PowerJection III by Professional Products?

Has anyone used one the PowerJection III's or know of someone who has? For any application for that matter.

The specs read convincing and it seems to be a very elegant design. The throttle body is rated for 750cfm (stating to support up to 550hp). Obviously this is well sized for the small block applications, perhaps even for the 300's. I'm wondering how well it may work on small cube engines. Since the fuel discharge is not contingent on venturi vacuum, assuming the injectors are not too large and the ECM can calibrate for the lesser flow, it seems the large throttle body may not necessarily be too large to work. The system does have a standard computer link port for user end custom programming. I've requested info from Professional Products about this possibility, albeit after their business hours.

Also, PP claims the throttle body is good for pressures up to 2.5 bars, 22 psi boost for those forcing it. If you boost a 200 that far you'll be using the bulk of the TB's capacity, either drawing or blowing.

The TB is based on the Holley 4150 squarebore flange. Other than that adaptation (CI head and manifold or other custom job) it seems plausible.

I've never seen first hand any aftermarket EFI system. I'm open to any comments...

This is the first I have ever of this brand. is it fuel only? or fuel and spark controls only?

I'm still learning about it. It appears to be both, or capable of both.

Apparently, it is capable of controlling fuel discharge only if the application is using a pre-existing non-computer distributor. It is designed to be an "afternoon" carb to EFI conversion system.

They do make a companion distributor to mate with the same unit. I suppose if the system senses this distributor, it will take advantage of it. If not, it will assume a standard stand alone distri.

There are plenty of You Tube videos of various installations from 289's to stroked big blocks. There a few boosted applications shown, both small and big block, all (that I have seen) are blow through.

Apparently the EMS is pre-loaded with common "muscle car" strategies based on average parameters requested. But the system is computer connectible for custom tailoring. There is a video of a guy stating that he has been toying around with the settings for his 67 Mustang.

I haven't seen any videos with 6-cyl engines. Being that the injectors are in the throttle body, before the intake manifold, it seems that number of cyl should have little effect. As far as the manifold is concerned, it's a Holley 4150. I believe the injectors (62#) are of a standard design and are swappable with smaller ones should the application need. Though, it seems like even having the bigger injectors, the EMS will just short pulse the injectors as needed. If it is adjusting the injector pulses to achieve the desired AFR (based on input from the several sensors contained within the TB, only the temp and WB O2 are external) then it seems plausible that this system is "Small 6" compliant.

There are other guys here that are far wiser to EFI than I am.

So I just noticed that this thread is in "Aluminum Cylinder Head" when I intended it to be in the EFI category. Evidently I wasn't where I thought I was when I started it. Sorry about that. opsie:

How do I move it to the right place? Or, if someone with greater capability than I can move it, please do so. Thanks.

It was developed by retrotek speed.com, professional products sells their products and have deeper pockets for the R & D, I run the powerjection 2 and it is fantastic, but I wish I had the 111 because in my opinion it is the best and simplist TBI system out their, it looks like it can go together very very quickly and their support is fantastic, Cody at retrotek is only 21 and a genius on the phone and knows the system completely and yes it can run on the six with the right injectors and manifold, but it is not cheap, if on a budget I would get a GM TBI set up, so much support out there for it also and very easy, and yes to the critics of GM TBI, I have finished my modified 350 from a 305 with the help of TBI chips dot com and will it run with the manifold punched out to 2 inches and a 2 inch throttle body and a mild cam, was very very simple.

There is a limit to how small a pulse you can get out of an injector. That is one reason most systems use variable fuel pressure. The injector in itself does not have the range for even a factory application but by varying the fuel pressure you can get a little more range and usually make em work. The newest systems actually control the speed of the fuel pump. Older systems used a pressure regulator that was connected to a vacuum source which basically made the fuel pressure raise as the load on the engine increased. Having more injectors usually gives you a bit more range also.

You can also have too large of a throttle body. You can end up with too much air and not enough movement to tell the ecu what is going on. This would also make for pretty bad driveability assuming you could even keep it running.

On a 300 with the 4bbl intake this may be pretty cool, still a bit big with those injectors but should be possible. On a 200 I dont see it working that well if at all. I think a direct mount 2bbl would be much better. The GM and Holley TBI's use the same mounting scheme so there are plates for a Holley 2bbl and Square/spread bore 4bbls. Gm also made 1bbls but they were physically almost as large as the 2bbls so its not like they would be a direct mount to our engines anyway plus they were only used for a couple of years in the earlier 80's. The 2 bbls were used from 80-95 which included every truck and suv made from 87-95 so there are literally tons of them out there which means they are really cheap and easy to find used and that you can also get rebuilt ones if you wanted to. Basically the Gm 2bbl injector options will cover you from 100 to about 350 HP. That totally covers the 200 and also a NA 300. Another interesting option if you want something a little more trick looking and are willing to make it all work is there is someone making a 1bbl webber looking TB that has a single Bosh style injector in it. Thee of those on a log would for sure look pretty dang cool but you would have to come up with the mounts, linkage, and air cleaners on your own.

