Very high knock count
07-10-2022, 05:37 PM
#46
Rennlist Member
Bonjour,
Yes FredR sorry for my English... I succeed to induce few knocks by adding more advance at WOT. few Knocks (2) show up over 6000 RPM...
However, by adding advance to get knocks I did not noticed more power.
With the sharktuner and E85, about power I only succeed to get better results by adding 3 degrees at WOT. Maybe better tuning could be achieved but to be honest, I don't have a mean of measuring power/torque simply and precisely enough to be able to do better.
At low load I retarded between 1 and 3 degrees because I understand that E85 burn faster. And at low load (cruise), the engine looks now super smooth... like a "flying carpet" feeling... so I think it make sense. I will see if I get fuel savings.
For the rest of the map I added between 1 and 3 degrees... but I verified nothing so far... again, I will check it I have fuel savings or not.
A lot of people advise me that I should get issues with E85, in particular for corrosion, fuel pump and fuel hoses.
So far (since 2014) I get only one of my stock injector leaking and I replace all of them by 0280150943 injectors.
My interpretation of things about E85 is that if there is at least 8% of regular fuel, the rubber and seals does not dry. E85 has a minimum of 15%. I may be wrong and if so I will pay the consequences one day.
I advise nobody to use E85. I just report what I did.
If I decided to buy a sharktuner it is because of this knock count issue and because with these new injectors the fuel map was not good for regular fuel... far too rich, in particular at idle. And under hard acceleration I get black smoke... 3 month ago I went to Germany and there is no E85 there... so it recall me this issue.
When i change my injectors in 2018, I fix that by using... E85... lol... Enrichment when in cat mode with E85 has always been correct... I just had some lean condition at low load and low RPM under acceleration and sometime, with high temp, the idle was too rich.
Reading the sharktuner manual an important note was mentioned : injector open time is important and could modify a lot the maps. I realized that my issues could come from here.
I determined open time of 0280150943 injectors with the method described by the Sharktuner to be 0.7, so very different than the stock value or 0.94ms.
With this new parameter, the car suddenly run much better...
As I'm using only E85 I did not check the maps with 100% regular fuel yet. But with a blend of 50%, stock map is much better in particular at idle : no more too rich. The LH handle it quite well. I just have a O2 adaptation very negative.
Conclusion : With an open time too important, the response of the LH was not adequate with 0280150943 injectors.
For the fuel map, I just adjusted it slightly except at high load. Here, instead of a stock target AFR of 13, I targeted a lambda of 0.82 (equivalent to 12 for regular fuel).
Fred, you think lambda 0.68 should be better? I see recommendations for 0.78.
I stay so far at about 0.8 in order to stay below 100% duty cycle at 6000 RPM and up. For more fuel, 24lbs injectors are required.
For track use I did an open loop map that enrich a lot almost everywhere so I get more throttle response in particular below 3000RPM. But limited to lambda 0.8 at the top end. The car run good yesterday. Fuel consumption was 30% more than last time on the same track! To be safe, EZK map was stock except at WOT where I added 3 degrees.
Here is summarized what I did. Good or not? It is just what I did.
Have a great Sunday,
Raphaël
Yes FredR sorry for my English... I succeed to induce few knocks by adding more advance at WOT. few Knocks (2) show up over 6000 RPM...
However, by adding advance to get knocks I did not noticed more power.
With the sharktuner and E85, about power I only succeed to get better results by adding 3 degrees at WOT. Maybe better tuning could be achieved but to be honest, I don't have a mean of measuring power/torque simply and precisely enough to be able to do better.
At low load I retarded between 1 and 3 degrees because I understand that E85 burn faster. And at low load (cruise), the engine looks now super smooth... like a "flying carpet" feeling... so I think it make sense. I will see if I get fuel savings.
For the rest of the map I added between 1 and 3 degrees... but I verified nothing so far... again, I will check it I have fuel savings or not.
A lot of people advise me that I should get issues with E85, in particular for corrosion, fuel pump and fuel hoses.
So far (since 2014) I get only one of my stock injector leaking and I replace all of them by 0280150943 injectors.
