low power reading in virtual dyno

[yangliu]

hi guys,
nearly finish my self-tune map, mods are below.
tuned for 98 pump (Australia) 20psi 10degree@6000rpm (get actually 2.19 load). vdyno settings are CF=1.01, smoothing=2
i hit over MAF 330g/s and suppose to get 300whp but can only see 256whp in virtual dyno. i post my vdyno result and logs here, can anyone have a look?

mods:
bnr s3 bolt on stock block
hpfp
tmic
JBR 3" intake
colder plugs
3bar and 3ports
3" dumppipe, stock catback

updates 1:
adding boost target, ignition and vvt tables of my current map

[Vansquish]

So...that's only part of the story. If you post some screenshots of your tune, we might be able to help you out a bit more. Saying that you're targeting 10° at 6000RPM tells us a little bit, but it sort of depends on what calculated loads you're hitting at a given RPM. You might want to post screenshots of your Ignition tables, your VVT tables, your Boost target tables and so forth.

[yangliu]

Originally Posted by Vansquish So...that's only part of the story. If you post some screenshots of your tune, we might be able to help you out a bit more. Saying that you're targeting 10° at 6000RPM tells us a little bit, but it sort of depends on what calculated loads you're hitting at a given RPM. You might want to post screenshots of your Ignition tables, your VVT tables, your Boost target tables and so forth.

i already upload target boost, vvt and ignition tables of my current map.
i hit 2.19 load@6000rpm

[Vansquish]

Hm. I wonder if VDyno is using different algorithms for calculating power/torque than it used to. What does the "Dynojet" setting give you?

[yangliu]

Originally Posted by Vansquish Hm. I wonder if VDyno is using different algorithms for calculating power/torque than it used to. What does the "Dynojet" setting give you?

Only difference is cf value. Like I’m using custom cf 1.01 and others using 1.09, 0.9, etc that can affect the dyno result. But most guys here using CF1.01 for ms3

[Vansquish]

Originally Posted by yangliu Only difference is cf value. Like I’m using custom cf 1.01 and others using 1.09, 0.9, etc that can affect the dyno result. But most guys here using CF1.01 for ms3

I know that the only difference is the correction factor value. That's not what I'm saying. I'm saying that it is possible that Vdyno might've changed the behind-the-scenes algorithms for determining power and torque, and that would've effected all of the power/torque ratings that Vdyno produces.

I have had the experience of loading the same log into different Vdyno build versions and finding substantial variations in the power/torque ratings with the same CF loaded.

[yangliu]

Originally Posted by Vansquish I know that the only difference is the correction factor value. That's not what I'm saying. I'm saying that it is possible that Vdyno might've changed the behind-the-scenes algorithms for determining power and torque, and that would've effected all of the power/torque ratings that Vdyno produces. I have had the experience of loading the same log into different Vdyno build versions and finding substantial variations in the power/torque ratings with the same CF loaded.

That make sense

[Fstrnyou]

I'm not a "tuner", but 10 degrees sounds conservative for 2.19 load.

[yangliu]

Originally Posted by Fstrnyou I'm not a "tuner", but 10 degrees sounds conservative for 2.19 load.

Maybe, so far I haven’t reached the ignition limit.

[Vansquish]

Originally Posted by Fstrnyou I'm not a "tuner", but 10 degrees sounds conservative for 2.19 load.

To be fair, that's about what I'm running, and my car is pretty happy with it.

[Fstrnyou]

I push my timing tables until I see KR. If multiple pulls show a consistent KR at the same place, then I'll back off a bit in that spot. Random/small KR blips are ignored. BUT, I run a more agressive timing retard in the ECT/BAT table to add a little bit of safety margin.

I repeat: I'm not a tuner! That just how I've set my tune up.

[Jeff23spl]

I never been lucky with vdyno but if you really flow 330g/s, you should be making more than that unless it is very rich or very retarded...
Despite it isn't a thru and accurate mesure, air flow in g/s isn't far from dynojet fwd whp when afr and timing is correctly dialed in.

I did see ''third gear'' is it right ? With a fwd you may rather use 4th gear. I had wheel spin in third with a gt2871 ms3 and wheel spin screw up vdyno results. It may not be your case since the graph seem linear without any shifted data but.....

[yangliu]

Originally Posted by Jeff23spl I never been lucky with vdyno but if you really flow 330g/s, you should be making more than that unless it is very rich or very retarded... Despite it isn't a thru and accurate mesure, air flow in g/s isn't far from dynojet fwd whp when afr and timing is correctly dialed in. I did see ''third gear'' is it right ? With a fwd you may rather use 4th gear. I had wheel spin in third with a gt2871 ms3 and wheel spin screw up vdyno results. It may not be your case since the graph seem linear without any shifted data but.....

My log attached on top maybe you can have a look? It is 3rd and no wheel spin, actually I never have wheel spin when WOT
Thanks

[Jeff23spl]

According to your log and boost target, the only thing that rise a question is why to you drop boost above 6000rpm ? You miss the k04 choking curve?

[yangliu]

Originally Posted by Jeff23spl According to your log and boost target, the only thing that rise a question is why to you drop boost above 6000rpm ? You miss the k04 choking curve?

Oh, just want a long life motor
Anything else I need to pay attention?

[Jeff23spl]

it may help to extend the life of the timing chain but the most common damages on these engine happen at peak torque below 6000

[yangliu]

Originally Posted by Jeff23spl it may help to extend the life of the timing chain but the most common damages on these engine happen at peak torque below 6000

Yes, that’s why I have slower spool time and most time I won’t go past 6000rpm, so I don’t mind to taper down boost after 6000