Aeromotive Stealth Fuel tank issues

[bryant]

this may be a good solution
https://www.holley.com/products/fuel_systems/hydramat/
im not sure how to integrate it in to the stealth tank but it should fix the slosh issues.

[another69]

I was pretty excited about this, and hope it works, but Aeromotive tech said it would likely cavitate the pump and advised against using it. I hope someone has used it in this application with good results because it seems like a great idea...

[bryant]

I was pretty excited about this, and hope it works, but Aeromotive tech said it would likely cavitate the pump and advised against using it. I hope someone has used it in this application with good results because it seems like a great idea...

i find what aeromotive is saying highly suspect. first were tying to stop fuel slosh which takes gas away from the fuel pump pick up and causes it to cavitate. so holley makes a product designed specifically to prevent this and aeromotoive says it will cause it. now aeromotive is the one with the design problem allowing for cavitation and then says another manufactures product wont work.

about 15 years ago i put an aeromotive sumped tank into a fox mustang and at 1/2 tank level it would suck air (cavitation) in a regular turn on the street. the owner contacted aeromotive and they said it was only for drag race use and that it just how it works. we ended up using a fuel pick up in the stock tank that used the stock baffle and had no problems.

2 years ago i put a stealth tank in a mustang and it was leaking gas around the fuel pump assembly. we tightened the bolts/nuts (dont remember now) because they felt really loose. that made it worse. we then pulled the pump and found the gasket used was split. the gasket is about 1/4" thick soft rubbery stuff. they said they had never seen that before and sent another one, but i would say the gasket needs a anti crush sleeve or spacer or needs to be more durable.

i can understand a company standing by its product and defending it, but if the product has limitations and the company wont acnowlage them in their advertising or at the time of when the customer complains, it just starts looking bad.

areomotive is cool in that they are constantly trying to expand the fuel system industry but they seem to lack the final quality control finish and reluctance to acknowledge another company's possible better solution.

[n77nxc]

Here is the response I got from Aeromotive:

Okay, first thanks for choosing Aeromotive. To address your questions:

1.) As I’m sure you realize, the fluctuations you’re seeing on the gauge is a reflection of the fluctuations of fuel around the sending unit. When the tank is not full and fuel surges in the fuel tank, the float is going to rise and fall and the gauge is going to reflect that movement. OEM fuel sending units and OEM fuel level gauges are sometimes engineered to dampen these fluctuations, but the approach to this varies with the manufacturer and the year/model of the vehicle. Typically the factory damping action is performed in the factory gauge or gauge wiring harness.



For example, Ford used a non-linear sending unit and a heat compensating gauge in the dash to try and limit the movement of the needle. Other OEM manufacturers used various methods to mask fuel slosh in the tank from the gauge, but it has varied significantly over the years. The fuel gauge sending unit provided in the Aeromotive tank is a standard, pivot and float style sending unit from Classic Instruments. It’s calibrated for the OEM ohm rating to work the stock style gauge in the dash, and it’s accurate and relatively inexpensive.


For aftermarket tanks and/or gauges, there are a couple possible solutions, including using a baffled/tube type sending unit (which this helps but is expensive as sending units goes), or an electronic damper circuit might be an option, though building something like this yourself would require some pretty good electronic knowledge. There will be a product like this on the market soon, not from Aeromotive, which we can talk about after it’s introduced next week.

Classic Instruments has a tube type, baffled sending unit with 0-90 Ohm output for a 6” deep tank under P/N SN38T6. There are plastic stand-offs on the top side of the sender, where the wires hookup, that are slightly too tall and could contact the floor. These could be trimmed down I believe. You can learn more about these here: http://shop.classicinstruments.com/sn38t


2.) As for the issue with hard acceleration at 1/4 full and below, this is basically a physics thing. When the tank is at 1/4 full, the baffle the pump sets in is also at 1/4 full. The size of the baffle is as large as is practicable in the tank given the shape/taper of the bottom (runs up hill from the differential up toward the bumper). When the engine goes under high load, and is making real power, the fuel in the baffle can’t escape, but the rest of the fuel in the tank runs toward the rear, in the meantime the engine is consuming what fuel was in the baffle to start with but it’s not enough to carry the car far enough before the baffle empties out, creating the problem.