My interpretation of things about E85 is that if there is at least 8% of regular fuel, the rubber and seals does not dry. E85 has a minimum of 15%. I may be wrong and if so I will pay the consequences one day.
I advise nobody to use E85. I just report what I did.
If I decided to buy a sharktuner it is because of this knock count issue and because with these new injectors the fuel map was not good for regular fuel... far too rich, in particular at idle. And under hard acceleration I get black smoke... 3 month ago I went to Germany and there is no E85 there... so it recall me this issue.
When i change my injectors in 2018, I fix that by using... E85... lol... Enrichment when in cat mode with E85 has always been correct... I just had some lean condition at low load and low RPM under acceleration and sometime, with high temp, the idle was too rich.
Reading the sharktuner manual an important note was mentioned : injector open time is important and could modify a lot the maps. I realized that my issues could come from here.
I determined open time of 0280150943 injectors with the method described by the Sharktuner to be 0.7, so very different than the stock value or 0.94ms.
With this new parameter, the car suddenly run much better...
As I'm using only E85 I did not check the maps with 100% regular fuel yet. But with a blend of 50%, stock map is much better in particular at idle : no more too rich. The LH handle it quite well. I just have a O2 adaptation very negative.
Conclusion : With an open time too important, the response of the LH was not adequate with 0280150943 injectors.
For the fuel map, I just adjusted it slightly except at high load. Here, instead of a stock target AFR of 13, I targeted a lambda of 0.82 (equivalent to 12 for regular fuel).
Fred, you think lambda 0.68 should be better? I see recommendations for 0.78.
I stay so far at about 0.8 in order to stay below 100% duty cycle at 6000 RPM and up. For more fuel, 24lbs injectors are required.
For track use I did an open loop map that enrich a lot almost everywhere so I get more throttle response in particular below 3000RPM. But limited to lambda 0.8 at the top end. The car run good yesterday. Fuel consumption was 30% more than last time on the same track! To be safe, EZK map was stock except at WOT where I added 3 degrees.
Here is summarized what I did. Good or not? It is just what I did.
Have a great Sunday,
Raphaël
Last edited by ador117; 07-10-2022 at 06:10 PM.
07-10-2022, 07:00 PM
#47
Rennlist Member
Bonjour,
Yes FredR sorry for my English... I succeed to induce few knocks by adding more advance at WOT. few Knocks (2) show up over 6000 RPM...
However, by adding advance to get knocks I did not noticed more power.
With the sharktuner and E85, about power I only succeed to get better results by adding 3 degrees at WOT. Maybe better tuning could be achieved but to be honest, I don't have a mean of measuring power/torque simply and precisely enough to be able to do better.
At low load I retarded between 1 and 3 degrees because I understand that E85 burn faster. And at low load (cruise), the engine looks now super smooth... like a "flying carpet" feeling... so I think it make sense. I will see if I get fuel savings.
For the rest of the map I added between 1 and 3 degrees... but I verified nothing so far... again, I will check it I have fuel savings or not.
A lot of people advise me that I should get issues with E85, in particular for corrosion, fuel pump and fuel hoses.
So far (since 2014) I get only one of my stock injector leaking and I replace all of them by 0280150943 injectors.
My interpretation of things about E85 is that if there is at least 8% of regular fuel, the rubber and seals does not dry. E85 has a minimum of 15%. I may be wrong and if so I will pay the consequences one day.
I advise nobody to use E85. I just report what I did.
If I decided to buy a sharktuner it is because of this knock count issue and because with these new injectors the fuel map was not good for regular fuel... far too rich, in particular at idle. And under hard acceleration I get black smoke... 3 month ago I went to Germany and there is no E85 there... so it recall me this issue.
When i change my injectors in 2018, I fix that by using... E85... lol... Enrichment when in cat mode with E85 has always been correct... I just had some lean condition at low load and low RPM under acceleration and sometime, with high temp, the idle was too rich.
Reading the sharktuner manual an important note was mentioned : injector open time is important and could modify a lot the maps. I realized that my issues could come from here.
I determined open time of 0280150943 injectors with the method described by the Sharktuner to be 0.7, so very different than the stock value or 0.94ms.
