

 

I think it would be something like a "Y" with the pumps on the arms (legs?) of the Y, feeding into a common line. This way, one pump isn't presurizing what the other pump is trying to presurize.

 

Yes. Provides more volume, not more pressure.
But will maintain the working pressure even at WOT.

 

cool thanks..

Daz