Breaking the Silence

[arghx7]

Sorry for not getting back to you sooner, I'm not so active on this forum these days. If the logic is, "this DI system wasn't optimized for a turbo, it's easier to just get rid of it when you go that route if you can control knock" then I agree with that. If you're arguing for deleting the DI on any but the most extremely modified n/a applications I just don't agree with that. This combustion system was designed for n/a operation.

A few points:

1) if you've got a boosted engine with something suppressing knock (straight E85 for example), the DI is probably superfluous at best and a liability at worst.

There's a lot of mixing and wall wetting problems avoided by just getting rid of it.

2) Whatever this other person who turned off the DI in the ISF did, we don't know what injection timing he was running on the PFI injectors. If that was more optimized his problem could have potentially been avoided.

3) Toyota already has a turbo DI version of D-4S in production. It's in the Lexus NX. It's significantly different from this engine.




4) Knock limit is mostly opinion, unless you can hear the engine rattling with the naked ear. Then it's self-evident.

You would need to provide details on how you set your center frequency, gains, and other filtering parameters. "It knocked less because Motec said so." With the stock ECU you are trusting the decisions of whoever set the signal processing at Subaru, but now with an aftermarket system it's just guesswork at best.

[hmong337]

any update?

[King Tut]

Originally Posted by hmong337

any update?

Sounds like silence to me.

[cdrazic93]

Those exhaust ports on that DI system

[350matt]

that'll be for an integrated exhaust manifold so the turbo bolts directly to the head

[Readytoxplod]

Interesting

[BRZR1]

Originally Posted by Carolina Dyno

...We will shortly be offering our... ...direct injection delete kit...

What's next Fuel injection delete for those that want to go Carburetor?!?!?


Deleting the Direct injection doesn't serve any practical purpose (other than allowing for easier tuning for those tuners who fail to understand how to tune Direct Injection).

ABSURD!!

[Carolina Dyno]

Originally Posted by BRZR1

What's next Fuel injection delete for those that want to go Carburetor?!?!?

Deleting the Direct injection doesn't serve any practical purpose (other than allowing for easier tuning for those tuners who fail to understand how to tune Direct Injection).

ABSURD!!

You mean like when fuel injection first came out and the best thing to do for power, reliability, and racing was to swap a carb back on?

I assume you think I did this because I don't know how to tune a DI car, but that's far from the truth. I initially tuned this car with the factory ECU and DI. I then replaced the factory ECU with a MoTeC M142 for development purposes and data collection. I then tested with and without the DI extensively. I have written custom firmware to control DI cars on the M1 platform so not only do I understand the tuning I understand the fundamental operation down to the actual fueling calculations and I/O logic. I even wrote extra maps and control strategies for the DI just to give it every chance.

When you say deleting the DI serves no practical purpose I have to laugh, here's a few you can't even debate.

1) Weight reduction: In a serious race effort weight is hugely important, the lightest cars out there don't get that way by removing one 500lb object, they remove hundreds of objects that weigh a couple ounces. This system is actually pretty heavy considering.

2) Reliability: Sure if everything is perfect the DI can work perfectly fine and we have plenty of customers running it with no issue. On the other hand removing the system removes no less than 10 potential points of failure, two of which are some of the most common track failures hands down. Long term getting rid of the DI will help reduce cylinder wall wetting, ring wear, and damage to the bore surface.

3) Parasitic Loss & Cams: Removing the DI directly takes parasitic load off the cam, reduces chain stretch & wear, eliminates cam timing errors, etc. It also opens up the potential for custom cams from a variety of manufactures that otherwise wouldn't touch the platform.

4) RPM: For guys planning serious builds that want more RPM out of the motor the piston style DI pump is a major issue, I shouldn't even have to go into detail about why.

Our car with the current turbo setup made more power without the DI than with it and was less prone to knock even with more timing. Results below.

Graph of knock, timing, and load for DI/PI.


Graph of knock, timing, and load for PI only (note overall timing is 1 degree higher with less knock).



Here's the resulting difference in power, as you can see the main advantage to DI was a knock deterrent at low RPM which is expected.



A small glimpse into the actual firmware controlling the DI/PI that we developed for a BMW race car. Keep in mind on this car we did the exact same DI vs PI test on this car and determined the DI was extremely beneficial to this application. The major difference in the two systems was the HPFP and the DI spray pattern. The N54 in this BMW makes 600whp on the DI alone and close to 700whp with just enough PI to keep the DI pump from losing pressure.




