HP EFI CNP upgrade

Paul P · Posted: Fri May 19, 2017 7:33 am Post subject:

IAC counts while idling are 0-5% and if I put it in gear they are 15-25% which is I think just right. Throttle is good I would say. IAC parked is up near 80 and cranking fuel hot is down at 13. Still if I open the throttle a little it does fire. This is a too rich indication. Thus my conclusion is I have too much fuel/fuel pressure. I am going to try backing down the fuel pressure since it makes the most sense to me. These are 66lb/hr injectors at 43psi so there is plenty of extra. I don't think changing the fuel pressure will hurt. It might get me there. If crank fuel and IAC are at opposite ends of the spectrum it would make sense to try this since I am running out of air ability to add IAC and have too much fuel at the low limit of crank fuel. I know the adjustments I am making are there since when I connect to the ECU and download the data it is the same as the global folder settings.

Paul P · Posted: Sun May 21, 2017 6:46 pm Post subject:

So I took another crack at it and it paid off. Started with the global folder file from back in March. Changed the fuel pressure down to 44lbs to rescale the crank fuel and IAC % ranges. Set the actual fuel pressure on the ECU setup page. Then went to then now back to what I had crank fuel and IAC % pages. I changed the entire range down quite a bit and left the IAC alone. I also thought my target AFR Kyle use a change so I went to another custom file 480HPLS2 and grabbed the whole table. I had to tweak the idle area a little but otherwise left it alone. Went back to the main ECU page and set the running rpm to 250 sine it cranks at 130rpm and 400 was the default which would definitely be running. Gave it a try and it started right up cold and then hot too. I might add a little IAC parked % to it but it was pretty good. Test drive was amazing. It pulled hard and had a lot of power all good just have to drive it some more.

Funny the Holley engineer on their support site was kind of a dick about helping me. I told him what I was thinking was going on with tables and the pressure and he said to RTFM basically which really pissed me off. I made the changes I just described and posted it. He did then say oh that might affect them after the fact. I think he just gets mostly bonehead questions and assumes everyone is clueless. Set him straight just saying it worked and I have been doing this a long time with other systems. Hard I guess to know who you are dealing with. I figured if I said what I was thinking was going on and why he might have said that was possible but instead just a read this post response which had nothing in it about what I was referring to 🙄

10sec.et · Posted: Thu May 25, 2017 12:14 am Post subject:

those tech help guys rarely are any help if you have more than basic questions. they kinda get stuck "inside the box". there's always more than one way to skin a cat.

Paul P · Posted: Fri May 26, 2017 6:53 pm Post subject:

Paul P · Posted: Sun Jun 11, 2017 1:36 pm Post subject:

Having fun tuning. Have almost ran a drum of the new gas (93octane pump, Torco Accelerator and Ethanol Equalizer) through it. Finding that it likes a 16/1 AFR at idle like the projection used to do. Basically I think it is getting false readings from the race cam and actually needs that for idle. Hot and cold start have been challenging but lower fuel pressure and playing with crank fuel and IAC park is now sorted for the most part hot and cold. Almost ready for some track action.
Pulls hard to 4500-7500! Burn Out

Big Dave · Posted: Sun Jun 11, 2017 3:33 pm Post subject:

Paul is your system MAP based or MAF with MAP?

As you know race cams and EFI are darn near mutually exclusive as I am half way through watching PRO Stock that leave the line at 7,600 RPM and Shift at 10,500 due to rev limiter restrictions. Not exactly street friendly.

Been following your thread and wonder if their is any advantage to your EFI if you are going to remain normally aspirated. The only thing that could motivate me to give up my screw driver would be some form of boost.

I had in the back of my mind for my last build a 8-71 blower driven with a Potvin drive (now sold by Mooneyes) running up to a EFI injection manifold on top of a 540 to 555 BBC motor all in a flat hood Nova. The economy and my health have gutted those plans.

Big Dave

Paul P · Posted: Mon Jun 12, 2017 12:06 pm Post subject:

Hi Dave,
Right now it is Map based. There are other methods using VE, Alpha-N, Combo of the 2. What I am interested in trying now is playing with is injector phase angles. Car makes great power and has street manners a carb could never dream of touching. Gave up the screw driver in 1993 with the first Pro-Jection system and haven't looked back.

Big Dave · Posted: Mon Jun 12, 2017 1:32 pm Post subject:

We will have to consult with Keith, but I think the top end EFI aftermarket systems support both MAF for air flow and a two bar MAP sensor being referenced to determine engine load (just like the back barrel of a Rochester QuadraJet never opening unless the motor is under load).

Relying upon only a MAP sensor and a big cam will yield all kinds of tuning problems due to reversion in the intake manifold due to the cam leaving the intake valve open while the piston is rising in the bore off bottom dead center. If you are willing to live with a 2,300 to 2,400 RPM idle speed like a top fuel car, I suppose it could work out. The factory went to a higher lift, shorter duration wider LSA cam to make for a smooth idling high performance EFI engine. Of course the biggest difference between a modern LS-x engine and the old school SBC isn't the heads so much, as the ability to change cam timing based upon MAP and TPS input. That feature alone allows many three and a half liter V6 engines to run with many old school V8's.