With this new parameter, the car suddenly run much better...
As I'm using only E85 I did not check the maps with 100% regular fuel yet. But with a blend of 50%, stock map is much better in particular at idle : no more too rich. The LH handle it quite well. I just have a O2 adaptation very negative.
Conclusion : With an open time too important, the response of the LH was not adequate with 0280150943 injectors.
For the fuel map, I just adjusted it slightly except at high load. Here, instead of a stock target AFR of 13, I targeted a lambda of 0.82 (equivalent to 12 for regular fuel).
Fred, you think lambda 0.68 should be better? I see recommendations for 0.78.
I stay so far at about 0.8 in order to stay below 100% duty cycle at 6000 RPM and up. For more fuel, 24lbs injectors are required.
For track use I did an open loop map that enrich a lot almost everywhere so I get more throttle response in particular below 3000RPM. But limited to lambda 0.8 at the top end. The car run good yesterday. Fuel consumption was 30% more than last time on the same track! To be safe, EZK map was stock except at WOT where I added 3 degrees.
Here is summarized what I did. Good or not? It is just what I did.
Have a great Sunday,
Raphaël
Yes FredR sorry for my English... I succeed to induce few knocks by adding more advance at WOT. few Knocks (2) show up over 6000 RPM...
However, by adding advance to get knocks I did not noticed more power.
With the sharktuner and E85, about power I only succeed to get better results by adding 3 degrees at WOT. Maybe better tuning could be achieved but to be honest, I don't have a mean of measuring power/torque simply and precisely enough to be able to do better.
At low load I retarded between 1 and 3 degrees because I understand that E85 burn faster. And at low load (cruise), the engine looks now super smooth... like a "flying carpet" feeling... so I think it make sense. I will see if I get fuel savings.
For the rest of the map I added between 1 and 3 degrees... but I verified nothing so far... again, I will check it I have fuel savings or not.
A lot of people advise me that I should get issues with E85, in particular for corrosion, fuel pump and fuel hoses.
So far (since 2014) I get only one of my stock injector leaking and I replace all of them by 0280150943 injectors.
My interpretation of things about E85 is that if there is at least 8% of regular fuel, the rubber and seals does not dry. E85 has a minimum of 15%. I may be wrong and if so I will pay the consequences one day.
I advise nobody to use E85. I just report what I did.
If I decided to buy a sharktuner it is because of this knock count issue and because with these new injectors the fuel map was not good for regular fuel... far too rich, in particular at idle. And under hard acceleration I get black smoke... 3 month ago I went to Germany and there is no E85 there... so it recall me this issue.
When i change my injectors in 2018, I fix that by using... E85... lol... Enrichment when in cat mode with E85 has always been correct... I just had some lean condition at low load and low RPM under acceleration and sometime, with high temp, the idle was too rich.
Reading the sharktuner manual an important note was mentioned : injector open time is important and could modify a lot the maps. I realized that my issues could come from here.
I determined open time of 0280150943 injectors with the method described by the Sharktuner to be 0.7, so very different than the stock value or 0.94ms.
With this new parameter, the car suddenly run much better...
As I'm using only E85 I did not check the maps with 100% regular fuel yet. But with a blend of 50%, stock map is much better in particular at idle : no more too rich. The LH handle it quite well. I just have a O2 adaptation very negative.
Conclusion : With an open time too important, the response of the LH was not adequate with 0280150943 injectors.
For the fuel map, I just adjusted it slightly except at high load. Here, instead of a stock target AFR of 13, I targeted a lambda of 0.82 (equivalent to 12 for regular fuel).
Fred, you think lambda 0.68 should be better? I see recommendations for 0.78.
I stay so far at about 0.8 in order to stay below 100% duty cycle at 6000 RPM and up. For more fuel, 24lbs injectors are required.
For track use I did an open loop map that enrich a lot almost everywhere so I get more throttle response in particular below 3000RPM. But limited to lambda 0.8 at the top end. The car run good yesterday. Fuel consumption was 30% more than last time on the same track! To be safe, EZK map was stock except at WOT where I added 3 degrees.
