Direct Injection Delete
- Thread starter 135iTX
- Start date
Firstly, let me say this is a debate and not an argument so don't get your feathers ruffled;
Do you really believe that adding PI to our platform, a backwards technology according to you, held this platform back? And by that I mean, we had a lack of innovation and progressive advancements in other areas of the platform specifically due to the addition of the supplemental PI? You do remember where we were before that time, right? People were running four M1 meth nozzles through various areas of the intake tract, apparently that is DI doing its job according to you. It wasn't until people kept blowing their cars up this way that people were willing to turn a leaf and try supplemental PI which works far more reliably and is used on all the top power producing N54's today. It is excruciatingly clear and has been for years, that our fuel system has been the largest weak point of our cars without an easy solution, the drive train following immediately after. No matter how fancy the technology is, it sucks and has sucked prior to the shotgun in the peak fuel delivery department. We have a peak fuel problem, not a technology problem. The newer occurrence on the technology timeline does not solve our peak fuel throughput issues. We were capable of supplemental PI the moment we had the Procede or JB3 and probably sooner, yet nobody messed with it because there were lots of sissies, most of those people aren't even around anymore. And all of this is being said in the face of the HPFP failure issues we were plagued with for years. Its good you can limp your car home, because most people actually needed to do that, in fact the first 335i I ever drove as a loaner died on me from a failed HPFP. Great times to be DI it was not.
If you remember that shop undercover performance, they said they had the car running on port fuel only using their intake manifold and the ProEFI, their problem was money and interest. It may have slowed down the shotgun, but the shotgun already took 10 years from the time the N54 was out. If you think a decade is a normal time frame to get to where we are now, you're wrong and its evidence that DI only had plenty of time to push the limits and did not. People like Jake Yamona have no reason to spend countless hours digging around for something we don't need or can't use. Nobody built hardware because there was no fuel, they said it over and over, the hardware is the easy part. So it makes sense to me there is no reason to build the shotgun or spend 100k+ designing a new HPFP when there is no backlog of big single, big power, big wallet guys who will buy it. DI caused us to be too little, too late for big risky moves like that early on. You should also remember that AMS left our platform because of this same reason, fuel. Now that we have PI fuel, everyone and their mom is now flocking to the N54 to buy and build a single turbo kit, this creates an audience for performance shops to target creating more opportunity, its just a damn shame that did not happen when the people with money who actually bought these cars new still owned these cars. That is what makes the M3/M4 so much of a better platform, there is actual progress being made and people with money to buy those mods. All you gotta do is look back for occurences of people being interested in an upgraded HPFP and you'll see just how long DI has kept us from being where we were the moment people started using PI spacers.
Who doesn't understand the problem with our fuel system? I hope everyone understands the problem by now so that analogy is not the 'same', it would be akin to saying the sky is blue, therefore the problem is our DI system.
The reason I made this point is because most people would not make that wager even if they could. Ask Tony what the best way to make north of 900whp is today, yesterday and five years ago. He will tell you that Port Injection is the most realistic answer, in fact, I've seen this stated on multiple occasions by Chris.
Saying you're going to wager me $100 to race a PI only car that doesn't exist is like gasoline guys saying electric cars will never compete while at the same time making sure they never have a chance at going into production. Lets give someone a chance to put a stand alone on their car and run PI only and you'd just be flat out wrong, DI has a limit even with the double shotgun. You might be able to limp your car home better, but as I stated, who cares. I'm talking about peak power delivery not fuel efficiency, emissions or daily driving amenities.
So to keep this apples to apples, you could start by replying with your explanation on how you can make our DI only fuel system flow more peak fuel than an equally thought out PI only system, with the hardware available today, or yesterday, or any day prior for the last 10+ years.
I may be alone on this, but I think that head flow has also held the platform back, not just fueling. For example, there are 4 cylinder cars with really good heads making more hp on pump gas than the N54's...
That’s what ive been saying all along. DI will eventually be better no doubt but it cant do what the big power cars need it to do. PI does and does it fairly cheaply and easily and is a known quantity. It can be done as the OP has asked but will likely need a supplemental controller or switch to a standalone.
The head will be the next limiting factor after that as above and the next big one is the drivetrain.
I reckon if you did want a wheelstander.... syvecs with PI(supplement or on its own), powerglide AD-e 8.8, and a whopper single will be the the way to get these things hauling. 1/2 mile id go DCT and before anybody starts, the DCT has been proven behind 1100 whp f10 with just clutches and baskets.
The head will be the next limiting factor after that as above and the next big one is the drivetrain.
I reckon if you did want a wheelstander.... syvecs with PI(supplement or on its own), powerglide AD-e 8.8, and a whopper single will be the the way to get these things hauling. 1/2 mile id go DCT and before anybody starts, the DCT has been proven behind 1100 whp f10 with just clutches and baskets.
