Please confirm the best way to log data for determining my horse power?

1. Pull from all gears
2. Pull from a specific gear to redline

 

4th gear to redline.

 

Actually, the most commonly used gear (on a 5-speed at least) is 3rd gear. It gives fair resolution and doesn't require going over 80mph, which is the gear that almost all dyno shops tune with, occassionally doing a 4th gear pull afterward to check for any touchy areas.

If you're using Evoscan:

For JUST power logging you want to log the least amount possible for the best resolution. Log just your Speed and RPM (not 2 byte RPM, evoscan uses the standard RPM for its calculations). Start your 3rd gear pull on a flat surface at 3k rpm and keep it at wide open throttle until redline and let off the gas.

Be sure to edit the "Power/Torque Vehicle Settings" info to get the most accurate results possible. The "People Contents Weight" column does nothing (though its supposed to) so add your vehicle weight and occupants weight together and enter it in the "Factory Vehicle Weight" column. Go online and lookup your local weather for the Barometric pressure and ambient Air temps too, these make a big difference.

The "dyno correction factor" column does nothing either (though its supposed to).

Also, some might notice that the torque and HP curves do not cross at 5252 RPM like they are supposed to which means Hamish's calculations for the power section are slightly off anyhow so dont go bragging to your buddies that they are solid numbers lol.

Its best to use the EXACT same stretch of road each time to get the best A/B comparison logs.

 

So your HP and Torque calculations work for Evoscan?
I have never got it to work reliably. Which version of Evoscan are you using and do you mind sharing your Evoscan data.xml?

TIA

 

My method is 3rd gear so the end speeds aren't too crazy high. and to start with 3rd gear 2000rpm to 6000rpm, make sure your AFR and Knock is safe, then continue with some runs higher up to 7200rpm etc. keep dataitems logged to a minimum for maximum EvoScan resolution of datalogged items.

 

Hamish, still gonna be able to give the power section a good "once over" before the next revision? I love the feature and use it very often but its just those few problem area's that I would be excited to see fixed.

• People Contents Weight
• Dyno Correction factor
• HP/TQ curves not crossing at 5252 RPM

 

Thanks a million guys for you input as there is not dyno's in my region in the Caribbean.

 

Someone needs a portable dyno on-board a Cruise Ship, lol.

 

That would be great, sail down the islands doing tuning and dyno pulls, they would make some $$$$

 

has anyone tested the accuracy of the evoscan dyno? assuming u get a flat piece of road, and account for the vehicle weight properly, how accurate is it really?

 

ive never been able to get it to work correctly, i always get something like 14 hp and 2xx torque

 

In order for it to work, you need to highlight JUST the 3rd gear pull, right up to the point where you let off the gas. Then do your pull. You just need to log SPEED and RPM. Obviously, you gotta set up the "Vehicle Settings" by choosing your vehicle type from the dropdown list, adding the air temperature and barometric pressure.