View Full Version : fuel pump / fuel pumps


s-cam
05-14-2012, 04:35 PM
I just replaced my factory pump with the denso /kyosan pump from racetronix in the fuel bucket and i am still running low on fuel pressure (using a kenne bell boost a pump) I know i am asking too much out of one pump (approx 800 rwhp). Has anyone tried to stuff another complete fuel pump bucket and all into the drivers side of the tank and made it work? I need to go to 2 pumps in the tank to solve my problem but it would be nice to maybe use a stock fuel bucket assembly on both sides with upgraded pumps. Also if anyone really understands how the crossflow / suction works on the stock tank to transfer fuel from the drivers side to the passenger side that would be good to know. I am a bit confused how that system actually works.
Thanks

Sheldon

SeeTSvee
05-14-2012, 07:29 PM
Just curious....are you running factory fuel lines?

itsslow98
05-14-2012, 09:37 PM
Contact Lonnies performance, I spoke with him about doing twin in tank pumps. It aint cheap, and it wont be as good as it would in other cars due to tank design but he said it would handle some power.

vmapper
05-14-2012, 10:18 PM
Ain't cheap is right... yea, when 4 figures was mentioned, i dont think so.
You could try to do it yourself. Second pump only on with a 5 lbs hobbs switch.

DMM
05-14-2012, 11:19 PM
The best I can figure out (tentatively speaking of course) is to run a square/rectangular surge tank fed by the OE bucket fitted with a Walboro 255 in the fuel tank...then have the surge tank gravity feed two separate Walboro 255 external pumps (one for each fuel rail).

Granted, I would have to run two new 3/8" steel lines (not too hard, or expensive) with -6 AN lines feeding each fuel rail with them being tied together at a boost referenced FPR, and a -6 AN/3/8" steel return.

Not the ideal setup, but I don't think I want to see Lonnie's bill.

I have not gotten any measurements yet, just thinking about what would work given the shortcomings that we have.

heavymetals
05-14-2012, 11:41 PM
I bought one of these:

http://www.amazon.com/gp/product/B007SNR3BG/ref=oh_details_o02_s00_i00

And one of these:

http://www.summitracing.com/parts/AEI-13109/

I don't plan on going up in size of the fuel line, but will probably do it later.

s-cam
05-14-2012, 11:45 PM
Just curious....are you running factory fuel lines?

Yes i am running factory lines.

I have spoke with Lonnie and if i did not live in Canada (Calgary) I would have sent him the tank but the shipping alone adds alot of cost to the fuel pump assembly.

I have also given the surge tank alot of thought. I am unsure how to deal with the return side of the surge tank as its suppose to return at 0 pressure but my understanding is that it takes 50 plus pounds of return pressure to make the tank crossfeed from the drivers side to the passenger side. That being said I dont have a clue how the siphon / return forces fuel from the drivers to passenger side of the tank.

For some reason i would just like to buy a second pump assembly and drop it in there and see what happens. Hopefully someone can explain how the internal workings of the fuel tank actually work so i can maybe try it.

The pictures of the second pump coming out of the drivers side of the tank would be an easy fix. I have read about that second pump install but have not heard how it really worked out. Any issues with adaquate fuel since there is no fuel bucket and it just sits with a filter sock on the bottom of the tank.

The tank is too much of a pain to drop it multiple times to try a bunch of different options. I dropped it once to do the existing pump and found it dont have enough lph at 60-70 psi so if i have to drop it again i would like it to be the last time.

vmapper
05-15-2012, 10:01 AM
Calgary. Same here. Shipping is never cheap.
Im guessing your running a Return regulator setup now.
I dont know enough about the tank design to comment, but want to know if someone else has experience as well...

GulfM3
05-15-2012, 10:04 AM
I have also given the surge tank alot of thought. I am unsure how to deal with the return side of the surge tank as its suppose to return at 0 pressure but my understanding is that it takes 50 plus pounds of return pressure to make the tank crossfeed from the drivers side to the passenger side. That being said I dont have a clue how the siphon / return forces fuel from the drivers to passenger side of the tank.




Like I mentioned in the PM, the need for return line pressure is news to me, but you may be right.

I'm going to push ahead with my surge tank design. Just finished welding it yesterday. The volume is just a hair over a gallon.

http://img213.imageshack.us/img213/1742/surgetank2.jpg

http://img543.imageshack.us/img543/4410/surgetank1.jpg

http://img100.imageshack.us/img100/1513/surgetank3.jpg

The walbro will be running all the time, and the bosch 044 will be boost referenced. I didn't want an annoying loud fuel pump, but if it turns out the walbro doesnt cut it it's an easy enough fix to replace it with a second bosch 044.... Plus, I had the walbro sitting around so I'm not out anything by using it. I'm going to mount the tank just above the passenger muffler, it fits great and is close to the stock lines for easy routing. Plan on wrapping the muffler in heat tape to keep heat transfer to the surge tank at a minimum.

