Intake manifolds
- Thread starter Alky V6
- Start date
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
Donnie, you could use a stepper motor to move the barrel valve, instead of a boost actuator. Stepper motors can be controlled to a VERY finite movement. That would probably be a better way to control the fuel curve.
I really think that -10AN lines are too big. They will have to be pushing the gravitational forces of one G (at launch). I know most people think that bigger is better, but most Sprint car guys around here run Methanol and 750HP through one -6AN. The pump has to fill the hose and fill the nozzles. I think that two -8AN will still be over kill after the pump. Feed the pumps with -12 or larger, though. Front mount the fuel cell, too. Better way to feed the engine. Electronic pumps don't make good sucker pumps, so let gravitational forces work in your favor.
We use to use big electronic aircraft pumps to feed our 5,000+ hp V-12's. I can get a manufacturer and number if you think you NEED huge volumes. I mean HUGE volumes. We used one pump and it fed both the pressure carb ( a PR-100 off of a R-4360, with one BIG nozzle that sprayed into the supercharger) AND a nitrous sytem that we would empty 150lbs. of nitrous in 4 minutes of racing.
(Man I HATED filling those bottles!!!) We would also go through 65 gallons of 115/145 AV gas (with a special addative that would drop you to the floor if you breathed it.....ask me hw I know THAT! ) and 25 gallons of water/methanol (ADI) in about 4 minutes. We had (5) 30lb. bottles of nitrous in the boat, and they would be empty after every 4 minute race. The driver would only use the nitrous coming out of a turn, but the boat would accelerate from about 100mph in the turn to 220mph at a push of a button. The boat would walk 8 feet sideways (with only 1/2 the 15.5" prop in the water). Here is pic of the props we used. They only cost $10-12,000 EACH! (back in 1985) I remember the UPS guy dropping off 10 of them one day. (thank God I wasn't writing the checks for them.)
Here's a pic of one of the pistons and the blade rod/fork rod of a Griffon, and a melted piston from a nitrous valve failure. (the fuel valve shut off, but the nitrous valve froze open.)
I really think that -10AN lines are too big. They will have to be pushing the gravitational forces of one G (at launch). I know most people think that bigger is better, but most Sprint car guys around here run Methanol and 750HP through one -6AN. The pump has to fill the hose and fill the nozzles. I think that two -8AN will still be over kill after the pump. Feed the pumps with -12 or larger, though. Front mount the fuel cell, too. Better way to feed the engine. Electronic pumps don't make good sucker pumps, so let gravitational forces work in your favor.
We use to use big electronic aircraft pumps to feed our 5,000+ hp V-12's. I can get a manufacturer and number if you think you NEED huge volumes. I mean HUGE volumes. We used one pump and it fed both the pressure carb ( a PR-100 off of a R-4360, with one BIG nozzle that sprayed into the supercharger) AND a nitrous sytem that we would empty 150lbs. of nitrous in 4 minutes of racing.
(Man I HATED filling those bottles!!!) We would also go through 65 gallons of 115/145 AV gas (with a special addative that would drop you to the floor if you breathed it.....ask me hw I know THAT! ) and 25 gallons of water/methanol (ADI) in about 4 minutes. We had (5) 30lb. bottles of nitrous in the boat, and they would be empty after every 4 minute race. The driver would only use the nitrous coming out of a turn, but the boat would accelerate from about 100mph in the turn to 220mph at a push of a button. The boat would walk 8 feet sideways (with only 1/2 the 15.5" prop in the water). Here is pic of the props we used. They only cost $10-12,000 EACH! (back in 1985) I remember the UPS guy dropping off 10 of them one day. (thank God I wasn't writing the checks for them.)Here's a pic of one of the pistons and the blade rod/fork rod of a Griffon, and a melted piston from a nitrous valve failure. (the fuel valve shut off, but the nitrous valve froze open.)
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Good food for thought.
Thanks for the pictures and fact tidbits. Very interesting stuff. Please post more, if you have it. I never tire from pictures and stories of fine machinery.
Stepper motor. Very good idea.
I agree with the supply line size. Since each line will be supporting half the hp requirement, there's no need for the big line. It'll be cheaper too.
The fuel cell will remain in the rear. It's purely a safety thing with me. The capacity of the cell is going to be increased. More weight over the rear tires.
Thanks for the pictures and fact tidbits. Very interesting stuff. Please post more, if you have it. I never tire from pictures and stories of fine machinery.
Stepper motor. Very good idea.
I agree with the supply line size. Since each line will be supporting half the hp requirement, there's no need for the big line. It'll be cheaper too.
The fuel cell will remain in the rear. It's purely a safety thing with me. The capacity of the cell is going to be increased. More weight over the rear tires.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
Don. Can your ECU run more than 8 injectors? Most of the alky cars are running 2-3 injectors per cylinder and letting the ECU turn them on in stages for a more linear fuel curve.
Yes. It will run another set of injectors. The problem is I have no room to mount another set of electronic injectors and I don't want to mount electronics inside the plenum. The plastic fuel rail I was using came out with part of it melted. I assume an intake backfire started a fire in the plenum that burned long enough to cause the damage to the fuel rail. Wires probably wouldn't fair well in there.
