jonathan_ed3

iTrader: (1)

Maybe a few of you are interested in this...probably overkill for the average FBer, though.

I originally had this mounted under the car in the stock GSL-SE location, but I needed room for exhaust and I didn't like how noisey it was down there so I switched it to inside the tank. It should also stay cooler since it's not so close to my exhaust.

Took some trial and error to get the placement just perfect since the fuel bowl is offset from the inlet hole on top of the tank, but I finally got it.

I also had to enlarge the opening at the top of the tank a few mm with a file because the pump is so wide, and also use a band-style clamp because the drive on the worm clamps sticks out too far.

The stock Bosch check valve wont fit inside there (makes the pump assembly too tall) so I'm using a Summit check valve underneath the car with -6 hardline in the stock location along the driverside frame rail.

To get it to fit down inside the tank you have to tilt it, and then rotate...and then it sits just right.

And, for the record, yes I have a fuel sock on the inlet of the pump. The blue fitting you see is from when I was using it as an inline pump and I didn't snap another one before I sealed everything back up.

rxtasy3

iTrader: (2)

is it a submersible type pump?

jonathan_ed3

iTrader: (1)

Well the 44 is not "technically" an in-tank pump (the 40 is)....but lots of Supra guys have used the 44 submersed. That's good enough for me. It's good for about 600-700whp.

If I had known originally I was going to go in-tank, I probably would have gotten a 40. I didn't realize these gas tanks have an access port on top when I bought the 44 originally. However, like I said, lots of the Supra guys use the 44 mounted submersed and that's a good enough reference for me.

Jeff20B

iTrader: (13)

This won't really help you, but maybe it will help me understand why so many people chose to go with an in-tank style pump. Why do so many people chose to go with an in-tank style pump when an inline pump under the car in the stock location seems so much better and easier to access in the future? Is it about the noise they make? I don't buy that for a second as the few EFI pumps I have heard have always been very quiet compared with Carter and Holley (carb) pumps.

I've got a Walbro 255 that is darn quiet under the car. It wobles the mind why you'd go through all that extra drama (tank dropping+annoying mods+tank reinstall) just to have a virtually silent pump when all the inlines I've ever heard are so quiet they can not be heard over the exhaust, and can barely be heard in the car when you first turn the key, before the engine starts. In fact during a MegaSquirt install a while back, I actually prefered to hear the little 2 second "priming pulse" of the fuel pump just to know that it was working and that the fuel system was fully pressurized and ready to go. It brought peace of mind more than anything else. I would not like a completely silent pump in that situation, or during troubleshooting.

To me, an MSD or Walbro is virtually silent. There is absoutely nothing offensive about the type of sound they make. Nothing. No need, what so ever, to have an in-tank pump as far as I'm concerned.

So then why does it seem to be such a popular mod? Why have so many done it? Can somebody please explain this love affair with in-tank pumps to me? I'd really like to understand. Thank you.

Rx-7Doctor

iTrader: (13)

This is his reason for doing it Jeff.

Quote-

I originally had this mounted under the car in the stock GSL-SE location, but I needed room for exhaust and I didn't like how noisey it was down there so I switched it to inside the tank. It should also stay cooler since it's not so close to my exhaust.


Room for the Exhaust? Exhaust goes out the other side, not on the side where the fuel pump would sit. Perhaps he put in dual mufflers?

jonathan_ed3

iTrader: (1)

Yes, the car has dual exhaust. Ground clearance isn't so great, but with the pump/filter/shielding gone I can now reroute it and hopefully gain some clearance.

Oh, and Jeff, I agree with you on most fronts in most situations.

I have converted to EFI on 1st gen Honda Civics/Engine swaps and the inline pumps have been an absolute NIGHTMARE as far as reliability is concerned.

I switched to a custom in-tank pump on my '79 Civics and problem solved. I wish I had done it from the get-go on those cars.

Since my RX7 is also a conversion/hybrid car....and because I wanted the room, I went ahead and switched it to an intank. It wasn't *too* much extra work. I already had the tank dropped to hot tank/coat it.

