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