When the timing is right, cutting back the injectors works just fine. It takes a bit to find the sweet spot for the cut back, but once it's found, it works great. My ECM only allows a certain percentage plus or minus off of the chosen linear fuel curve for the fuel map. Plus 50% and minus 50%. When the amount of fuel that is needed from the aux system is increased, the amount of needed cut back from the electronic injectors when the aux system is first turned on also becomes greater. As it is now, I'm using all the range, plus and minus, that I'm allowed. If I can have the aux fuel system come on with a smaller volume, requiring less cut back of the electronic injectors and then have a steeper ramp up of aux fuel volume to boost, I would not have to cut back the E injectors so drastically (-48%), and I wouldn't run out of electronic injectors on the upper end (duty cycle of 85%). I really think running the extra bypass regulator with a higher reference ratio will do the trick. Start the aux fuel with a lower line psi, say 35 at 8 psi boost and have it ramp up 1.5 to 1, pressure to boost. I'd have a delta of 40.5 at 35 psi boost. Last time I dared to glance at my fuel pressure gauge with the old fuel pump, I swear I saw less than 50 psi at a boost of 24. That's a delta of 26 psi with the 1 to 1 referenced bypass valve I was using. There's definitely more fuel to be had if I can get the supply line pressures where they need to be.
Hmmm. We may need to see some pics of your wife then.
Don, rather than ramping the fuel pressure mechanically to bring in the extra fuel after you enable it, how about using a fixed (referenced to boost as usual) pressure and two or three solenoid valves in parallel with a precision restrictor in series with each valve in a 1-2-4 flow progression on the restrictors. Hit the first valve, turn it off and hit the second, turn the first back on, turn those off and hit the third, etc to count your way up in flow from zero to three (two valves) or eight (three valves). That would let you spread the extra fuel over an arbitrary sized transition region in your fuel map instead of all at once, so you should have fewer problems with a lean or rich spike. If you don't want to turn the valves on and off you could use a different restrictor progression and just get fewer fuel steps as you bring in each valve. Actually, this would let you stay with one fuel pump, as well, if you wanted to keep it simpler.
An interesting idea, but impossible to trim. At each step, the fuel delivery changes would demand the electronic injectors be adjusted at each step to trim the mixture into a smooth curve. It would take a tremendous amount of cells with rpms and maps paired closely together to affect the E injector changes throughout all these steps. Believe me, it's hard enough with just one step. I do not want to create more. An engine would not tolerate steps in fuel delivery. Even small ones.
The reason I need to run another fuel pump is because I've already been running at the edge of capacity with this one, and if I'm going to try to pump pressures up, the fuel volume is going to drop for each pump. The more pressure, the less volume. So the two of them being run at a higher pressure should be able to supply the needed volume between the both of them.
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
The barrel valve is sounding better all the time. I think a stepper motor linked to a barrel valve would do the trick. You could mechanically try a barrel valve with a boost can, first, to see if you are on the right track. A stepper motor can be programmed to do what ever you want, BUT.....that is out of my field of expertise. I can ask around at work and find a Einstien MR&D guy that could whip something up during his lunch break. Me?........I can put it together, and build the parts, but, making it all work as you need it, I'll leave that to an electronic engineer. All I know about electronics is that if I stick my tongue on a 480v power feeder, they will be calling my wife telling her she has a check coming to her, but not her husband. (not really, I do have to install/trouble shoot complex aircraft electrical systems, but programming and designing is for folks smarter than me.)
Here's some pics of a Ferrari we built in 2001 (355FI engine in a 288GTO. We twin turbo'd it with a M800 box) and a pic of a TTA with a Precision front mount. I had to make aluminum oval tubing for ground clearance. I have lots of pics of some of the fun stuff I have made with over the years. Some stuff is now being built and sold by vendors on this board. I should have got a pantent. I'm changing my name to Pat Pending.
(not really, I do have to install/trouble shoot complex aircraft electrical systems, but programming and designing is for folks smarter than me.) Here's some pics of a Ferrari we built in 2001 (355FI engine in a 288GTO. We twin turbo'd it with a M800 box) and a pic of a TTA with a Precision front mount. I had to make aluminum oval tubing for ground clearance. I have lots of pics of some of the fun stuff I have made with over the years. Some stuff is now being built and sold by vendors on this board. I should have got a pantent.
I'm changing my name to Pat Pending.Attachments
This is the distribution pattern of the internal aux fueling distribution manifold. It's perfect at this low pressure and flow. If you can get a distribution manifold to flow like this at low pressure and flow, it will be perfect at high pressure and flow.
The manifold is stainless steel and the smaller fittings are stainless steel.
I couldn't get the larger fitting in stainless steel so I reused the anodized aluminum fitting. It held up well with the old system, so I expect it to do just as well with the new system.
The manifold is stainless steel and the smaller fittings are stainless steel.
I couldn't get the larger fitting in stainless steel so I reused the anodized aluminum fitting. It held up well with the old system, so I expect it to do just as well with the new system.
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These days, I'd give anything to be able to piss like that.
