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Finally got to the dyno for some fine tuning on my turbo S54.
at around 11-11.5 psi it made a final number of 529 hp and 428 tq on stock internals stock clutch and e85 AFRs were in the mid 11's
tuning done by HTE on stock DME MSS54HP
Some videos too
before anyone says anything, i didnt catch that the dyno HP and TQ were not scaled equally thus the numbers will not cross at 5252 but the numbers are accurate.
The reason i said it doesn't look like AFR is the stock CSL and PCS tune show the same fundamental behaviour. The issue is from ~6000rpm upto 7500rpm where the power noses over quicker than it should but the AFR dont look out to lunch enough to cause that.
With the stock CSL the AFR is fairly flat 12 to 12.5 for red and blue so fairly constant but there is drastic change to the power curve.
To me it looks like the inlet cam being slightly slow to reach the correct amount of retard but it does eventually wakes up and gets there at 7500rpm.
I'm not sure if you have the capability to log ignition timing, and cam position during a dyno pull but it would probably help you troubleshoot
+1 on this! Logging is the way to go.
But with this consistency in the runs (6k-7.5k rpm), you should easily replicate this while doing a street pull (and safe that money from dyno time). So install testo and do some logging to find out what happening.
I´m very very sure Paul knows what he doing (way more than me), otherwise i could thinked of a bit mismatched Vanosmap.
If i remember correct, the impact of the knock sensor input was higher in some particular rpm areas. Maybe 2 Cylinders have a bad knock sensor or cylinder leakage from headgasket or need some more fuel individualy because every engine is different.
Also it can depend on what CSL version for instance PD31, PD11...etc. is used. I have seen differences in these CSL base tunes in terms of knock sensitivity. I prefer PD31 and have seen other version with PD31 values transfered.
Thanks for the insight S54B32 and digger. When reviewing the graphs, I assumed it was an O2 issue, as the car gets rich past 7250 rpm. But the WOT throttle remark makes sense to me.
VANOS is rebuilt with everything Beisan offers and S62 diaphragm springs. VANOS test passes without issues as well. Only thing I haven't done is change the solenoid pack, as it works just fine. I'll open it up and reflow the solder joints this weekend though, since that's an easy job, but I really don't think it'll make much difference.
The AFRs up top make me think this might just be a matter of adjusting the WOT fueling. Should be easy to fix with a dyno tune.
The reason i said it doesn't look like AFR is the stock CSL and PCS tune show the same fundamental behaviour. The issue is from ~6000rpm upto 7500rpm where the power noses over quicker than it should but the AFR dont look out to lunch enough to cause that.
With the stock CSL the AFR is fairly flat 12 to 12.5 for red and blue so fairly constant but there is drastic change to the power curve.
To me it looks like the inlet cam being slightly slow to reach the correct amount of retard but it does eventually wakes up and gets there at 7500rpm.
I'm not sure if you have the capability to log ignition timing, and cam position during a dyno pull but it would probably help you troubleshoot
o2´s in M3 e46 are narrowband and therefore only used in idle and part load to correct fuel. The DME only determines 3 conditions with o2s: lean, stoichiometric and rich. And on full load its always rich to control heat in the combustion chamber. So beside full trims(but these should be resettet before the run/tune) there should be no affect on full load dyno runs.
Good insight! How about this: What could explain a dip in power near the top end, WOT, if the ecu is stock? So not a tune issue. Wonky knock sensors? I guess Vanos is most likely? I think if fuel were an issue, you'd see it at all or many RPM points, not just one. Same with spark or coils.
I got a besian rebuilt solenoid (though I've heard they're not always good), with all maintenance up to date, but I can *just* feel it pulling timing once or twice between 5-7k. Vanos error codes never returned, but I'm not sure if that guarantees that the rebuilt solenoid is 100% functioning.
