SHOW ME YOUR TIMING ;)
- Thread starter Bmwfixerguy1
- Start date
@Maroon_e90
I have a ST 6466 at 700 rwhp (auto tranny) at 30 psi boost and 7.9 timing. Fueling is 93+boostane+methanol. My calculated octane is about 101 octane. Try boostane. It is a miracle. Mix 1 can with 1 tank of gas. It will bring 93 octane up to about 98 or 99. 1 can is about $20. See if it solves your problem.
On full e85+boostane+methanol my boost/timing is significantly higher. I'm still dialing it in and DocVu is tuning the car. I dont want to share numbers yet because it is still in flux.
A built motor can cause false timing issues. You will notice it in cyl 2 and 5 (center cylinders closest to the sensors). Your timing drops look real to me, but I'm no expert. Your tuner can dampen the sensors in the tune. But that has some risk if it is real. Or you can add potentiometers to the sensors. I believe that many (most?) People with a built motor and a ST require some sensor dampening, the harmonics are changed. My tuner does have some dampening in my tune.
When I switched from 93 toe85, at the same piwer level. I also had some timing drops, only in cyl 2 and 5. I learned that my driveshaft center bearing bolts were a bit loose and a heat shield was tapping my exhaust. I believe this noise carried into engine... My theory... Once corrected, the timing drops on cyl 2 and 5 stopped.
I have a ST 6466 at 700 rwhp (auto tranny) at 30 psi boost and 7.9 timing. Fueling is 93+boostane+methanol. My calculated octane is about 101 octane. Try boostane. It is a miracle. Mix 1 can with 1 tank of gas. It will bring 93 octane up to about 98 or 99. 1 can is about $20. See if it solves your problem.
On full e85+boostane+methanol my boost/timing is significantly higher. I'm still dialing it in and DocVu is tuning the car. I dont want to share numbers yet because it is still in flux.
A built motor can cause false timing issues. You will notice it in cyl 2 and 5 (center cylinders closest to the sensors). Your timing drops look real to me, but I'm no expert. Your tuner can dampen the sensors in the tune. But that has some risk if it is real. Or you can add potentiometers to the sensors. I believe that many (most?) People with a built motor and a ST require some sensor dampening, the harmonics are changed. My tuner does have some dampening in my tune.
When I switched from 93 toe85, at the same piwer level. I also had some timing drops, only in cyl 2 and 5. I learned that my driveshaft center bearing bolts were a bit loose and a heat shield was tapping my exhaust. I believe this noise carried into engine... My theory... Once corrected, the timing drops on cyl 2 and 5 stopped.
@Maroon_e90
I'm no expert, but your rail pressure seems a bit low. Smarter folks could check me. That could contribute. 1900 psi seems low. Maybe add more PI fuel.
Something to talk about with your tuner at least.
I'm no expert, but your rail pressure seems a bit low. Smarter folks could check me. That could contribute. 1900 psi seems low. Maybe add more PI fuel.
Something to talk about with your tuner at least.
First concern "I am not using stock vanos." - This can already cause your issue
Secondly i would take the knock tables and up the values to about 3 in the areas of issue and check if anyhting changes.
I was suffering from false knock for quite some time and changed the knock table values to 3. Car was happy and we checked the piston surface for real knock. Nope.
Rail pressure is absolutely fine @Thunderstorm1250
No it was on a stock engine. I simply had timing corrections and post shift timing reduction (DCT) where i just thought that this cannot be real. Less science more gut feeling. But post shift timing corrections and phantom misfire are known issues on DCT cars.
When i reduced timing in those areas it also barely changed.
So i figured why not alter the knock tables and see what happens. Many did that before already and never experienced issues. People just don´t talk about it openly in the internet
I did not go up to "3" as it does in MHD when you click the option desensitize knock sensors. Even putting a 3 in the cells shouldn´t be an issue. In my opinion BMW set the knock sensors to sensitive as this was a new platform for them?! I don´t know but what i know is that i have no issues at all with my modified values and piston surface is perfectly fine.
Thanks everyone for the suggestions. I raised 6200RPM and up the knock sensor sensitivity to 2.6 I also changed back to stock VANOS.
Seems all of this helped a bit I am turning down boost now and gonna try to get some more timing in there. But as you can see changing the VANOS significantly changed how much air the engine moves. much less WGDC to make the same boost and more fuel required. (my rail is dying and unhappy)
I will be getting the fuel pressure regulator upgrade soon as you can see my LPFP was dropping into the 50s.
Seems all of this helped a bit I am turning down boost now and gonna try to get some more timing in there. But as you can see changing the VANOS significantly changed how much air the engine moves. much less WGDC to make the same boost and more fuel required. (my rail is dying and unhappy)
I will be getting the fuel pressure regulator upgrade soon as you can see my LPFP was dropping into the 50s.
