[travislambert]

Originally Posted by SFV1LE

Here is an adapter that could be used to add a Hydramat to Ti 285 pumps in the Fore kit.

https://www.holley.com/products/fuel...s/parts/16-136

IF there is enough clearance under the pumps, you could attach one wide Hydramat directly to one pump under the Fore hanger, and connect a -6 PTFE hose to the other pump and run it over the saddle tank hump to another wide coverage Hydramat on the other side of the tank, pulling fuel by high-flow pumps from both sides.

If there is clearance to fit these adapters with low profile straight or 90 deg ORB to -6 male fittings, this might be a good and reliable solution eliminating need for FST. But the Fore dual + 2x Hydramats would be almost $3k parts alone I think.

It's an interesting thought, but the only way it would work on a road course is if the single pump attached to the remote hydramat could itself support the full fuel requirements at WOT. Otherwise, when there is only fuel in the left side (or either side for that matter), the car would still run out of fuel. Seems like that somewhat defeats the purpose of running multiple pumps.

[travislambert]

If you could adapt another stock pump to fit within the left hanger (which has a significantly different shape), then you could run a true dual pump setup. Both pumps would need their own jet pump in the opposite side of the tank (4 pickups in total). Then you could use a dual pump PWM controller from vaporworx to make it all work together.

With this setup, even when fuel is only in one side of the tank, both pumps would be working to supply fuel.

This setup would be less than $1,000, but it would require some work for fitment.

[SFV1LE]

Originally Posted by travislambert

It's an interesting thought, but the only way it would work on a road course is if the single pump attached to the remote hydramat could itself support the full fuel requirements at WOT. Otherwise, when there is only fuel in the left side (or either side for that matter), the car would still run out of fuel. Seems like that somewhat defeats the purpose of running multiple pumps.

This is 2 pumps with a Hydramat connected to each--each one pumping from a different side. In theory, both pumps connected to a properly sized Hydramat will most likely always be in contact with fuel on either side unless you run your tank well under 1/8 on track.

[travislambert]

Originally Posted by SFV1LE

This is 2 pumps with a Hydramat connected to each--each one pumping from a different side. In theory, both pumps connected to a properly sized Hydramat will most likely always be in contact with fuel on either side unless you run your tank well under 1/8 on track.

When you have less than a 1/2 tank of fuel and go around a turn hard, there is only fuel in one side of the tank or the other. It doesn't have to get to an 1/8 and it's not that most of the fuel transfers.... all of the fuel transfers. (I have countless hours of data logs on this.)

Maybe I'm misunderstanding your suggestion, but from what I understand, if fuel is only in one side of the tank, you're only supplying fuel from one pump. If this pump isn't sufficient on its own to supply all of the fuel needed for the engine, then that won't work. (The other pump is just going to suck air after the mat is dry because the fuel doesn't come back on its own.)

[SFV1LE]

Originally Posted by travislambert

When you have less than a 1/2 tank of fuel and go around a turn hard, there is only fuel in one side of the tank or the other. It doesn't have to get to an 1/8 and it's not that most of the fuel transfers.... all of the fuel transfers. (I have countless hours of data logs on this.)

Maybe I'm misunderstanding your suggestion, but from what I understand, if fuel is only in one side of the tank, you're only supplying fuel from one pump. If this pump isn't sufficient on its own to supply all of the fuel needed for the engine, then that won't work. (The other pump is just going to suck air after the mat is dry because the fuel doesn't come back on its own.)

Your logs show that there isn't fuel on one side, with respect to pressure from the stock setup with bucket right? Your logs dont read a sensor in the tank that measure the % presence of fuel on each side right? I'm not being sarcastic, I'm asking. I dont have details on the ZL1 sensor tech but doubt the answer is yes. How do your logs tell you that 1 side of the tank doesnt have some fuel pooling under Gs on one side of the hump, that a far-reaching Hydramat can access?

Are you certain that the side of the saddle tank hump doesn't contain a large volume of fuel that's just leaning too far from the stock pickup? You seem certain all fuel has crossed over this hump. The Hydramat is designed to reach out much farther than the stock pickup to pull fuel from the far recesses of the tank that the stock pickup doesnt reach, and unlike the stock fuel sock which is just a filter, if the Hydramat it touches any fuel it draws it through the pump.

A well designed dual-pump and dual-Hydramat system covering most of the tank area may solve this. Also, consider that as the fuel returns (gushes) back to the tank it sprays right down on the area under the hanger, where a Hydramat would be placed.

And all of what I'm describing, which is just theoretical, only needs to be designed to support bursts or pulses of WOT and Gs, some longer than others. It's not designed to sustain 150 MPH in a continuous high G left turn on banking. But no fuel system except in a race car like NASCAR, is design for this, or needs to be.

[Heartbreaker]

Originally Posted by swisstyphoon

lets hear pros and cons.

I don't like to drill the tank, and heard the Aux kit won't work for road corse racing, because of the fuel pick up location...

Wish there would be an option that uses the stock pump basket...

Have you looked into Ted Jannetty’s 125 hp flex fuel mod? He runs this on a road course and the JMS Voltage Booster solves the problem. It’s a proven mod. Why the double pump work around?

[SFV1LE]

Jannetty is good for 125 HP, these guys want to go much bigger requiring a lot more fuel.

The Janetty kit seems great to me for road course with no pulley and added heat. If you go bigger and want reliability on track, 2650 seems like the way to go.

[travislambert]

Originally Posted by SFV1LE

Your logs show that there isn't fuel on one side, with respect to pressure from the stock setup with bucket right? Your logs dont read a sensor in the tank that measure the % presence of fuel on each side right? I'm not being sarcastic, I'm asking. I dont have details on the ZL1 sensor tech but doubt the answer is yes.

