Effective NA Power Mods

[-Willis-86touge]

Oh and for some people who beleive its to high on pump numbers, remember dynos read diffent. I noticed in one pick the dynapack sign so seeing how that's there I assume it was on a dyna pack. Dyno pack it a higher reading dyno so if you do the math a good number woul be roughly 180hp sounds about right to me. The importance is how 12 volt added roughy 10 hp with the intake manifold.

[justatroll]

Originally Posted by churchx

What was the dyno type? I'm thinking that FD is main culprit for such drastic difference over completely stock baseline. Even if doing run in same gear, you DO have different gearing.

I agree. Many ways to "skew" the dyno numbers.
Example:
Dynapack setup requires Final Drive, Drivetrain loss, AND wheel diameter to be entered.

If you were to enter those values wrong by just a little, you would get errors in the final value.

Even running with low tire pressure in the rear would give inflated HP numbers because the effective wheel diameter would be less than the machine thinks.

[Teseo]

Originally Posted by justatroll

I agree. Many ways to "skew" the dyno numbers.
Example:
Dynapack setup requires Final Drive, Drivetrain loss, AND wheel diameter to be entered.

If you were to enter those values wrong by just a little, you would get errors in the final value.

Even running with low tire pressure in the rear would give inflated HP numbers because the effective wheel diameter would be less than the machine thinks.

What about this kind of dyno? Variable of tyres is not present at least.

[justatroll]

Originally Posted by Teseo

What about this kind of dyno? Variable of tyres is not present at least.

I was even wondering if all dynapack dynos connect directly to the wheel hubs?

If they DO, why is there a wheel diameter setting in the setup menu?

[Ultramaroon]

Maybe that part is just so the customer can get some sort of vehicle speed chart.

[Lantana frs]

In the middle of the summer, my car runs almost as strong as the one on the dyno.

[Dr. BRZ]

looking at getting an aluminum driveshaft, 6.67 final drive, and lightweight flywheel and hoping to hit mid 13s in the drag.

[Lantana frs]

Originally Posted by Dr. BRZ

looking at getting an aluminum driveshaft, 6.67 final drive, and lightweight flywheel and hoping to hit mid 13s in the drag.

What other mods do you have?

[CSG Mike]

Originally Posted by justatroll

I was even wondering if all dynapack dynos connect directly to the wheel hubs?

If they DO, why is there a wheel diameter setting in the setup menu?

Yes, they do.

I wasn't aware it asked for wheel diameter...

[gramicci101]

Originally Posted by CSG Mike

Yes, they do.

I wasn't aware it asked for wheel diameter...

He probably meant tire outside diameter. That would be more important than wheel diameter for determining rolling speed.

[justatroll]

Originally Posted by CSG Mike

Yes, they do.

I wasn't aware it asked for wheel diameter...

Here

http://www.dynapackusa.com/vehicle.htm

I should have read the description.

Wheel Dia - for entering wheel diameter so equivalent ground speed can be calculated for display - not used or necessary for power and torque measurements

[GenRuleAThumb]

JDL UEL header
OFT E85 Tune
Top Speed axel back

[justatroll]

Originally Posted by GenRuleAThumb

JDL UEL header
OFT E85 Tune
Top Speed axel back

Sorry but our cars have ~12-13% drivetrain loss (MT).
Your peak wheel HP shows up as 174.6

174.6 * 1.13 = 197.3 HP
So your engine is outputting right about 200 hp

What am I missing?
(Hint: 'drag power' is way too high @ 41 hp).
41 hp of drivetrain loss on a engine hp of 216 is 19% loss

See what I mean about "tweaking dyno settings" to show power where it isnt?
And thats without being able to see any of the Rotating mass numbers.

[gramicci101]

Originally Posted by justatroll

Sorry but our cars have ~12-13% drivetrain loss (MT).
Your peak wheel HP shows up as 174.6

174.6 * 1.13 = 197.3 HP
So your engine is outputting right about 200 hp

What am I missing?
(Hint: 'drag power' is way too high @ 41 hp).
41 hp of drivetrain loss on a engine hp of 216 is 19% loss

See what I mean about "tweaking dyno settings" to show power where it isnt?
And thats without being able to see any of the Rotating mass numbers.

Ok, you're an engineer, so hopefully you can explain this to me. Why is drivetrain loss expressed as a percentage instead of a static number?

Say your car makes 200 bhp, and for ease of math it loses 20 hp (10%) through drivetrain loss. You do some mods to it and now it's making 300 bhp. You're still spinning the same gears at the same speed in the same fluid, so it should still only lose 20 hp, not 30 hp (10%), right? If expressing it as a percentage is correct, why would drivetrain loss go up just because power went up, when the workload to spin all the gears and whatnot hasn't changed?