i think id like to see a separate small pump run the jets. that would effectively be the feeder pump for the basket and then the two stage 450s in the basket dont have to lose pressure and flow to the jets.

 

In theory if restricted properly.. The two should work. It doesn't take much flow... Just velocity to drive a jet pump. Lol @theory

 

yes definitely can work but always at expense of fuel at the rails. did you try a larger restricter yet? this should have been tested by SRM before these kits went out the door.

stock setup has a separate smaller output on one pump to feed the jets so the rail flow or pressure is effected by the jets. the second pump doesn't feed the jets except for a tiny amount going to equalize the tank level from the bottom of each stock pump

 

I have not tried anything else yet. I figure once Garth has tested yours we will know if it s just my lines/rails causing the issue. I should add a second FP sensor at the outlet of the tank..

 

For it to break up bad...it had to go LEAN, real LEAN, like almost fuel cut lean. But in the end...that might be a good thing as it showed a major fueling issue and not just a minor issue such as tune to where it caused detonation, etc.

I ended up dumping the using the arms of the jet pumps to run each pump down in the sump....and then drilling giant holes in the fuel basket and return the fuel in there. Simplified the system by a million percent!! :P And now I actually have fuel pressure...lots of it.

 

what exactly did you do?

 

I've done that before too.. But never on a car with the fuel bucket to high up. I would be concerned on long wot runs drying the bucket.


As far as a third pump for the jets... That would have to fit in the main bucket or way down in the saddle...

Atl makes a jet pump now.. Maybe switch to that and just run a rubber hose with a weigt on the end to the lower saddles?

 

Exactly...


Johnny.dangerous did his this way on his 996tt after he was having some FP issues as well.....I like it and after I had some issues, said FCK it and copied it. Should have done it this way from the start IMO. But that's just me.

Link to it - https://www.6speedonline.com/forums/...mp-system.html

I used the arm of the jet pumps to connect my fuel pumps too (1 each side) so they now sit in the tank sumps. My return (8an) feed the basket on the saddle, and I have drilled 3 - 1" holes for it to drain back out into the tank. I do like the idea of the pumps being down in the sumps of the tank...seems more logical that way. Even with a modded basked and dual pumps, it was tough to make the fuel hose setup work w/jet pumps, etc due to it being in such close proximity to the top hat. It felt all crunched up in there IMO.

 

Interesting. My concern would be one side starving for fuel. I guess as long as you stay above 1/4 tank it would be ok.

Edit: i see that discussed in your thread.

Sean has been working his *** off solving this.. supposed to be sending out some updated parts to Mark and I.

 

very cool! I'm sure SRM will get it nailed down.

 

Garth and Drew machined down the AN fiting that goes into the aluminum block where the jet pumps attach and put a nitrous jet in it. So far the fuel pressure works but havent done any higher hp pulls yet.

I hope we struck a good median with the size, because if you go too big you lose to much pressure and flow, you go too small you risk having the pumps sucking the basket dry...

 

It would be great if someone could put the basket on a bench with the jet pumps sitting in containers of fuel, and put both pumps from low-high voltage and test the correct sized restrictor to just keep the basket full..... (The return line also returns unused fuel to the basket).

Sounds like a good job for you Mark

 

yea, ive got a restrictor in mine per SRM and it works.. but still falls off more than it should.

I think Sean/Garth were talking about using the low pressure side to drive the jets (return..)


Could put a "mini" fuel system in the tank.. small regulator on the jet pump side that would keep pressure at whatever it needs (10psi? ish?) and then it wouldn't waste any fuel.

 

we did it a little different and a a more restrictive piece.

i wouldn't as it helps keep the basket filled

yeah that could work but there would have to be testing done and and need someone with a good actual understanding to do the testing. Sean from SRM lost credibility in my eyes after he tried convincing me that 6-7 psi fluctuation in fuel pressure in boost was in fact normal... lol .... i disagree. solid fuel system and tune are backbones of any fast cars, fuel pressure should always rise 1 to 1 if you did it right.

 

If you lose any PSI under boost, you're pumps are too small.... Another simple, yet not ideal solution would be to strap a smaller fuel pump to 1 of the jet pumps (or a pump on each jet pump) with the fuel line dedicated to filing the basket but do you really need 4 pumps in the already small tank?