http://www.stratifiedauto.com/blog/low-speed-pre-ignition-in-the-mazdaspeed-disi-and-ford-ecoboost-motors/ (http://www.stratifiedauto.com/blog/low-speed-pre-ignition-in-the-mazdaspeed-disi-and-ford-ecoboost-motors/)
Bottom line, low RPM coupled with boost and a hot spot = big boom.
IMHO running a high quality oil coupled with the correct heat range plugs is the first defense and even more important since we are running typically at least 100 Ft/Lbs higher than stock.
The ecoboost has oil squirters under the pistons and a higher quality oil that can remove more heat will only help the situation. lower quality or degraded oil equals less protection.
Mixing E-85 also aids with cylinder cooling. Too much though can cause low pressure which can lead to wall wetting which can also lead to hot spots. this is why I believe running leaner keeping rail pressure high is something that might need to be explored and it is surely a balancing act.
I run ACES IV in my fuel as well for its effective octane boost but also because as it burns, it leaves a lubrication layer in the cylinder, again helping to combat any hot spot activity. I'm running a pretty hot tune and KR activity is low to zilch. Maybe its just luck but the 2015 has much less KR than the 2013 and the only difference on my end is the ACES, and I'm actually running a lower blend of E.
There is a ton of info about this on the interwebz, feel free to add any research or discussion to this thread.
"Low-speed pre-ignition afflicts many highly boosted engines and is major industry challenge"
http://futurepowertrains.co.uk/wp-content/uploads/2016/01/Future_Powertrain_Conf_2016_BP_dist.pdf (http://futurepowertrains.co.uk/wp-content/uploads/2016/01/Future_Powertrain_Conf_2016_BP_dist.pdf)
Take a look at slide 10 and the effect of detergents in fuel.
Agreed....and its surprisingly not entirely understood at this point...high rish/high reward with GTDI
More...
http://saeeng.saejournals.org/content/4/1/274.abstract (http://saeeng.saejournals.org/content/4/1/274.abstract)
http://www.slideshare.net/AftonChemical/afton-chemical-the-impact-of-low-speed-preignition-on-next-generation-engine-oils (http://www.slideshare.net/AftonChemical/afton-chemical-the-impact-of-low-speed-preignition-on-next-generation-engine-oils)
http://www.ukintpress-conferences.com/uploads/SPEX12/Day1_6_Rik_Alewjinse.pdf (http://www.ukintpress-conferences.com/uploads/SPEX12/Day1_6_Rik_Alewjinse.pdf)
Some takeaways.....
Soot formation has been pegged as one of the possible causes and much of the research shows higher oxygenated fuel helps. (ie corn) Notice the correlation we've all seen with running higher corn blends and soot on the tailpipes. (ACES plus corn keeps my pipes clean all the time)
Keeping rail pressure high at low rpm boosted operation to combat wall wetting is important.
Noack may not be the biggest factor when selecting oil....high flash points are what we're looking for.
Fancy detergent packs may be causing more problems, especially since we get none of the washing benefits on the valves.
Noack is still important, just not for LSPI apparently. Think of the many other undesirable conditions within the combustion cycle including and up to hydrolock & turbo failure. By having lower Noack, you have lower oil content in the combustion chamber. What is not being accounted for is the oil that sweeps gets past the rings, which may be the greater contributor to LSPI rather than the oil making it past the intake valves.
Interesting that the difference in LSPI between Group III & PAO oils is not as much as the difference between Group II & III. Still PAO wins. Not sure what their definition of high viscosity is, but lower viscosity (apparently equated with lower calcium content and higher molybdenum/phosphorus) PAO is even more important to have.
What flash point would be optimal for decreasing LSPI?
Detergent packs ... HE or non-HE ... LOL. Good point.
