FRS-BRZ Port Fuel Injector (interesting)

[Element Tuning]

Originally Posted by serialk11r

I haven't completely thought this through but with E85 especially and boost, wouldn't it be better to spray E85 into the manifold or something rather than the ports, assuming the direct injectors are maxed out? That way it evaporates before it hits the valves, and with boost it will help cool things down too. Reducing available air mass isn't a big deal since the lower temperature and pressure will allow more air to come in anyways.

arghx7 gave you the technical reason but I'll break it down simply for you.

If the fuel evaporates before it reaches the combustion chamber you will not have as much cooling effect. Therefore if you spray the E85 directly into the combustion chamber you have a greater cooling effect along with the extra cooling effect you get from the evaporation of ethanol vs. gasoline.

[Allch Chcar]

Originally Posted by Element Tuning

I'm currently on E85 but I may also be running some race fuel. Trying to get more power out of this car for Ultimate Track Car Challenge which is next week so I need to move faster than I want.

I'm sure there will be a nice OEM like replacement port injector in the future. For now I'm just sharing what information I've gathered. Port fuel injection runs at 55 psi by the way.

Rocketbrand sells E85 that is cut with racing Gasoline if you want to stick with E85 but need something stable with a higher octane value. It's good to see somebody running E85 already. That's what I'd like to do but I'm more concerned with safe, reliable power.

Originally Posted by Element Tuning

arghx7 gave you the technical reason but I'll break it down simply for you.

If the fuel evaporates before it reaches the combustion chamber you will not have as much cooling effect. Therefore if you spray the E85 directly into the combustion chamber you have a greater cooling effect along with the extra cooling effect you get from the evaporation of ethanol vs. gasoline.

I think Cereal is thinking about a certain supercharged experimental Lotus engine that used a pre-throttlebody injector spraying E85 instead of an intercooler. In that case it made sense but DI is clearly superior for the cooling effect.

Arghx7, was that the "E85 boost" engine that was showcased several years ago? It had a separate but smaller fuel tank for E85 that was designed to last multiple fill ups due to it only used E85 under heavy loads.

[Boosted2.0]

Originally Posted by Element Tuning

Here's a picture of the OEM port injectors on our FRS vs. the blue top feed injectors used in the WRX/STi



They appear to extend way into the intake runner and are very small. I can't say I've seen these used in any other application but if you have let me know on what vehicle.

Too small for our FRS and what we'll be doing so in went some 750cc I'm running a Hydra EMS so no these will not bolt in your stock FRS/BRZ. I had to make some fuel rail spacers to utilize the OEM fuel rails.

Thanks,
Phil Grabow

The Tundra 3UR uses a similar style of injector, but with a full length upper body as well not a shorty one.

[Boosted2.0]

Oh Phil - are you guys just running on 100% port injection with the Hydra?

[Symbiont]

Possibly a noob question, but I'm curious; how many port injectors does the FR-S/BRZ have?

[Allch Chcar]

Originally Posted by Symbiont

Possibly a noob question, but I'm curious; how many port injectors does the FR-S/BRZ have?

4 just like any other 4 cylinder multi port fuel injected engine. The difference is there are 4 more direct injectors, one inside each cylinder.

[Symbiont]

Originally Posted by Allch Chcar

4 just like any other 4 cylinder multi port fuel injected engine. The difference is there are 4 more direct injectors, one inside each cylinder.

I thought so, but wasn't sure. Thanks!

[bimmerboy]

curious to see the spray pattern of the oem injectors vs your aftermarket ones.

[Element Tuning]

Originally Posted by Boosted2.0

Oh Phil - are you guys just running on 100% port injection with the Hydra?

Yes until we finish the direct injection strategy which i migh have befoe UTCC. For now I'm 100% port injection and E85. I've been tweaking cam maps for now and as of today the car finally has that intake roar and pull I've been after! Its audibly obvious when you have the overlap right.

[arghx7]

Originally Posted by Allch Chcar

Arghx7, was that the "E85 boost" engine that was showcased several years ago? It had a separate but smaller fuel tank for E85 that was designed to last multiple fill ups due to it only used E85 under heavy loads.