There are fuel level sensors on both sides of the tank that are independently accessible on the CAN network. My logs show what each fuel level sensor is reading.

Originally Posted by SFV1LE

How do your logs tell you that 1 side of the tank doesnt have some fuel pooling under Gs on one side of the hump, that a far-reaching Hydramat can access?

The fuel pressure loss doesn't happen in the corners. It happens well after the car is level and no longer under a lateral G load. This combined with the fact that one of the sensors will be maxed out in the empty position (2.55v) until the next turn is pretty good evidence there is no meaningful amount of fuel available in a particular side of the tank.

Originally Posted by SFV1LE

Are you certain that the side of the saddle tank hump doesn't contain a large volume of fuel that's just leaning too far from the stock pickup? You seem certain all fuel has crossed over this hump.

Yes, I'm very confident because I've spent countless hours researching this problem with my laptop riding shotgun on the road course. Trust me, effectively all of the fuel transfers. In addition to the sensor data, when I had the DSX tuning pump, it was tapped at the bottom near the rear of the rightside tank where the fuel would certainly migrate to under acceleration. A hard right turn followed by a long straight would run the pump dry every time if there was less than 1/2 tank of fuel.

Originally Posted by SFV1LE

The Hydramat is designed to reach out much farther than the stock pickup to pull fuel from the far recesses of the tank that the stock pickup doesnt reach, and unlike the stock fuel sock which is just a filter, if the Hydramat it touches any fuel it draws it through the pump.

A well designed dual-pump and dual-Hydramat system covering most of the tank area may solve this. Also, consider that as the fuel returns (gushes) back to the tank it sprays right down on the area under the hanger, where a Hydramat would be placed.

And all of what I'm describing, which is just theoretical, only needs to be designed to support bursts or pulses of WOT and Gs, some longer than others. It's not designed to sustain 150 MPH in a continuous high G left turn on banking. But no fuel system except in a race car like NASCAR, is design for this, or needs to be.

The G load effect on the fuel pickup isn't the problem that needs solved. With even the small factory pickups, at least one or the other will be submerged until the car is effectively out of fuel (under any G load the car is capable of). The problem is how to meet a fuel demand while fuel is only in one side of the saddle tank.

Planning for short bursts at WOT isn't ideal because there are some very long straights on road courses. VIR has one that is 3/4 mile, and there is a straight on the Nurburgring that is 1.3 miles+. A good solution is not going to leverage an assumption that WOT will only come in short bursts. An OEM quality solution is one that can sustain a sufficient fuel supply indefinitely while fuel is only present in one side of the tank. If a solution under this scenario relies on one pump, then we're basically right back at the original problem. If we had a single pump available that could pull this off, we could just swap the factory pump and leave everything else.

It's a tough problem. If it were easy the aftermarket would have it right by now, but they don't. The aftermarket providers like DSX Tuning, Fore Innovations, etc. all think they have the problem solved too... until it's tested on a road course.

[SFV1LE]

Originally Posted by travislambert

There are fuel level sensors on both sides of the tank that are independently accessible on the CAN network. My logs show what each fuel level sensor is reading.

The fuel pressure loss doesn't happen in the corners. It happens well after the car is level and no longer under a lateral G load. This combined with the fact that one of the sensors will be maxed out in the empty position (2.55v) until the next turn is pretty good evidence there is no meaningful amount of fuel available in a particular side of the tank.


Yes, I'm very confident because I've spent countless hours researching this problem with my laptop riding shotgun on the road course. Trust me, effectively all of the fuel transfers. In addition to the sensor data, when I had the DSX tuning pump, it was tapped at the bottom near the rear of the rightside tank where the fuel would certainly migrate to under acceleration. A hard right turn followed by a long straight would run the pump dry every time if there was less than 1/2 tank of fuel.


The G load effect on the fuel pickup isn't the problem that needs solved. With even the small factory pickups, at least one or the other will be submerged until the car is effectively out of fuel (under any G load the car is capable of). The problem is how to meet a fuel demand while fuel is only in one side of the saddle tank.

Planning for short bursts at WOT isn't ideal because there are some very long straights on road courses. VIR has one that is 3/4 mile, and there is a straight on the Nurburgring that is 1.3 miles+. A good solution is not going to leverage an assumption that WOT will only come in short bursts. An OEM quality solution is one that can sustain a sufficient fuel supply indefinitely while fuel is only present in one side of the tank. If a solution under this scenario relies on one pump, then we're basically right back at the original problem. If we had a single pump available that could pull this off, we could just swap the factory pump and leave everything else.

It's a tough problem. If it were easy the aftermarket would have it right by now, but they don't. The aftermarket providers like DSX Tuning, Fore Innovations, etc. all think they have the problem solved too... until it's tested on a road course.

Thanks for all that info, that all makes sense and answers many of my questions. Based on that it sounds like we need a better solution, I'm not planning any upgrades I just enjoy learning about this and brainstorming solutions.

I dont agree there isn't a great aftermarket solution: a real fuel cell (e.g. Radium, Fuelsafe) with a Fuel Cell Surge Tank (Ti 285 lift pump, dual Ti 285 FST pumps), would solve all fuel tank supply issues up to the engine bay (pre HP pump, cam and injectors, etc). The price of a FC and FCST is not THAT much more than one of these inadequate in tank kits from Fore.

The cell has foam that stabilizes fuel movement, and you can install a big cell sized Hydramat on the lift pump if you want to go really far. And if you sell the car you can easily remove and install in your new car.