Disappointing Dyno: New 2016 Z06 A8
11-01-2016, 04:21 PM
#61
Le Mans Master
PS. Had the car back on the dyno today to test an AFE intake and also a mild E85 mix on the factory tuning. Of course I forgot to bring along the stock intake for the intended comparison so I'll get to that later. I have a hunch most of the gain was just from the colder weather and more favorable timing curve... 18 degrees ramping up to 24 degrees at redline in 5th. With the colder weather and a consistent one min cool down between runs power didn't drop much run after run which was nice.
I feel you have no dog in this CAI hunt and are providing accurate assessments. 17hp for the AFE is pretty disappointing, especially considering it was in better air... However using the correction factor takes out the weather variable, at least if you use the SAE correction as opposed to STD.
I REALLY would like to see you test a Halltech vs stock cai, same day, pump gas, SAE correction, battery disconnect before each test.. Log the boost and afr trends for both. Thats as apples to apples as you can get.
I find it interesting that no one else is logging boost/afr trends on the dyno charts as you did.
11-01-2016, 04:21 PM
#62
Melting Slicks
At say 3700 pounds with driver to go an extra tenth you are in the 20 hp area from 10.1 to 10.0 and say 134 to 135 mph is like 16 hp.
11-01-2016, 04:30 PM
#63
Racer
speed
I was on an open highway in central Texas Sunday and had enough clear road in front of me to push the car. At 160mph the car red lined in 5th gear and was still pulling but I ran out of courage. I don't know what my hp would test out to be but it is incredibly stronger than my c6 Z.
rrm
rrm
11-01-2016, 05:06 PM
#64
Former Vendor
I feel you have no dog in this CAI hunt and are providing accurate assessments. 17hp for the AFE is pretty disappointing, especially considering it was in better air... However using the correction factor takes out the weather variable, at least if you use the SAE correction as opposed to STD.
While I don't have a dog in this fight I am "in the business" and have some predisposed opinions on intake design. I do try to leave my opinions out of these posts though.
I noticed something I thought was odd installing the intake, maybe someone with a Haltech can check theirs for comparison. The throttle body opening is ~3.7". The factory elbow expands over it so its ~3.7" ID also but stretches a good amount to fit over the lip. The AFE intake rotomolded tube though is only 3.4". I don't think the factory tube is a restriction to start with (will flow test later to verify) but if you're going to make one why not at least make it larger than stock?
Last edited by Terry@BMS; 11-01-2016 at 05:06 PM.
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HPT (11-17-2016)
11-01-2016, 06:53 PM
#65
I was playing with his head to see what lame excuse he would come up with. The C7 Z06 didn't lose 54.1 HP. The gearing difference is what narrowed the difference in the ET's.
As we both know, torque accelerates a car, not the peak horsepower.
Gearing accounts for the difference. Even though the C7 Z06 has 650 lb-ft peak torque vs the C6 Z06's 470 lb-ft, the transmission in the C7 Z06 multiplies the engines torque 2.29 times where as the C6 Z06 1st gear multiples the 470 lb-ft 2.66 times. That better gearing holds true in 2nd and 3rd gears also. While the overall torque is larger with the C7 Z06, the greater torque multiplication of the C6 Z06 helps to negate some of that advantage, allowing the C6 Z06 to run much closer to the C7 Z06's ET then shown strictly by the 145 HP difference.
Also the additional 500 RPM redline that the L7 has helps by allowing the C6 Z06 to stay it it's lower gears longer, thereby putting more of that torque to the ground for a longer period of time.
Put the C6 Z06 gearing in the C7 Z06, and you would see a much larger spread in the ET's between the two cars. More like what you would expect with a 145 HP delta.
Gearing is why the A8 runs .25 seconds quicker 0-60 vs the M7, and because they both have 650Hp and 650 lb-ft the M7 never catches up with what it lost to the A8's lower gearing in 1st and 2nd gear, thus that .25 second advantage remains with the A8 car through the 1/4 mile.
Same was true with the C6 Z06 vs the C6 ZR1. Want to make a ZR1 faster without touching the engine. Just install the gears from a C6 Z06 into the ZR1's transmission(as some have done).
As we both know, torque accelerates a car, not the peak horsepower.
Gearing accounts for the difference. Even though the C7 Z06 has 650 lb-ft peak torque vs the C6 Z06's 470 lb-ft, the transmission in the C7 Z06 multiplies the engines torque 2.29 times where as the C6 Z06 1st gear multiples the 470 lb-ft 2.66 times. That better gearing holds true in 2nd and 3rd gears also. While the overall torque is larger with the C7 Z06, the greater torque multiplication of the C6 Z06 helps to negate some of that advantage, allowing the C6 Z06 to run much closer to the C7 Z06's ET then shown strictly by the 145 HP difference.