That was a Ford program, using direct injected E85 as a knock suppressant for a twin turbo 5.0 engine (or something built off that architecture). It was intended as a possible replacement for a diesel, because of the expensive emissions equipment required for diesels. I know a few guys who worked on some of the testing of the prototypes. I'm not sure if the program is still around or not. That was in-house stuff done in Ford's Michigan labs to explore a specific commercial application. This information I'm referring to is an MIT study released in April with funding from a group of companies including GM. It's more about basic R&D and was not part of developing a specific engine.

[Allch Chcar]

Originally Posted by arghx7

That was a Ford program, using direct injected E85 as a knock suppressant for a twin turbo 5.0 engine (or something built off that architecture). It was intended as a possible replacement for a diesel, because of the expensive emissions equipment required for diesels. I know a few guys who worked on some of the testing of the prototypes. I'm not sure if the program is still around or not. That was in-house stuff done in Ford's Michigan labs to explore a specific commercial application. This information I'm referring to is an MIT study released in April with funding from a group of companies including GM. It's more about basic R&D and was not part of developing a specific engine.

I've heard of that one too, though I didn't hear the part about using it as a diesel replacement until now. I was referring to the MIT project specifically for engine downsizing using turbocharged engines.

I think it's this one: http://www.ethanolboost.com/

[Element Tuning]

Hydra EMS has started working on the direct injection code for me after analyzing the OEM scopes of the DI system. It's very interesting and enlightening and we'll have no problems adapting this version of D4S system into the current Hydra EMS hardware.

We will be adopting the OEM direct injection and port injection strategy mostly but we are going to leave DI timing tunable so should I find benefit as we boost this engine we'll have that option to change timing based on load.

Based on the direct injector pulse width at idle I'm going to estimate the OEM direct injector flow is around 400-450cc. As RPM gets towards redline and both the port and DI injectors are firing the total pulse width would suggest less flow however than the sum of both injection systems. Regardless there seems to be plenty of injector pulse width left to play with between the two systems.

The torque drop off in the 4k rpm range can be seen in the injector pulse width scopes also. Clearly a VE drop off there but that will tune out nicely with a turbocharger system

As it sits I think we can get away with some low boost turbocharger systems on the OEM fuel setup but at higher boost levels at least a rising rate fuel pressure regulator is going to be needed for the port injector system.

Thanks,
Phil Grabow

[Fuel Injector Clinic]

Hey Phil, I'm happy to see the work you're doing here and that you're sharing it with everyone, thank you for that. I've followed your race program for a long time as a Subaru owner and its great to see you with a new project here with the FR-S.

I wanted to let you know that we do have some great injector upgrades available for the FR-S and BR-Z. If your development takes you this way I'd love to help you out with an injector solution to fit your setup. We have the following sizes available:

660cc
770cc
1100cc
2150cc

We also have a 900cc option available IF it is possible to space the fuel rail up slightly to accomodate the extra height of this injector. This is a perfectly normal solution and something commonly done on other applications, but it will come down to whether or not you have the physical height to move the rail up slightly without any obstructions.

The 1100cc injector listed above has the same extended tip as the stock injector, whereas the others I listed have a normal short tip. Either setup will be fine for this car as we have not found any discernible differences in real world results for fuel economy or performance going between the two tip styles.


Also arghx7... thanks for posting the info about port and direct injected E85 octane and temperature differences... it is really interesting to see the data comparison there.

I'm going to subscribe to this thread to follow along with the progress here and of course if anyone has any questions just let me know and I'll try to help out.

[Element Tuning]

Thank you for your input on injector options. I didn't subscribe to my own thread and didn't notice you posted. I've been a little quiet lately as I shipped my FRS after the Ultimate Track Car Challenge to Hydra EMS in California so they could accelerate the direct injection/port injection strategies in the Hydra EMS along with all the sophisticated CAN bus based systems.

In any event the Hydra EMS is finished and it's going to be amazing and will solve many issues people currently have with forced induction and reflashing. I still have my work cut out for me as I'm responsible for all the performance tuning and maps.

There is room to move the rail up as I did this so as we progress with supercharging and or turbocharging we'll be in touch about an injector solution.

Thanks,
Phil Grabow