Also I have yet to meet one person that has ever installed a 'plug n play' or 'self tuning' EFI system. There are enough of them advertised now that you would think I would have seen one. I have been seeing more and more systems but even the ones on SBC's take some tuning. I can imagine the software is getting better but it can still be fooled by a messed up or odd setup so it does need some guidance from the operator to get it in the ballpark.

I have a Holley 650 2bbl with 2 85/hr injectors on a Cadillac 500 in a Cadillac. Started out with the holley ECU and I just could not get it to run. I had it on a Caddy 425 and it was alright, it reminded me of a Holley carb. It seemed to need constant tweaking and used lots of gas. Guessing the holley ecu was designed around a 350 ish motor since those are by far the most common out there. Ended up with a Megasquirt and its running great. I still have some mechanical issues that are getting expensive but the fuel system runs great. If I was trying to spin this thing at 6K I may have issues but since its in its original home 4K is screaming and so far I am not seeing the upper limits of air or fuel. I do know Im close to the lower limit of the injectors at idle. When I first got it running I had way too much throttle response. A sandy road was impossible to keep traction, even a dry road was a bit tricky (this is a FWD car that weighs almost 6K). I ended up redoing the linkage to change the pedal to throttle ratio. Currently I cant quite get it to WOT but its totally drivable now.

Thanks for the input! It seems like the most elegant option I've seen yet. My 2 biggest questions are injector size and TB bore. I suspect that a smaller injector may be needed. PP also offeres a variable pressure, pulsating fuel pump to mate with this system. The idea being that the running of the pump can be metered to match the engine's needs without a return line. This may help assuage some sizing issues.

My ambitions don't match my income, so who knows when I'll get around to such a system. I've been reading that the MS and the GM TBI systems are quite popular. However both seem to require time and some trial and error or outside assistance. Once all of that is factored in, it seems that the systems are of similar cost.

More to think about...

Megasquirt does for sure have a learning curve but in the end I think it was well worth it because I now have a real good understanding of the hows and whys of tuning. Doing my project I discovered that most people have no concept of tuning and pretty much if it runs it must be properly tuned. The few that do understand it usually seem to know carbs and dont want to know EFI and cant get the limitations of carbs out of their heads so they dont tend to be of much use. Everyone told me there was no way my plan would work on my caddy. I did my research and thought it would. I did have some glitches but none of them were related to TB or injector size which were the main things I was told were not possible. Its been running for over 2 years now. Even if you dont end up going with MS the megga manual does have some good info in it and is worth reading. They have charts and calculators for sizing injectors for various fuels.

As for cost... I did not check your link but everything I have seen in the way of a complete kit of new parts have been in the $1000-3500 range. The $1000 ones seem to be missing some options or features so they are not really that cheap. I think I had about $1000 into my system parts wise. For that I have the MS2, wideband o2, throttle body(used) with some new refresh parts, fuel pump, filters, lines, harnesses, electronic controlled dizzy(used) with some new refresh parts. Now if there was truly a bolt on plug and play self tuning system for say $2000 would I do it? I may but I still dont believe its possible especially for the non small block V8's that I seem to like.

I really like the Megasquirt. It is NOT plug 'n play, for sure, but it is extremely capable and can run almost any kind of junkyard system you can come up with.

I'm running it on the Locost and it is working very well with a kludged combo of Bosch crossflow parts, Buick injectors, Ford van fuel pump, a homemade hall sensor distributor, MSD, and even some lawn irrigation solenoids for the fast idle air control. In about 15 minutes I could probably retune it to run acceptably well a TBI with a duraspark. When used with a wideband o2 controller, it can even tune itself as you drive it.

SoCar I run the returnless fuel system on my mpfi blown 200 and its flawless, I got the 400hp model and can change the fuel pressure at any time with the click of a mouse and enter the # with the soft ware from Professional products, they also won many awards at sema with this system 3, especially because of the ease of instalation, just a nudge, if you want real performance and have the new head and intake, mpfi and use a gm TBI for your air valve. I ran mine N/A with 19lb injectors with a cam for a blower and it still ran like crazy, then I moved to 30lb injectors with the blower, WOW is all I can say. With all the mega squirt people on the board, I can't believe someone hasn't mpfi the new head or I may have missed it, its just a matter of punching 44 mm holes on the bosses on the new head at a slight angle to get a better aim at the inake valve and putting a throttle body and then wiring it up with the claimed knowledge of some with mega squirt on the board it should be very simple.

Broncitis : Good to know that someone has done this, and congrats on the success. I wish I had the coin to match my ideas. Such is life. I really like the elegance of the PJ III. I research the MS system as well. Always keeping options open.