Also the additional 500 RPM redline that the L7 has helps by allowing the C6 Z06 to stay it it's lower gears longer, thereby putting more of that torque to the ground for a longer period of time.
Put the C6 Z06 gearing in the C7 Z06, and you would see a much larger spread in the ET's between the two cars. More like what you would expect with a 145 HP delta.
Gearing is why the A8 runs .25 seconds quicker 0-60 vs the M7, and because they both have 650Hp and 650 lb-ft the M7 never catches up with what it lost to the A8's lower gearing in 1st and 2nd gear, thus that .25 second advantage remains with the A8 car through the 1/4 mile.
Same was true with the C6 Z06 vs the C6 ZR1. Want to make a ZR1 faster without touching the engine. Just install the gears from a C6 Z06 into the ZR1's transmission(as some have done).
If a person with a C6 ZR1 installed C6 Z06 transmission gears, he went slower...link us up with the people who made this expensive change to go slower. The large RPM drops between shifts with the Z06 transmission vs the ZR1 close ratio transmission would have the ZR1 falling so far off its HP curve, the engine would be making much less HP than the Z06. The large drop from 4th to 5th would result in the Z06 running away from the ZR1, especially with the ZR1 weighing more. I can't imagine anybody with half a brain doing that mod, what an expensive mistake. Your "theory" is way off, the reason the C6Z06 is close to the C7Z06 is the HP curve of the LT4 (and LS9) is not nearly as good as the LS7, the close ratio transmission of the C6ZR1/C7Z06 is used to mitigate the inferior HP curves of their engines.
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Lavender (11-02-2016)
11-01-2016, 07:01 PM
#66
Burning Brakes
I agree but the numbers are funny. Car & Drive tested the 2009 Z06 and 0-150 was 17.4 seconds. They also tested the 2015 Z06 and 0-150 was 17.8 seconds.
Take my example(both cars are on their respective fast lists and both have almost identical 60' times(C7 was a little quicker and both show that both cars were hooking just fine on their street tires so both cars seemed to have identical traction and equal driver skill) and the C6 Z06 was almost 2 MPH quicker at the 1/4 at 130 MPH; doesn't it seem strange that in the next 1/4 mile distance(1/2 mile total) both cars will be approximately at 150 and the C6 Z06 has enough horsepower to over come that 4-7 car length disadvantage(at the 1/4) and pull ahead of the C7 Z06 by .4 of a second at 150 MPH.
Just looking at the trap speed of both cars(and they were almost identical 60' and 1/4 mile ET's) the C6 Z06 had a higher trap speed(indicating more horsepower).
Now we both know that the C6's 505 HP is less than the C7's 650 HP, but the trap speeds don't show that, nor do the almost identical 60' and the 1/4 mile ET's.
And if the C7 is 4-7 car lengths ahead at the 1/4, how did less HP get the C6 Z06 ahead by maybe 5.866 car lengths at the 1/2 mile(17.4 vs 17.8 seconds; a difference of .4 seconds in favor of the C6 Z06). Both cars have identical 1:1 gearing from 130(1/4 mile) to 150 MPH(1/2 mile) so no advantage to the C6 Z06.
See what I mean about funny numbers.
Take my example(both cars are on their respective fast lists and both have almost identical 60' times(C7 was a little quicker and both show that both cars were hooking just fine on their street tires so both cars seemed to have identical traction and equal driver skill) and the C6 Z06 was almost 2 MPH quicker at the 1/4 at 130 MPH; doesn't it seem strange that in the next 1/4 mile distance(1/2 mile total) both cars will be approximately at 150 and the C6 Z06 has enough horsepower to over come that 4-7 car length disadvantage(at the 1/4) and pull ahead of the C7 Z06 by .4 of a second at 150 MPH.
Just looking at the trap speed of both cars(and they were almost identical 60' and 1/4 mile ET's) the C6 Z06 had a higher trap speed(indicating more horsepower).
Now we both know that the C6's 505 HP is less than the C7's 650 HP, but the trap speeds don't show that, nor do the almost identical 60' and the 1/4 mile ET's.
And if the C7 is 4-7 car lengths ahead at the 1/4, how did less HP get the C6 Z06 ahead by maybe 5.866 car lengths at the 1/2 mile(17.4 vs 17.8 seconds; a difference of .4 seconds in favor of the C6 Z06). Both cars have identical 1:1 gearing from 130(1/4 mile) to 150 MPH(1/2 mile) so no advantage to the C6 Z06.
