[Z06] Late Z06 Exhaust backdate
03-07-2014, 11:42 PM
#41
Pro Mechanic
Pro Mechanic
Thread Starter
Ran the car at Westech Performance Group (Mira Loma CA) yesterday (7 Mar) and I was surprised. I expected an increase, but not quite as much.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
Last edited by Hib Halverson; 03-07-2014 at 11:47 PM. Reason: added content
03-07-2014, 11:50 PM
#42
Team Owner
Ran the car at Westech Performance Group (Mira Loma CA) yesterday (7 Mar) and I was surprised. I expected an increase, but not quite as much.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
03-08-2014, 10:52 AM
#43
Melting Slicks
Hib, thanks for posting your results and helping validate the claim that I have been making since 2011 that the 2011 Z06 exhaust makes for the most powerful C6 Z06 to leave the Factory!
Now if the truth be told....after personally experiencing over several hundred chassis dyno's with my LS motors I can tell you that you typically don't have the run's stabilized until the 3rd run so a more accurate averaging method is to take runs 3, 4 & 5, however in your case this isn't possible if only three runs were made.
I made three passes and averaged them then compared that to the three run average from my base line session.
03-08-2014, 11:05 AM
#44
Pro Mechanic
Pro Mechanic
Thread Starter
Hib, thanks for posting your results and helping validate the claim that I have been making since 2011 that the 2011 Z06 exhaust makes for the most powerful C6 Z06 to leave the Factory!
Now if the truth be told....after personally experiencing over several hundred chassis dyno's with my LS motors I can tell you that you typically don't have the run's stabilized until the 3rd run so a more accurate averaging method is to take runs 3, 4 & 5, however in your case this isn't possible if only three runs were made.
Now if the truth be told....after personally experiencing over several hundred chassis dyno's with my LS motors I can tell you that you typically don't have the run's stabilized until the 3rd run so a more accurate averaging method is to take runs 3, 4 & 5, however in your case this isn't possible if only three runs were made.
As far as the stabilziing thing? Yeah...I've seen that with just about all the cars I've ever run on a chassis dyno–along with the few engines I've run on engine dynos. I usually look at ECT, IAT and oil temp (if available). Also I look at the early runs and see how consistent they are. All that plays into which three I average.
In talking with GM engineers back in the Spring of '11 about the four-cat exhaust coming for '12, I knew there'd be a performance difference, I just didn't expect it to be as much as it was.
03-08-2014, 11:07 AM
#45
Team Owner
The new cam might have had a bit more to do with the HP increase.
03-08-2014, 11:08 AM
#46
Team Owner
I believe that increase happened when they switched to the LS6 intake manifold.
. I seem to remember something about "windowing" the main bearing bosses also to help with "pumping" of air in the block (much like what is done on the LS7) is that true, or was that when the LS1 went from 345 to 350 HP?
03-08-2014, 11:16 AM
#47
Team Owner
Ran the car at Westech Performance Group (Mira Loma CA) yesterday (7 Mar) and I was surprised. I expected an increase, but not quite as much.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
I made three passes and averaged them then compared that to the three run average from my base line session.
The difference was 11.0-rwhp SAE and 11.6-rw lb/ft SAE. That's a pretty significant difference. I expected about half that. so, now, I'm at 464.7 rwhp and 441.2 rw lb/ft, SAE-corrected.
The only change was removing the '12 cat assys and the '12 mid-section and replacing them with '11 cat assys and catless, '11 mid-section.
A revealing test, for sure.
I also noted in all the dyno runs so far, the engine gets pretty rich in PE over 4000 rpm so, my next step is to do some calibration work.
Then I'm going to put one of Zip Products' "Mamba" AISes on the car.
Once again, thanks to Eric at Westech for great service on the chassis dyno. One of the reasons I'll make a 300 mile round trip to run there is their chass dyno set up, a Superflow AutoDyn, and the professionalism with which they run it.
03-08-2014, 11:34 AM
#48
Drifting
This is about what a I expected
I am not an expert on LS7 engines but I was told straight out by a Corvette development engineer that the 2011 LS7 would have the highest HP and torque from the factory due to the changes with cats and the X pipe cross.
I have driven a 2008 Z06 and compared to my 2011 there is a difference.
Sorry to the doubters and haters, and yes it was just dumb luck that I purchased the 2011.
I am more impressed with the sound difference that the extra 11 horses though
Thanks Hib, for putting this to rest once and for all!
I have driven a 2008 Z06 and compared to my 2011 there is a difference.
Sorry to the doubters and haters, and yes it was just dumb luck that I purchased the 2011.
I am more impressed with the sound difference that the extra 11 horses though
Thanks Hib, for putting this to rest once and for all!
03-08-2014, 02:47 PM
#50
Team Owner
You missed the part of the conversation when the '01 C5Z 4 cat set-up was brought up in comparison...'02-'04 went to 2 cats, but also a different cam in the LS6 for those years. HP climbed from 385 to 405, but that wasnt because they dropped 2 of the cats.
03-08-2014, 02:49 PM
#51
Team Owner
03-09-2014, 01:48 PM
#53
Pro Mechanic
Pro Mechanic
Thread Starter
That was the hard part for me. I searched for months to find the parts. I was never able to get them all from one source. I ended up getting the left and right cat assemblies and the mid-section all from different vendors of used parts.
03-09-2014, 01:57 PM
#54
Pro Mechanic
Pro Mechanic
Thread Starter
For 2002, the LS6 was further upgraded with a more aggressive camshaft, different intake and exhaust valves, a different air filter assy, a different MAF sensor and an exhaust system specific to Z06es which used only two under-floor cats.
The combination of all those changes gained 20-hp.
Last edited by Hib Halverson; 03-09-2014 at 02:00 PM.
03-10-2014, 11:14 PM
#56
Pro Mechanic
Pro Mechanic
Thread Starter
Wish I'd have known that before I spent the money to buy all the '11 parts.
How long has it been on the market? Also, what's Corsa's part number for it?
03-11-2014, 10:11 PM
#58
Team Owner
it came out a few months ago. Part number is 14331
http://www.corsaperformance.com/view...=14331&cfg=394
http://www.corsaperformance.com/view...=14331&cfg=394
#14331
Description & Features
3.0" XO Pipe
Fits: 2012-2013 Chevrolet Corvette C6 Z06 7.0L V8
2012-2013 Chevrolet Corvette C6 Z06 6.2L V8
2012-2013 Chevrolet Corvette C6 ZR1 7.0L V8
2012-2013 Chevrolet Corvette C6 ZR1 6.2L V8
03-12-2014, 02:24 PM
#60
Burning Brakes
It will not pass smog, as you are elminating the secondary cats on your car. But, the swap out is fairly easy if you have access to a lift. Or, you have a mecahnic do it for less than an hours work.
