Streetwiseguy said:I don't think that statement is particularly political. It's a comment on where E85 is available.
Well you said a "political construct"............
Streetwiseguy said:I don't think that statement is particularly political. It's a comment on where E85 is available.
Well you said a "political construct"............
z31maniac said:STM317 said:Keith Tanner said:81cpcamaro said:On the 5th Gen Camaros like mine (2012 SS), you can add the flex-fuel sensor and tune in the computer and run on E85. Pretty cool, I might consider this down the road. The discussions did say not to do it on the ZL1, as the stock fuel system barely has the capacity for E85 on a stock engine, mods will make it worse. Of course you can upgrade the fuel system to get around that.
Upgrading the fuel system on a DI car is not as easy as you might think at the aftermarket level. Port injection, no worries.
I think I recently saw where Edelbrock or Lingenfelter or somebody now has direct injection fuel system upgrades for C7 ZO6, complete with high pressure pump and injectors. I think...that was the first complete upgrade that I'd seen via the aftermarket.
Interesting.
Although I still think the PFI-DI engines are superior. Look at all the BMW DI engines, and others, that have problems with carbon build up on the intake tract/valves. The port injection helps keep that clean.
Then you can use a larger pump and port injectors for the added fuel, like the Toyobaru Twins :)
I know I reference them alot, but the fuel setup and tuning options have proven what you can do with the dual setup.
That is more a BMW problem than a DI problem. I've seen more than one high mileage DI engine with barely any intake deposits.
And it's interesting to hear someone suggest that PFI cleans the valves, when it also adds to the deposits of valves and intake systems. It's far better than it was when I worked at Chevron 30 years ago, but detergents are not perfect. The only really super awesome system cleaner is E85. There's hardly anything to deposit from that.
Streetwiseguy said:E85 is a political construct of the US Midwest corn producers. I've never seen an E85 pump in Canada, and I presume its not very much more common on the coasts of the US.
It's an economic construct that came from the massive over production of corn.
The fact that is has tax advantages over alternatives like beets for the midwest and sugar for the south and Caribbean is political.
See, I'm not crazy. What I find interesting though, is that this kit generates better power with gasoline than e85 because of fuel flow limitations. I'm used to e85 giving better power numbers. I'm assuming it's high octane race gas that was used to achieve the highest numbers though, not standard pump gas.
In reply to STM317 :
Is that a DI only engine, or both DI/PFI? If it's DI only- it's a second pump added to the system. Which explains the very high cost of it.
I'd have to do the math, but I don't see that pump even at 100% moving enough fuel to make 900lbft of output at any speed.
As mentioned, E85 availability varies quite a bit on location. Here in Minnesota it's available most anywhere.
alfadriver said:In reply to STM317 :
Is that a DI only engine, or both DI/PFI? If it's DI only- it's a second pump added to the system. Which explains the very high cost of it.
I'd have to do the math, but I don't see that pump even at 100% moving enough fuel to make 900lbft of output at any speed.
As far as I know, the LT4 is direct injection only. It looks to me like it's a replacement for the stock high pressure pump, rather than an additional unit. I'll defer to you on the math/pump sizing. Does changing the cam lobe for the pump just result in overdriving or underdriving the pump?
STM317 said:alfadriver said:In reply to STM317 :
Is that a DI only engine, or both DI/PFI? If it's DI only- it's a second pump added to the system. Which explains the very high cost of it.
I'd have to do the math, but I don't see that pump even at 100% moving enough fuel to make 900lbft of output at any speed.
As far as I know, the LT4 is direct injection only. I'll defer to you on the math/pump sizing.
Ok, so it adds a second high pressure pump. It would be totally awesome if there was a single DI pump that can put out north of 500hp of fuel- that would fix quite a few things. Not that there is anything wrong with that.
But that also explains why it's a pretty hard limit on gasoline and not E85. That's a pretty reasonable output limit for two pumps on gas.
Here are some details on the DI pump itself: http://www.lingenfelter.com/product/L710156914.html#.WbqEy2cwxGQ
They certainly make it sound like it's a replacement, rather than a secondary pump.
In reply to STM317 :
That's a very big pump. Makes me ask a lot of questions. Not to them, but to other people.
z31maniac said:Keith Tanner said:81cpcamaro said:On the 5th Gen Camaros like mine (2012 SS), you can add the flex-fuel sensor and tune in the computer and run on E85. Pretty cool, I might consider this down the road. The discussions did say not to do it on the ZL1, as the stock fuel system barely has the capacity for E85 on a stock engine, mods will make it worse. Of course you can upgrade the fuel system to get around that.
Upgrading the fuel system on a DI car is not as easy as you might think at the aftermarket level. Port injection, no worries.
Keith, are there not upgraded DI pump internals like there are for the MazdaSpeed 3's and Audi's and such?
Not that I've seen yet. We're out of injector, but I suppose you could raise the pressure further. Interestingly, the 2.5 turbo engine in the CX9 apparently uses closed loop fuel pressure on the low pressure pump.
So, question. I'm not an OE powertrain engineer nor do I pretend to be one. I want to make sure I understand the acronyms here. PFI - Port Fuel Injection? PFI-DE - a car with both direct injection and port injection?
I've spoken to Mazda about the intake valve buildup. We've seen it on an ND engine, but it was not evenly distributed across the cylinders like there was an airflow artifact at work. They say that there's initial buildup, then it stops and it's not a problem on the long term.