See what I mean about funny numbers.
Higher DF car needs more power to achieve the same top speed.
Heavier car needs more power to achieve the same top speed.
It's not rocket science here...
With regard to the 10.98 from the C6Z vs. the 10.90 from the C7Z...You are making some serious assumptions. It was at PBIR, not Atco or MIR, where most of the 'hero' runs are from, including the 10.98. The C7Z has been out for less than 2 years and only 30-40% of them are manuals. So you are comparing a car that has been out for 10 years and are ALL manuals to a car that is less than 2yrs old and only 30-40% are manuals...Hmmm, which one do you think has more track time/qtr runs in the manual?? The C6Z by ALOT!! Get back to me in 7 years and we'll compare. There are already more C7Z's in the 10's than the ZR1. Only ONE C6Z has EVER run 10's in stock form = hero run.
Next, it's OBVIOUS the C7Z is making the power because the A8 ran a 10.21 at 137mph on DR's, and 10.3 at 134.70mph in the M7.
You wanted to talk about MPH? Well, what better way to discuss then to take out the traction issue and use DR's. It's .5 seconds faster, period, and it's heavier with more downforce/drag, so clearly it's making more power.
This is such obvious stuff...but it seems hard for you to grasp. I know you try your very best to discredit the C7Z, but you still can't get around the 10.21 at 137mph, which is 7mph faster than ANY stock (on DR) C6Z has EVER run...7mph is ALOT! It makes the power, deal with it!
So, in conclusion: The C7Z is a lot heavier, it has more downforce/drag and it STILL ran 7mph more. What's the problem Joe?
Last edited by ZoratZ06; 11-01-2016 at 07:06 PM.
11-02-2016, 02:34 AM
#67
I noticed something I thought was odd installing the intake, maybe someone with a Haltech can check theirs for comparison. The throttle body opening is ~3.7". The factory elbow expands over it so its ~3.7" ID also but stretches a good amount to fit over the lip. The AFE intake rotomolded tube though is only 3.4". I don't think the factory tube is a restriction to start with (will flow test later to verify) but if you're going to make one why not at least make it larger than stock?
11-02-2016, 04:04 AM
#68
Safety Car
Not to get to deep into the weeds.
What is the diameter on the inside of the throttle body in the butterfly area?
If that diameter is smaller than that would be the choke point in the system.
If that diameter is smaller than that would be the choke point in the system.
Last edited by C7/Z06 Man; 11-02-2016 at 04:05 AM.
11-02-2016, 05:38 AM
#69
Drifting
You are looking at this the right way but at only one variable at one point. The other determinates of flow are length, diameter/radius and viscosity of product being moved through the system. These have to be looked at over the entire length of the system being analyzed. We also have changes in flow direction, right angles that have to be addressed. The last variable is the flow characteristics within the intake itself, laminar v. turbulent flow of the air. Laminar air moves faster than turbulent air, so what does the inside surface of the intake look like. Polished surfaces impart less drag on the flow of air/fluids. It is hard to look at only one point and make "guesses" as to what is happening in the whole system.
11-02-2016, 08:28 AM
#70
Le Mans Master
The problem is not the air inlet piping, the problem is the tiny factory air filter with the flame arrestor on it...that and the small entry into the air box itself.
I agree that an aftermarket CAI should definitely NOT be smaller then stock at any point.
I agree that an aftermarket CAI should definitely NOT be smaller then stock at any point.
11-02-2016, 11:54 AM
#71
Former Vendor
On the filter adapter when considering what is cut off from the screen perimeter you have around 7.25" x around 3.25", so around 23.5 sq inches of surface area. Then we need to subtract for the grate itself. Maybe it's an 8% density? We can just call it 10% to be conservative. So that 23.5 sq in becomes around 21 sq in. Still much larger than the 12.5 sq in of the MAF entry. The grate does also add some turbulence but I suspect its there mainly to "straighten" the air coming in across the MAF for a more accurate reading.
There is a minor caveat though. I noticed both the factory and K&N replacement filters both protrude a good 3/4" in to the flow stream due to how they seal within the factory box.
Last edited by Terry@BMS; 11-02-2016 at 12:22 PM.
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ajrothm (11-02-2016)
11-02-2016, 12:08 PM
#72
Former Vendor
Photos of the filters lined up. Stock, K&N drop in, AFE for their air intake. The AFE filter itself looks awesomely huge compared to the factory filter. Note how the factory filter shrinks down to maybe 6.75" x 2.5", only ~16.8 sq inches.
For the dyno comparison I want to rig up a way to attach the AFE huge filter to the factory MAF housing for another comparison point.