Here is summarized what I did. Good or not? It is just what I did.
Have a great Sunday,
Raphaël
Do not worry about the English- i would be very proud of myself if I could write French as well as you write in English! At high school I was semi fluent in spoken French but alas with no real practice for 50 years [another lazy Englishman!] I can only pick up a little of what is spoken- a shame really becuase la Francaise is a beautiful language.
I am somewhat baffled as to how your motor is able to run E85 thus my specific interest. The stock gasoline mapping tends to be a bit lean mid range and a bit rich on top end but not massively so. If you stick E85 in the gas tank I would have thought it needs significantly more fuel to achieve stoich and match the stock output. When correctly fuelled it should produce in the region of 20% more power but with stock fuel mapping logic says it must be running very lean. Clearly there is something I am not grasping here. Maybe others can explain your situation but it is a bit beyond my comprehension at the moment.
Getting hold of injector opening times is amazingly difficult but with sharktuner it is not problem, well not when running gasoline. If the opening time is set too large the engine will run rich and the opposite if set too short.
07-11-2022, 06:58 PM
#48
Rennlist Member
FredR,
I have been also surprise when I start trying E85 on all my cars. On the 928 I was surprised how the stock car run correctly with E85 fuel without any modification. You could use 80% E85 and crank quite well even when cold (40 degrees F)...
And the LH handle it quite well.
When I used the 0280150953 injectors, everything was much more complicated... works globally great will E85 but far too rich with regular fuel.
As you said, open time set too high => too much fuel!
And as Jim told me, the open time change a lot the maps... so my understanding is that I was super lucky to choose 0280150953 injectors!!!
Again, I agree that stock maps had tendency to be lean mid range. When I did my track open loop map, I had to add a lot of fuel mid range.
And at high RPM and load, the stock map for close loop provided in the sharktuner leads to a lambda of about 0,75!!! I had to minimize fuel to stay at 0,8 in order to get a reasonable duty cycle at the top end..
One thing I did not try is to shoot a lambda of 0.7. I will try that at WOT and see it the car respond better. I will just let lambda of 0.8 at 6000RPM.
For me should not improve. If I'm wrong, the car should provide more power and then I'm now running not rich enough... and so 24LBS injectors should be required.
But there is one more thing that could explain why 19LBS injectors are still good for E85 fuel on my S4 : injectors are the same on the GTS that provide 350 HP...
Porsche should have kept a small margin for the GTS and it could explain why I have no margin with my injectors from 6000RPM to top end with E85 fuel...
I will let you know what's happening at lambda 0.7 at WOT.
bye
Raphaël
I have been also surprise when I start trying E85 on all my cars. On the 928 I was surprised how the stock car run correctly with E85 fuel without any modification. You could use 80% E85 and crank quite well even when cold (40 degrees F)...
And the LH handle it quite well.
When I used the 0280150953 injectors, everything was much more complicated... works globally great will E85 but far too rich with regular fuel.
As you said, open time set too high => too much fuel!
And as Jim told me, the open time change a lot the maps... so my understanding is that I was super lucky to choose 0280150953 injectors!!!
Again, I agree that stock maps had tendency to be lean mid range. When I did my track open loop map, I had to add a lot of fuel mid range.
And at high RPM and load, the stock map for close loop provided in the sharktuner leads to a lambda of about 0,75!!! I had to minimize fuel to stay at 0,8 in order to get a reasonable duty cycle at the top end..
One thing I did not try is to shoot a lambda of 0.7. I will try that at WOT and see it the car respond better. I will just let lambda of 0.8 at 6000RPM.
For me should not improve. If I'm wrong, the car should provide more power and then I'm now running not rich enough... and so 24LBS injectors should be required.
But there is one more thing that could explain why 19LBS injectors are still good for E85 fuel on my S4 : injectors are the same on the GTS that provide 350 HP...
Porsche should have kept a small margin for the GTS and it could explain why I have no margin with my injectors from 6000RPM to top end with E85 fuel...
I will let you know what's happening at lambda 0.7 at WOT.
bye
Raphaël
07-12-2022, 03:05 AM
#49
Rennlist Member
Gotta be something missing...all due respect.