Like I said, it's probably overkill for the average FB.

dj55b

iTrader: (2)

I've done this myself also for the FB:

https://www.rx7club.com/showthread.p...&highlight=044

I actually re-changed the top fitting from what that thread says to a m12 to - 6AN and then from there the top is just a bulkhead fitting on the top piece of the tank and a straight female to female coupler. I have had a bit of a problem before where it was a bit too close to the bottom of the tank and it scuffed the bottom of the filter and put a whole through it.

Also i was having problems with the regular hose staying on there which is why i went AN on everything. I run mine at 60 psi currently due to the fact that I only run 2 x 720cc injectors.

jonathan_ed3

iTrader: (1)

Are you using a 44? How did you strap yours in...a regular worm clamp? Did you have to
enlarge the opening? Looks like you have a pretty solid setup

dj55b

iTrader: (2)

ya its the 44 one, the top of the tank has been cut and fitted with a second gen top. also the slosh cup from the second gen has been welded to the bottom of the tank. I originally started with a carburated tank.

elwood

iTrader: (1)

There are a lot of people that mount -44's in-tank. There's a setup for FDs that mounts a pair of them in-tank. The pump doesn't much care whether it's in the tank or out of it. The fuel that flows through the pump cools it.

As far as the noise is concerned, the -44 is relatively loud. My car is even louder, so having it mounted outside the tank isn't an issue for me. But . . . if I did have a very quiet car, I could see why it would be nice to have it in the tank.

Man, you must have used every banjo and A/N fitting in the catalog. They should give you frequent flier bucks or something!

Don't know how you plan to drive your car, but you may have fuel starvation problems. Even with that little cup or "reservoir" the pump sits in, I had problems under sustained hard cornering. I ended up going with a surge tank.

If you haven't already planned on it, use a "sock" or some kind of filter on the inlet. It'll keep the crud out of the pump and avoid issues.

jonathan_ed3

iTrader: (1)

It's just a street car so I won't worry too much
about fuel starvation.I have the return line feeding
back into the bowl. I do have a sock on the inlet
of the pump. So far so good.

Where do you have yours mounted?

dj55b

iTrader: (2)

ya I'm battling that cup issue, it needs to be about half or more to not fuel cut.

elwood

iTrader: (1)

Mine's mounted in the OEM location. Unless there's something else in that spot (like your exhaust), it's a very good place to put it. Do you have any pics of your exhaust?

Here's the post on my setup --> https://www.rx7club.com/showthread.p...ight=swirl+pot

Jeff20B

iTrader: (13)

I guess I got lucky when I found a GSL-SE tank, with its 1/2" pickup tube and small, but still somewhat useful slosh cup. Having an external fuel pump allows me to easily swap from a carb pump (big old Carter with 1/2" fittings) to an EFI pump (with a 1/2" to 3/8" reducer fitting before the pump).

diabolical1

iTrader: (3)

although i don't know exactly what is involved making the 044 work as an in-tank pump, for what it's worth, the 040 has identical specs and is already an in-tank pump. also, it usually runs a few buck cheaper from what i've seen. i just wanted to put that out there.

jonathan_ed3

iTrader: (1)

My car is a gsl-se and even though the
stock pickup and fuel pump location are
pretty efficient it just wasn't working out
very well in my unique situation. I'll see
if I can snap some underneath photos of
my car when I get back into town....won't
be til september though. So far I have been
very pleased with this setup, although if I had
known originally I was gonna go in tank I probably
would have started out with a 40 instead
if a 44

elwood

iTrader: (1)

Identical specs? The -040 is rated at 102 L/hr at 6.5 Bar, while the -044 is rated at 200 L/hr at 5 Bar. In addition, the current consumption on the -044 is significantly higher.

But . . . to make the comparison apples-to-apples, heres the data from 034 Motorsport:

-040 pump: In house tested 176Lt/Hr @ 55lbs and 159Lt/Hr @ 75lbs

-044 pump: In house tested 265Lt/Hr @ 55lbs and 255Lt/Hr @ 75lbs

The performance isn't even close. The -044 far outflows the -040.

diabolical1

iTrader: (3)

okay. i was mistaken. i was unaware of the 034 Motorsport data. i remembered comparing the two last year for an Audi project of mine and i had taken the data from the www.boschfuelpumps.com site. i trust 034 Motorsport, so i guess you're right.