Keith Tanner said:So, question. I'm not an OE powertrain engineer nor do I pretend to be one. I want to make sure I understand the acronyms here. PFI - Port Fuel Injection? PFI-DI - a car with both direct injection and port injection?
Yes, that's it. Other than the correction from E to I.
You may sometimes also see PFI-DI as PFDI as well. Not to be confused with GTDI.
The purpose of PFI-DI is simply more fuel flow than DI can deliver? Are there any production cars doing it or is it simply an aftermarket workaround?
In reply to Keith Tanner :
From my understanding it's also used to get some fuel across the intake valves, which reduces the buildup some DI only engines have trouble with. IIRC, Toyota uses the combo in some engines, not sure who else is doing it.
Keith Tanner said:The purpose of PFI-DI is simply more fuel flow than DI can deliver? Are there any production cars doing it or is it simply an aftermarket workaround?
The 2018 Mustang GT 5.0 will have PFI-DI. Curious to see how it works out.
Port injection in conjunction with direct injection is becoming pretty common. Pretty sure that most of the current EcoBoost engines are PFi and Di, the 2018 Coyote is supposed to be as well. Toyota does it. Audi does it. The Frisbee twins use it too.
The timing, location, and amount of fuel injected has wide ranging effects on emissions, fuel economy, engine power, and NVH so different manufacturers have different strategies for utilizing the tech depending on the application. This seems like a decent cliff-notes
Keith Tanner said:The purpose of PFI-DI is simply more fuel flow than DI can deliver? Are there any production cars doing it or is it simply an aftermarket workaround?
There have been production cars doing it for quite a while, and you will be seeing it soon in many other new DI engines.
Up until recently, all of the previous reasons why the PFI injector was needed, I had figured had been solved, *other* than fuel flow. Now that I see that the fuel flow problem has also been solved, I'm not sure why PFI is needed, honestly. (other than DI not delivering it's stated promises, but that's ranting to different people).
So, in theory, the best reason USED to be for additional fuel flow. Now, I am not so sure.
STM317 said:Port injection in conjunction with direct injection is becoming pretty common. Pretty sure that most of the current EcoBoost engines are PFi and Di, the 2018 Coyote is supposed to be as well. Toyota does it. Audi does it. The Frisbee twins use it too.
The timing, location, and amount of fuel injected has wide ranging effects on emissions, fuel economy, engine power, and NVH so different manufacturers have different strategies for utilizing the tech depending on the application. This seems like a decent cliff-notes
That's a pretty good article, but I will still like to point out- all of the issues that were pointed out, including the ones by Ford managers, had been solved with DI only.
Heck, I take a lot of pride in the fact that when we first did DI, Toyota had been doing PF-DI because they could not solve the emissions issues, but we did.
This is NOT to say that I'm a big fan of DI- I'm more a big fan of a great combustion chamber system. I personally lean toward whatever the most efficient solution is at the lowest cost.
In reply to alfadriver :
Have the DI only issues been resolved in the short term, or long term over the life of the engine? It still seems like the valves would need something to clean them with EGR, PCV, etc putting so much contamination back into the intake tract. Can you elaborate on how those issues are overcome without jeopardizing yourself or revealing proprietary ideas?
STM317 said:In reply to alfadriver :
Have the DI only issues been resolved in the short term, or long term over the life of the engine? It still seems like the valves would need something to clean them with EGR, PCV, etc putting so much contamination back into the intake tract. Can you elaborate on how those issues are overcome without jeopardizing yourself or revealing proprietary ideas?
Long term. The easy answer is to make sure the PVC is not oil, and there are some very tight oil consumption targets for many reasons. And most of our engines don't use external EGR, so there's none of that. Our DI engines have been in the field for 7.5 years now, and I'm not aware of any problems like BMW has.
I'm more confused why BMW has the problem more than why others don't. They do some very elegant engineering, and this one is not exactly a difficult one to source. Then again, I knew back in the late 80's that BMW were well known for intake system deposits- so it's also not as if this is that new.
Maybe we got lucky....
In reply to alfadriver :
European engines have historically tended not to be quite as tight with oil, so that might contribute to their issues.
rslifkin said:In reply to alfadriver :
European engines have historically tended not to be quite as tight with oil, so that might contribute to their issues.
Which is incredibly ironic, since the European market were the ones driving oil changes to 10k miles and up. So, in theory, they have good reason to be very tight on oil. Interesting.
Thanks for the extra info, guys. I tend to focus on a particular tree in the forest, so I don't always know what "everybody" is doing.
In reply to alfadriver :
European drivers don't tend to be as maintenance-phobic as Americans, however. So dumping a quart in every 3 - 5k miles isn't a big deal. Plus, making it to 10k+ before the oil is used up gets a lot easier when more of that oil has been replaced along the way. And their engines tend to have bigger sumps too.
rslifkin said:In reply to alfadriver :
European drivers don't tend to be as maintenance-phobic as Americans, however. So dumping a quart in every 3 - 5k miles isn't a big deal. Plus, making it to 10k+ before the oil is used up gets a lot easier when more of that oil has been replaced along the way. And their engines tend to have bigger sumps too.
I actually disagree. European drivers are no different than here in the US. Except that 1) they have less space- so smaller is better, and 2) gas is about twice the cost. Other than that, they buy with their pocketbooks, and abuse just like everyone else does.
So while some people may add oil, I'd wager that most don't. Just like here.
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