Blame squarely laid on the Calcium Carbonate in detergent packs (not good for people either ;) )
LSPI: A KNOCK ON THE NEWEST ENGINES
http://fuelsandlubes.com/fli-article/lspi-a-knock-on-the-newest-engines/ (http://fuelsandlubes.com/fli-article/lspi-a-knock-on-the-newest-engines/)
Quote from: SHOdded on April 30, 2016, 03:33:25 PM
Noack is still important, just not for LSPI apparently. Think of the many other undesirable conditions within the combustion cycle including and up to hydrolock & turbo failure. By having lower Noack, you have lower oil content in the combustion chamber. What is not being accounted for is the oil that sweeps gets past the rings, which may be the greater contributor to LSPI rather than the oil making it past the intake valves.
Interesting that the difference in LSPI between Group III & PAO oils is not as much as the difference between Group II & III. Still PAO wins. Not sure what their definition of high viscosity is, but lower viscosity (apparently equated with lower calcium content and higher molybdenum/phosphorus) PAO is even more important to have.
What flash point would be optimal for decreasing LSPI?
Detergent packs ... HE or non-HE ... LOL. Good point.
You are correct, I didn't mean to discount NOACK, flash point is just an additional factor that needs considered.....maybe?
It seems to me that in cylinder conditions will always be higher than the flash point of any manufactured oil
I'm curious about the lower viscosity factor because there is a certain straight 0 weight oil I'd like to try. Of course that is tempered by all of the unknowns like what happens when oil pressure drops.....then again you don't need as high of oil pressure to get the lighter oil to travel the same distance....which brings me to :banghead:
Something BND Brian told me which ties into that SAE article is that 91 octane with less detergents and aromatics blended with ACES is superior to 93.....maybe he's onto something.
Well, you are getting results with ACES, so ...
And it also makes the case for better rotating assemblies, as currently available from Livernois and others.
Investigating low speed pre-ignition
http://www.infineuminsight.com/insight/may-2015/investigating-low-speed-pre-ignition (http://www.infineuminsight.com/insight/may-2015/investigating-low-speed-pre-ignition)
Related articles at bottom of page ...
This was a hot topic with the DISI, I had a 2013 so my engine was not as susceptible. One rule of thumb I always followed was to not get into boost at low RPMs and a tall gear. Being a manual this is not an issue and you would likely downshift anyways. In the SHO/MKS you have to give that some thought, though I don't think we are as susceptible to this issue as the early DISI's were. Now that I am spraying meth those deposits will be cleaned up quickly and eliminate one of the possible causes of this as well as reducing another with the cooled intake air and cooler combustion. I don't think I have ever heard of this happening in the EB, and I never knew anyone with the issue in the DISI, didn't even see it come up in the last few years in the mazdaspeed forums. Thanks for sharing!
The ecoboost is not immune to it...come with the territory of direct injection and boost...the ecoboost piston design actually helps to combat lspi
There are tables in the tune specifically for LSPI
The answer is not to avoid high boost at low rpm...that defeats the purpose of the tiny turbos oems are using...look at all the new turbo motors...they are making peak torque sometimes below 2000 rpm...
