Hi All,

I am relatively new to this forum so please take it easy on me. I have read and reserched alot in the archives but still have alot to learn.

I have owned and worked on many performance type cars over the years but I was always a "seat of the pants" type guy so I don't have alot of dyno experience. I took my stock 2006 m6 w/z51 option to a local speed shop for some baseline dyno pulls (see printouts below) prior to starting my header/cai/160° thermo/tune project. At the bottom of the printouts, there were some run conditions listed. How do these conditions affect the pull and what are good/bad conditions? Also, I read on the forum that if the runs are SAE corrected, it should be listed on the dyno sheet. I don't see it listed anywhere so does that mean the runs were not corrected (that might make sense since the hp/tq numbers look high to me for a stock LS2)? I do see "CF: STD Smoothing 5" in the upper right hand corner but can only make an assumption to what the meaning is at this point.

Another question I have has to do with my gearing. Is 145 mph at 6500 rpm's pretty much standard for a stock 2006 C6 with the z51 option? That number kind of jumped out at me and indicates some pretty long gears (maybe 2.73's?).

Any input would be greatly appreciated. Thanks all.


Tom

 

Click 3.42 gears for your type car. See 4th gear at 6500 rpm. 4th gear used as its 1 to 1 in pulls.
http://mysite.verizon.net/foofoo2/c6/

 

[QUOTE=ChevyDave;1580621769]Click 3.42 gears for your type car. See 4th gear at 6500 rpm. 4th gear used as its 1 to 1 in pulls.
http://mysite.verizon.net/foofoo2/c6/


Thanks ChevyDave, looks like I am right where I should be for 3.42's.

 

All C6's with a manual trasmission have 1:1 gearing in fourth gear, with a 3.42:1 rear gear. AT 6500 RPM, they all would be doing 150 MPH. Slight differences in the car's rear loaded wheel radius can affect the speed at any given RPM of the engine.

 

Always more fun when you base line a car, maybe even maximize the tune so it's a good as can be stock.

Your runs were uncorrected, thats bad. If you want to compare future runs they all need to be corrected.

As always repeatable & consistent results are difficult, that means the conditions from the base line to modifications need to be the same. Same weather, atmosphere pressure, & anything else that the dyno may be fussy to.

 

The "CF" is correction Factor, yours was standard, not SAE. SAE is usually a stricter factor, higher correction factor, lower HP/TQ reading.

The "Smoothing" takes out the peak fluctuations on the graph, some say to use 5 as standard, it will be the highest correction/lowest HP/TQ reading.

 

Thanks guys. I now know why the hp/tq numbers were higher than expected. I wonder why the shop would not do an SAE correction factor? Just an oversite I guess.

Do shops keep the dyno run files stored where they could reproduce the printouts with the SAE correction factor? If not, I guess I lost my ability to compare baseline to modded/tuned pulls unless the weather conditions are exactly the same. I would go back to the shop and have them redo the pulls but I already have two of the mods done.

 

The shops I've been at kept the files and could show me a different correction at a later date... Wouldn't hurt to ask if they could print you an SAE corrected graph.

 

Since your car was dynoed on a Dynojet, you're in luck !!!!

You can download the WinPep software directly from Dynajet's website here http://www.dynojet.com/downloads/software.aspx

With the software loaded on your computer, you can then open ANY Dynojet run log and change the displayed values for correction and smoothing. Just ask the shop to send you your dyno log files, then open them locally on your computer to review and change the values that are displayed

Generally speaking, Standard correction factors will show roughly 5% higher HP/TQ values than SAE correction.

 

Thanks FNBADAZ06 of the link and the info. I am back in business. I downloaded the WinPEP 7 program and stopped by the speed shop to pick up copies the run files. After loading the files and making a few adjustments, I reprinted the graphs using the SAE correction factor.

This forum is a wealth of knowledge and a good place to learn. I now feel I know enough about dyno's to be dangerous but I do plan on reading more to give me a better understanding (especially about the correction factors).

Thanks again to all who helped!