So-Cal you still didn't answer my question. You said you got before number on your car stock. What did it put down and what does the G-Tech say your putting down. Answering that question will put all this to rest. I guess if G-tech is the greatest thing we better tell all those who tune on a dyno all they need is a G-tech, and better bring it up to the NHRA as well, no need to race at the track just slap a g-tech in the car and use that to figure out point standings.

 

I guess you don't understand that since I had my "stock" HHR dyno'ed at AEM I have changed the exhaust - so those numbers won't tell us anything. Apples and oranges.

I never said the G-tech is "the greatest thing" - but was merely pointing out innacuracies in your statements regarding it. A dyno can never take into account aerodynamics - but the G-Tech has to! It's accelerometers are sensing G-forces against time and this equates to distance travelled. If you have wheelspin off the line; G-forces go down and it is factored in. If your engine is putting out good power but the HHR is "built like a brick wall" at 90mph - G-forces exerted show this and it is also factored in. Dyno rollers "move" when you push the gas - the ground doesn't. The ground also has different effects on your suspension, motor mounts, frame flex, etc. than a dyno does. Real world values will always be lower than dyno figures - but they (real world ground horsepower), are the most accurate.

Face it, a dyno was designed to be a tool to allow engine builders to repeat testing in a lab under (nearly), identical conditions. Aerodynamics are not included, real-world airflow into the engine compartment is not included (*there is still much controversy over this.), suspension torque and frame flex against an unmoving earth are not included. Have you ever seen someone do a full 1/4-mile run from a dead stop on a dyno? That's not how they are used and it was never intended to be.

The G-Tech was designed and built specifically for this application and if you took the time to watch the video I provided a link to above, you would see just how accurate a properly calibrated G-Tech is (dead accurate), compared to the trap lights. Welcome the technology.

Both are great tools (dyno & G-Tech), both operate differently.
I think we should just agree to disagree and leave it at that.

 

I think you should stop side stepping my question and post what your car put down stock. All you've added since then is what, a muffler?? Difference won't be that great. What did your car put down stock and what does the G-Tech say you are putting down now. If it is as accurate as you claim it to be they should be fairly close. My feeling is the numbers are far off and thats why you wont post it.

All I'm saying is that the G-tech is only accurate in certain cars, in my experience. Then you went spouting off how your the worlds greatest driver because you ran a 15 according to your g-tech, which is all fine and dandy but go back it up at the track. I know exactly what a dyno was intended for, it's a tuning tool nothing more nothing less.

 

I think the rule of thumb most users use is for every 100 pounds of vehicle weight removed equates to one tenth of a second off on the quarter mile. Vehicle weight accuracy is very important.

Since all the results are mathmaticlly related as Long Tall Texan point out (thanks for that, too) it seems to me that the accuracy of the G-Tech is only as good as the accuracy of the vehicle's weight and cargo entered in to the device. A few pounds of difference is going to influance the results.

Would this not be true?

FYI, some of the guys on the GTO boards (ls2gto.com) use G-Tech or simular devices and they are saying the results from these devices match very close to the time and speed tickets issued by the track.

 

I am under a non-disclusure agreement with AEM and cannot release any information gained during preliminary testing. Sorry, you'll have to dyno your own stock HHR.

Once again - you've misread my post. I'm not sidestepping anything. The G-Tech numbers WILL NOT match dyno numbers. It's never going to happen. Reread my post above to understand why...hopefully (jeesh!).

"All I'm saying is that the G-tech is only accurate in certain cars, in my experience."

Very limited experience too, I'm guessing. The G-tech must be calibrated properly to give accurate results. If you move it from car to car (unless they are identical models), the results will be waaay off.

Your hoopla about "aerodynamics" was a bunch of pootie and it is clear that you don't know what you're talking about when it comes to the G-Tech regarding this. Any basic physics student can confirm this.

 

That is all part of the calibration process.

 

Here is something else to consider.

All dynos do not offer the same result. For example, a GTO measured on a Dynojet will show 400 HP and 400 Torque, but on a Mustang Dyno, the same vehicle will show around 5% less. All dynos are not created equal.

A dyno (same model) is a good baseline for comparision, but I think you will find devices like the G-Tech (properly calibrated) closer to real word results.

 

i actually don't give a **** about the G-tech, because I personally don't like them, I'd rather go to the track. My hoopla about aerodynamics and such might be "a bunch of pootie" regarding there newest version, but with the older ones it wasn't. So if you can't say what your car put down stock, which is total BS, what does the g-tech say it is putting down now? Or can you not disclose that either. How do you calibrate this nifty little device of yours for aerodynamics, just out of curiousity.

 

I agree like I said all a dyno is, is a tuning tool, nothing more nothing less.

 

Good Gosh. What an interesting read....pootieheads :) I don't know much and don't pretend that i know much either. BUT i can understand how a dyno can't account for aerodynamics, etc. The car isn't moving. It just can't. However whatever socal has, (if calibrated correctly) would account for everything, bc the car actually is moving and having to deal with all aspects, aerodynamics, bla bla bla.