EFI tech stuff

Jim LaGuardia · Post by **Jim LaGuardia** » Thu Feb 05, 2009 1:27 pm

Your math is flawed, Min injector size is 24lbs, but the Pinz engine runs better with 30lb . I tried 24lb, 26lb, 30lb, 40lb.
Dyno results chose the 30lb as anything less ran too high or too low a duty cycle.
My Dyno tuner is very experienced(and well known).

dokatd · Post by **dokatd** » Thu Feb 05, 2009 3:29 pm

My Math is right, I just looked back and found your only using 2.5 bar. I assumed you were using typical multiport pressures.

You might try going up to 55-65PSI as is more common on a multiport style system like yours. A 14-15 lb injector would be ideal with the higher pressures.

Lower pressures under 35PSI ish are typically reserved for TBI systems. Without going to high pressure your not gaining the full benifits of Multiport. Better atomization, less puddling effect and more accurate fuel delivery are two specific areas you will improve.

MASSIVE PINZ · Post by **MASSIVE PINZ** » Thu Feb 05, 2009 3:35 pm

My system optimized with a 24 lb injector with the V3 Plenum.. All my kits were shipped with a 24 pound injector because I liked the injector working a bit harder, atomizing the fuel a bit better.. especially at low speeds at heavy load.

The #30 probably works better for Jim due to his injector location..

I make over 200HP N/A with a 30# injector applied to aircooled 4 cylinders... But not the Pinz!

Anything will work, hell I went as small as 19# and as big as 42# during testing and ranged fuel pressures from 28 pounds all the way to 60 with most of them.. The absolute best low end ower and response came from the 19# injector with 60 PSI fuel pressure, but man it ran out of steam past peak torque!

dokatd · Post by **dokatd** » Thu Feb 05, 2009 3:50 pm

Jake

Are your injectors located farther down the intake manifolds closer to the valve openings like typical Multi port. Do you have any theories regarding the "loss of steam". Does your managment system have the ability to compensate if programed.

MASSIVE PINZ · Post by **MASSIVE PINZ** » Thu Feb 05, 2009 4:00 pm

Our injectors are located near the parting line of the intake/plenum. We tested a plenum with the injectors only 1" up the intake tract (as close as possible) and the benefits were not worth the compromise of fire hazard, maintenance and installation difficulty. The Pinz manifolds are very difficult to weld and are prone to cracking, so thats another reason for the location we used, which was as low as physically possible without intake manifold removal.

The management system we use does have the OPTIONAL ability to compensate within 25% from the fuel values that are programmed. This is still in BETA testing at the moment in automotive applications and I have two vehicles using it with success. It has been used in aircraft for 2 years now with excellent results. None of the kits we produced have this option as it complicates tuning and install to a point that the Novice could easily be overcome with complications and never be able to make the engine run optimally.

As far as theorry goes: I try to stay out of those debates, there is no right answer and everyone is an expert... What I learned from the Pinz FI project was brutally painful and reiterated that calculations aren't reality. I give engines what they tell me they want as I have invested thousands of dollars and over a decade of my life in the ability to interface with engines to gather their optimum performance. Do what makes the engine run best and then try to figure out why thats what it wanted... Too many people design things on paper and are unwilling to change them.

dokatd · Post by **dokatd** » Thu Feb 05, 2009 4:06 pm

Jake

Are your injectors set perpendicular to the plenum air flow or at a 45 degree. If perpendicular this might explain the drop off past peak torque.

Not trying to force you into a theory, just curious.

And I agree paper is paper, not an engine. But like you said its nice to find out why certain things dont work even close to the paper numbers.

MASSIVE PINZ · Post by **MASSIVE PINZ** » Thu Feb 05, 2009 4:44 pm

45 degrees, spraying directly at the tulip of the intake valves.

This was not my intake set up, it belonged to Herbert Krois- I was just using it for comparative analysis when selecting gathering data.

