Virtual Dyno issues

[Vansquish]

Originally Posted by RJTSi I'm not trying to compare the two cars power outputs to each other at all really. I'm just showing that this older log from a speed6 is on point for its mods etc. this new speed3 and a bunch of others are not making what they should in VD. The graphs are shifted down by some weird factor. Correct me if I'm wrong, but these cars should make over 180 whp with bolt-ons and an aftermarket OTS tune. If not, than that's one hell of a drivetrain loss. Ruff Crowds are fine, but don't sit here and call me a retard without going out, doing a log, putting it in VD and posting your results

OK, I sort of understand what you're trying to do, but what you're actually doing and saying is "compare old vs. new." This would be all well and good IF the cars were running the same tune (hence my focus on the OTS SF 93 tune graphs), and IF the atmospheric conditions were similar. At least then we could be talking Fuji Apples to Honeycrisp Apples instead of Honeycrisp Apples to Mandarin Oranges.

I've gone back through a year's worth of logs at this point and dumped a variety of them into VD. The results are pretty conclusive, as far as I'm concerned. Changing the final drive ratio is absolutely wrong. (There's no way that my car is making in excess of 430whp on pump gas.) I'm seeing precisely the same kinds of numbers that I've been seeing all along. At CF 1.01 on my current tune at almost 90ºF, that comes out to an average of about 310awhp/335awtq. At 50ºF, my logged values average out to ~325awhp/350awtq at the same boost pressures.

Now, I will say that at least as far as the MS6 is concerned, I know a few people have been using the Dynojet setting (CF 1.09), as at least in some instances, it seems to be closer to what people are actually seeing on the rollers. If I do that, then the numbers above jump significantly to around
~330/365 @ 90ºF, and ~350/380 @ 50ºF.

Make of that what you will.

[RJTSi]

So you guys have gone out and done logs within the past 2 days and are getting the same results as a few weeks ago and prior? That's all I want to know. Not trying to compare these 2 completely different cars to each other. All I'm saying is up until a week a go I have always gotten numbers on par with where they should be. I know it needs to be a flat surface. Like I said this isn't my first rodeo. 3 different local gen 2s, all with similar mods, all put down 185-196 whp and super low torque values as well. I'm only tuning 1 of these cars. The others are being tuned by another local guy. From my experience, with their mods, I normally see 230-250 whp as a base. Not 180 If you guys are saying everything is jiving for you, than all I can do at this point is toss these cars on an actual dyno.

[NCspecV81]

Originally Posted by RJTSi So you guys have gone out and done logs within the past 2 days and are getting the same results as a few weeks ago and prior? That's all I want to know. Not trying to compare these 2 completely different cars to each other. All I'm saying is up until a week a go I have always gotten numbers on par with where they should be. I know it needs to be a flat surface. Like I said this isn't my first rodeo. 3 different local gen 2s, all with similar mods, all put down 185-196 whp and super low torque values as well. I'm only tuning 1 of these cars. The others are being tuned by another local guy. From my experience, with their mods, I normally see 230-250 whp as a base. Not 180 If you guys are saying everything is jiving for you, than all I can do at this point is toss these cars on an actual dyno.

I have logs that are 20-30 degrees in IAT difference that are close. In fact my highest CF1.01 is 568whp with IAT's at or near 100f.

[RJTSi]

Thank you for posting actual data

[Vansquish]

Originally Posted by RJTSi So you guys have gone out and done logs within the past 2 days and are getting the same results as a few weeks ago and prior? That's all I want to know. . . If you guys are saying everything is jiving for you, than all I can do at this point is toss these cars on an actual dyno.

Yes. It was 88degrees here two days ago at 22psi, and the car made 308/330, according to VDyno at CF 1.01.

[Enki]

Loaded up a log from over a year ago (updated settings to make it match prior vdyno) and it's 6 WHP (low; lower rpm) and 0 WTQ (same rpm) difference. The smoothing has been changed over time but not super drastically.

[Realgib3]

I never got an answer to this in the other thread, but have you checked your mechanical timing yet?

Aside from that, it's hot and humid as shit and that will effect things a lot.

One of the BT cars I did earlier this year went from 410/365 in April to 370/330 in June ( @sho; ). Ohio has shit weather for cars between June and October.

Also I didn't see it, but what version of VD are you on? I have a couple dif versions I can run a log through if you want me to compare.

EDIT: Found the logs you posted on page one, analyzed them some, and ran them through my VD, and I'm seeing pretty much what I'd expect power wise. I also loaded this week's logs vs last week's logs from 3 dif Ohio cars (PU, 6, 1) with 3 dif setups (93/GTX2867R, 93/k04, and E85/ko4) and everything is still lining up where I'd expect it.

Aside from the mechanical timing check and the heat, I would run a boost leak test on the cars as well.

[sho]

^The heat and humidity in ohio is 10x worse this year than the mild summer we got last year. I can go take a log in the middle of the day and see poop numbers, then go hit the same stretch of rd at 1am when it is 25 degrees cooler and get a higher output graph. It is what it is, until i grab a meth kit

[RJTSi]

Update...it's working properly for me now and probably always was. I guess those gen 2s are just really slow and my car was having timing issues before it snapped a cam. It's much stronger now on my base map I threw together for my new intake. I'm at 4-5 deg less timing (14.5) and 4 psi lower (18psi) and it's pretty impressive already. I'm not afraid to admit when I'm wrong. My bad. Need to get my maf dialed in now with this 3.5" intake. Have some super rich spots. Then throw some more boost and timing at it and see what it can do.

[Realgib3]

Originally Posted by RJTSi Update...it's working properly for me now and probably always was. I guess those gen 2s are just really slow and my car was having timing issues before it snapped a cam. It's much stronger now on my base map I threw together for my new intake. I'm at 4-5 deg less timing (14.5) and 4 psi lower (18psi) and it's pretty impressive already. I'm not afraid to admit when I'm wrong. My bad. Need to get my maf dialed in now with this 3.5" intake. Have some super rich spots. Then throw some more boost and timing at it and see what it can do.

Glad to see you got it worked out. You've been through enough with these in the past couple months.

[RJTSi]

Originally Posted by Realgib3 Glad to see you got it worked out. You've been through enough with these in the past couple months.

Thanks Mark. Much appreciated. With as all the crap I've been through lately, I'm a little on edge and do not take kindly to being called a retarded, incompetent, etc whatever. Ron and I have literally spent every waking moment (when I'm not at me real job) working on getting a things together. Feels great to be behind the wheel of a speed again. After the past few weeks, I'm super burnt out on wrenching. I don't even want to look at a tool for a week or 2 lol. Well, I do have coil overs and diff brace on the way, so maybe after that I'll take a break.

[mituc]

Old thread is old but still doesn't worth opening another one for the same issue.
So I just noticed. I have the attached log file which gave me this graph:


Apart from the holy flatness of the power curve (a bit unnatural, but let's admit I have a restriction), why is the AFR curve diving into low 8's while in the log the AFR values never go below 11?? Now seriously...

[Enki]

Originally Posted by mituc Old thread is old but still doesn't worth opening another one for the same issue. So I just noticed. I have the attached log file which gave me this graph: Apart from the holy flatness of the power curve (a bit unnatural, but let's admit I have a restriction), why is the AFR curve diving into low 8's while in the log the AFR values never go below 11?? Now seriously...

It's not. Vertical scale on the right is for boost, left is AFR. It's still above 11 AFR.

[mituc]

Man... I was blind, now I can see!

[Enki]

Originally Posted by mituc Man... I was blind, now I can see!

Couldn't resist.