EFI Anyone?

[Luce]

Also, keep in mind, the stories I read were from Corvette people. 'nuf said.

They don't have the imagination or cognitive abilities to solve their own problems. If it's not a complete bolt on solution with instructions down to the manufacture and model number of each socket, ratchet and extension needed to install the canned overpriced made just for bla bla bla, they think it's crap.

[RallySnake]

There is no space in a Cobra's engine bay for a surge tank. Besides, that adds a lot more stuff that can fail in Cali's mountain roads. I believe the the surge tank in the gas tank is the best option. Using the return flow to fill the surge tank is a great way to ensure constant pressure without adding complexity. The thing I have learned about using the Venturi pump is that many manufacturers are using it for the same reason. It works 100's of thousands of miles reliably.

[RallySnake]

I have found a venturi jet pump and bought it. It's made by Radium Engineering and comes with 3 jets. You use the silver one with a tiny hole if you want to use high pressure flow directly from the pump. The green one is for low pressure from the return line. The gold one is for high pressure return lines for 700+ LPM pumps. It is item# 20-0180 and $90. There is a picture in my gallery.

Now I really need to find a round stainless steel or aluminum cup 3.75" in diameter and 6" or 7" tall to use as a reservoir to contain the fuel pumps. Can't find anything cheap on the Internet so I think I'll make a trip to Apex Electronics. They have all kinds of old aircraft and computer stuff and I might get lucky. Unless someone out there has one laying around?

[joyridin']

Originally Posted by RallySnake

I have found a venturi jet pump and bought it. It's made by Radium Engineering and comes with 3 jets. You use the silver one with a tiny hole if you want to use high pressure flow directly from the pump. The green one is for low pressure from the return line. The gold one is for high pressure return lines for 700+ LPM pumps. It is item# 20-0180 and $90. There is a picture in my gallery.

Now I really need to find a round stainless steel or aluminum cup 3.75" in diameter and 6" or 7" tall to use as a reservoir to contain the fuel pumps. Can't find anything cheap on the Internet so I think I'll make a trip to Apex Electronics. They have all kinds of old aircraft and computer stuff and I might get lucky. Unless someone out there has one laying around?

I used 304 SS exhaust tubing. Easy to find.

[RallySnake]

I am hoping to avoid welding a bottom plate on if I can.

[Luce]

Come on now. You can do it.

Truth is, if the surge pot is sitting in the tank, you want a little hole in the bottom.

Here's why...

Say you run out of gas. There needs to be a way that by adding just a couple of gallons (soda bottles carried from the gas station 2 miles down the road) will get enough gas into the pot to prime the pump.

I situated my home made venturi pump as low as possible so 2-3 gallons would be enough to get fuel to the pump to start the venturi action.

[RallySnake]

That is a great point, thank you!

[RallySnake]

I have been giving the hole in the tank idea a lot of thought. I am thinking of running a 3/8" tube from the filler neck down to the surge tank. That way, if the tank were to run dry, you would automatically fill the surge tank enough to start the pumping process. Also, under normal startup the tank will be full.

The other idea I am working on is a float switch in the surge tank that connects to a bright light on the dash. That will give you warning before the car stalls.

[Luce]

I really wanted to do this on mine (have filler dump into surge pot) but the geometry didn't allow it. The top of my tank is 1/2" from the floor of trunk and I didn't want the fuel fill tube encroaching in that area.

I also thought a reed switch on a float would be cool to let you know if the pot was less that 2/3 full or so, but ended up KISS. Just another thing to worry about.

I've never ran out of fuel, or even starved it out, but I can see a long sweeper with less than 1/4 tank becoming a problem. It would have to be one long never ending sweeper to burn 1/2 gallon of gas.


Lets see... lets assume 8 MPG on the track, at 80 MPH. 1/2 gallon would get you 4 miles...that's a 3 minute sweeper. I don't think I'm too far off on MPG. you're not accelerating too much on a long turn. But then again, if it's that gradual of a turn to take 3 minutes, you could be running 200 MPH and using a lot more fuel.

