Breaking the Silence

[Carolina Dyno]

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.

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

Nice reading comprehension, first of all I clearly stated it's the pump that's the issue. Second the fact that you think a single stroke takes microseconds (that's one millionth of a second btw) tells me just how clueless you are on the topic.

I also clearly stated that many applications benefit greatly from DI, and F1 may be one of them although it took a rule change in F1 for them to switch (and they used to rev higher). Comparing our DI system to that of an F1 car is laughable, we probably couldn't trade our cars in exchange for their DI pump.

I won't bother with the rest of your rebuttals I'm sure any reasonable person can see I already posted the real world relevant test data countering your points that you seem to have ignored completely.

Go do some real world testing and quit regurgitating stuff you read on google you don't know anything about.

[Ashikabi]

This is very interesting OP other than the bickering. I don't fully understand how removing the DI (which I'm sure toyota spent a great deal of money to put in for a reason) is making better power but I'm open to new ideas. I am definitely on board for updates and new information on this. From your dyno charts it looks like you trade power below 4500 for top end power, do you see this smoothing out for those of us with daily drivers?

[Carolina Dyno]

Originally Posted by Ashikabi

This is very interesting OP other than the bickering. I don't fully understand how removing the DI (which I'm sure toyota spent a great deal of money to put in for a reason) is making better power but I'm open to new ideas. I am definitely on board for updates and new information on this. From your dyno charts it looks like you trade power below 4500 for top end power, do you see this smoothing out for those of us with daily drivers?

You have to understand that the OE manufactures put tons of money into fuel economy and emissions not power density which is what we are after. By all performance standards the FA20 is a joke, in the 70's you could buy a 260whp naturally aspirated 2 liter 4 cylinder engine that ran on pump gas. In 45 years manufactures haven't forgotten how to do that, they just cater to the masses. Your average person buys based on mpg. On top of that they have to meet strict emissions standards. That's where the money is spent.

I can't say I know what you mean for "do you see this smoothing out for those of us with daily drivers"

If you mean can it be corrected with tuning or something along those lines than to be perfectly honest no, it definitely can't. The DI system has a definite advantage at low RPM and medium to high load. This could be fixed with a built motor but that's another story all together.

[Ashikabi]

I figured as much, and that was exactly what I meant. I also understand the fuel economy emissions thing. Kinda send like they could have more or less copied Hondas F20 and made the same power without the expense of DI. But I'm no engineer, I just want more power and the cheaper I can get it the better. From what it looks like, in the future I could buy a set of plugs and a tune, maybe some bigger injectors and be able to run much better power if I'm following this all properly... or is this FI only?

[Ashikabi]

Also, what made you guys think... "You know what? This direct inject makes this engine different than all the other subies... let's get rid of it and see what happens..." I'm not hating, I'm just curious. It's a pretty crazy idea. But that's how shit gets done. I'm sure everyone thought the idea of direct inject was pretty ridiculous when that got started too but it seems to be doing well

[Carolina Dyno]

Originally Posted by Ashikabi

I figured as much, and that was exactly what I meant. I also understand the fuel economy emissions thing. Kinda send like they could have more or less copied Hondas F20 and made the same power without the expense of DI. But I'm no engineer, I just want more power and the cheaper I can get it the better. From what it looks like, in the future I could buy a set of plugs and a tune, maybe some bigger injectors and be able to run much better power if I'm following this all properly... or is this FI only?

Honda to be honest is a much better R&D company, Subaru has been behind the ball for a long time (how long can you really have a fuel distribution problem and not fix it). The main advantage Honda has is their VTEC system. It allows a car to get great fuel economy and emissions and then have a radical (over 300 degrees duration) cam profile. It's miles better than variable cam control in terms of performance, the F20c cylinder head is drastically better as well.

