Why don't people here talk about the coolest VCM feature? (HP and Torque gauges)

[Mr. Smith]

What the hell?
We can calculate/see how much power/torque our engines are making (cool as phuk) then tune/flash our engines/computers and see improvements in power/torque... but everyone here seems "meh" about it and I've only read about 5 posts about it

This is pretty much the only thread I could find regarding engine power/torque gauges http://www.hptuners.com/forum/showth...t=power+torque and no one replied.

I guess what I really wanna know is, just HOW ACCURATE are these gauges + what math parameters does everyone use + has anyone compared their power/torque figures on VCM Suite to a dyno???

I found "Calculated Engine HP ([50108.127]*[50070.56])/5252" from someone here, tried it, wasn't expecting it to work let alone be accurate.. got it to work and tried it on that Demo Sample Silverado Cruise Log, and it seems to be fairly accurate.

Can't wait to get HPT and check it out on my car.

[schpenxel]

Too many variables for it to really be accurate. It should be in the ballpark but that's about it

[5FDP]

Yeah, it's just a guess on the computers part. Like Schpenxel said, there are so many variables to get good solid numbers.

[Markmx6]

Would it be good for showing improvement while tuning? As in not that the number is accurate, but a higher number is still more...

[ghostofnyc]

good tool indeed

[Mr. Smith]

Thanks guys.

So how "off" do you think it is? 2%? Do you think it reads higher than what you have or lower? Has anyone here compared them to a dyno (how can there not be at least 1 person????????)?

Would it be good for showing improvement while tuning? As in not that the number is accurate, but a higher number is still more...

Exactly what I was thinking.

[schpenxel]

Still too many variables.

There are some "virtual dyno" programs out there that will take a log and based on the vehicle weight, etc. figure out HP/TQ based on how fast you're accelerating, gear ratios, etc. I'd almost trust that more than trying to do it this way.

[Mr. Smith]

Still too many variables.

There are some "virtual dyno" programs out there that will take a log and based on the vehicle weight, etc. figure out HP/TQ based on how fast you're accelerating, gear ratios, etc. I'd almost trust that more than trying to do it this way.

Yeah, like G-Tech Pro..
Maybe HP Tuners can do something like that in future... We can already enter our tyre size, engine, see our speed, rpm's, see time... I don't think it would be too hard for them to incorporate an accurate 1/4mile time/speed reading, accurate HP reading...

[NJ_Phil]

I've been using Marcin's street dyno but will give that a try too

http://redhardsupra.blogspot.com

[schpenxel]

Yeah, like G-Tech Pro..
Maybe HP Tuners can do something like that in future... We can already enter our tyre size, engine, see our speed, rpm's, see time... I don't think it would be too hard for them to incorporate an accurate 1/4mile time/speed reading, accurate HP reading...

I'm sure they "could" but it really isn't what they do..

[Jggregory99]

I think fueling errors affect it as well... While tuning the VE on my Silverado, it was giving torque values over 500ft/lbs... on a NA 06' Silverado 6.0L w/ CAI, 80mm TB, Magnaflow Open Dual exhaust....at a MAP of 100Kpa... All because my fueling was off... So I don't know if I would trust the Torque/HP calculations. JMO

[Mr. Smith]

I'm sure they "could" but it really isn't what they do..

Agreed. But I think if they did and promoted it well on their website, they'd get a lot more people buying their product + make us happier.

[Mr. Smith]

I think fueling errors affect it as well... While tuning the VE on my Silverado, it was giving torque values over 500ft/lbs... on a NA 06' Silverado 6.0L w/ CAI, 80mm TB, Magnaflow Open Dual exhaust....at a MAP of 100Kpa... All because my fueling was off... So I don't know if I would trust the Torque/HP calculations. JMO

I'm not sure, but 500ft/lbs (or a bit over) of torque sounds about right to me for a Silverado 6L with intake/exhaust mods.
Are you saying the figure is too high?

[Jggregory99]

I'm not sure, but 500ft/lbs (or a bit over) of torque sounds about right to me for a Silverado 6L with intake/exhaust mods.
Are you saying the figure is too high?

WAY over... The mods I did don't support those numbers... A cold air intake, 2mm larger TB and exhaust...? I doubt that would be enough to give me a 28-30% increase in HP and Torque...Especially when you factor in that a naturally aspirated motor should almost NEVER max out to 100% of Kpa... And as Ed said to me "105kpa on a NA 6.0L...That in itself would be impressive."... 90 to 95% showing 94-96kpa...OK... but a maxed out kpa reading of 105...NATURALLY ASPIRATED via a K&N....! Nah... Don't buy it... If it WAS correct, I would have to upgrade my OS to 1.5-2 Bar. Ed was right because after I finished the tune, my torque dropped to a more reasonable 450-460 but as I will explain in a second.. That was still off... at 5000rpm which is close to redline....and Kpa's peaked at redline around 94-98kpa. Even if you go to the high end and say the mods added 20% to HP and Torque... From stock, (369HP/380ftlb @ 4900) that's only 74 RWHP and 76ft/lb @ 4900... Which is right about 15ft/lbs and 18HP higher than where I'm at (441ft/lbs/425HP @ 5000rpm on Load Dyno)....Still not bad, but, that is why I said, if fueling is off, I can almost guarantee the TQ/HP calculation is off. Also, one log I studied before completing the tune showed 522lbs That's a 12% error in the value.... So yeah, my values were WAY off... just from a 15% rich VE fueling error... So that just makes me question what else in the tune could cause an error value in the HP/Torque values.