You could always make the pot bigger, like 2 gallons. Then you could make a lap on just the pot's contents.

But if there's any back and forth, no problems. The fuel is in the middle.

[RallySnake]

I have had many fuel system problems on long distance car rallies. For years, I used a NOS pressure switch connected to a very bright dash light to warn me of problems. This has saved me a few times. Knowing that my engine is going to quit in a few seconds gave me time to get off the freeway and that may have saved my life! That happened a few times lately and it turned out there was a piece of debris in the tank that would occasionally plug the outlet.

I am getting the car ready for a new season of rallies including Targa California in June. Three days of running twisty mountain roads is a lot more fun when your car is reliable. So I am doing everything I can to make it bulletproof.

[RallySnake]

I have just finished installing and testing the Holley Sniper EFI System. I intention was to keep the cost to a reasonable level. After removing and inspecting my 30 year old tank, I found that it was surprisingly clean with only a small area of rust where I had welded on the filler tube. So, I decided to use it.

The fuel tank was a lot of work. I bought a Tanks.inc PA-4 kit which is an in-tank assembly with a fuel pump. It costs $236 from Summit and requires a 4.128" hole to be cut in the top of the fuel tank. After cutting the hole, I was able to stick my hand inside with a die grinder and remove the rust scale from the weld. I had to uses a hammer and dolly to beat out one of the ribs in the top of the tank to get a flat surface an inch wide around the hole. The PA-4 kit comes with a small tray which is supposed to keep a small pool of fuel at the bottom of the vertically mounted pump. I did not like this idea and I MUST HAVE a backup pump in case the primary fails. (It's happened too many times!) I will take pictures of these parts soon. So I went to a local muffler shop and had them cut off an 6.5" piece of 4" tailpipe. They also cut a circle out of some 1/8" plate and welded it on one end. I cut down the vertical bracket from the tanks.inc to 3.5" so it just reached inside the surge tank 1/2" (while the surge tank sat on the bottom of the gas tank). I drilled holes in both so I could screw the two together. I mounted the fuel pump that came with the kit onto a strap of stainless steel and attached it to the two screws on one side. I bought a second Walbro GCA3366-2 ($106 at Summit) which is very similar to the one that came with the kit and mounted it the same way on the other side. It was difficult to get the two filter screens to fit into the tank so I ordered the smallest ones I could find. One fit well, the other bent 90 degrees in the middle.

I bought a venturi jet pump (mentioned in a earlier post) and used 5/16" brake lines to connect and position it outside the tank. I brazed a 3/8" brake line into a hole about an inch from the bottom of the tank for the jet pump to spray into.

After everything fit together, I used a KBS Coatings Auto Fuel Tank Sealer Kit from Jegs ($70) . It is a 3 part kit that cleans, then acid etches and then coats the inside of the tank with an unbelievably tough coating. I also used it to coat the surge tank and the vertical bracket's cut section. This had to dry for a week, but I got a bad cold and for it sat for 3 weeks before I could continue.

The install of the Holley Sniper kit was pretty easy. I used an open 1/2 inch spacer on top of the Edelbrock EPS manifold with a heat shield to keep heat away from the throttle body's internal CPU. After much thought, I installed the oxygen sensor into the #3 cylinder's header tube just before it comes out the side of the car. I figured, if it didn't work, I would move it. I bought 10' of beautiful stainless 3/8" tubing for Orme Brothers ($100) and used it from the throttle body to the underside of the car. I used regular brake line under the car to the tank. I used a "Y" fitting to connect the output from the 2 pumps together and to one of the lines. The other was the return line to the third fitting on the Tanks.inc top plate (I had to order the extra one from Tanks.inc ($21). I used a 555-15175 fuel filter from Jegs ($14.44) in an accessible place under the car to connect the pressure line together.

As an electronics technician, the wiring was easy. Please see Part 2.