I unplug the MAF and it runs perfectly though WTF? Already tried 2 known to be good MAFs. As soon as they're plugged in, it goes back to pulling timing. I'm starting to run out of ideas. Though new pre cat o2s were gonna solve it. I know undoing MAF puts it into Alpha N, but I don't know exactly which sensors are bypassed besides MAF/IAT. All I can think left to replace would be CamPSs, CrankPS, knock sensors. Everything else is new.
Thanks for the insight S54B32 and digger. When reviewing the graphs, I assumed it was an O2 issue, as the car gets rich past 7250 rpm. But the WOT throttle remark makes sense to me.
VANOS is rebuilt with everything Beisan offers and S62 diaphragm springs. VANOS test passes without issues as well. Only thing I haven't done is change the solenoid pack, as it works just fine. I'll open it up and reflow the solder joints this weekend though, since that's an easy job, but I really don't think it'll make much difference.
The AFRs up top make me think this might just be a matter of adjusting the WOT fueling. Should be easy to fix with a dyno tune.
Something fishy going on at 7250, could be o2 related due to high mileage.
o2´s in M3 e46 are narrowband and therefore only used in idle and part load to correct fuel. The DME only determines 3 conditions with o2s: lean, stoichiometric and rich. And on full load its always rich to control heat in the combustion chamber. So beside full trims(but these should be resettet before the run/tune) there should be no affect on full load dyno runs.
btw. fuel trims/corrections from o2s should be switched off for afr tuning. And while/after the tune in over 5000km of driving without o2s (because there is my WBO) i did not get a single downside from this (not in power, driveability or fuel consumption)
O2s are a gradually deteriorating item and a good idea to be changed at 100k so yours is quite a bit overdue. I suspect a few hps will be credited towards the headers from that.
Agreed on the overdue bit. I've just been lazy and haven't done them
O2s are a gradually deteriorating item and a good idea to be changed at 100k so yours is quite a bit overdue. I suspect a few hps will be credited towards the headers from that.
Something fishy going on at 7250, could be o2 related due to high mileage.
Yeah that dip does look weird, but it seems like other cars in this thread have similar looking curves. Hoping that new O2s and a dyno tune take care of that.
Put the car on the dyno again with the CSL airbox on. This time I tried out two different tunes, the stock CSL one (that I modified to work with stock cams) and an off the shelf PCS tune for my specific setup. Did this mostly just out of curiosity, but I'll be going back to get a dyno tune from Paul when I get my V1s on the car.
Updated setup:
128210 mi
US spec pre-facelift M3
Karbonius full carbon intake with carbon snorkel
Kassel MAP
Stock CSL IAT location and sensor
HP converted MSS54
Fully stock US exhaust
All engine maintenance done
Rod bearings replaced ~15k mi ago
VANOS done ~15k mi ago, passes VANOS test with no issues
Engine retimed ~4k mi ago
Valve adjustment done ~4k mi ago
New front and rear TPSs <500 mi ago
No mechanical fan, just aux
Dynoed at Sonoma racetrack so altitude is ~sea level
75ºF ambient temp
50% humidity
All O2s are original, got new ones in a box ready to go in when my V1s arrive, but potentially left some power on the table because of this
Running Shell V-Power 91 octane
Stock CSL tune:
285 max WHP, 234 max WTQ
As expected, the car was running rich, but made more power than I was expecting.
PCS tune:
294 max WHP, 245 max WTQ (different runs)
All runs were done back to back, so you can see the car progressively get heat soaked. I flashed the car while it was on the dyno so it had a good ten minutes to cool down then for the PCS tune, but looking at the last PCS run, I think it could have made a little bit more power if we had let it cool down some more. Torque was up significantly from the first PCS run and then it just fell off.
Not the most insane numbers, but happy to have satisfied my curiosity. I'm excited to see what the car will do with the Supersprint stuff and Paul's dyno tune. Also attached the individual runs in case anyone is curious.
Attached Files
Last edited by heinzboehmer; 09-13-2021, 11:30 AM.
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