Member
I've never seen too many comparisons thrown out openly on this so I thought I'd share some:
Intake Cam Comparison.jpgExhaust Cam Comparison.jpg
It's not really shown in these graphs but the exhaust cam is pretty beneficial for the low end spool/torque. I could feel the differences more dynamically when adjusting on the road; in the future I might try to find a Mainline Dyno to verify optimal settings.
Last edited by Commanderwiggin; 10-09-2017 at 01:21 AM.
1000+RWHP, Lab22 Built Turbo S54 - BMW Half Mile Record Holder
Member
what are the actual values for each curve?
Member
I've shared a small piece of that information on the images. Most configurations will be different and I'd gladly point you to my tuner if anyone with a standalone ems is interested in optimizing things remotely. Ian - bendcalibration@gmail.comOriginally Posted by stefm5
Intake 10 degrees advance vs Optimized vs 50 degrees advance
Exhaust 0 degrees vs -10 degrees
Last edited by Commanderwiggin; 10-09-2017 at 02:48 AM.
1000+RWHP, Lab22 Built Turbo S54 - BMW Half Mile Record Holder
M54B30 Inside
Forgot to hit the "post" button 2 months ago Kenton?
LOL
Member
You know me...I share most of my stuff privately
1000+RWHP, Lab22 Built Turbo S54 - BMW Half Mile Record Holder
Member
he pretty much posted them for you. the timing isn't going to be a static number across the rpm range, he posted the low and high, the rest is blended together. As he said different setups such as turbos, manifolds, headwork will yield different results
Member
i was curious to see the full load maps just for the strategy used. i don't even own the s54 engine.
but you're right i got the point.
Luchador
Cool graphs, thanks for sharing! Makes you lol at people who remove variable valve timing for turbo engines thinking its no benefit!!
M54B30 Inside
There are actually some issues with running it with large cams.
In some cases a camshaft can be so big that in a static position, the open and close events cover the entire range of a "stock" camshaft fully advanced and retarded. Depending on piston design, you could end up with piston to valve contact if you rotated the big camshaft.
Secondly, there can be issues with moving the camshaft. If there isn't enough hydraulic force available, it can be next to impossible to move the camshaft to target position as RPM increases rapidly. Conversely, you could be asking the camshaft mechanisms to move at a rate faster than they were designed to do, and end up causing damage, misalignment, or component failure.
According to Kenny Dutweiller, most people put too much camshaft in their FI engines...where optimizing the position of a mild valve train provides a better all around package.
Personally, I think the dyno is the only place to form opinions on this topic.....
Member
You're limited by the design of the actuators/oil pressure/supply and load on the valve train for speed... but it's not something to worry about. The time it takes is the time it takes.
Not sure I follow.. How do you ask it to move faster? It only moves as fast is it can. I don't see how you can cause damage, failure or misalignment.Conversely, you could be asking the camshaft mechanisms to move at a rate faster than they were designed to do, and end up causing damage, misalignment, or component failure.
If you're talking about a poorly setup system and the control system is bad then that is different and certainly you will never get a good result. But again I don't see how that can result in any damage to the VVT system. I've seen plenty of poorly setup VVT systems in standalone ECU's... never any damage as a result though (mechanically).
M54B30 Inside
Ah..easy answers.
I've had situations where I couldn't move the cam out of a position fast enough and it cost power. The solution is to move it only part way there, then roll out early. This had a lot to do with engine oil viscosity changes influencing the PID setting of the actuator control. (Feed forward)
On the M54, the Vanos helix spline is not pinned to the cam, it's bolted on and can be snapped lose / moved if enough force is applied to it. 3 times now I've had situations where I've done this. Most recently, I inverted the the polarity of the Exhaust Vanos actuation (Table changed from 0% to 100% instantly) when doing a test, and the engine never ran right after that single key stroke. I tore the VANOS down to find that the helix spline on the exhaust cam had rotated causing a 23 degree misalignment in timing.
Member
The s54 can move cams quickly... u can actually adjust the modulation to help move the cams individually at any rpm to achieve target. Its like 2000psi... the accumulator makes sure there is always full psi on reserve so u don’t have to build psi. when I’m tuning I look at targets and actual cam degree very carefully to ensure they r achieved.
Sent from my iPhone using Tapatalk
Last edited by being3; 10-13-2017 at 10:52 AM.
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