[parish8]

I did a similar set up and it didn’t work out. It don’t know exactly why but it would end up caveating even with a nearly full tank. It was worse on warm days and I was on e85.

I can’t tell exactly where your pumps are. Yours might be a little farther back and your feed line to the filter is a little shorter. Maybe you will be ok. I think the kits out there work because they have no filter and the pump is very far back. Aren’t they right next to the tank?

[parbreak]

Originally Posted by parish8

I did a similar set up and it didn’t work out. It don’t know exactly why but it would end up caveating even with a nearly full tank. It was worse on warm days and I was on e85.

I can’t tell exactly where your pumps are. Yours might be a little farther back and your feed line to the filter is a little shorter. Maybe you will be ok. I think the kits out there work because they have no filter and the pump is very far back. Aren’t they right next to the tank?

My pump is about 1 foot back from the front of the door. What size hose were you running out of the tank to the filter?

[oldman]

the smaller black line... is that a return line?

[parish8]

-8 from the tank to the filter. The black line was the return.

[oldman]

amazing with so much HP you are on the stock exhaust system (me too, but I'm not at your HP level).

[DorkMissile]

Out of curiosity - what are you guys using to seal up the fitting where it goes into the tank?

I have the DSX low side kit, their drill and tap, using their sealant and have not had much luck. Going to give it one last try with some epoxy and if that doesn't work I will drop the tank and put a bulkhead in.

[oldman]

I used the DSX stuff, it never hardens though...

[parbreak]

Originally Posted by DorkMissile

Out of curiosity - what are you guys using to seal up the fitting where it goes into the tank?

I have the DSX low side kit, their drill and tap, using their sealant and have not had much luck. Going to give it one last try with some epoxy and if that doesn't work I will drop the tank and put a bulkhead in.

Panelbond adhesive.

[Choda]

Originally Posted by parish8

snip

Gotta ask why you put the feeds on the tank in that location instead of on the right side of the tank straps? Also did you completely stop using the factory pump and feed?

Has anyone had to upgrade the 255 from the DSX to a bigger pump for more fuel or has the stock pump and 255 been enough for most peoples needs.

I like the idea of panel bond instead of the soft seal from DSX.

Besides easy mounting, why would DSX want the pump so far away from the tank? Seems like there are about 6 extra feet of hose the fuel goes through before it gets Tee'd into the factory feed.

[oldman]

I mounted mine per instructions from DSX (passenger side low by the strap), mine is slightly higher than the instructions, it will cavitate at under 3 gallons at WOT.

I also run a stock ZL1 pump in-tank just to be sure. The DSX T's back in under the rear seat area and the long (not really that long) line is so the pump can sit in the frame rila so there is less chance of road damage. Like 2 feet of line "extra".

[parbreak]

Also, remember DSX is making these kits for the "masses" who may not have that many tools or skill level. They tee into the stock fuel line with a GM adapter so no cutting required and they mount where they do so no drilling required. Basically anyone with the most basic of hand tools can mount it. This requires that 180 degree fitting coming out of the pump, running back towards the tank and then teeing into the stock line.


Ours was built on the car and we were able to place everything exactly where we wanted. Cavitation occurs, IIRC, due to restrictions going into the pump. We used -10 to TRY to reduce that. We will see how it pans out, but so far on the dyno, things are looking good.

[parish8]

Originally Posted by Choda

Gotta ask why you put the feeds on the tank in that location instead of on the right side of the tank straps? Also did you completely stop using the factory pump and feed?.

Seemed like the most accessible spot at the time. Clearly it didn’t work. I don’t think the location of those fittings was the biggest problem. I think using a pre filter and having the pumps too far forward were the bigger issues.

Yes I still use the stock pump. My set up then and now is to have my fuel pressure regulator set at 70psi so under normal driving it is a normal returnless system controlled by the factory controller. Then when I need more fuel I fire up the aux pumps, the pressure goes over 70psi and any extra fuel gets sent back to the tank.

My current set up has similar control but with a surge tank in the back and the pumps mounted right in the tank. Returnless most of the time. Return style when aux pumps fired up. I should be good for 2000hp on e85 now.

[oldman]

I do think that the external pump low and behind the fuel tank will have less cavitation problems vs a mid-mounted pump that is mounted to the floor pan/rail. Over 3 gallons or so there is no cavitation problems. I know that seems trivial but it is a streetcar and I may get on it sub 3 gallons... I'll try and snap a picture of where mine is on the tank.

[parish8]

Originally Posted by oldman

I do think that the external pump low and behind the fuel tank will have less cavitation problems vs a mid-mounted pump that is mounted to the floor pan/rail. Over 3 gallons or so there is no cavitation problems. I know that seems trivial but it is a streetcar and I may get on it sub 3 gallons... I'll try and snap a picture of where mine is on the tank.

I would be careful. If it does it at 3 gallons sometimes it will do it with more when the fuel is warmer. Also I am told the cavitation is bad for the pump and hurts it quickly which may cause it to cavitate even sooner.

I have a safety built in where if either my fuel pressure goes low or my a/f goes high it cuts spark. It without a doubt saved me from engine failure when I was sorting through my fuel system issues.