Originally Posted by Ashikabi

Also, what made you guys think... "You know what? This direct inject makes this engine different than all the other subies... let's get rid of it and see what happens..." I'm not hating, I'm just curious. It's a pretty crazy idea. But that's how shit gets done. I'm sure everyone thought the idea of direct inject was pretty ridiculous when that got started too but it seems to be doing well

Honestly we started the project back when everyone was blowing DI seals and wiping cam lobes left and right. It had nothing to do with wanting to make more or less power, the first few months these cars were out it seemed like it might be a bare necessity for track guys and although we never had a problem with ours (probably because it was tuned the day we bought it) we wanted to make sure we never would and other guys had a viable solution.

At the time I was certain that at worst half a point lower compression would make the DI a moot point. It was obvious Toyota didn't gain anything with it based on the factory power output and to be honest terrible drivability from the factory. I was honestly a little bit surprised that it was actually better without the DI but it does make sense from an engineering standpoint.

As for using it on an NA car, I can't say that we've tried that. My hunch is that you wouldn't gain anything and would probably still lose power down low. I will undoubtedly try it at some point and post up the results but as of right now I couldn't recommend it.

[Ashikabi]

Well I'm looking forward to updates. Please keep us posted

[Carolina Dyno]

Originally Posted by vroom4

Are you doing ecutek stuff still? Maybe I just need to call or stop in....

We do still do ECUTek, however we stopped tuning BRZEdit on anything but NA cars. ECUTek is just to much better at this point.

By all means call or stop by anytime. If you want a ride in the shop car you better do it quick before we start on the next project

[Shankenstein]

Originally Posted by Carolina Dyno

On top of that they have to meet strict emissions standards. That's where the money is spent.

Serious understatement. Huge amounts of research was/is done to minimize the amount of time and air flow before the TWC reaches light-off temperature and the O2 sensor(s) provides useful feedback. The bulk of preventable emissions happen during that early part of the driving cycle.

OEMs are really creative at dealing with this... with injection methods, stratified combustion chambers, valve timing, knock-based control, and some really impressive prediction algorithms that emulate the O2 sensor behavior as things warm up. All to meet the Tier 2 (etc) targets.

There's still plenty of value in these complex systems, but Carolina Dyno seems to be focused on supporting reliable race cars with high power density. To make high-power DI reliable, you're diving into the deep end of combustion chamber modelling (which is a dark art even with the right software). Couple that with the early issues we had with the DI system, and I'd be hitting the eject button too.

Keep up the good work OP, and know that the silent masses enjoy your posts.

And for the sake of the forum:
60 secs/min * 2 rotations/cycle / 10,000 rotations/min = 12 ms

You generally don't want to run injectors over 80% duty cycle, so the open time will be between 0 and 10 ms. You also have to consider the 0.5 - 1.5 ms latency of injector opening for most systems.

[Carolina Dyno]

For the sake of the forum:
60 secs/min * 2 rotations/cycle / 10,000 rotations/min = 12 ms

You generally don't want to run injectors over 80% duty cycle, so the open time will be between 0 and 10 ms. You also have to consider the 0.5 - 1.5 ms latency of injector opening for most systems.

Don't forget that's milliseconds. 12ms = 12000us (microseconds).

You're exactly right about the startup emissions. Combustion modeling for DI has a long way to come and even if the software was there, small shops like ours would never have access. I haven't had that luxury since school. To be honest though the oems put to much faith in models and not enough in testing.

[hmong337]

Any progress on this?

[Carolina Dyno]

The DI delete or the shop car? Nothing new on the delete but we've posted a bunch of shop car updates lately.

[Tim Radley]

Originally Posted by Carolina Dyno

To be honest though the oems put to much faith in models and not enough in testing.

Probably why the power hasn't climbed for an engine like this

Don't let negative comments get you down. Just do what you do and ignore the rest. Smart people will come to you, idiots won't

[hmong337]

Originally Posted by Carolina Dyno

The DI delete or the shop car? Nothing new on the delete but we've posted a bunch of shop car updates lately.

The perfirmance of the DI delete. And observations you have made on the deletion as compared to keeping it?