[Mr. Smith]

(There is too much info/numbers/calculations there ^ for me to take in now lol. I'll get back to you later with a "proper reply".)

[Mr. Smith]

WAY over... The mods I did don't support those numbers... A cold air intake, 2mm larger TB and exhaust...? I doubt that would be enough to give me a 28-30% increase in HP and Torque...Especially when you factor in that a naturally aspirated motor should almost NEVER max out to 100% of Kpa... And as Ed said to me "105kpa on a NA 6.0L...That in itself would be impressive."... 90 to 95% showing 94-96kpa...OK... but a maxed out kpa reading of 105...NATURALLY ASPIRATED via a K&N....! Nah... Don't buy it... If it WAS correct, I would have to upgrade my OS to 1.5-2 Bar. Ed was right because after I finished the tune, my torque dropped to a more reasonable 450-460 but as I will explain in a second.. That was still off... at 5000rpm which is close to redline....and Kpa's peaked at redline around 94-98kpa. Even if you go to the high end and say the mods added 20% to HP and Torque... From stock, (369HP/380ftlb @ 4900) that's only 74 RWHP and 76ft/lb @ 4900... Which is right about 15ft/lbs and 18HP higher than where I'm at (441ft/lbs/425HP @ 5000rpm on Load Dyno)....Still not bad, but, that is why I said, if fueling is off, I can almost guarantee the TQ/HP calculation is off. Also, one log I studied before completing the tune showed 522lbs That's a 12% error in the value.... So yeah, my values were WAY off... just from a 15% rich VE fueling error... So that just makes me question what else in the tune could cause an error value in the HP/Torque values.

Very interesting stuff.
The kpa you're talking about is Baro, right? Fyi, with my old scanning software on my old laptop I used to get around 98-101kpa. I have a custom OTR intake using the standard air lid/box (but cut 95% of the lid) and panel filter + 2mm bigger T/B and MAF (LS1).

Man I keep reading the 2nd half of your comment and my brain just can't absorb it all lol.
Are you saying - because your engine was running rich, it was making your power/torque values on your VCM read too high???

[gofastwclass]

I agree with Jggregory99 on the calculated torque reading. If everything is factory trim and or calibrated properly it may be accurate, but I've also experienced wide swings in the numbers while tuning due to variables I can't explain. The variable could have been anything from timing, fuel or airflow but it taught me this calculation is just like every other calculation - bad data equals odd, unexpected or inaccurate results. Not long ago I had a combination showing 600 ft lbs of torque at something like 2500 RPM on it's first WOT pass while tuning. If that number was legit we would have either been on the side of the road staring at broken driveline parts or boiling tires like John Force - we were doing neither.

[Jggregory99]

Very interesting stuff.
The kpa you're talking about is Baro, right? Fyi, with my old scanning software on my old laptop I used to get around 98-101kpa. I have a custom OTR intake using the standard air lid/box (but cut 95% of the lid) and panel filter + 2mm bigger T/B and MAF (LS1).

Man I keep reading the 2nd half of your comment and my brain just can't absorb it all lol.
Are you saying - because your engine was running rich, it was making your power/torque values on your VCM read too high???

That is correct sir... Because my understanding..and I am no wiz at this, is that the calculations were way off in the MAP. When you use the Dynamic Cyl Air math vs. the MAP there is a variance. ([2320.71] / ([50070.56] / 60 * 4)) The Dynamic Cyl Air shows more accurate airflow values, but the Torque calculation is based on the MAP reading, and a fueling error can cause an invalid value. Thus the Torque value itself, based on the faulty MAP data is also invalid. At least that was how it was explained to me. All I know for sure, is that when I started dialing in my fueling and getting my VE closer to stoich, my max Torque readings began to drop significantly, and my Map readings came down to closer values to what I was getting in DynCyl Air. I no longer see 105kpa unless I REALLY run it out to max RPM of 55-5700. Generally at 5000 RPM I see around 96-98kpa. Where as before the tune I would see 105kpa consistently. Even though Dynamic Air was showing 94-96.... Now I just use Dynamic Cyl Air for my tune, as I get much better accuracy.

[Mr. Smith]

That is correct sir... Because my understanding..and I am no wiz at this, is that the calculations were way off in the MAP. When you use the Dynamic Cyl Air math vs. the MAP there is a variance. ([2320.71] / ([50070.56] / 60 * 3)) The Dynamic Cyl Air shows more accurate airflow values, but the Torque calculation is based on the MAP reading, and a fueling error can cause an invalid value. Thus the Torque value itself, based on the faulty MAP data is also invalid. At least that was how it was explained to me. All I know for sure, is that when I started dialing in my fueling and getting my VE closer to stoich, my max Torque readings began to drop significantly, and my Map readings came down to closer values to what I was getting in DynCyl Air. I no longer see 105kpa unless I REALLY run it out to max RPM of 55-5700. Generally at 5000 RPM I see around 96-98kpa. Where as before the tune I would see 105kpa consistently. Even though Dynamic Air was showing 94-96.... Now I just use Dynamic Cyl Air for my tune, as I get much better accuracy.

Okay, thank you for that info.
I think what I'm going to do is run my car on the dyno after I (hopefully) tune it (some day.. when I know what WB controller to buy), then compare the power and torque readings to VCM Suite and recalibrate it so they're the same.

[15PSI]

Try Virtual dyno....