Jim LaGuardia · Post by **Jim LaGuardia** » Thu Feb 05, 2009 8:14 pm

That particular set up almost cost Red Bull a truck, the injectors melted and sprayed gas everywhere

Also on the fuel pressure issue as a general rule, 18 psi is normal for throttle body injection, 29-36 psi is multiport, and 55-60 is CPI(Center point injection} this is one fuel distributor inside the manifold (GM Vortex type)with separate "POPPET valves at each port. While similar to Multiport the Poppets only open after being pressurized by the central fuel unit as the fuel distributor has all control.
The largest injector I tried was 48lb and ran a -2.9% fuel trim, but was still totally tuneable.
I calculate for 125HP as my set up is also mapped for 2.7L 8.7:1 with a high torque cam, Just a little detuning and it will also run a stock engine, this standardizes the parts list.
You also have to remember, if you don't own a Dyno, it is a couple hundred dollars an hour for Dyno time. Between the 3 trucks running on EMS systems and 1 truck( Mozo2) running on a Haltec fuel controller paired with an MSD spark controller, lots of dyno$ were spent in development.
As Jake has said , he used the simplest computer setup(SDS), I used mid grade(EMS Stinger4) and very high performance set ups(EMS8860). These systems work well, I have been running mine for 3 years now without any component failures.
I would hope the SDS system is as robust and the other EFI Pinz owners get to enjoy the benefits of EFI for a long time

Now get back to that tranny< I want pic's

MASSIVE PINZ · Post by **MASSIVE PINZ** » Thu Feb 05, 2009 8:32 pm

I would hope the SDS system is as robust and the other EFI Pinz owners get to enjoy the benefits of EFI for a long time

I have 85 engines running SDS, the smallest of these is the Pinz, most others feed 150-330 HP aircooled engines, one has fed over 500HP and now we are doing another that will be 700 RWHP with twin injectors and twin plugs..

Most of those engines are Daily Drivers running on every Continent in the World.. I believe in SDS and have my personal cars equipped with the systems as well.

Out of all these SDS installs and applications I have NEVER had an instance where an SDS unit failed, or even had to be sent back to the manufacturer due to any issues... The primary application for SDS from day one was aircraft applications..

I like it because it is simple to interface with, simple to understand and simple to tune.

russ · Post by **russ** » Sun Feb 08, 2009 12:52 am

Sure would like to see an EFI system at the Florida Treffen, er, uh, Steel Soldiers Rally this month!

McCall Pinz · Post by **McCall Pinz** » Mon Feb 09, 2009 11:23 am

Great thread. I never thought I'd understand the tech side of an EFI installation, but this seems to make sense and is now in the realm of possible upgrades. Thanks to all the contributors.

pinztrek · Post by **pinztrek** » Tue Feb 10, 2009 10:00 pm

russ wrote:Sure would like to see an EFI system at the Florida Treffen, er, uh, Steel Soldiers Rally this month!

Should be two there for sure, Herbert & I are planning on driving down with ours.

Have fun,

Alan

pinztrek · Post by **pinztrek** » Tue Feb 10, 2009 10:18 pm

dokatd wrote:My Math is right, I just looked back and found your only using 2.5 bar. I assumed you were using typical multiport pressures.

Your math is right, Jim's 30# injectors are most likely delivering much less at the lower fuel pressure. Probably down around 22-25# per hour, depending on how the originals were spec'd. (Most injectors are spec'd at 45 psi minimum, can be as high as 55)

What works best in a vehicle will depend on how many shot's per stroke, individual controller precision, etc. Even the injector driver circuit will impact the real fuel flow. Different driver circuits & voltages can create a 10% or larger variance in fuel flow just by having longer on/off times. It becomes a big issue if you are down around minimum pulsewidth. Not all controllers are alike in this regard! Some have fairly involved circuitry to minimize turn on/off time.

Have fun,

Alan

Jim LaGuardia · Post by **Jim LaGuardia** » Wed Feb 11, 2009 1:19 am

Alan, I find most of your comments very amusing.

Until you try true sequential injection( if your Megasquirt system is capable), you will never know just how good a Pinz can run.

pinztrek · Post by **pinztrek** » Wed Feb 11, 2009 8:53 am

Jim LaGuardia wrote:Alan, I find most of your comments very amusing.

Glad you find it amusing. Just a statement of fact about injector fuel flow, and ratings..... Injectors are typically rated at higher psi's than you are using. If you run them at a lower psi, they deliver lower flow. This is a known, well understood effect. There are even nice charts from the mfg's showing what their injector will deliver at different supply pressures. And recommendations for operating pressure for proper atomization.

30# injectors at first glance are quite large for the pinz engine until it surfaced you were running at lower PSI. Then it made more sense. Maybe you find that amusing, but unless your injector is rated 30# at 35 psi, you are not delivering that much fuel.

30# injectors rated at a nominal 45-50psi deliver approx 24# when run at 35psi. That's a fact, is well understood in the EFI world, and can be measured. They also tend to atomize a bit less effectively, as Jake pointed out.

Maybe you found some special injectors that are spec'd for 35psi. Some rice rocket guys run GM TBI injectors because they can run at much lower fuel pressures because they had fuel pump/supply problems.