There’s really nothing that can be done in this case but drive a little more gingerly when the tank is low on fuel. High horsepower engines consume large amounts of fuel during WOT operation. There has to be enough fuel in the baffle to carry the car the intended difference before the engine goes to WOT, or the baffle will not have enough fuel to handle the duration of the event. A completely different tank bottom, with a rear mounted pump and a deep sump that carried to the rear of the car would help, but it would also destroy the stock appearance of the tank.

[n77nxc]

Follow up...I asked for them to take the tank back since it doesn't function as described and this is their response:

I can appreciate what you’re saying, but don’t you think this is a bit of apples to oranges? The “vaporworx” solution is based on an OEM Camaro in-tank module. This does have the benefit of a Jet-Siphon arrangement, which coupled with the Walbro pickups is able to put fuel into the module, however it’s both much more expensive (from $400-$1,200 more depending on the tank construction) and with the Camaro module falls about a 180 HP shy in capacity and does not support an adjustable regulator or a full flow, return style fuel system.

As a practical matter, using the Jet Siphon on the Camaro module (used to draw fuel from the other side of the factory saddle tank) to pull from the corners is smart, but it’s also a flow loss to the system (fuel flow is used to power the jet), which does reduce the HP capability. Of course using this module requires a specialty tank that has a much larger opening, and a much larger depression in the top of the tank, requiring the tank be much deeper to regain capacity. The Aeromotive Stealth Tank was designed to mimic the stock tank exactly, to retain stock fitment and appearance, hence the “Stealth” name.

All I can say is, if road racing with under 1/3 of a tank of fuel is necessary, you definitely need a different tank. The Aeromotive Stealth Tank is engineered to provide an EFI conversion platform that maintains good drivability when the tank is low on fuel. It was not necessarily designed for road racing with low fuel levels in the tank, nor have we promoted it for this type of application.

[parsonsj]

You're probably not going to have much luck returning the tank. Aftermarket automotive is a different business model than Home Depot or Macy's. Especially since the part has been installed and cannot be put back on the shelf.

Your best bet is to try and sell it via Craigslist or the classifieds here.

[n77nxc]

John,

I'm fully aware but it just irks me they put out a product that should have been labeled an EFI replacement tank instead of a performance based EFI tank with "innovative baffling/tray system to control fuel slosh and keep the fuel pump submerged". Its unfortunate I had to install it and run the car to find out its a POS.

The purpose of my posts is to show others to steer clear of this setup if they plan on driving their cars harder than a Prius.

[parsonsj]

Noted. I'm moving this thread to the Feedback section.

[CarlC]

"As a practical matter, using the Jet Siphon on the Camaro module (used to draw fuel from the other side of the factory saddle tank) to pull from the corners is smart, but it’s also a flow loss to the system (fuel flow is used to power the jet), which does reduce the HP capability."

Interesting answer, but it begs the question: What good is that extra HP capability when fuel sloshes away from the pump?

Just for reference, single Cadillac CTS-V fuel modules can support 800hp @ 0.6BSFC/60psi/13.5 volts. ZL1 650hp. Even the lowly LS3 module can support 600hp naturally aspirated (and can be found for $80 low-mileage used on camaro5.com.) All vaporworx pwm systems come standard with the option to be manifold referenced for 1bar, 2bar, 2.5bar, or 3bar (standard) MAP sensors. Stand alone sensors are also available.

As far as being a full return style, that defeats the purpose and the benefits of having a single line to the fuel rail. We have supported many engines in the 1000+hp range using twin ZL1 and CTS-V modules with a single AN8 line to the rail with good results. The full return system is a product of a time that has come and gone with every modern OE GM, Ford, and Chrysler fuel system.

