Guys, sorry about the away time but I have good news and bad news.

[djuosnteisn]

Originally Posted by 06Speed6 Based off of Ron's testing, assuming they were tested at the 5ms Ron spoke of in his thread, our injectors should flow enough fuel at 7000rpm for 320chp @ 80% duty cycle based off of them being approximately 60lb/hr injectors. Speaking of more math, 7000rpm / 60sec = 116 revolutions per second * 2 = 232 cycles per second / 4 = 58 intake cycles per second. Then if we take 1 second / 58 cycles we have 1 intake cycle per .017 second, which is 3.44 times more than .005 seconds. So if we took our 320chp @ .005sec injectors and used them for the full intake stroke we would have 1103chp injectors. I knew that 5ms number was crap.

Don't forget that with DI you really only have 1/2 * 0.17 seconds, so 0.085 seconds. The calculation above is accurate only for port injection, and christian mentioned we have about half that time. His chart is a couple pages back. So it's more like 0.085 seconds, but nonetheless still more.

[06Speed6]

Originally Posted by djuosnteisn Don't forget that with DI you really only have 1/2 * 0.17 seconds, so 0.085 seconds. The calculation above is accurate only for port injection, and christian mentioned we have about half that time. His chart is a couple pages back. So it's more like 0.085 seconds, but nonetheless still more.

Explain this logic to me.

[Boother]

The 80% rule used for regular low pressure fuel injectors DOES NOT APPLY TO DI. The reason regular fuel injectors can't run over 80% DC is due to heat, but you are not understanding what the 80% means. That refers to the on-time of the injector between cycles. 100% would mean that the injector was ALWAYS on and 80% means that the injector is on for 80% of the full cycle time (two full crank revolutions, or 4 'strokes').

With DI, we cannot run the injectors for a full cycle as we can only inject during the intake and part of the compression strokes. This roughly equates to 40% of cycle time, thus 40% duty for the injector as it is off the rest of the time.

With DI, duty cycle will never be a problem and we certainly can't use the calculations from RC Engineering for regular fuel injectors as they do not apply.

[djuosnteisn]

Originally Posted by Christian. First off, please take my posts as me simply trying to help. I have most likely tuned the greatest number of these vehicles across the world...nothing I am trying to brag about, I am simply stating facts. I would like to help and I have a pretty good understanding about what questions you all will ask concerning these issues that will need to be dealt with, or at least understood. Simply put, DI engines have approximately 1/2 the injection time available as Lex stated. The below picture and data should demonstrate this for you all. I have this information on a spreadsheet if you are interested in looking at it in detail?

Hence the pretty chart and explanation.

Your calculation was dead nuts on for 7000rpm, but for regular PI.

[djuosnteisn]

Regardless though, even with 8.5ms window, that's still 58% more than 5ms, so the point stands IMO. So the 320chp @ .005 becomes roughly 510 @ .0085.

[06Speed6]

Originally Posted by djuosnteisn Regardless though, even with 8.5ms window, that's still 58% more than 5ms, so the point stands IMO. So the 320chp @ .005 becomes roughly 510 @ .0085.

Well a simple injector timing change that would work perfectly for 95% of the people who mod this car seems pretty good to me.

[cld12pk2go]

So the time window is limited for injection. Ok, that is just the physics of the situation.

But I am still not understanding why larger injectors with adequate pressure, flow, and tuning would not allow sufficient fueling at higher HP levels?

I guess I am missing the assumptions that go into why there is a HP wall at ~400 (with current parts/tuning?).

If it is because the proper parts and tuning does not yet exist, then that is understandable, but it doesn't seem like it should be a !!!OMGHUGE!!! deal.

My background is in engineering (fluid flow is nothing new to me), so I must be missing a basic assumption here...