For the dyno comparison I want to rig up a way to attach the AFE huge filter to the factory MAF housing for another comparison point.
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ajrothm (11-02-2016)
11-02-2016, 12:34 PM
#73
Team Owner
While the GM filter looks more "compact" than the huge AFE filter, compare the number of pleats. It appears that the GM filter has more of them compared to the K&N filter and possibly the AFE filter.
Since you have all three filters on your workbench, could you measure the size of the pleats in each filter and the number of pleats and calculate the amount of surface area of the filtering media of each filter?
Since you have all three filters on your workbench, could you measure the size of the pleats in each filter and the number of pleats and calculate the amount of surface area of the filtering media of each filter?
11-02-2016, 12:42 PM
#74
Former Vendor
I can, when I get back from SEMA. Typically paper filters have more pleats but the material itself is more restrictive. While I can just cut out the filter element to measure it what is more difficult is determining how well it flows. So what really needs to be done is flow bench testing of each setup IMHO.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
Last edited by Terry@BMS; 11-02-2016 at 12:43 PM.
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tail_lights (11-02-2016)
11-02-2016, 01:46 PM
#75
Thanx Terry, for the fascinating testing you are doing.
11-02-2016, 02:36 PM
#76
Le Mans Master
I can, when I get back from SEMA. Typically paper filters have more pleats but the material itself is more restrictive. While I can just cut out the filter element to measure it what is more difficult is determining how well it flows. So what really needs to be done is flow bench testing of each setup IMHO.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
Thanks for your research, testing and pics... This is very intesting stuff... I'd definitely like to see your various tests on the bench and the dyno. Lets see where the real problem is.
A Halltech intake would be great for testing as I'd say over half of the CAI intake users here are using the Halltech.
From my limited research, it definitely seems to make the most power by a measurable amount.
**Also, I'm thinking the restriction is not from the actual surface area of the filter, it is more so of the exit hole of the filter into the inlet pipe. That hole in the stock filter/K&N filter is just too small to get air through it. I think thats where the AFE and Halltech filters shine.
Last edited by ajrothm; 11-02-2016 at 02:49 PM.
11-02-2016, 02:51 PM
#77
Melting Slicks
Thanks for the photo. I personally really don't like the look of the black wheels and I've been looking for photos of Torch Red cars with the base wheels before I place my order. In reality, I really like the plain silver cup wheels the Grand Sports are shipping with. If I could order a Z06 with those, I'd be all over it.
Either way, I figured I could pick up a set of Grand Sport take offs for my second set of wheels (I autocross, so I like to have an extra set of wheels for autocross weekends). But...that being said, if you upgrade to black and you want to sell those, keep me in mind.
Anyway, thanks for the photo.
Either way, I figured I could pick up a set of Grand Sport take offs for my second set of wheels (I autocross, so I like to have an extra set of wheels for autocross weekends). But...that being said, if you upgrade to black and you want to sell those, keep me in mind.
Anyway, thanks for the photo.
11-02-2016, 03:01 PM
#78
Team Owner
I can, when I get back from SEMA. Typically paper filters have more pleats but the material itself is more restrictive. While I can just cut out the filter element to measure it what is more difficult is determining how well it flows. So what really needs to be done is flow bench testing of each setup IMHO.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
e.g.
1) Stock intake
2) Stock intake w/ K&N drop in
3) AFE intake w/ dry AFE filter
4) AFE intake w/ oiled AFE filter
5) Stock intake w/ filter deleted (data point)
6) Stock intake w/ larger AFE filter retrofit on top
I should probably buy/borrow a Haltech intake too for comparison since that seems to be the most popular one on the forum.
Back in the C6 days when GM used the Donaldson PowerCore paper filter(with synthetic media to filter the best in the industry) some people on the CF didn't have as clue as to how the filter functioned and were always saying the after market cotton gauze filters were better because they "appeared" to be larger. They were only looking at the front face of the filter, not realizing that the Donaldson used tubes instead of pleats and that the Donaldson filter had tubes that were 5 inches long that could not be viewed when looking at the face of the filter. If you were to lengthen the tubes by 1 inch you increased the surface area of the filter by 20%, even though the size of the "face" of the filter remained the same.
But, the Donaldson flowed 921 CFM of air for the LS3 and the LS7. Donaldson made some changes in the filter used in the LS9(ZR1) that increased air flow(but not by letting golf ***** pass through). When a ZR1 Donaldson filter was installed on a LS7(no other changes) and then dyno'd, the horsepower only increased by 2HP, an indication that the LS7 was not being starved for air with it's factory installed filter.
