SLC 24 Howard Jones
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Howard Jones
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Thanks for that. Great minds think alike, Ya? I am considering a 1 gal tank separate from the main tank that receives the fuel being pumped from the main pump as well as the return line from the fuel pressure regulator. Then that smaller tank will incorporate an overflow back to the main tank. A second primary pump drawing fuel from the smaller "surge" tank would supply the carb via the inlet to the regulator. I'm going to draw something up so I can get a better idea of what I am doing. I would like to have an emergency/reserve tank in the system that I can use if I run the main system out of fuel. Enough to return to the paddock if that happens. I gallon would be plenty. Maybe I can get some dual-use from the second "surge" tank and pump system.
Howard Jones
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Howard Jones
Supporter
Ya, I signed up for Sunday, May 12th with Edge Addicts. Come on out. I'd love to have some company. Look for me in the paddock. I have a white F150 and an enclosed white trailer.
Howard a gallon is a lot. A quart is a lot for a carb setup. Carter Black https://www.summitracing.com/parts/crt-p4601hp works well for lift and carb applications.
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Howard Jones
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That is exactly what I was thinking! I was going to research pumps next. To confirm, I will need to pump out of the top of the fuel tank and into the 'serge tank sitting next to it. The total lift height will be about a foot and the length of the fuel line from the main tank to the surge tank will be about 2 feet. I am making about 550 hp so I think about 50 gph ought to work. OK Don?
The Carter Black pump in free flow is 50 gph free flow. Lift pump is free flow into surge tank.
As in diagram, main pump from bottom of surge. Return to tank out top. Lift and regulator return on side at top at an angle creating a swirling motion. Hence swirl pot. Prevents air bubbles from reaching bottom of surge tank under low fuel tank pickup conditions.
Questions:
What are you doing for pickups in the main tank?
Holley hydramat?
Does the main tank contain foam baffling?
Rock crawler pickups?
I would call you but I lost a few #'s when transferring to new phone.
As in diagram, main pump from bottom of surge. Return to tank out top. Lift and regulator return on side at top at an angle creating a swirling motion. Hence swirl pot. Prevents air bubbles from reaching bottom of surge tank under low fuel tank pickup conditions.
Questions:
What are you doing for pickups in the main tank?
Holley hydramat?
Does the main tank contain foam baffling?
Rock crawler pickups?
I would call you but I lost a few #'s when transferring to new phone.
Howard Jones
Supporter
The main tank is a big aluminum box about 5 feet long a foot tall and about 14 inches wide, It is divided with full width and height baffles into three sections of equal area with holes in the rear bottom of the panels about 1 1/2 in diameter to allow fuel to transfer between them. I have added a sump in the center section located at the center rear, 6 inches square and, 2 inches deep.
The pickup is a length of hose that comes from the top of the tank and terminates down in the center of the sump. I used an aluminum AN 'T' fitting attached to the hose and sitting on the bottom of the sump as a weighted pickup. It cannot move enough to contact the sides of the sump walls. I would estimate that there is about a 1/2 inch clearance to the bottom of the sump from the two 'T' openings and therefore the inlet would be about a 1 to 11/2 below the floor level of the main tank.
No foam. The tank is all welded up and replacing foam would be a big deal.
I am pretty sure fuel will normally find its way into the sump while on track pretty consistently. However, I agree that a surge tank would probably solve the problem. I just ordered a length of aluminum tubing to make a surge tank.
I'll send you my contact info via PM. Thanks again, Don.
The pickup is a length of hose that comes from the top of the tank and terminates down in the center of the sump. I used an aluminum AN 'T' fitting attached to the hose and sitting on the bottom of the sump as a weighted pickup. It cannot move enough to contact the sides of the sump walls. I would estimate that there is about a 1/2 inch clearance to the bottom of the sump from the two 'T' openings and therefore the inlet would be about a 1 to 11/2 below the floor level of the main tank.
No foam. The tank is all welded up and replacing foam would be a big deal.
I am pretty sure fuel will normally find its way into the sump while on track pretty consistently. However, I agree that a surge tank would probably solve the problem. I just ordered a length of aluminum tubing to make a surge tank.
I'll send you my contact info via PM. Thanks again, Don.
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Howard Jones
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Another outing at COTA yesterday, this time with Edge Addicts. The weather was cool in the morning and really nice in the afternoon. Temps varied from about 70F to 85ish. When the sun came out after the morning overcast the track grip came up and I think I finally got the tires up to temp in the last session. I didn't really try anything new except to add a degree of rear wing. I also didn't get the new BP30 brake pads from Summit in time to use them so I left the BP28s in the front until the BP30s arrive. I don't think I like the BP28s anyway. They seem kinda vague and with a bit less grip than the "B" I have been using for years.
The fuel issue went away by adding 7.5 gas after each session. My best guess is I am using 7 gals every 30 mins.
