To make sure I am following along with the Play At Home™ game correctly -
In order to accommodate the new pumps you are Y-ing the jet pumps together directly to a second Y which feeds the two fuel pumps? Then they are running in parallel? In following the diagram I'm having a hard time figuring out what the fuel flow actually is through the system before/after your modifications.

The diagram doesn't show the bottom connections you have pictured so I'm not 100% sure if I get where everything is going.

 

the 996/997 headers are nearly identical

 

Anyone know if the dual fuel pump basket arrangement could be adapted to the 996TT platform??? That would be a much better set up than the stock single pump basket on the 996..

 

If you get a chance to do a pump gas run at 20psi and log your spool in 3rd and/or 4th I'd love to see how it compares with that setup. I've provided some boost logs as well in our thread for comparison. We don't have E85 here at the pumps unfortunately so any comparison on higher octane would be easiest if done with meth or race gas in case you'd like to compare with our data.

 

A lot of very valuable and hard earned IP in this thread.

Thanks Mark and Dzenno, great stuff. I will be fascinated to see how these 997.1s can do once you hit the hyper car whp levels > 1000

 

I'm already using 4 bar map sensor with stock ecu since nearly 1 year, but your datalogger must be compatible with it.

 

Yep I will make a separate thread with my project info. Once we are finished with e85 and get the car to 700ish we will move right to pump gas and shoot for around 625-650. I won't use meth. I have before and it was a pain. So far the spool is awesome and obviously comes on faster than what you posted but that's ethanol... We will see what it does on pump.

That's a good thing. I did not know. There is not too much info about your stuff besides that the cars are lighting quick ! Are you using a sensor that's a plug and play with built in IAT sensor or are you separating the two ?

 

the diagram does show the bottom connections. they are just hard to see , they are the two lines between the pumps that go to Low Pressure jet pump. this is to equalize gas level in the tank.

the fuel flow thru the system is basically this. when tank is full pump 2 (no jet pump) runs as primary and feeds from basket which is kept full by the gas level being above it. it also runs the low pressure jet out the bottom ( basically for no reason at this stage). when tank level is below the fuel basket, the ECU switches pump 1 ( one with jet) to be the "always on" pump, this pump feeds the passenger side jet (reffered to as high pressure jet) and it also feeds the fuel rail AND the low pressure jet to equalize the level in the tank. because this pump feeds the main jet it flows about 30% less than the second pump which is turned on by the ECU when certain fuel demand is reached in the ECU.

since my new pumps do not have that lower small low pressure outputs I came up with a way to feed them just like 996TT does and Undercover machined up a fitting to do this. basically my idea was to Y off the one pump that ECU runs under 13.7 Gals as Primary, one that has the two outlets on top from the factory. Y off that pump and run both sides jet pumps from that pump and the other side off the Y to the factory Y going to the fuel rail. Pump number 2 will operate just like OEM and not drive any jet pumps, providing full flow when it kicks in. Each of these pumps is rated to 750hp on gas and 450-500whp on E85. Unfortunately when you Y the pumps together its not as simple as X2 the flow its more like x1.5-1.7 or so.

 

Hello guys. Hope someone still reads this. I have one of my pumps not working, car runs fine if I take that fuse out but I want to get it properly working again. New dual pump is around $1K. Since you seem to know so much. Is there a less expensive alternative to buying OEM pump for a stock car? I am no expert but was able to take the dual pump canister out and can replace it. Thanks in advance!

 

holy resurrection!

so I think I saw someone 3d print a new can. Much more expensive route I think. The only cheaper thing to do is, remove the can all together and all the hoses. Then just wire up 2 pumps and throw them down into the sumps. Done. It’s pretty simple and doesn’t need to be as complicated as Porsche made it

 

Thank you, which pumps would you use for this application? Do you have a link where I can buy them?

 

I'm in the same boat!

Suncoast may have a reasonable price on the OE pump

They are unavailable through local Porsche dealer