Ported & coated stock exhaust manifolds
#61
Le Mans Master
Thread Starter
Excellent! If you happen to find a set listed online feel free to pass it along.
#62
Le Mans Master
Thread Starter
#63
Le Mans Master
Thread Starter
Back from the coaters:
Now the real fun begins
Now the real fun begins
Last edited by Kracka; 12-03-2014 at 04:24 PM.
#64
Safety Car
#65
Le Mans Master
Thread Starter
#66
Safety Car
Today I spoke to Ian Peterson at MAP and all the details are taken care of and the order is underway. I hope that I will be provided with flow and balance numbers, before & after, and with the dragstrip logs and information I currently have, we can see how the performance will benefit.....now when do the tracks re-open....LOL...I can't wait..
Last edited by Redvette_22; 12-04-2014 at 04:23 PM.
#67
Le Mans Master
Thread Starter
Today I spoke to Ian Peterson at MAP and all the details are taken care of and the order is underway. I hope that I will be provided with flow and balance numbers, before & after, and with the dragstrip logs and information I currently have, we can see how the performance will benefit.....now when do the tracks re-open....LOL...I can't wait..
#68
Safety Car
Kracka, the next time I go to visit my daughter in Princeton, TX maybe we can meet. It would be great if we went to North Star Dragway (if I drive down again with my Vette) and we can compare drag times, and I'll even bring my daughters Hemi Challanger.
#69
Le Mans Master
Thread Starter
Let me know next time you're down, and I'll do the same regarding my travels to NJ (my grandfather lives in Whiting...not too far from ECS much to my surprise). It appears Brick isn't far from him...mmmmmm Jersey Mike's...I actually spent some time on the Shore in May.
#70
Le Mans Master
Thread Starter
After battling a busy work and holiday schedule, I finally got the opportunity to have these manifolds installed, along with a before & after dyno chart. The work was performed by 21st Century Muscle Cars in Addison, TX. To give you an idea to the install difficulty, the complete process only took them 3 hours, which includes both dyno pulls.
+11WHP/+8WTQ
I'm very happy with the results, and they said they were surprised by the gains too. These should remain emissions, warranty, and stock tune friendly by retaining the stock pair of primary cats. If you opt to leave the manifolds uncoated they will look identical to stock from the outside, but even coated you can barely they're modified once hidden underneath the factory heat shields.
Flow bench results (originally posted 11/25/14):
CFM (Y-axis) by runner (X-axis)
Dark line = ported
Light line = stock
Well, there you have it, laboratory and real-world results
Full mod list:
-AFE intake
-WeaponX ported throttle body
-MAP ported & coated exhaust manifolds
-Borla X pipe
-Diablo InTune (custom DiabLew tuned)
+11WHP/+8WTQ
I'm very happy with the results, and they said they were surprised by the gains too. These should remain emissions, warranty, and stock tune friendly by retaining the stock pair of primary cats. If you opt to leave the manifolds uncoated they will look identical to stock from the outside, but even coated you can barely they're modified once hidden underneath the factory heat shields.
Flow bench results (originally posted 11/25/14):
CFM (Y-axis) by runner (X-axis)
Dark line = ported
Light line = stock
Well, there you have it, laboratory and real-world results
Full mod list:
-AFE intake
-WeaponX ported throttle body
-MAP ported & coated exhaust manifolds
-Borla X pipe
-Diablo InTune (custom DiabLew tuned)
Last edited by Kracka; 01-05-2016 at 08:06 AM. Reason: added mod list
#71
Melting Slicks
After battling a busy work and holiday schedule, I finally got the opportunity to have these manifolds installed, along with a before & after dyno chart. The work was performed by 21st Century Muscle Cars in Addison, TX. To give you an idea to the install difficulty, the complete process only took them 3 hours, which includes both dyno pulls.
+11WHP/+8WTQ
I'm very happy with the results, and they said they were surprised by the gains too. These should remain emissions, warranty, and stock tune friendly by retaining the stock pair of primary cats. If you opt to leave the manifolds uncoated they will look identical to stock from the outside, but even coated you can barely they're modified once hidden underneath the factory heat shields.
Flow bench results (originally posted 11/25/14):
CFM (Y-axis) by runner (X-axis)
Dark line = ported
Light line = stock
Well, there you have it, laboratory and real-world results
Full mod list:
-AFE intake
-WeaponX ported throttle body
-MAP ported & coated exhaust manifolds
-Borla X pipe
-Diablo InTune (custom DiabLew tuned)
+11WHP/+8WTQ
I'm very happy with the results, and they said they were surprised by the gains too. These should remain emissions, warranty, and stock tune friendly by retaining the stock pair of primary cats. If you opt to leave the manifolds uncoated they will look identical to stock from the outside, but even coated you can barely they're modified once hidden underneath the factory heat shields.
Flow bench results (originally posted 11/25/14):
CFM (Y-axis) by runner (X-axis)
Dark line = ported
Light line = stock
Well, there you have it, laboratory and real-world results
Full mod list:
-AFE intake
-WeaponX ported throttle body
-MAP ported & coated exhaust manifolds
-Borla X pipe
-Diablo InTune (custom DiabLew tuned)
#73
Le Mans Master
Thread Starter
Feels nice too! Great setup with stock-like drivability.