It's a physics problem...E85 NO changes, wont run .7 lambda...which is a power _losing_ 10.2 AFR....on 19lb injectors.
They would have to be flowing _30lbs_ to make 320 stock 928 HP on E85, unless you're running 80psi base fuel pressure...and then I'm not sure the injector pattern would make good power anyways..
19lb will make 350 crank HP nicely on gasoline..its only 9% more power. They are a bit thin to sharktune another 10 out of a GTS safely..
It's a physics problem...E85 NO changes, wont run .7 lambda...which is a power _losing_ 10.2 AFR....on 19lb injectors.
They would have to be flowing _30lbs_ to make 320 stock 928 HP on E85, unless you're running 80psi base fuel pressure...and then I'm not sure the injector pattern would make good power anyways..
19lb will make 350 crank HP nicely on gasoline..its only 9% more power. They are a bit thin to sharktune another 10 out of a GTS safely..
07-15-2022, 07:09 PM
#50
Rennlist Member
Bonjour,
Here is the power curves I did in the past (blue, when I get the car in 2011, at that time the car has a GT LH and she was lacking power at high RPM with it).
Since then I found a S4 LH, made a custom X pipe and now tuned fuel and ignition maps with E85.
Power curves.pdf
As you get some interrogations about enrichment and power, today I did a 0-100Km/h test. Easy with the sharktuner! I measured it from when RPM dropped and when RPM passed 5625 RPM! Today it was quite warm here : 98 degrees F. I get between 5.2 to 5.9 seconds and I did that with no training... 1rst time since 2012! Tank was near low fuel.
And attached is the datalog with the sharktuner : Power is here, the injectors are saturated at 6000 RPM but I'm not lean.
run 0 100 kmh.xlsx
Have a great day,
Raphaël
Here is the power curves I did in the past (blue, when I get the car in 2011, at that time the car has a GT LH and she was lacking power at high RPM with it).
Since then I found a S4 LH, made a custom X pipe and now tuned fuel and ignition maps with E85.
Power curves.pdf
As you get some interrogations about enrichment and power, today I did a 0-100Km/h test. Easy with the sharktuner! I measured it from when RPM dropped and when RPM passed 5625 RPM! Today it was quite warm here : 98 degrees F. I get between 5.2 to 5.9 seconds and I did that with no training... 1rst time since 2012! Tank was near low fuel.
And attached is the datalog with the sharktuner : Power is here, the injectors are saturated at 6000 RPM but I'm not lean.
run 0 100 kmh.xlsx
Have a great day,
Raphaël
07-28-2022, 10:24 PM
#51
Rennlist Member
Bonjour,
The car works better than ever on track the other day… but one of the head gaskets gave up!!! I have pressure in the coolant circuit… and CO2 in it… the test with the blue liquid turns yellow…
I’m good to pull the engine out…
I hope all of you will enjoy your miles with your 928… On m’y side I will have to be patient before enjoying it again…
Raphael
The car works better than ever on track the other day… but one of the head gaskets gave up!!! I have pressure in the coolant circuit… and CO2 in it… the test with the blue liquid turns yellow…
I’m good to pull the engine out…
I hope all of you will enjoy your miles with your 928… On m’y side I will have to be patient before enjoying it again…
Raphael
07-29-2022, 04:36 AM
#52
Rennlist Member
Bonjour,
The car works better than ever on track the other day… but one of the head gaskets gave up!!! I have pressure in the coolant circuit… and CO2 in it… the test with the blue liquid turns yellow…
I’m good to pull the engine out…
I hope all of you will enjoy your miles with your 928… On m’y side I will have to be patient before enjoying it again…
Raphael
The car works better than ever on track the other day… but one of the head gaskets gave up!!! I have pressure in the coolant circuit… and CO2 in it… the test with the blue liquid turns yellow…
I’m good to pull the engine out…
I hope all of you will enjoy your miles with your 928… On m’y side I will have to be patient before enjoying it again…
Raphael
Saddened to learn of your situation.
When you strip the engine please take some photos of the head surfaces before any cleaning and the gasket surfaces on the head side.