[Jawknee5]

So, I'm big turbo with all supporting mods. GTX2867r blah blah blah.

Currently tuning with stratified, they asked for a 3rd log and a 4th log. This is about my 7th time tuning(different companies different stages) in the year and a half I've owned the car, so I'm pretty sure I know how to use vdyno correctly.

So my 3rd gear pull showed 339hp/356tq

And my 4th gear log showed 320Hp/370tq.

I had to stop my 4th log a couple hundred RPMs short, but in that range power drops anyway.

Anywho, the 4th logs I've done throughout the tune have showed lower horsepower numbers consistently, but more torque.

Is this normal? I know 4th pulls show more torque, but I've never heard of horsepower dropping off so much...

Maybe there's more adjustment in Vdyno to account for 4th pulls aside from changing it to 4th gear?

 

[Redline727]

On an actual dyno you want to do your pull in whatever gear is 1:1 unfortunately for when I had my Mustang the MT82 transmission 1:1 is 5th! So no way in hell I would log in 5th haha what gear is 1:1 in the ST? If it's 4th like most transmissions that should be the one you want to look at.

 

[Jawknee5]

But wouldn't that mean if fourth is as close to 1:1 you get, that numbers in 3rd would be lower?

Maybe I'm gear ratio stupid, but I would assume that Vdyno would adjust and wouldn't think it would be so far off...? I know vdyno isn't 100% accurate anyway, but using as a compare and contrast it's accurate to see modification changes since I use the exact same road...

 

[Redline727]

Also does vdyno have any way to set a standard correction factor like an actual dyno? Temp, humidity, barometric pressure would play a huge factor in comparisons even if on the same road. You need some way to standardize conditions.

 

[Jawknee5]

Yeah it does for temp and bar. Pressure, maybe I need to look more into it.

 

[Redline727]

My point is I wouldn't invest to much time going down this rabbit hole. There are plenty of ways to rip apart actual dyno comparisons. Never mind a virtual one. Trust your gut if you feel down on power then trust the logs and your tuner. If you don't feel there are any issues don't go looking for one lol it will drive you crazy.