[RallySnake]

Part 2

The first problem popped up as soon as I connected the wires to the battery. The EFI system started up and the key was not on! After some research, I learned the the pink (switched power) wire could not share connections with other devices. So, I wired it to a relay so when the power was off, it was not connected to anything. Evidently, residual voltages from other devices will confuse the ECU. The relay solved the problem.

When I turned the key on and the system booted up, I was able to enter the basic information and restart. Then, the fuel pump started and I started chasing leaks. I had 2 fire extinguishers and a bucket of water standing by while I tightened up one connection after another. So, 63 psi is NO JOKE! Finally, when everything was dry and the gasoline soaked rags were outside, I hit the starter. The engine started fine! I went back to looking for leaks and found another in the return line.

I eased the car out of the garage and let it warm up. With it up to 160 degrees, I started around the block. It was not pretty! The system felt like it had a huge delay in my gas pedal movements. I took it to the gas station and filled it to 1/2 tank, then headed home. It was running better but the throttle did not feel right. It hit it hard for a few seconds and then the throttle felt really bad. When I got home, I found that my old home made bracket had twisted and the cable was severely misaligned. I took it off and used the throttle cable bracket that came with the Sniper EFI. This fit much better and with the cable aligned right, the car was transformed. So much better! I set the idle speed to 800 and this turned out to be a little low. It's up to 890 now. I tried changing the target A/F ratio from the default 14 to 1 to 14.7 to 1. The engine ran rougher and started getting hot, so I went back to 14. The oxygen sensor seems perfectly happy on one cylinder's input.

My son and I took the Cobra on a trip. We left LA and cruised up to Fresno. We ran an old 1996 rally called "The Gold Mines" through North Fork, by Bass Lake, to Oakhurst. We ran up many back country roads through the historic gold country near Yosemite National Park. The car was amazing and the gas mileage was greatly improved over my carefully tuned 750 Holley Ultra Double Pumper and the gasoline fumes were gone! I have to mention an amazingly beautiful piece of pavement called Hornitos Road. The hills and meadows filled with cows, horses and rock outcroppings is just gorgeous! We ran over 800 miles on the 3 day trip. The power was so effortless with the 406 ci engine and the new EFI. A little pressure on the loud pedal gets it to triple digits very quickly in 5th gear!

I am very pleased with the Holley system. After studying all the information about tuning and buying a cable to connect to a laptop, I didn't use any of it (except idle speed info). I did turn the "ramp down" to 1 second so the engine would drop down faster while shifting. Otherwise, it just tuned itself and made me a very happy camper.

[fastd]

Originally Posted by Texasdoc

I tried a Holley Terminator system and it was a colossal failure. I went thru three WBO2 sensors at $120 each over a few months. Ended up needing a complete head rebuild. The whole ordeal is documented on this site. Don't know what the problem was - did the heads cause the holley to fail or did the Holley system cause damage the heads? Which was first, chicken or the egg?

I ripped it all out and went back to carb. YMMV (hopefully).

texasdoc,
do you have a single or dual plane intake? i see that the terminator efi doesnt work well with dual plane.

[fastd]

All,
I'm going to go for the Holley EFI.
Plan on getting the Holley Sniper with the Holley Dual Sync. The Sniper is cheaper and since it's going into a 351W, I don't need all the sensor inputs that the Terminator system has.
Terminator is a 5-6 year old platform; Sniper is 2 or so years old.

Holley said that Terminator really helps those that plan to drag strip the car; with inputs for trans brakes, crank position sensors, etc.

The Holley Dual sync allows the Sniper to adjust timing.

Anyone that has used these components, would appreciate your advice but I'm going to have my local shop install; they said that they just completed a Sniper install and are very pleased with it.

Thanks.

[Grey 65]

I installed the Terminator stealth system with a MSD TFI distributor on my 351W stroked to 408 in place of the FAST system I had on 3/9/18 and proceeded to win a Goodguys race the same day. And yes I am using a dual plane manifold.

FYI: Sniper cannot make use of Davis Technologies Traction Control. The Terminator system can.