[FantasmoNegro]

Originally Posted by cld12pk2go So the time window is limited for injection. Ok, that is just the physics of the situation. But I am still not understanding why larger injectors with adequate pressure, flow, and tuning would not allow sufficient fueling at higher HP levels? I guess I am missing the assumptions that go into why there is a HP wall at ~400 (with current parts/tuning?). If it is because the proper parts and tuning does not yet exist, then that is understandable, but it doesn't seem like it should be a !!!OMGHUGE!!! deal. My background is in engineering (fluid flow is nothing new to me), so I must be missing a basic assumption here...

I beleive that is it. I beleive that because larger injectors that work for our application don't exist, that people are buggin out. EVERY other kind of induction requires a larger orifice to deliver more fuel, ours just absolutely need it. I know some people can get around the injector thing by increasing the duration or just dumping more pressure on the injector to get more out of the same hole. With this system in our cars there is no extending the injector duration with any type of positive effect. I have dubbed it peter northing our fuel.

[ptperformance]

Originally Posted by Darksun280 Looks Like PTP came in here with a reality check broom and cleaned up.

Not really, I just wanted to clarify what we have been seeing from out testing.

Originally Posted by palerider hardly. he offered an opinion as he has done before. there are others with experienced opinions who disagree. his sst route is gonna be one to take very seriously however. i like his approach on that one alot. it makes the most sense if youre going to stick with the factory stuff.

Yes its an opinion but until someone proves me other wise, my opinion can end up standing as fact. You have to remember, we have ran over 2500 psi of pump pressure, we have broken 2 feed lines to the rail (cracked them). We have ran more pressure at the rail that I am no longer comfortable standing by it when its running any more. We don't have the time to spray the fuel into the car and make the power. Have those that don't agree with me do the math (like it has been done several times in this thread). I will get to those questions here in a bit.

Originally Posted by 94jedi I told you something was up. They've dropped the MS3 platform. They're done with it. I am vindicated.

They didn't drop it, they reorganized.

Originally Posted by palerider dee, and darrell think its 100% doable and dees already done it. i am not only "putting up with this car".... i am excited about this car again.

It is 100% doable (I told you guys that there was someone making good numbers in FL over a year ago). Its just going to take money.

Originally Posted by 06Speed6 One thing you guys are completely missing that is fairly obvious to me is that the numbers christian gave out are slightly deceptive. If we have 5ms of injection time at 7000rpm, and that will support ~400chp, then we should have 10ms of injection time at 3500rpm which should support ~800chp. Hello dual cdfp that I wanted almost as soon as I bought the car. If you take this chart... I bet 600hp @ 4000rpm could be done. Interestingly the Mazda engineers who dont know anything start shutting down the TB as the rpm climbs and the injection window gets smaller and smaller. I think it is fairly obvious that they actually did know what they were doing when they programmed that in. I suggested this rpm limit almost a year ago on 6club, after studying the DI injectors on diesel engines. They are running about the same injector that we are except that they are rpm limited to around 4000rpm. That limit is what allows them to run 2500lb tq through a DI injector. I even went so far as to suggest that the physical limit of DI was approximately where the red line is on our engine, and that was why the red line was so low.

A 4000 RPM limit on the motor would be foolish, we don't have the motor to move the proper amounts of air or the chambers to hold the amount of air that it would require to make higher HP numbers. Its going to take RPM to get the cyl's filled and that is going to cause us to run into the restrictions up top with the pump and injection window.

Copairing a DI diesel to a DI gas motor is like compairing a 2 stroke to a 4 stroke, they just have to much different from them. You also have to remember that diesel engines run up to and over 30k psi, even if we could run 3k psi with our motors we would not be anywhere close to what the diesel application are capable of.

Originally Posted by Sleeper 362 Yall keep making the mistake of beleiving Mazda built this car for anything above what it came with from the factory. If there is room to grow, that was not planned. Something my father in law told me a long time ago was that the factory builds ONLY for what it was intended to do from the factory.

There is room to grow, you just have to find a way around the road blocks that Mazda built into the car.