The news is after running constant 2:34-35 and feeling like I know there's a lot more I had a go in the last session. Here's the SOLO 2 screen from that session. 5 seconds over that one lap by just giving the car what it wanted, deeper braking after full power runs down the two straights, and a good hard lean on it in the fast corners.
There's a lot more there, I just need to want to do it I guess. I need to get my head around bumping up my fun speed a bit. Gonna have to move up a group though. I had a couple of near misses on the brakes with 50MPH closing speeds at the end of the back straight. In an earlier session, I tried to go for top speed on the straight and saw 160. Letting the car have its head off the corner before the straight makes a lot of difference in terminal speed. That's also a lot of work for the brakes, as well as added wear and tear, and that is the downside to high top speeds.
So here's the SOLO 2 picture.
The fuel issue went away by adding 7.5 gas after each session. My best guess is I am using 7 gals every 30 mins.
The news is after running constant 2:34-35 and feeling like I know there's a lot more I had a go in the last session. Here's the SOLO 2 screen from that session. 5 seconds over that one lap by just giving the car what it wanted, deeper braking after full power runs down the two straights, and a good hard lean on it in the fast corners.
There's a lot more there, I just need to want to do it I guess. I need to get my head around bumping up my fun speed a bit. Gonna have to move up a group though. I had a couple of near misses on the brakes with 50MPH closing speeds at the end of the back straight. In an earlier session, I tried to go for top speed on the straight and saw 160. Letting the car have its head off the corner before the straight makes a lot of difference in terminal speed. That's also a lot of work for the brakes, as well as added wear and tear, and that is the downside to high top speeds.
So here's the SOLO 2 picture.
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Howard Jones
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I was a little surprised by that one myself. But to be honest I haven't run the car down the straights with full power and intent to max speed there. Otherwise, I moved the brake points deeper to a point that I believed was near maximum and ran both of the high-speed turns until I saw the beginnings of a little push. I used a lot of 4th gear and only down to 3rd in the slowest corners. New tires are a wonderful thing!
Throughout the day I had been trying these things one at a time and in the end, just did them all in one lap. That used to be my method when I raced motocross to work out a full lap min time. One section at a time. Then put it all together. Still works I guess.......
If you look at the SOLO 2 data you can see that both the min and max speeds went up quite a bit on that lap. On one earlier lap, I saw a 160 on the back straight but I just didn't feel good about it when I got to the braking zone so thereafter I sorta rolled off the power earlier and waited to get to the brake point instead of going from full power to full brake effort.
That's a pretty harry thing going to max brakes from 160MPH.
When I asked I was told that the fastest laps of the day were being run by 200HP radicals, In the 2:09 - 12 range. Ya, that's fast.
Throughout the day I had been trying these things one at a time and in the end, just did them all in one lap. That used to be my method when I raced motocross to work out a full lap min time. One section at a time. Then put it all together. Still works I guess.......
If you look at the SOLO 2 data you can see that both the min and max speeds went up quite a bit on that lap. On one earlier lap, I saw a 160 on the back straight but I just didn't feel good about it when I got to the braking zone so thereafter I sorta rolled off the power earlier and waited to get to the brake point instead of going from full power to full brake effort.
That's a pretty harry thing going to max brakes from 160MPH.
When I asked I was told that the fastest laps of the day were being run by 200HP radicals, In the 2:09 - 12 range. Ya, that's fast.
Howard Jones
Supporter
I have begun to build my swirl/surge tank. See post-1206 above for the layout. Here's my question. I would like to install a low fuel pressure switch in the lift pump output from the main tank to the surge tank so that I would know when the main tank has run low on fuel and be warned that the surge tank is not being supplied with fuel. This will give me a lap or so of fuel to return to the paddock without running out.
But I don't believe that there will be much if any pressure in that line since it is in freeflow to the surge tank. The surge tank is vented back to the main tank by a open return line and the main tank is vented to the atmosphere. Therefore I don't think any pressure will be present in that line. If I install a low-pressure switch there it will be on all the time. Fail.......
I was thinking that a restriction in that line might provide some pressure differential but I really need about a constant 6 PSI to use a 4 PSI sensor/switch. That much of a restriction would be excessive? I have a leftover inline fuel pressure regulator. If I used this inline with the surge tank inlet, do you think it would provide enough restriction to use the pressure switch?
Has anybody solved this problem? Ideas?
But I don't believe that there will be much if any pressure in that line since it is in freeflow to the surge tank. The surge tank is vented back to the main tank by a open return line and the main tank is vented to the atmosphere. Therefore I don't think any pressure will be present in that line. If I install a low-pressure switch there it will be on all the time. Fail.......
I was thinking that a restriction in that line might provide some pressure differential but I really need about a constant 6 PSI to use a 4 PSI sensor/switch. That much of a restriction would be excessive? I have a leftover inline fuel pressure regulator. If I used this inline with the surge tank inlet, do you think it would provide enough restriction to use the pressure switch?
Has anybody solved this problem? Ideas?
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