[fastd]

grey 65,

you installed traction control on your BDR? nice!

[RallySnake]

Holley has new firmware update for the Sniper that allows the use of progressive throttle linkage. The firmware is 1.1.15 for the handheld and 1.1.16 for the ECU. The new link is available for about $14 at efisystempro.com. You can also get an adjustable link for a little more. This makes the system smoother off the line. It should get better gas mileage too, because you're running on 2 barrels most of the time. I have just installed it and will test drive it tomorrow.

I have just finished a complete reinstall of the system. I did not like the big harness pigtail in the engine bay. So, I cut it out and installed the relay and a fuse block in the trunk. The first relay controls power to the fuel pump. The second one switches power to the 2nd pump. The third one turns on both pumps. This pushes the pressure to 85 psi. May be good for racing?

I also installed 3 Walbro fuel pickups in the fuel tank. One in each rear corner and one in the front center. This should help during hard corners and braking when the fuel level is low.

[Texasdoc]

Originally Posted by fastd

texasdoc,
do you have a single or dual plane intake? i see that the terminator efi doesnt work well with dual plane.

I have a dual plane intake (Edelbrock Performer RPM with a 3/4 phenolic, open spacer.

Glad the Sniper is working for you. I seriously tried for over a year to get it to work. I even bought a new laptop with an Ethernet port to edit the fuel and timing tables, air temp tables, AFR table, etc. It just didn't work. Either Holley has improved their setup with the Sniper or my bad heads confused it so much it kept failing.

[RallySnake]

TexasDoc,

I think a key issue is the camshaft and intake. EFI doesn't like much overlap. I choose a COMP Cams Nitrous HP Camshaft 12-415-8 which has a lot of lift but not too much overlap. I ran the Edelbrock Air Gap manifold for a few months on my car and it made my engine very unhappy (except at full throttle). It was a $325 Endurashine model too. I practically gave it away on eBay. My engine likes a heated manifold. I've had probably 7 or 8 different Edelbrock intakes and the standard RPM is the best for all around power and drivability. You can open up the intake gasket and let the exhaust gas heat the underside of the plenum. My engine runs so much better with all the fuel heated and vaporized. However, the RPM and the Air Gap are so tall that my severely lowered air filter still rubs on the underside of the hood. For the Sniper EFI, I found a nice Endurashine EPS manifold at a good price on eBay and that's on my car now. Because the EPS is 1" lower, I can run a 1/2" open spacer on it. The low RPM power is dramatically better! With 500+ ft lbs of torque, I can power out of slow curves in 3rd gear! The Air Gap may be great for high RPM 1/4 miles. But, it sucks around town. A lot of people have gone back to a heated manifold and you probably should too, unless you have a drag race only car.

The test drive with the Sniper progressive linkage went very well with much smoother power delivery from a stop. Power transition to 4 barrels is pretty smooth and strong. I am hoping that the learning mode will make it even better.

However, I am having a problem at idle. The engine's rpm drops quickly about every 3 seconds. Usually the system catches it and revs it back up but sometimes it stalls. It was doing that before the firmware update and the new secondary link install, too. So, I suspect the PCV valve may be causing a periodic vacuum leak. I am going to block it off and see if that helps. Any other ideas?

RS

[Texasdoc]

If it is hunting at idle, you may be running lean for what your motor wants. Most of these big motors like a fairly rich idle. My 408 is best at 13.5. I don't know how the Sniper system works, but if it is anything like the terminator, you can go into the AFR table and set the idle area and surrounding cells to 13.5. Make sure your timing is set to be stable in those cells as well. You can actually set the lower rpm cells to have more timing to help push the rpms back up.

Then go to your fuel table, give the idle area about a 5-10% increase, smooth everything out, then test it. Make sure you are warmed up and in closed loop mode and watch what the learn table does.

I ditched the EFI and went back to carb. Took a while to get that tuned but all is well now. Sometimes I consider going back to EFI but had such a colossal failure at it the first time, I am just gonna stay with what works.