Team ZR-1 Corvette Racers
Custom Tuning
>Enter Here
Test and Tune
Common Information
How Corvettes Gen 6,7 and 8 Place at VIR
by teamzr1. 02/22/24 07:15 PM
94 year old guy and a Corvette Sports Car
by teamzr1. 02/22/24 11:48 AM
WEC Season Starts Feb 28th
by teamzr1. 02/21/24 06:53 AM
Hig Speed C7 Crash
by teamzr1. 02/20/24 09:45 AM
Carvana Sells a Stolen Corvette
by teamzr1. 02/19/24 03:39 PM
Gang Banger Steals whole tractor load of C8s
by teamzr1. 02/16/24 06:53 PM
Corvette GT3.R reliability issues
by teamzr1. 02/01/24 08:40 PM
2024 IMSA Rolex Race
by teamzr1. 01/28/24 01:22 PM
Newer Corvettes
2021 C8 DCT TSB N212350930
by teamzr1. 02/10/24 08:13 AM
2024 C8 Invoice Numbers
by teamzr1. 02/09/24 08:31 AM
Recall C8 Headlight Problem
by teamzr1. 02/08/24 12:14 PM
Tech Talk
Forum Statistics
Forums27
Topics3,407
Posts6,099
Members50
Most Online265
Jan 21st, 2023
Previous Thread
Next Thread
Print Thread
Rate This Thread
#1294 - 08/18/05 11:20 AM Dyno Cheats  
Joined: Dec 2000
Posts: 5,232
teamzr1 Offline
Owner - Pays the bills
teamzr1  Offline
Owner - Pays the bills
Lives in Engine Bay

Joined: Dec 2000
Posts: 5,232
America
The Ploys
Hot Run vs. Cool Run
The first dyno run when the engine is cool usually produces the biggest power. As heat builds in the engine, the peak power number usually settles at a lower level. This is especially true in turbo applications where heat rises. Intercooler efficiency and the placement of cooling fans can play a role in the heating trend.

The scheme here is to take a hot baseline and compare it to a cool product-test run. A lower-whp baseline coupled with a higher-whp test makes the product appear to make more power than it actually does.

Daisy Chain/Rapid-Fire Runs
Performing back-to-back-to-back pulls without ample cooling time between runs can cause an unnatural buildup of heat. This will adversely affect the before-and-after testing of components. The goal is to conduct testing at consistent, normal engine operating temperatures.

The Density Intensity Game
Another way of cheating is to play the density intensity game - conducting baseline runs in the heat of the afternoon and run the after-tests in the cool evening air. While some dynos can adjust for atmospheric conditions, the bottom line is denser air makes more power.

Beat the Drum
The crooked dyno operator can reprogram the weight of the drum, which will allow the dyno to create anomalous power numbers.

The High Ground
The same crooked dyno operator could elect to change the elevation value in the computer, which would have a critical impact in power generation. Naturally aspirated engines are especially susceptible to this ploy.

Change Load
Changing the load by tightening or loosening the tie-down between runs can compromise any comparisons made with the dyno testing.

Frosty
Turning on the air conditioning during baseline testing will cost a few horses and make the after-test all the more impressive.

The Old Switch-a-roo
Swapping in a Civic DX graph in place of your Integra GS-R baseline will make for some big power gains later.

Acceptable Compromises
ReStrapping the Car When possible, have work conducted while the vehicle is still strapped to the dyno after baseline testing. On some dynos the positioning of the tires on the rollers and the tautness of the straps can change the load characteristics seen during testing. Items like intakes, exhaust systems and most headers are the types of products that can be installed without unstrapping the car.

Different Day Dynoing
This one can be hard to avoid if you are having extensive work done. Check to see if the dyno in question has a weather station that can correct for any big differences. Beyond that try to arrange testing for about the same time of day as baseline runs were performed. This will lessen the effect.

Things to Know
Correction Factor
A key element to producing comparable dyno charts on a global basis is the Correction Factor, SAE Standard J1349, which applies the following weather station data--atmospheric pressure 29.23, air temperature 77 degrees Fahrenheit and humidity 0 percent--to all tests. These exact figures allow apples-to-apples comparison of runs from different cars, different facilities, etc. So graphs with SAE-corrected power were made to this standard. The dyno in question must have a weather station and the proper software in order to generate SAE-corrected data.

Smoothing
An option on Dynojets, smoothing takes a jagged graph and delivers a more readable curve. Smoothing of the graph can be done by entering a value between one and four at the appropriate place in the computer.

Alignment
The alignment of the vehicle being tested does affect the outcome of a dyno test. So if a car is dyno'd, then run over a curb, thus altering the toe or camber, the car may not have repeatable runs. This is especially true on Dynojets.

Other tricks.

1. Changing tire air pressure.
2. Allowing engine to idle a long time so that the fuel trims are leaner effecting PCM changes to AFR as it goes into PE and WOT modes.
3. Starting the run at higher RPMs rather then around 2,000 RPMs.
3. Not allowing engine to get to 100% engine load.
4. If the hood is open or not.
5. Putting weather station in hotter temps will bogus the SAE results to bloat the real results.


Team ZR-1
True Custom Performance Tuning
Teamzr1.com
Team ZR-1 Store
Enter Here
#1295 - 01/08/06 02:12 PM Re: Dyno Cheats  

**DONOTDELETE**
Unregistered
Anonymous
Unregistered


Very informative!

Next time im at a dyno im gonna ask all that, hope im not gonna get them too mad LOL laugh


Moderated by  teamzr1 

Who's Online Now
0 registered members (), 13 guests, and 3 spiders.
Key: Admin, Global Mod, Mod
What's New
How Corvettes Gen 6,7 and 8 Place at VIR
by teamzr1. 02/22/24 03:32 PM
2024 E-Ray Results at VIR
by teamzr1. 02/22/24 03:28 PM
94 year old guy and a Corvette Sports Car
by teamzr1. 02/22/24 11:48 AM
Hig Speed C7 Crash
by teamzr1. 02/20/24 09:45 AM
Carvana Sells a Stolen Corvette
by teamzr1. 02/19/24 03:39 PM
Sound like a Supercar ?
by teamzr1. 02/17/24 01:32 PM
Gang Banger Steals whole tractor load of C8s
by teamzr1. 02/16/24 06:53 PM
Popular Topics(Views)
Techie
2021 C8 DCT TSB N212350930
by teamzr1. 02/10/24 08:13 AM
2024 C8 Invoice Numbers
by teamzr1. 02/09/24 08:31 AM
Recall C8 Headlight Problem
by teamzr1. 02/08/24 12:14 PM
Powered by UBB.threads™ PHP Forum Software 7.6.0