When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Anyone have any timing logs from 3rd or 4th gear pulls? Looking to see what your timing doe's when you first jump on it. Seems mine pulls very low to 0-5 at degrees at 3,500 rpm and than slowly starts to climb regardless of temperature. Will only max out at 17-18* at 120* AIT. Timing commanded is 25*
Just seems very low to me.
I have a couple recent ones I can post later today. Who is doing your tuning though? Stating that they are "commanding 25 degrees" is way over simplifying it. Timing will have multiple tables usually taking inputs from air temps, rpms, and map pressure to determine actual timing. As boost pressure goes up timing is generally reduced to prevent detonation. With your stacked pullies to be safe you should certainly not have the timing some one with say a 77mm pulley has.
If I had to guess, I would say that "25* commanded" was a EC statement haha, because I got very similar responses when I was trying to get them to fine tune my AFRs haha.
Just for reference on the timing over simplification, here is what the WOT spark map looks like when tuning in Sct advantage 3 for my old neon SRT4:
Along with several other tables that are timing modifiers. I doubt the Mercedes ECU is any more simplified haha :-P some one is just giving you a simplified answer.
Interesting compared to what I see.
My AIT is not dictating my timing numbers. I proved this by removing the sensor and installing it on the intake filter just to test. So it saw basic ambient temps throughout the rpm range and did very little to add any more timing.
My temps are never over 120* normally with sensor in stock position.
Tune is Race IQ and I run 100 octane fuel.
Dang. I remember you said you were using a scan gauge. Have you verified don't have any knock and also are you sure the scan gauge would display knock correctly for the Mercedes ECU? Are you using colder than stock plugs?
Just for comparison it might be worth getting a couple gallons of 110 and making some logs running that. If your timing is higher with 110 you might be having a little bit of detonation that the knock sensors are picking up on the 100.
I am logging with a separate system, Inovate data logger,that is linked to my laptop. No knock because I have switched between stock pulley and smaller and no difference. Plus in the logs it just keeps adding timing but starts off really low and goes from there. Yes colder plugs and rich AFR.
I put in 100octane RON. It made a big diff up at high revs. I am certain i was getting a little knock with 98 RON i used to use. But its hard to tell seat of pants in already high hp. Just feels...smoother and more consistent.
Anyone have any timing logs from 3rd or 4th gear pulls? Looking to see what your timing doe's when you first jump on it. Seems mine pulls very low to 0-5 at degrees at 3,500 rpm and than slowly starts to climb regardless of temperature. Will only max out at 17-18* at 120* AIT. Timing commanded is 25*
Just seems very low to me.
I have recently changed altitude moving back to sea level. My timing is sounding just like yours, did you figure out your issue? Was it Detonation pulling timing or was it a dud tune?
I really do not know what my ECU was doing and could never make sense of the timing stratagy.
What I did do was eliminate the temperature correction in the tune and she stays solid at 21-22* up top every time now. I also run 108 octane at the track and 104 on the street so it is always safe.
Can anyone explain why I see my timing jump to +18 when I lift after a pull? I saw that today after each pull. Timing would go from a negative value to +18 as soon as I lift.
Can anyone explain why I see my timing jump to +18 when I lift after a pull? I saw that today after each pull. Timing would go from a negative value to +18 as soon as I lift.
Its normal, the positive and negative should be the other way round in my head as well, but to make sense of it, just reverse the polarity lol... Ie the + is retarding the timing after you lift off. Nothing to stress about there.
Its normal, the positive and negative should be the other way round in my head as well, but to make sense of it, just reverse the polarity lol... Ie the + is retarding the timing after you lift off. Nothing to stress about there.
Thanks, I get the +/- .
But I don't see that on previous logs ever nor do I see it on logs of a friend's car using the same OBD II and same torque app. His car as soon as it's off boost the timing goes to -37, mine goes to +18. It would be nice to understand why. Belt slip? Vacuum leak? Exhaust leak? Difference in tunes? What's normal(I realize there are many variables)?
Can anyone explain why I see my timing jump to +18 when I lift after a pull? I saw that today after each pull. Timing would go from a negative value to +18 as soon as I lift.
Is it one really fast spike or consistant? I usually see a quick drop in timing at shifts and let off. I can't recall how much and I don't think I've ever seen it go positive. That's after TDC and doesn't make any sense to me.
Is it one really fast spike or consistant? I usually see a quick drop in timing at shifts and let off. I can't recall how much and I don't think I've ever seen it go positive. That's after TDC and doesn't make any sense to me.
I think only briefly on lift off, didn't have the room for multiple gear pulls. If you can access the file look at line 30, 94, 132, 178. It happens when going from boost to vacuum.
Maybe try the built in gaphing tool in torque, select timing as the PID (and no others) and watch the graph it spits out. You can save it as well when you stop logging.
When you log multiple PIDs the rate becomes very poor. Our OBDII will only spit out about 5-6 PIDs/second max, split between how ever many you select. So if you only have on your sample rate will be 5-6 times a second. If you have three PID selected it will poll each one once every half second at best, and so on. I don't know why that would make it positive still but give it a shot with only the timing PID to give it some better resolution and see what you get.
Maybe try the built in gaphing tool in torque, select timing as the PID (and no others) and watch the graph it spits out. You can save it as well when you stop logging.
When you log multiple PIDs the rate becomes very poor. Our OBDII will only spit out about 5-6 PIDs/second max, split between how ever many you select. So if you only have on your sample rate will be 5-6 times a second. If you have three PID selected it will poll each one once every half second at best, and so on. I don't know why that would make it positive still but give it a shot with only the timing PID to give it some better resolution and see what you get.
I will do that, thanks.
I selected only timing in the graph data option menu as well as changed what to log to timing only in data logging option. Snow on the ground today so I will have to wait to get data and report back. Thanks for your input.
Yes. Although there has never been any knock detected to begin with.
Yes, if you have fuel that is not knock limited in that area, it would seem to simplify the solution. Ethanol is fine up to 150 or more degrees of IAT with no knock. But I do not recall what you did to your system to ensure no IAT over 120.
Got this all figured out but I run Two 3.5 gallon rear tanks, one feeds the other and temps stay around 110* on 1/2 mile runs and 22-23 degrees timing holdind solid. I also have no IAT timing pull any more and the crazy timing slopes are now steady and solid.
Maybe try the built in gaphing tool in torque, select timing as the PID (and no others) and watch the graph it spits out. You can save it as well when you stop logging.
When you log multiple PIDs the rate becomes very poor. Our OBDII will only spit out about 5-6 PIDs/second max, split between how ever many you select. So if you only have on your sample rate will be 5-6 times a second. If you have three PID selected it will poll each one once every half second at best, and so on. I don't know why that would make it positive still but give it a shot with only the timing PID to give it some better resolution and see what you get.
I see this every time I lift after hard acceleration.
09-21-2018, 09:04 AM
