D-4S Thread

[madfast]

Originally Posted by serialk11r

I remember someone posted a link to an article about the D4S system on the GR engines, and I remember it mentioned they do not use stratified charge because the NOx levels were too high. That article mentioned that the principal advantage to D4S was that they were able to create nearly homogeneous mixtures, while port injection and direct injection alone are not able to. They had some charts showing how there was more fuel in certain areas of the cylinder with only one injector operating, but with both they were able to get it pretty close to homogeneous.

here ya go!

http://www.sae.org/automag/techbrief...1-114-1-17.pdf

[4agze]

Any info on maybe a compression ratio?

[serialk11r]

2GR-FSE was 11.8:1 says that article...I think they can beat that this time around. I'd guess approximately 12:1. More would be awesome

So that article seems to say that D-4S achieves very good fuel mixing and combustion efficiency compared to your typical fuel injector setup. Now the GR engines were rev limited pretty low as I remember, but someone said it's possible to get a crapton more power out of them. Does this require new cams though? I definitely remember looking up that motor, torque drops off towards its low redline, sounds like cams weren't that aggressive.

[Matador]

Originally Posted by Random_Art

Ah... The joys of new technology. The race begins when it hits the market to be the first one to effectively tune it without blowing it up or frying something important.

This... and holy shit this is goign to open the door on the GR and UR engines... I've been practically salivating. What would I pay to be very close friends with a rogue Toyota ECU engineer ***sigh***

Originally Posted by Snaps

^ But IIRC that's because Toyota's ECU's are some ofthe hardest to crack

This. Nigh impossible is the more appropriate description.

Originally Posted by serialk11r

2GR-FSE was 11.8:1 says that article...I think they can beat that this time around. I'd guess approximately 12:1. More would be awesome

So that article seems to say that D-4S achieves very good fuel mixing and combustion efficiency compared to your typical fuel injector setup. Now the GR engines were rev limited pretty low as I remember, but someone said it's possible to get a crapton more power out of them. Does this require new cams though? I definitely remember looking up that motor, torque drops off towards its low redline, sounds like cams weren't that aggressive.

Yeah.. these engines have a shit ton of power corked up in them and might even be slightly underrated. I think I need to buy me and engine brake setup and a couple 2GRs.. someone needs to crack this puzzle...

[chulooz]

So no word on who is actually providing the ECUs yet? I doubt each model to have its own, though its a possibility.

[Random_Art]

Originally Posted by chulooz

So no word on who is actually providing the ECUs yet? I doubt each model to have its own, though its a possibility.

That would be silly for a badge engineering job. Unnecessary work to create two different ECU's for what is mechanically the same car.

[Matador]

I think what will happen is that it will be a toyota ecu, but the plugs that connects to the body and transmission harness (subject to configuration of course) will be Subaru spec. Why? If they are going to make it so "easy" to plop in a Subaru EJXXX motor, might as well make it easy to just take a subbie ECU, engine harness and plug em up. Couldn't get easier than that. It is however, very wishful thinking.

Why wouldn't it be a Subaru ECU/Software running the whole shebang? D4-S.

[old greg]

Originally Posted by chulooz

So no word on who is actually providing the ECUs yet?

Denso. I'll bet you five bucks.

[Allch Chcar]

Originally Posted by Jordo!

I think by "tuner friendly" they were referring to body kits, wheels, dampeners, and chassis bracing.

I'd hope for a TRD reflahed ECU...

Although I thought the way around tuning DI was to get a bigger fuel pump -- is that not panning out?

That isn't "tuner" Jordo. Tuners work on ECUs and maybe the chassis not the body/show stuff.

With D4s you can upgrade injectors easier and you can always upgrade the fuel pump but the tuning is a whole separate issue.

Originally Posted by madfast

AFAIK the IS350 guys still dont have ecu tuning so...

Originally Posted by Snaps

^ But IIRC that's because Toyota's ECU's are some ofthe hardest to crack

This is not encouraging for a Toyota ECU .

Originally Posted by serialk11r

2GR-FSE was 11.8:1 says that article...I think they can beat that this time around. I'd guess approximately 12:1. More would be awesome

So that article seems to say that D-4S achieves very good fuel mixing and combustion efficiency compared to your typical fuel injector setup. Now the GR engines were rev limited pretty low as I remember, but someone said it's possible to get a crapton more power out of them. Does this require new cams though? I definitely remember looking up that motor, torque drops off towards its low redline, sounds like cams weren't that aggressive.