Can you read my post again? I don't think you understand what I wrote. I never once said PI is bad.
No, you didn't I see that. But you did allude to the notion it was better to keep sticking with DI and to stop all conversation about any alternatives, which I only partially agree with, up until the point where the goal is maximum power, today.
I'm cool with alternatives in parallel with di but I still stand by the fact that completely disabling di completely is stupid.
To the point @Reaper0995 made about head flow and the n54 limitations there. Think about this: If you were to eliminate the in cylinder fuel source(di injector) you now have to provide that fuel via port injection. This fuel mass is now competing for space in the runner and across the undersized n54 intake valve.
I don't have data to back up the following claims, but my shoot from hip guess says a DI only head would flow more air mass over a port injection setup and here's why:
We can all agree these cars run between 11:1 and 12:1 mass based air fuel ratio at WOT. This means 8-9% of the total mass in the cylinder is fuel. The only way for this mass to enter the cylinder is via intake port or di injector.
Using solely DI you would flow 100% air past the intake valve
Using solely PI you would flow 91-92% air mass and 8-9% fuel mass past the valve
Using a mix... well you have somewhere between the two
I can't say for sure what kind of power this is good for, but i would guess an additional 4-5% wouldn't be out of the question. Again, another reason to retain DI.
The assumptions are roughly correct I think but once you delete the injector and valve size changes, even marginally that all goes out the window. Even a 1mm valve size increase will reap a massive increase in flow.
I like this discussion, Tyler good work on this forum sir. Its got all the great aspects of a quality place to discuss the platform, and a lot less of the garbage found elsewhere.
delete DI, hpfp, msd81
add any standalone of your choice, PI, 2000cc injectors
or do what motiv did, replace piezo di with bosch DI (camaro style) and run a standalone(haltech) that has bosch DI drivers
add any standalone of your choice, PI, 2000cc injectors
or do what motiv did, replace piezo di with bosch DI (camaro style) and run a standalone(haltech) that has bosch DI drivers
Just for talking sake, here are some head flow numbers from various engines. Obviously more to the discussion than just the DI space in the head, but an interesting start point. These are values I found on fast google searches, they may be higher/lower but in any case they all crush the N54! These are for the intake ports in CFM, most values are taken around .500 lift, but not al (LS series might be higher).
N54 stock: 165 cfm
N54 ported: 225 cfm
hayabusa motorcycle: 223 cfm
GTR stock: 276 cfm
GTR ported: 330 cfm
B18 stock: 260 cfm
B18 ported: 288 cfm
LS3 stock: 300 cfm
2JZ stock: 225 cfm
2JZ ported: 280 cfm
Evo 8 ported: 277 cfm
N54 stock: 165 cfm
N54 ported: 225 cfm
hayabusa motorcycle: 223 cfm
GTR stock: 276 cfm
GTR ported: 330 cfm
B18 stock: 260 cfm
B18 ported: 288 cfm
LS3 stock: 300 cfm
2JZ stock: 225 cfm
2JZ ported: 280 cfm
Evo 8 ported: 277 cfm
Is our head really that bad? Crazy we can make the HP numbers we do on a stock head.
I have to admit.... I’ve contemplated putting an entire LSX drivetrain into my 1 series
In liquid form, yes, but what about vapour?
That's why the GTR is so fast
Yes, they do suck. Compare an n54 to a supra on the same turbo and the supra makes more power on pump, e85 or race fuel.
In liquid form, yes, but what about vapour?
That's why the GTR is so fast
Yes, they do suck. Compare an n54 to a supra on the same turbo and the supra makes more power on pump, e85 or race fuel.
The extra displacement and ease tuning with PI also help with those GTR and Supra.
Doing any sort of mod with a clear goal and good plan is not stupid not a step back. Since there is no proven solution with DI, bypassing it all together with PI is not necessarily a bad idea. That way you are just using proven off the shelf parts and can all be done with a bit of patience and money.
The DI implementation on our engine has been a source of headache for this platform since day one and will continue to be until those stand alone ECU solutions mature/become more widespread and allow better PI integration with DI or until someone finally offers a better hpfp setup.
Well if we assume that the double barrel fixes one aspect, the next is that the piezos do something funny over 800whp. Looks like Twisted might have some idea on that....that should mean.....that Tony may be the first over 1000whp DI only...
Who said PI is a bad thing? I said it's pointless to delete the DI and just run PI. We have a standalone ECU that fully control both the problem is people on this platform are extremely cheap and don't want to fork over 4800 to run it. As far as headflow is concerns the stock N54 heads suck but what they lack in airflow is made up with the efficiency of DI system.
the problem isn't being cheap for some of us really... it is the tuning and emission headache. lack of obd support is probably the biggest problem of them all.