I'm very interested in your outcome, and I'll let you know how my surge tank works.

s-cam
05-15-2012, 11:21 AM
I found a little article on the "jet pump" and how it uses a orfice for the siphon system to draw fuel from the Drivers sump side of the tank.


"A little background. People suggested using two fuel pumps and a surge tank.
What we came up with is a fuel pump setup that sits in its own buck the fills the bucket with “jet” pumps. Jet pump are siphon pumps that use some of the fuel flow to run through an orifice to create a pressure drop to pump fuel. Many factory fuel pumps have jet pumps. Many new cars have split fuel tanks and need one jet pump to keep the bucket full and one to pull fuel from the other half of the tank. Corvettes have two tanks connected by a transfer tube and Cadillac CTS’s have saddle tanks and a transfer tube."

I am thinking of buying a complete second pump assembly- upgrading it also with a kyosan/ denso pump, putting it in the drivers side of the tank and returning to both buckets.

The FPR fuel pressure regulator is in the tank on the end of the return hose so to run a surge tank it may need to be removed.

see post #18
http://ls1tech.com/forums/cadillac-cts-v/1535926-fuel-surge-tank-vs-tank-pumps.html

vmapper
05-15-2012, 12:47 PM
I know many F-bodys have an issue with pressure drop, and fixed by simply removing the in-tank and going with a FPR on the rails.

I like your idea of having a return to both buckets...

What specifically does the drivers side do? Will a bucket assembly fit? (same depth as passenger - tank dimensions)

VeryWhiteDevil
05-15-2012, 03:21 PM
I have my tank out now and can measure if anyone needs to know. I also am running the Kyosan and I am interested know if the second pump assembly on driver sides works. seems possible.

I understood the FPR was on the fuel filter??

where on the fuel pump assembly is the FPR?? I have everything out now.

GulfM3
05-15-2012, 04:14 PM
I understood the FPR was on the fuel filter??

where on the fuel pump assembly is the FPR?? I have everything out now.

Apparently the FPR is not incorporated into the fuel filter, I always thought it was too.

If you check the post by S-cam above linking to the previous thread, in post 18 by psychobillycaddy he shows our cts-v fuel bucket. The black valve looking piece on bottom of the bucket is the FPR.

All this throws me back to the drawing board for my surge tank :bomb:

vmapper
05-15-2012, 04:14 PM
Item in question - fpr
When this is removed, is there a trap door to allow return fuel into the bucket? Or is this the 'JET' Pump?

vmapper
05-15-2012, 04:21 PM
My question is, can the drivers side be 'unplugged' and still have your fuel gauge work properly? or is that float even for your fuel gauge?
And will the depth of the tank be the same to bring in another bucket and mimique the passenger side.

s-cam
05-15-2012, 05:46 PM
I have my tank out now and can measure if anyone needs to know. I also am running the Kyosan and I am interested know if the second pump assembly on driver sides works. seems possible.

I understood the FPR was on the fuel filter??

where on the fuel pump assembly is the FPR?? I have everything out now.

If everything is out ( i had mine apart 2 weeks ago) can you try to slide you fuel bucket into the drivers side. it looked the same dimensionally when i had the tank apart. If it fits all i am thinking is using my second racetronix harness to power the 2nd fuel bucket, using a hoobs switch to activate the pump. I think it maybe possible to breakdown the harness and use the fuel sender on bucket #2 with bucket #1 and put the power out of the race tronix harness to the 2 other terminals for the pump. All this pending that it fits. Then the crossover tube can be mounted somewhere on the floor so it works all like stock siphon setup but the second bucket and pump is for boost only. then do a front mount fpr etc.

If it looks like the bucket will fit it maybe a viable option. Let us know how you make out if it will fit the drivers side verywhitedevil. Thanks

s-cam
05-15-2012, 05:51 PM
Item in question - fpr
When this is removed, is there a trap door to allow return fuel into the bucket? Or is this the 'JET' Pump?

my understanding is on the very end of the return line is the fpr where it pushes the fuel back into the bucket. The jet pump is where the line from the fuel pump hooks to the plastic fitting and then pretty much turns 180 degrees and the hose in your tank hooks up to that same fitting (the large white one with no hose on it) in there has to be an orfice that restricts fuel flow to create a suction/ siphon effect to draw the fuel from the drivers side.

A502slo
01-08-2013, 10:44 AM
Ain't cheap is right... yea, when 4 figures was mentioned, i dont think so.
You could try to do it yourself. Second pump only on with a 5 lbs hobbs switch.

where you get the fuel lines and adapters from?