Originally Posted by ATE BALLER Probably all 3 desisions were made in tandem. Since this fuel system is only good til 'here', we'll use this turbo that is useless after 'here', and incase these guys try to crank the boost anyway we'll close the throttle on them 'here' as well.

I think that is what they had planned but like Randy said, its all opinion until someone proves it.

Originally Posted by Erich It is very likely they paired K04 and DI system components knowing that their limitations matched up well.

Ding, I am very sure that is what they had planned when they brough the car to market.

Originally Posted by SSinstaller The fact of the matter is we really have no idea why they chose to close the throttle. We don't have a verified compressor map for the K04, we don't even know conclusively how large out injectors are--without knowing that how can anyone even attepmt to say we don't have enough fuel at 7000rpm for the OEM hp levels After two years the only directly measured info we have about this fuel system came from whoosh regarding the intank pump. Until we have some concrete information, it's all speculation. For all we know mazda did it to protect the tranny/transfercase/diff....or just to satisfy the bean counters.. I've been thinking this myself. It almost seems like someone at hitachi pitched the DI system to mazda, and they designed this entire engine and turbo system around it and it's limitations...

Where do we gte the information from? Specualtion? I have seen the lab scope readings from ignition to injetor on times and, no! we don't have the injector pulsewidth to sustain 300 WHP at 7000 RPM. I have seen this first hand with the open and close times while monitoring the dwel and discharge of the ignition coils. So this I can tell you is not specualtion.

I agree that there may be protections built into the PCM software to save the drivetrain but that is even more off the mark then some of the other comments that have been posted in here.

I guess we will have to wait for another more respected member to do the testing before you or other believe what I am saying.

Originally Posted by Sleeper 362 But does it relay those changes to the injectors? I understand what Z tuner is saying and it makes sense. My only question about that is that two degrees enough to make a big difference? Also it may not change the total volume of fuel in the cylinder whichis what I beleive the problem is not the time it is injected. Its just we don't have enough time to inject enough fuel, so I thought.

You have to also understand that it takes time to lift and close the injector. Sure this is programmed into the PCM but that is where 10 to 15% of the flow from the injector fails. We need a larger window or a longer "on" time for the injectors. This would allow for a much larger HP out put from the DI system that is on the car. Until we have control of this, we are going to be limited.

[ptperformance]

Originally Posted by djuosnteisn Regardless though, even with 8.5ms window, that's still 58% more than 5ms, so the point stands IMO. So the 320chp @ .005 becomes roughly 510 @ .0085.

The DI injectors have a longer switching time, higher pressures will make it more difficult to turn on and off the injectors, several things play a part in this. I talked with Cobb and asked them if we could turn the injectors on during the exhaust stroke to cool things down with the EGT's. This would be huge for us. I have yet to hear anything back on this.

The standard math is not going to work when it comes to the DI fuel systems. There are so many different variables that play a part with the control, on, off, cycle, ect ect that PI doesn't have to deal with. Has anyone check the control of the injectors? That would explain a lot if you were to look at the cycle of the injector control drivers, nothing like any PI I have ever seen.

Originally Posted by 06Speed6 Well a simple injector timing change that would work perfectly for 95% of the people who mod this car seems pretty good to me.

This is what we are talking about, open up the window or give us more "on" time for the injector.

Originally Posted by cld12pk2go So the time window is limited for injection. Ok, that is just the physics of the situation. But I am still not understanding why larger injectors with adequate pressure, flow, and tuning would not allow sufficient fueling at higher HP levels? I guess I am missing the assumptions that go into why there is a HP wall at ~400 (with current parts/tuning?). If it is because the proper parts and tuning does not yet exist, then that is understandable, but it doesn't seem like it should be a !!!OMGHUGE!!! deal. My background is in engineering (fluid flow is nothing new to me), so I must be missing a basic assumption here...

Higher pressure means it will take more time to open the injector (injector driver has to over come the pressure). Larger injectors will work, Whoosh and myself have proven this. We just need a way to tune for them... we should have an answer for you guys when we get the injectors installed with the SST and get the car down to Surgeline for a tune.