Video of the above car:
https://www.facebook.com/salaskoraci...40922/?theater

Forums like this are in a sad state, everyone wants to knock someone down despite having absolutely no experience in the field. Next time you post consider whether you are helping the community or just being a jackass to make yourself feel cool.

If you actually want to educate yourself on the topic there are numerous SAE papers that discuss in depth the pro's and con's of DI fuel systems in various applications.

[King Tut]

You should really break the silence more often.

[cdrazic93]

Originally Posted by Carolina Dyno

3) Parasitic Loss & Cams: Removing the DI directly takes parasitic load off the cam, reduces chain stretch & wear, eliminates cam timing errors, etc. It also opens up the potential for custom cams from a variety of manufactures that otherwise wouldn't touch the platform.

I was lead to believe that the valves were long enough that if any extra lobe was added it would run some serious interferances. Please tell me the interferance is from the DI injectors instead rather than the actual cams (I was heart broken when i talked to kelford cams about this).

[hmong337]

Cutting edge! I would love to see what comes of this in the end.

[BRZR1]

Originally Posted by Carolina Dyno

When you say deleting the DI serves no practical purpose I have to laugh, here's a few you can't even debate.

1) Weight reduction: In a serious race effort weight is hugely important, the lightest cars out there don't get that way by removing one 500lb object, they remove hundreds of objects that weigh a couple ounces. This system is actually pretty heavy considering.

2) Reliability: Sure if everything is perfect the DI can work perfectly fine and we have plenty of customers running it with no issue. On the other hand removing the system removes no less than 10 potential points of failure, two of which are some of the most common track failures hands down. Long term getting rid of the DI will help reduce cylinder wall wetting, ring wear, and damage to the bore surface.

3) Parasitic Loss & Cams: Removing the DI directly takes parasitic load off the cam, reduces chain stretch & wear, eliminates cam timing errors, etc. It also opens up the potential for custom cams from a variety of manufactures that otherwise wouldn't touch the platform.

4) RPM: For guys planning serious builds that want more RPM out of the motor the piston style DI pump is a major issue, I shouldn't even have to go into detail about why.

Weight reduction... in this case, i can think of lots of things that aren't necessary.. like glass, doors, hood, trunks, lets start drilling holes in sh!t while we are at it too...

This is a ridiculous point

reliability The reliability issue argument can be made by just about every system on the car. The bases for your arguement was defeated by yourself. "Lets remove DI so we have ten less points of failure, but add F/I which adds a multitude more "points of failure."

parasitic loss.. well this "would" be a valid argument if there were specific requirements for your class that allowed removale of this system to free up horsepower but didn't allow much other forms of adding power. otherwise this is ridiculous. Direct injection paired with port injection has far more benefits than detriments. burn efficiency and combustion chamber temps are two big ones that come to mind.

RPM.. This isn't a direct injection issue as much as it is equipment issue. If we can tune these cars ti fire multiple pulses of fuel with in the micro seconds of a single stroke at 7krpm I'm sure it can handle single pulses at 9k rpm just fine. F1 cars use Direct Inject at 15,000 RPMs... yes thats right .. Fifteen thousand rotations per minute.. http://www.formula1-dictionary.net/d...injection.html

But i will digress, you are here to sell a product and if you can provide information to the extent that someone benefits from your product go ahead. There was a time like you said when people though EFI was shit and ripped it off for Carbs. Same goes for turbos, superchargers etc. The reality is we as humans are resistant to change and until direct injection has been around 15 - 20 years and gains the acceptance of the aftermarket it will be treated like a bastard child by those who don't understand it.


So when can we expext a carb intake manifold with EFI/DI delete kits included? We'll also need a new peddle and throttle cable unless you plan to release a drive by wire carburetor.

[taylork057]

Originally Posted by BRZR1

RPM.. This isn't a direct injection issue as much as it is equipment issue. If we can tune these cars ti fire multiple pulses of fuel with in the micro seconds of a single stroke at 7krpm I'm sure it can handle single pulses at 9k rpm just fine. F1 cars use Direct Inject at 15,000 RPMs... yes thats right .. Fifteen thousand rotations per minute.. http://www.formula1-dictionary.net/d...injection.html

I can rev my fa 20 to 15000 rpm then?

[BRZR1]

Originally Posted by taylork057

I can rev my fa 20 to 150000 rpm then?

If you de-stroke it to 1.06L and upgrade and rebalance everything sure.