But even if someone uses injectors really delivering 30#/hr, a normally aspirated pinz can only use so much fuel. Larger injectors mean shorter pulsewidths, and open/close times become more of a factor. Larger injectors do not add power by themselves. Add your super charger and maybe you need the 24#, who knows. The knobs on your guitar amp probably go to 11 as well.

Jim LaGuardia wrote: Until you try true sequential injection( if your Megasquirt system is capable), you will never know just how good a Pinz can run.

How do you know we have not? You have zero data on our controller, you can't buy one, and it's not what you think. No one outside of a few people have seen the controller on my truck.

There is a reason OEM's have gone to sequential, but it has nothing to do with power, or even how the engine runs. It's purely emissions. In the EFI aftermarket, it's an opportunity to sell more expensive & complex controllers, which sells more dyno time and primarily gives rice rocket owners numbers to brag about. "Yeah, man, mine's sequential. And uses a 512x512 tuning map!"

As to "never know how good a pinz can run", I'll just say that's a pretty subjective measure.

So I'll ask you this.. does your pinz run better with sequential because:
1) It delivers more fuel? We'll call this "How much"
2) You have carefully tuned exactly when to inject the fuel on the open valve? We'll call this "when the fuel arrives"
3) You can trim each cylinder to deal with airflow differences between them? We'll call this "compensating for plenum design problems"

Our experience:
1) does not fly, all the schemes can deliver the same amount of fuel. They just need to deliver the proper amount.

2) does not fly, as you are using the stock intake with unequal & extremely short runner lengths. Which cylinders did you tune for? What RPM? you know transit time from your high injector location to the valve will vary widely for every cylinder and every RPM combination. What's optimum for one RPM range is entirely wrong for the others

The pinz is not a long runner V-8 or sport car. It's runners are so short for it's RPM range that tuned port effect would not hit until 10-12k rpm or so. Not likely.

3) You've commented on the amount of cylinder trim needed in the past, which points to unequal airflow per cylinder. Not unusual with configurations with the injectors mounted near the plenum, especially if the throttle body is near the end.

So if you saw large benefit from moving to sequential my strong suspicion is that you just leveled out air/fuel flow. Long way around to do that, and you really need to level out airflow first in your plenum design.

You've made the same negative comments about wasted spark ignition. Care to tell us how that makes more power, smoother running? Hint: There is no performance advantage for sequential spark, if there was, every OEM would do it. COP (coil on plug) and newer techniques can lower production costs but offer no performance advantage.

By the way, based on postings, looks like your users who have gone sequential also changed to distributorless ignition at the same time. How do you differentiate between the two with regard to improvements?

Bottom line: Sequential injection in the pinz application largely fixes a problem we don't have. (And your assumption that we are using a basic batch fire system is flawed.) Instead of chasing sequential we've focused on other areas:

* full closed loop idle control. Until you idle up a 40-45 degree grade or over boulders with a steady idle, you have no idea. Proper idle at 10 or 100 degrees. This is probably the biggest drivability improvement offroad, this pinz is very difficult to stall now.

* No tune installation with adaptive feedback. More than just closed loop, we have different air/fuel ratios for different conditions. Idle, cruise, high load, and WOT all have different AFR tuning, which the pinz responds very well to

* start up & drive away as low as 10 degrees. Probably spent more time data logging & tuning cold starts than anything

* OEM grade distributorless ignition integrated with the EFI. But can run standalone if needed. No hotrod MSD boxes, no electrical tape & crimp connectors. Nice, clean factory level engineering

* Complete wiring harness, with automotive grade connectors. No wiring harness mods required. Plug & play. Uses stock pinz throttle linkages & air cleaner. Factory level engineering. Herbert will accept nothing less.

You can't buy most of these things off the shelf, it's more than on aftermarket EFI controller. Yet every OEM vehicle implements to this level. Yes, a few aftermarket controllers support some of these functions, but even so they are very complex to engineer & tune. Proper closed loop idle control is way more than just having a controller that supports it, etc.

So as you make judgments on how well our system can run based on you buying into the ricerocket focused sequential marketing, maybe you can comment on how much of the above you have implemented?

It really does not matter, we are not in competition. (Though you seem to think we are)

I can state as fact that the people who would buy our system if released would absolutely not buy your components. If they wanted to, they would have already bought yours. Not a slam, just a completely different market and expectations. Same for Jake's system. And that's OK, just like there are PC's and Mac's, there can be more than one EFI for pinz's.

Have fun,

Alan