I know that Halltech has posted on their website that the stock GM filter on the LT1/4 ONLY flows 224 CFM, but that is a bunch of bull. They also claim that their filter flows 689 CFM.
Not for a minute, do I believe that the GM engineers have forgotten how to calculate the amount of air that an engine requires and then put a filter on the C7 that supposedly flows 697 CFM less than the filter they installed on the C6 at Bowling Green. Even the stock GM air filter(not a Donaldson but a pleated paper filter) installed on the C5 350 HP LS1 flowed ~670 CFM.
Also Halltech claims that the AFE filter only flows 318 CFM.
The Callaway Honker filter used on the C6 Z06 flowed 1317 CFM(according to them)
Last edited by JoesC5; 11-02-2016 at 03:30 PM.
11-02-2016, 03:16 PM
#79
Le Mans Master
I know that Halltech has posted on their website that the stock GM filter on the LT1/4 ONLY flows 224 CFM, but that is a bunch of bull. They also claim that their filter flows 689 CFM.
Not for a minute, do I believe that the GM engineers have forgotten how to calculate the amount of air that an engine requires and then put a filter on the C7 that supposedly flows 697 CFM less than the filter they installed on the C6 at Bowling Green.
Also Halltech claims that the AFE filter only flows 318 CFM.
The Callaway filter used on the C6 Z06 flowed 1000CFM(according to them)
Not for a minute, do I believe that the GM engineers have forgotten how to calculate the amount of air that an engine requires and then put a filter on the C7 that supposedly flows 697 CFM less than the filter they installed on the C6 at Bowling Green.
Also Halltech claims that the AFE filter only flows 318 CFM.
The Callaway filter used on the C6 Z06 flowed 1000CFM(according to them)
Yeah I'm not buying that BS either.. 224 cfm would barely support 300 crank HP.
Also I don't particularly believe that gauze type filters flow any more then a properly sized paper filter, even if the paper filter has more pleats... Contrary to popular believe, most oil soaked/gauze filters do not out flow stock filters.
I've tested this many times, year after year on motorcycle dynos and I have yet to see "K&N style" drop in filter make more power then a stock paper air filter...This was true in Suzuki, Kawasaki and most recently the BMW S1000RR I tested. The only improvement I have ever seen from a filter was one that increased surface area and entry volume into the airbox, by way of a different shape design or a "race" type media...(very coarse media you wouldnt want for daily use).
I've tested a bunch of cone style filters on my 450 rwhp turbo hayabusa and you would be surprised what made the most power..
Last edited by ajrothm; 11-02-2016 at 03:17 PM.
11-02-2016, 03:51 PM
#80
Team Owner
Yeah I'm not buying that BS either.. 224 cfm would barely support 300 crank HP.
Also I don't particularly believe that gauze type filters flow any more then a properly sized paper filter, even if the paper filter has more pleats... Contrary to popular believe, most oil soaked/gauze filters do not out flow stock filters.
I've tested this many times, year after year on motorcycle dynos and I have yet to see "K&N style" drop in filter make more power then a stock paper air filter...This was true in Suzuki, Kawasaki and most recently the BMW S1000RR I tested. The only improvement I have ever seen from a filter was one that increased surface area and entry volume into the airbox, by way of a different shape design or a "race" type media...(very coarse media you wouldnt want for daily use).
I've tested a bunch of cone style filters on my 450 rwhp turbo hayabusa and you would be surprised what made the most power..
Also I don't particularly believe that gauze type filters flow any more then a properly sized paper filter, even if the paper filter has more pleats... Contrary to popular believe, most oil soaked/gauze filters do not out flow stock filters.
I've tested this many times, year after year on motorcycle dynos and I have yet to see "K&N style" drop in filter make more power then a stock paper air filter...This was true in Suzuki, Kawasaki and most recently the BMW S1000RR I tested. The only improvement I have ever seen from a filter was one that increased surface area and entry volume into the airbox, by way of a different shape design or a "race" type media...(very coarse media you wouldnt want for daily use).
I've tested a bunch of cone style filters on my 450 rwhp turbo hayabusa and you would be surprised what made the most power..
Back in the "good ole days" GM's air breather for the high performance engines(with a 780 CFM Holley carburetor), used a 3" tall X 14" diameter paper filter.
Wasn't running a Corvette back then, but a 427 powered 1964 Chevelle Malibu SS, so I had plenty of room under the hood. Hot rodders(including me) would double stack two of the filters so we ended up with a filter element that was 6" X 14" diameter, to make sure we had plenty of air.
PS-just because I doubled the size of the filter; I didn't double my horsepower. LOL
Last edited by JoesC5; 11-02-2016 at 03:52 PM.