I would think the end compression would depends on the bore x stroke. The old Subaru's weren't exactly high compression happy designs like say Honda's. With their wide bore x short stroke and their low rev setup for USDM cars. A square design isn't the most knock resistant design either though. That is the one advantage I could find with the undersquare design.

Originally Posted by MatadorRacing_F1

I think what will happen is that it will be a toyota ecu, but the plugs that connects to the body and transmission harness (subject to configuration of course) will be Subaru spec. Why? If they are going to make it so "easy" to plop in a Subaru EJXXX motor, might as well make it easy to just take a subbie ECU, engine harness and plug em up. Couldn't get easier than that. It is however, very wishful thinking.

Why wouldn't it be a Subaru ECU/Software running the whole shebang? D4-S.

That would be so cool. But sadly the ECUs pinouts differ between USDM and JDM so I don't believe that it is even possible.

Originally Posted by old greg

Denso. I'll bet you five bucks.

Heh. Does Denso usually supply ECUs for Toyota and Subaru?

[Spaceywilly]

Originally Posted by Allch Chcar

That would be so cool. But sadly the ECUs pinouts differ between USDM and JDM so I don't believe that it is even possible.

Do you mean Subaru ECUs? They are the same between JDM and USDM AFAIK, there is only AVCS and non AVCS ECUs that you have to watch out for. You can get a JDM EJ207 and run it off a 2002 USDM WRX ECU, you just have to make your own AVCS wiring bundle and obviously a new ROM.

[old greg]

Originally Posted by Allch Chcar

Heh. Does Denso usually supply ECUs for Toyota and Subaru?

Yep. OEMs never design their own ECUs, it's all outsourced to suppliers like Denso, Delphi, Bosch, Magneti Marelli, etc. Look at the labels on any ECU, there will be a logo for the vehicle manufacturer, and a logo for the ECU manufacturer.

To the best of my knowledge, Denso supplies ECUs for all of the turbo Subarus and some of the N/A ones as well. On top of that Denso is a part of the Toyota Group, so it seems like a pretty safe bet that they supply the majority of Toyota/Lexus ECUs as well (I don't have any first hand knowledge though).

[Allch Chcar]

Originally Posted by Spaceywilly

Do you mean Subaru ECUs? They are the same between JDM and USDM AFAIK, there is only AVCS and non AVCS ECUs that you have to watch out for. You can get a JDM EJ207 and run it off a 2002 USDM WRX ECU, you just have to make your own AVCS wiring bundle and obviously a new ROM.

That agrees with what I know and what I said actually. It's isn't as simple as a Honda B series swap, aka plug and play, because the wiring is different but it's limited to cutting and splicing a few wires and extending the harness and still nowhere near as complicated as a completely unrelated ECU pinout.

Originally Posted by old greg

Yep. OEMs never design their own ECUs, it's all outsourced to suppliers like Denso, Delphi, Bosch, Magneti Marelli, etc. Look at the labels on any ECU, there will be a logo for the vehicle manufacturer, and a logo for the ECU manufacturer.

To the best of my knowledge, Denso supplies ECUs for all of the turbo Subarus and some of the N/A ones as well. On top of that Denso is a part of the Toyota Group, so it seems like a pretty safe bet that they supply the majority of Toyota/Lexus ECUs as well (I don't have any first hand knowledge though).

I wouldn't know since I am not that knowledgeable about this but suggesting that ECUs are compatible simply because they come from the same supplier is not accurate.

Eg. even across a small manufacturer like Subaru the ECUs are not all designed to be compatible especially in different markets where they have offer different engines.

Am I right?

[old greg]

Originally Posted by Allch Chcar

suggesting that ECUs are compatible simply because they come from the same supplier is not accurate... Am I right?

I never suggested anything of the sort. I simply stated that Denso supplies ECUs to both Toyota and Subaru, and will likely supply the ECUs for this new car.

[Allch Chcar]

Originally Posted by old greg

I never suggested anything of the sort. I simply stated that Denso supplies ECUs to both Toyota and Subaru, and will likely supply the ECUs for this new car.

I actually didn't mean to say that you were suggesting the ECUs were similar. You only said Denso was an ECU supplier.

I was talking in regards to similar ECUs and BCMs.