The assumptions of the HP wall? The 3 and 6 have been on the market for 4 years now (close enough) and we have but a hand full of 400 WHP cars, none of which have been to the track or lasted more then 6 months. We still have yet to see a 11 second slip from a daily driven car running only on the DI system. We have CPE, COBB, DCR now and still... nothing consistantly over 400 WHP. I would have to say that stating it as an assumption is kind of foolish, especially now that the DI Cobalts are running into the same issues. Trust me, there are several that have tried like Whoosh, Randy, Darksun, ect ect. All these people have tried to break 400 WHP only to have there hopes dashed out by motor problems or tuning issues. We are limited by the control device and injector size. If we can tune or get injector control we might have something we can work with.

Originally Posted by Sleeper 362 I beleive that is it. I beleive that because larger injectors that work for our application don't exist, that people are buggin out. EVERY other kind of induction requires a larger orifice to deliver more fuel, ours just absolutely need it. I know some people can get around the injector thing by increasing the duration or just dumping more pressure on the injector to get more out of the same hole. With this system in our cars there is no extending the injector duration with any type of positive effect. I have dubbed it peter northing our fuel.

We have injectors that we are testing now, they are only 15% more and idle control is a bit off but its working. I have to get the AP tuned and installed here very soon but we have a whole list of parts we need to get running on the car as well. Just not enough time in the day.

We need more fuel, that is the plain and simple of it. With out it, we are stuck with running pure meth and larger nozzles or you will have to move over to a second fuel system with PI. I am really considering running a DI meth system with 4 M5 nozzles. This would be the equivilent of running 2 additional injectors on the car. I will report back on this as I get more info from it guys. Thanks.

[FantasmoNegro]

Originally Posted by ptperformance You have to also understand that it takes time to lift and close the injector. Sure this is programmed into the PCM but that is where 10 to 15% of the flow from the injector fails. We need a larger window or a longer "on" time for the injectors. This would allow for a much larger HP out put from the DI system that is on the car. Until we have control of this, we are going to be limited.

So maybe a faster injector with a quicker open close rate and a larger injection nozzle could give a two fold boost to our power? or is just a faster open close rate enough to jump this wall? You are far more knowledgeable than I am on these things, so any questions or beleifs that I have are based on past experience with port injection. Anything you can tell me about this stuff is knowledge to me and greatly appreciated.

[ptperformance]

Originally Posted by Sleeper 362 So maybe a faster injector with a quicker open close rate and a larger injection nozzle could give a two fold boost to our power? or is just a faster open close rate enough to jump this wall? You are far more knowledgeable than I am on these things, so any questions or beleifs that I have are based on past experience with port injection. Anything you can tell me about this stuff is knowledge to me and greatly appreciated.

Higher flowing injector would be key to make this happen for us. I would like to see Cobb give us more injector window, because that would allow us to set our limits up to and over the 600 WHP mark. Fingers crossed that we can make something like this happen.

If we were to go with a faster injectors or larger coils on them, that would take custom work and lots and lots of money. We just need something larger to work with.

[FantasmoNegro]