Roller lifters allow for much more aggressive cam lobes than were even though possible in the good old days (which before a roller relied upon mushroom tappets to allow for a larger diameter tappet base so it wouldn't dig into the flank of the cam lobe). But a hydraulic roller limits you to about 6,400 RPM due to the mass of the lifter over powering the valve spring. I used to run ridiculous spring pressures that would collapse a hydraulic lifter to get a BBC to rev to 8,600 RPM in my old 582. Needless to say it was equipped with feather weight solid roller tappets, and in addition to the triple wound Pac alloy springs I was using I had a rev limiter kit installed to maintain control over the valve train.

I had $34,600 dollars in that motor, with over eight grand in just the bare heads. That was the street motor I had in my Impala that had a hard time maintaining traction for some reason (though I could stand it on it's back bumper with a fresh set of slicks). Lot of fun but it wasn't practical either (nor would it pass NHRA safety inspections since I was running low nines without so much as a helmet). Hence it was a street car, that was too insane to drive on the street, so I finally grew tired of it, and pulled it apart after nearly seven years of tire smokin' fun.

Big Dave

Paul P · Posted: Mon Jun 12, 2017 1:57 pm Post subject:

Idles like a kitten at 1100rpm. Big cam and lots of compression. Trick is to tune the idle yourself and disable closed loop learning you would be amazed at what V4 software can do for you. You can take parts of the fuel table and adjust it on the fly. Then look at it graphically in MAP or VE mode. Now with injector end angle IEA that overlap can be tuned even further by not injecting fuel during the cam overlap period. All I can say is if you haven't tried it you don't know what you are missing.

That impala must have been something on the street. Low 9s is a lot of car and the $$ you put into it certainly paid off in the power department. What did you have for suspension in it? No pipe at all to stiffen it?

Big Dave · Posted: Mon Jun 12, 2017 3:40 pm Post subject:

I had a Dana 60 housing 4.56 gears on a Detroit locker held on by a S&W four link kit. Coil overs front and back 12 inch rotors up front and 10 inch in the back off of an old cop car. Boxed in the frame to complete the C channel, and added bracing from a station wagon frame to stiffen it to keep as much mass as low as possible as I turned corners with this car as well as going in a straight line. Installed the biggest sway bars I could find only to discover they kept ripping out of the frame on hard corners. Had to weld in reinforcing plates and used bigger end link bolts to fix that issue. Finally got it to drift perfectly flat around corners on the interstate at 85 mph. (you know those off ramps that say caution 35 mph).

I was never addicted to speed (it scares me if I am not in an airplane) but I love pulling G-forces. I have embarrassed more than one Corvette owner with that car, not to mention a herd of Rustang and coffee can Jap import car owners.

Yes It would have handled a lot better with a full cage as it stiffens up the suspension even further. But it was street car because I wanted to drive it and no one makes a fire suit in my size, or fire shoes (17 D sized feet). I could have put it in a Nova body or a Third gen Camaro (I have four bodies parked out behind my barn, one Camaro has a full cage already installed in it) but I have a hard time fitting in them without the Jungle Gym.

My daily driver is a Silverado, that I have to squeeze into as my back is all arthritic now.

Big Dave

Paul P · Posted: Mon Jun 12, 2017 7:27 pm Post subject:

That bumper drag speaks for itself. 8600 rpm with a 582 is wild. Wish you the best with your health.

10sec.et · Posted: Tue Jun 13, 2017 1:10 am Post subject:

the Holley system works VERY well with just a MAP. however, the tune will always be more precise with MAP and MAF. idle tuning is definitely tricky on big cam engines. Drive By Wire presents some challenges as well. ive had to compensate with timing more than a few times. its just a matter of learning to tune as a system and not just individual tables. all that being said, you can get real damn close to that with a carb IF you have the knowledge and determination to make it work. i built my own blow through carb.... it idles at 14:1 afr, cruises at 13 and is at 12.0 under boost. it was a long brutal battle to get it there. and yeah, i cheated... i isolated the PV circuits and control them with boost referenced vacuum and pressure solenoids. would have been a hundred times easier with EFI. i don't know if im stubborn or just stupid. LOL

Paul P · Posted: Fri Jun 23, 2017 11:00 pm Post subject:

Time for cam sensor bracket version 3. Just isn't right. The sensor insert is slightly flush to the bracket causing it to wiggle. Secondly I want to be able to remove it without removing the water pump!

Big Dave · Posted: Sat Jun 24, 2017 9:16 am Post subject:

I was going to suggest machining a steel insert to hold the sensor steady that could be threaded into the softer aluminum up until you said the water pump removal was an issue as well.

Big Dave

Paul P · Posted: Sat Jun 24, 2017 10:47 am Post subject:

Yeah the stainless steel insert that came with the sensor was just poking through a few thou. I'm recessing it and putting a heli-coil in the center point mount and drilling out the threads for the water pump cam load bolt that used to secure it from the cam side and now the bolt will be from the outside.