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.

[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]

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.

[RallySnake]

TexasDoc,

I tried your suggestion to change to a richer A/F ratio. It was at 13.5 with the new firmware. I dropped it to lower values and ended up at 13 to 1. I played with the idle speed too. It is much better now, but still hunts a little. The important thing is, it doesn't stall anymore! I just re-read your post and I will try the fuel table adjustment next.

Thanks!
RS

[Texasdoc]

If you ran it already with the new afr target, you probably don't need to edit the fuel table. Look at the learn table at the idle cells - how much adjustment is it making?

Boring EFI stuff to follow. Ignore it if you like. Maybe it will help somebody in the future. Took me forever to learn how the EFI system worked.

There is a table (don't remember it's name - let's call it the limits table) that limits how much the system will adjust the learn table to reach the desired AFR. Let's say this limit table is set at 5% in the idle area. Your system will start with the fuel table, read the O2 sensor, then compare that to the AFR table. If the measured AFR is lean, it will add fuel to the learn table. If it is rich, it will subtract fuel - it can even be negative in the learn table. The system always mathematically adds the fuel table to the learn table. If the learn table hits the maximum change listed in the limits table, it won't adjust it any further.

So if your fuel table is at 5, your learn table is at 1 and your limits table is at 25%, the system will increase the learn table to 1.25 in an effort to make it richer.

So, in your case, you adjusted your desired AFR then ran it. You didn't adjust the fuel table so the system likely increased the fuel by increasing the learn table. So unless your learn table is being limited by the limits table, you are okay. Got it?

If it still hunts, play with the afr a bit. Go to 12.5 - see what happens. Try adjusting the timing in the 9 cells of the idle - 9 cell grid - 3x3. Find the one cell that your car mostly idles in. Make the cells with a lower rpm (three on the left) one degree higher than your idle timing and the three on the right 1 degree lower. Try 2 degrees on either side. The faster timing helps the motor speed back up to the desired rpm, the lower timing helps to slow it back down. Find what your motor likes.

[Gaz64]

Originally Posted by Texasdoc

If you ran it already with the new afr target, you probably don't need to edit the fuel table. Look at the learn table at the idle cells - how much adjustment is it making?

Boring EFI stuff to follow. Ignore it if you like. Maybe it will help somebody in the future. Took me forever to learn how the EFI system worked.

There is a table (don't remember it's name - let's call it the limits table) that limits how much the system will adjust the learn table to reach the desired AFR. Let's say this limit table is set at 5% in the idle area. Your system will start with the fuel table, read the O2 sensor, then compare that to the AFR table. If the measured AFR is lean, it will add fuel to the learn table. If it is rich, it will subtract fuel - it can even be negative in the learn table. The system always mathematically adds the fuel table to the learn table. If the learn table hits the maximum change listed in the limits table, it won't adjust it any further.

So if your fuel table is at 5, your learn table is at 1 and your limits table is at 25%, the system will increase the learn table to 1.25 in an effort to make it richer.

So, in your case, you adjusted your desired AFR then ran it. You didn't adjust the fuel table so the system likely increased the fuel by increasing the learn table. So unless your learn table is being limited by the limits table, you are okay. Got it?

If it still hunts, play with the afr a bit. Go to 12.5 - see what happens. Try adjusting the timing in the 9 cells of the idle - 9 cell grid - 3x3. Find the one cell that your car mostly idles in. Make the cells with a lower rpm (three on the left) one degree higher than your idle timing and the three on the right 1 degree lower. Try 2 degrees on either side. The faster timing helps the motor speed back up to the desired rpm, the lower timing helps to slow it back down. Find what your motor likes.

I love reading from others that truly understand what they are talking about.

I use timing in the same manner to control idle speed on one of mine with a carb.

Gary

[fastd]

As a follow up, I just got my Sniper EFI system back from a professional installation; only put about 30 miles on the car but added about 35 hp (also went from 2.5" to 3" exhaust). I didn't have the carb dialed in all the way prior to switch - the engine was recently rebuilt and was still tuning the carb but decided to go with EFI instead.

Man, throttle response and more even power with not flat/rich spots...really please with it so far.

[RallySnake]

I have been making a lot of changes to my system after running the Targa California rally. During the 4 day event, my engine ran progressively worse. I tried everything I could think of with the EFI tuning and got it running OK at low speed. But any major power request was rewarded with spits and barks out the exhausts. While testing the car at home, the system got so bad I had to limp home.

After getting very frustrated and removing all the changes I had made, I finally started looking at my EDIS ignition system. I had a spare EDIS-8 module and switched it out. All the problems were solved! The EDIS module and system has been running great in my car for 4 years. Evidently, the hot weather during the rally and it's proximity to the upper radiator hose pushed it too far. I have protected the new unit with a couple of layers of heat protection and hope this never happens again.

There were also some issues with the throttle cable sticking. I decided to try to improve the leverage by making a small bracket that moved the throttle stud about 3/8" farther above the primary butterfly shaft. I also had to give the accelerator pedal about 1/2" more travel, too. Wow, this really made a difference! The engine is so much more controllable now. I don't think I will bother with the progressive link again.