Originally Posted by ptperformance The DI injectors have a longer switching time, higher pressures will make it more difficult to turn on and off the injectors, several things play a part in this. I talked with Cobb and asked them if we could turn the injectors on during the exhaust stroke to cool things down with the EGT's. This would be huge for us. I have yet to hear anything back on this. The standard math is not going to work when it comes to the DI fuel systems. There are so many different variables that play a part with the control, on, off, cycle, ect ect that PI doesn't have to deal with. Has anyone check the control of the injectors? That would explain a lot if you were to look at the cycle of the injector control drivers, nothing like any PI I have ever seen. This is what we are talking about, open up the window or give us more "on" time for the injector. Higher pressure means it will take more time to open the injector (injector driver has to over come the pressure). Larger injectors will work, Whoosh and myself have proven this. We just need a way to tune for them... we should have an answer for you guys when we get the injectors installed with the SST and get the car down to Surgeline for a tune. The assumptions of the HP wall? The 3 and 6 have been on the market for 4 years now (close enough) and we have but a hand full of 400 WHP cars, none of which have been to the track or lasted more then 6 months. We still have yet to see a 11 second slip from a daily driven car running only on the DI system. We have CPE, COBB, DCR now and still... nothing consistantly over 400 WHP. I would have to say that stating it as an assumption is kind of foolish, especially now that the DI Cobalts are running into the same issues. Trust me, there are several that have tried like Whoosh, Randy, Darksun, ect ect. All these people have tried to break 400 WHP only to have there hopes dashed out by motor problems or tuning issues. We are limited by the control device and injector size. If we can tune or get injector control we might have something we can work with. We have injectors that we are testing now, they are only 15% more and idle control is a bit off but its working. I have to get the AP tuned and installed here very soon but we have a whole list of parts we need to get running on the car as well. Just not enough time in the day. We need more fuel, that is the plain and simple of it. With out it, we are stuck with running pure meth and larger nozzles or you will have to move over to a second fuel system with PI. I am really considering running a DI meth system with 4 M5 nozzles. This would be the equivilent of running 2 additional injectors on the car. I will report back on this as I get more info from it guys. Thanks.

Are you considering making the four nozzle deal a permanent solution on your car or are you just using that as a stepping stone until you have a more permanent/more easily packaged solution?

[ptperformance]

Originally Posted by Sleeper 362 Are you considering making the four nozzle deal a permanent solution on your car or are you just using that as a stepping stone until you have a more permanent/more easily packaged solution?

I will be making a kit for resale. I have to see if there is enough material in the runners to directly tap and drill out for the application.

What I would really like to do is have a swap out program where I send you a manifold with everything installed (ported intake manifold as an option) and you send me your manifold back. This would make doing these a snap for the customer and for me.

I will see what I can come up with here in then next month for you guys.

[SSinstaller]

Isn't 4 M5 nozzles going to be tough on one pump?

[FantasmoNegro]

Originally Posted by ptperformance I will be making a kit for resale. I have to see if there is enough material in the runners to directly tap and drill out for the application. What I would really like to do is have a swap out program where I send you a manifold with everything installed (ported intake manifold as an option) and you send me your manifold back. This would make doing these a snap for the customer and for me. I will see what I can come up with here in then next month for you guys.

Mark Riley said it was good enough to run an auxillary injector system. If he felt they worked well than I agree. Look forward to seeing it in application.

[cld12pk2go]

Tks for the info John.

Good stuff.

[ptperformance]

Originally Posted by SSinstaller Isn't 4 M5 nozzles going to be tough on one pump?

If you run a single solenoid, yes. Dual solenoids, no. The pumps can move 30GPH max at 200 psi, so at 20 GPH with the 4 M5's I should be good.

Originally Posted by Sleeper 362 Mark Riley said it was good enough to run an auxillary injector system. If he felt they worked well than I agree. Look forward to seeing it in application.

I will be starting the build here very soon, just have to get the time.

Originally Posted by cld12pk2go Tks for the info John. Good stuff.

Thanks, if all goes well we will have something running here at the track in the next few weeks, I want to get the car into the mid 12's and 11's since those seem to be pretty easy marks to hit.

[Superstretch18]

Delphi is releasing a full DI system next year, including new injectors. Here are the injector specs that they have been working towards:

Targeted Performance Specifications Static flow rate Up to 20 g/sec Closing response time 0.4 msec Opening response time 0.4 msec Fuel pressure 30-150 bar Minimum linear flow (at 12.5 g/sec static flow rate) 3.0 mg/pulse D32 sauter mean diameter (SMD) 12 µm (at 100 bar) DV90 25 µm (at 100 bar) 0 after inject (no bounce) No bounce at close Cone angle as required by combustion 40o to 90o Delphi is continuing to develop a complete portfolio of injectors to cover the entire range from homogeneous lambda=1 and lambda>1 to spray guided lambda>>1 applications.