There have been many folks that have had their cars die on Power Tour due to fuel pump problems associated with the troubles noted above combined with pump size, type, etc. Just a few weeks ago we validated a system that can support 1600+hp gasoline (soon to be 2300+hp) in a C6 (single super small access/mounting hole) with an at cruise power requirement of just over 11 amps and 65psi constant fuel pressure. It's a single line to the rail system with the pumps staged according to boost levels but still under full closed-loop operation. The twin Walbro 450's (soon to be three on another application) move a lot of fuel but are OE reliable pieces. It is the pump used in the Hellcat, but the module output is rated at 315lph due to the jet pumps. The jet pumps are serving a purpose that no other pump in the aftermarket can perform. Oh, and at that flowrate, it can support over 800hp supercharged as well, so the jet pump loss argument is moot for 99% of the builds out there (CTS-V has similar performance.) The Walbro 450lph and CTS-V pumps (not the fuel level sensor) are also E85 OE validated systems.

Noting the Hellcat, in the recent Hot Rod article comparing the Hellcat and LT4 engines both companies address the challenges of high-horsepower fuel delivery. It's not easy or inexpensive to have a Dr. Jeckle/Mr. Hyde system + 100k mile reliability. I spent months trying to come up with a better, less expensive, method but kept coming back to the fuel module and PWM control via a liquid sensor feedback mechanism.

[n77nxc]

Update:

Aeromotive/Summit is refunding me the cost of the tank. While I'm pleased with the result, I just wish it didn't take so much effort to show Aeromotive they mis-advertised the tank.

Summit added the following to the description of the tank within the last week:

Stealth Fuel Tanks are not engineered for competition drag racing or road racing applications where extreme acceleration and cornering will occur with fuel levels lower than 1/2 tank

The 340 pump supports up to 700 hp EFI forced induction, 800 hp EFI naturally aspirated, and over 900 hp carbureted engines, as well as supporting normal driving down to very low levels of fuel in the tank.

I got my Rick's/vaporworx stamped tank in and it works perfectly. Its first test was just on a gallon of fuel and zero issues.

[parsonsj]

Glad to know that vaporworx solved the problem. Reminds me of an old golf joke:

God and Moses were playing golf, and Moses hit first on the first tee. He hit a nice fade down the middle, and had middle iron to the green. God pulled out his driver and smashed a drive way right, which hit a tree, bounced along the rough, rolled up the cart path, hit a rock, rolled on to the green and in to the cup.

(shortening the joke for brevity): After similar miraculous shots off the tee on holes 2 and 3, Moses had had enough. He turned to God and said, "So do you want to play golf, or do you want to **** around?"

That's how I feel about fuel tanks. "Do you want to get a VaporWorx, or do you want to **** around?"

[seanj]

Just found this thread... wish I had of read it before I purchased my stealth tank 12 months ago. I've got the same issues with my Aeromotive stealth tank in my 69 Camaro. Running a ~650hp big block with Holley Multi Point fuel injection and a return fuel system. Technically within the capability of this pump but I get starvation at anything less than 3/4 full in a straight line at full throttle.

Not an issue with the fuel sender, as it occurs shortly after brimming the tank when put under hard acceleration, eg. autocross and circuit work. Followed up with Aeromotive, but they told me to check my sender

I'm now looking to put a surge tank in the boot to compensate for the slosh.

[72Z/28]

Well I am having the same issues with my aeromotive fuel tank. The fuel gauge keeps fluctuating and the pressure drops when tank is near empty or 1/4 full. The car has not been driven for almost a year and a half. I have recently started to run the engine. However, I noticed that the sending unit is not functioning. The gauge reads past full. Also, apparently the fuel pump check valve is not performing its function anymore as it takes a bit of time to start the engine and the fuel pressure gauge drops instantanously to zero once the engines shuts off.

[73ta]

I have read about numerous issues with many different manufacturers tanks. I have modified my stock tank with a Walbro 340 pump using a return regulator system. It works just fine as long as I don't run it at less than 1/2 tank for autocross or 1/4 tank on the street. I am running a carb though. I don't think a carb is as fuel sensitive as it's run at 5lbs and has a fuel bowl and 1/2" supply return lines for volume. The baffles and sumps that these various manufacturers install don't seem to solve the issues associated with high g force, high hp setups. The vaporworks setup looks to be the answer, but the price!