The newer engines have inherent designs to suppress the lspi and tuning cam timing helps
Low Speed Pre-ignition (LSPI), an Unintended Consequence of Gasoline Direct Injection Turbo-charged (GDI-T) Engine Technology
http://pceo.com/GDI_and_Turbocharging_Rinek (http://pceo.com/GDI_and_Turbocharging_Rinek)
New Hardware, New Challenges: GDI Engines & LSPI
http://pceo.com/articles/gdi-lspi (http://pceo.com/articles/gdi-lspi)
LSPI Animation - Chinese Subtitles
https://lubrizol.mediaspace.kaltura.com/embed/secure/iframe/entryId/0_bym2aemp/uiConfId/28908951 (https://lubrizol.mediaspace.kaltura.com/embed/secure/iframe/entryId/0_bym2aemp/uiConfId/28908951)
GF-6 FAQ
http://pceo.com/faq (http://pceo.com/faq)
SwRI's HEDGE® technology eliminates low-speed pre-ignition in highly boosted engines - Cooled EGR + advanced ignition/boost technology
http://www.swri.org/9what/releases/2010/hedge.htm (http://www.swri.org/9what/releases/2010/hedge.htm)
Turbocharged Directinjection Is Engine Oil's Next Big Hurdle
http://gf-6.com/sites/default/files/Turbocharged%20Direct%20Injection%20Is%20Engine%20Oils%20Next%20Big%20Hurdle.pdf (http://gf-6.com/sites/default/files/Turbocharged%20Direct%20Injection%20Is%20Engine%20Oils%20Next%20Big%20Hurdle.pdf)
Systematic approach to analyze and characterize pre-ignition events in turbocharged direct-injected gasoline engines
http://www.fev.com/fileadmin/user_upload/Media/TechnicalPublications/Gasoline_Systems/2011-01-0343_Systematic_approach_to_analyze_and_characterize_pre-ignition_events_in_turbocharged_direct-injected_gasoline_engines_01.pdf (http://www.fev.com/fileadmin/user_upload/Media/TechnicalPublications/Gasoline_Systems/2011-01-0343_Systematic_approach_to_analyze_and_characterize_pre-ignition_events_in_turbocharged_direct-injected_gasoline_engines_01.pdf)
PC-11 and GF-6: New engines drive change in oil specs
http://digital.ipcprintservices.com/publication/?i=139567 (http://digital.ipcprintservices.com/publication/?i=139567)
Coming Soon: New Gasoline and Diesel Motor Oil Specifications December 2015
http://aspalliance.org/wp-content/uploads/2014/10/Lubrizol-ASPA-9Dec2015-Handout.pdf (http://aspalliance.org/wp-content/uploads/2014/10/Lubrizol-ASPA-9Dec2015-Handout.pdf)
Ultra Low Viscosity Oil from Mazda - better for the GTDI? or for NA engines only?
http://www.cleanmpg.com/community/index.php?threads/45295/ (http://www.cleanmpg.com/community/index.php?threads/45295/)
Quote from: AJP turbo on May 01, 2016, 04:30:49 PM
The ecoboost is not immune to it...come with the territory of direct injection and boost...the ecoboost piston design actually helps to combat lspi
There are tables in the tune specifically for LSPI
The answer is not to avoid high boost at low rpm...that defeats the purpose of the tiny turbos oems are using...look at all the new turbo motors...they are making peak torque sometimes below 2000 rpm...
The newer engines have inherent designs to suppress the lspi and tuning cam timing helps
There is even a "megaknock" dtc...
Appears the MiniCooper can experience Super-Knock phenomenon:
http://www.northamericanmotoring.com/forums/r56-hatch-talk-2007/229136-r56-super-knock-engine-fumbling-while-acceleration-loss-of-power.html (http://www.northamericanmotoring.com/forums/r56-hatch-talk-2007/229136-r56-super-knock-engine-fumbling-while-acceleration-loss-of-power.html)
Proposed method of elimination of Super-Knock:
Suppression of super-knock in TC-GDI engine using two-stage injection in intake stroke (TSII)
http://link.springer.com/article/10.1007/s11431-013-5374-3 (http://link.springer.com/article/10.1007/s11431-013-5374-3)
I'm curious on what the oil pressure is on a typical Ecoboost engine. The 4G63 found in the DSM's had an oil squirter for the pistons to help combat heat, but with the 150psi of oil pressure at higher RPM's and the squirter only squirting into one side of the piston head, they were deemed hazardous in aftermarket builds, and recommended for removal.
How does something like that affect the EcoBoost family?
The only spec I can readily find is "Oil pressure - Minimum 30 psi @ 1,500 rpm with engine at normal operating temperature". There may be a table providing the full-range of values, but I haven't found any.
Quote from: SHOdded on August 01, 2016, 02:35:36 PM
The only spec I can readily find is "Oil pressure - Minimum 30 psi @ 1,500 rpm with engine at normal operating temperature". There may be a table providing the full-range of values, but I haven't found any.
Hmm. I did find an archived thread where people were talking about the problems with the 1g DSM squirters, and upgrading to the EVO 8 squirters. I think the issue was less with the higher oil pressure, and more with the 1g squirters.