How do those flow rates/open and close times compare with the Hitachi units?

[ptperformance]

Originally Posted by Superstretch18 Delphi is releasing a full DI system next year, including new injectors. Here are the injector specs that they have been working towards: How do those flow rates/open and close times compare with the Hitachi units?

I don't think anyone has taken the time to check the Hitachi units? To be honest with you, I have no idea.

[hnda etr]

So did this just die? 4 months since last update...

[ptperformance]

Originally Posted by hnda etr So did this just die? 4 months since last update...

Nope, the install is still going as planned but we have to much on our plate right now. We are getting customers set up for this DP WI set ups middle of next month. Should have 2 of them running around with this set up.

[hnda etr]

Other than the WI / MI methods though, there's nomote news about Cobb cracking the injector phase issue? Or with running bigger injectors?

[ptperformance]

Originally Posted by hnda etr Other than the WI / MI methods though, there's nomote news about Cobb cracking the injector phase issue? Or with running bigger injectors?

Bigger injectors are on the market, we just have to get Cobb to build us a rescale for them.

I don't know if you can crack the phase issue or not, have to do some more checking on that with Cobb.

[hnda etr]

Originally Posted by ptperformance Bigger injectors are on the market, we just have to get Cobb to build us a rescale for them. I don't know if you can crack the phase issue or not, have to do some more checking on that with Cobb.

Now, I'm fairly ignorant when it comes to this but I have a thought...

I'm going under the assumption that installing larger flowing injectors only, without any other change - so same fuel pressure, same ECU, etc, will cause more fuel to be injected, correct?

Now, wouldn't the ECU automatically correct for these larger injectors once it "learned" the new injectors? Wouldn't it know to shorten the injection pulse from the feedback received from the WBO2 sensor saying that the car was running too rich? Your ST/LT fuel trims would reflect a negative value showing this reduction in fuel...

I remember when I installed larger injectors on my turboed Maxima, that in the beginning, I had a rough idle, but it eventually smoothed out....

Also, wouldn't the reverse be true? Wouldn't the ECU automatically lengthen the injection pulse (up to it's maximum programmed amount of time) to compensate for the WBO2 showing exhaust gasses being too lean - such as what would happen when you start forcing more air in with a BT? Your ST/LT fuel trims would show positive values....

I'm probably not understanding this fully though....

[ptperformance]

Originally Posted by hnda etr Now, I'm fairly ignorant when it comes to this but I have a thought... I'm going under the assumption that installing larger flowing injectors only, without any other change - so same fuel pressure, same ECU, etc, will cause more fuel to be injected, correct? Now, wouldn't the ECU automatically correct for these larger injectors once it "learned" the new injectors? Wouldn't it know to shorten the injection pulse from the feedback received from the WBO2 sensor saying that the car was running too rich? Your ST/LT fuel trims would reflect a negative value showing this reduction in fuel... I remember when I installed larger injectors on my turboed Maxima, that in the beginning, I had a rough idle, but it eventually smoothed out.... Also, wouldn't the reverse be true? Wouldn't the ECU automatically lengthen the injection pulse (up to it's maximum programmed amount of time) to compensate for the WBO2 showing exhaust gasses being too lean - such as what would happen when you start forcing more air in with a BT? Your ST/LT fuel trims would show positive values.... I'm probably not understanding this fully though....

Yes your going to get more fuel, yes the PCM is going to adjust but the car will run like crap. The Mazda runs horrible with high fuel trims.

You are correct on the trims and such but the problem lies with the PCM that Mazda gave us, its full a fail in stock form and that is why we have the Cobb AP.

[Jessed87]

Good to know that this is being looked in to. Any other news or updates regarding this injector issue?