High boost, e85, fuel starvation on a road course: What's everyone doing in 2015?

[Xero-Limit]

I recall this problem being quite prevalent in 2013 and some have gone from just keeping the tank topped off, to others doing a full return conversion. What's the verdict now 2 years later? Anyone make headway or something relatively simple? We are pushing 19 psi on our Sprintex build and fuel starving in long left hand sweepers as full as 3/4 tank on street tires (re71r).

Unfortunately keeping the tank topped off is not really an option for us. By the end of a 20 minute session with 19 psi and e85, we'll be at half tank before it is over. Our goal is to set it up for NASA racing next year and this hurdle is first.

Surge tanks look like a decent option, but the size we'd need might be a limitation. What is everyone doing?

[rice_classic]

You want this. It's been a big hit with road racers, especially those who run in classes where fuel cells aren't allowed or are cost prohibitive.

Holley Hydra-Mat

[ame]http://www.youtube.com/watch?v=yfE1v65fNZI[/ame]

[ame]http://www.youtube.com/watch?v=4rG97UuVgmQ[/ame]

[CSG Mike]

Originally Posted by moto-mike

I recall this problem being quite prevalent in 2013 and some have gone from just keeping the tank topped off, to others doing a full return conversion. What's the verdict now 2 years later? Anyone make headway or something relatively simple? We are pushing 19 psi on our Sprintex build and fuel starving in long left hand sweepers as full as 3/4 tank on street tires (re71r).

Unfortunately keeping the tank topped off is not really an option for us. By the end of a 20 minute session with 19 psi and e85, we'll be at half tank before it is over. Our goal is to set it up for NASA racing next year and this hurdle is first.

Surge tanks look like a decent option, but the size we'd need might be a limitation. What is everyone doing?

Therein lies your problem.

I think you're confusing a fuel cell with a surge tank. I'd be shocked if you needed more than a minimally sized surge tank; a lot of the high hp cars i drive have small (0.5L ish capacity) surge tanks. The surge tank is just a buffer between your fuel tank and injectors.

[Xero-Limit]

Originally Posted by CSG Mike

Therein lies your problem.

I think you're confusing a fuel cell with a surge tank. I'd be shocked if you needed more than a minimally sized surge tank; a lot of the high hp cars i drive have small (0.5L ish capacity) surge tanks. The surge tank is just a buffer between your fuel tank and injectors.

Quite aware of the difference

I think the question is really are people using an off the shelf setup or still converting to a return system? In looking around I see a ton of universal surge tanks (we'd have no problem making our own) but in this case it would be much easier to go off the shelf. I'd like to see what folks have been running and whether anyone has had issues with a certain size tank.

[CSG Mike]

Originally Posted by moto-mike

Quite aware of the difference

I think the question is really are people using an off the shelf setup or still converting to a return system? In looking around I see a ton of universal surge tanks (we'd have no problem making our own) but in this case it would be much easier to go off the shelf. I'd like to see what folks have been running and whether anyone has had issues with a certain size tank.

For me, the larger issue is that for anything that's not a dedicated race car, there's no *safe* solution for a surge tank with this platform when it comes to placement. A custom gated unit using the spare tire space would be nice, but pricey...

How much volume are you needing to push through the system?

Also, I was pointing out the RE71R... they're sold/marketed as a street tire, but have more grip than entry level R-comps at the moment.

[Xero-Limit]

Originally Posted by CSG Mike

For me, the larger issue is that for anything that's not a dedicated race car, there's no *safe* solution for a surge tank with this platform when it comes to placement. A custom gated unit using the spare tire space would be nice, but pricey...

How much volume are you needing to push through the system?

Also, I was pointing out the RE71R... they're sold/marketed as a street tire, but have more grip than entry level R-comps at the moment.

That first point is what has me concerned. I've had customers come by with AN fittings drilled through the top of the bucket assembly, which gave me instant pause as that is far from ideal when it comes to safety. Trunk might be a good option, it may not be that expensive relative to a fuel cell, just a lot of AN lines. Then they would have to be secured very close to the fuel bucket to avoid putting pressure on the top plate.

Agreed on the RE71Rs...they are indeed better then r-comps from 5 years ago. We've sold nothing but that to autoxers this year and for good reasons.

But we will be putting on R7s later on and that should generate a good bit more in the sweepers, which won't help our problem any.

[CSG Mike]

Originally Posted by moto-mike

That first point is what has me concerned. I've had customers come by with AN fittings drilled through the top of the bucket assembly, which gave me instant pause as that is far from ideal when it comes to safety. Trunk might be a good option, it may not be that expensive relative to a fuel cell, just a lot of AN lines. Then they would have to be secured very close to the fuel bucket to avoid putting pressure on the top plate.

Agreed on the RE71Rs...they are indeed better then r-comps from 5 years ago. We've sold nothing but that to autoxers this year and for good reasons.

But we will be putting on R7s later on and that should generate a good bit more in the sweepers, which won't help our problem any.

If you can make a great in-tank solution, you can take bets on who'll be first in line....