#74
Le Mans Master
Thread Starter
#75
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Kracka
I applaud you on your work. The time and expertise that was spent on these manifolds and the research on flow and HP/TQ improvements is OUTSTANDING! Well done! Not many people would have undertaken this project. You did it and did it extremely well!
I have a few questions if you don’t mind?
- Internal port and outlet reshaping:
Did you maximize it or just clean it up and straighten the inlets and outlet mouth? If you would have done more grinding and shaping, do you think it would have made a little more difference or would it have reduced reliability?
C7 EXHAUST MANIFOLDS:
I have a 2011 Grand Sport. Are the C7 Manifolds & CATs & midpipe a direct bolt in fit for a C6?
Would the C7 manifolds bolt on the a C6 ZO6 exhaust system?
If not, can the C6 ZO6 cast iron manifolds yield the same results after porting? Do you think stainless steel vs cast iron makes any difference in performance vs reliability after porting.
INTAKE MANIFOLD IMPROVEMENTS:
Have you thought about hand porting and improving the flow in the intake manifold?? Do you think it would make a worthwhile difference?
Do you think that the combination of intake porting & exhaust porting would start to have an effect on OEM tuning?
I know that the C6 intake manifold yields HP/TQ improvements after porting.
Thanks
Bill
I applaud you on your work. The time and expertise that was spent on these manifolds and the research on flow and HP/TQ improvements is OUTSTANDING! Well done! Not many people would have undertaken this project. You did it and did it extremely well!
I have a few questions if you don’t mind?
- Internal port and outlet reshaping:
Did you maximize it or just clean it up and straighten the inlets and outlet mouth? If you would have done more grinding and shaping, do you think it would have made a little more difference or would it have reduced reliability?
C7 EXHAUST MANIFOLDS:
I have a 2011 Grand Sport. Are the C7 Manifolds & CATs & midpipe a direct bolt in fit for a C6?
Would the C7 manifolds bolt on the a C6 ZO6 exhaust system?
If not, can the C6 ZO6 cast iron manifolds yield the same results after porting? Do you think stainless steel vs cast iron makes any difference in performance vs reliability after porting.
INTAKE MANIFOLD IMPROVEMENTS:
Have you thought about hand porting and improving the flow in the intake manifold?? Do you think it would make a worthwhile difference?
Do you think that the combination of intake porting & exhaust porting would start to have an effect on OEM tuning?
I know that the C6 intake manifold yields HP/TQ improvements after porting.
Thanks
Bill
Last edited by Bill Curlee; 01-18-2015 at 02:54 PM.
#76
Race Director
Member Since: Jul 2007
Location: Texas Hill Country
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there are already several companies porting the stock intake with good results.
#77
Le Mans Master
Thread Starter
Kracka
I applaud you on your work. The time and expertise that was spent on these manifolds and the research on flow and HP/TQ improvements is OUTSTANDING! Well done! Not many people would have undertaken this project. You did it and did it extremely well!
I have a few questions if you don’t mind?
- Internal port and outlet reshaping:
Did you maximize it or just clean it up and straighten the inlets and outlet mouth? If you would have done more grinding and shaping, do you think it would have made a little more difference or would it have reduced reliability?
C7 EXHAUST MANIFOLDS:
I have a 2011 Grand Sport. Are the C7 Manifolds & CATs & midpipe a direct bolt in fit for a C6?
Would the C7 manifolds bolt on the a C6 ZO6 exhaust system?
If not, can the C6 ZO6 cast iron manifolds yield the same results after porting? Do you think stainless steel vs cast iron makes any difference in performance vs reliability after porting.
INTAKE MANIFOLD IMPROVEMENTS:
Have you thought about hand porting and improving the flow in the intake manifold?? Do you think it would make a worthwhile difference?
Do you think that the combination of intake porting & exhaust porting would start to have an effect on OEM tuning?
I know that the C6 intake manifold yields HP/TQ improvements after porting.
Thanks
Bill
I applaud you on your work. The time and expertise that was spent on these manifolds and the research on flow and HP/TQ improvements is OUTSTANDING! Well done! Not many people would have undertaken this project. You did it and did it extremely well!
I have a few questions if you don’t mind?
- Internal port and outlet reshaping:
Did you maximize it or just clean it up and straighten the inlets and outlet mouth? If you would have done more grinding and shaping, do you think it would have made a little more difference or would it have reduced reliability?
C7 EXHAUST MANIFOLDS:
I have a 2011 Grand Sport. Are the C7 Manifolds & CATs & midpipe a direct bolt in fit for a C6?
Would the C7 manifolds bolt on the a C6 ZO6 exhaust system?
If not, can the C6 ZO6 cast iron manifolds yield the same results after porting? Do you think stainless steel vs cast iron makes any difference in performance vs reliability after porting.
INTAKE MANIFOLD IMPROVEMENTS:
Have you thought about hand porting and improving the flow in the intake manifold?? Do you think it would make a worthwhile difference?
Do you think that the combination of intake porting & exhaust porting would start to have an effect on OEM tuning?
I know that the C6 intake manifold yields HP/TQ improvements after porting.
Thanks
Bill
1. You do have to keep a certain amount of wall thickness otherwise you will sacrifice reliability and increase your risk of cracking the manifold after extensive heat cycling. These manifolds were ported with a few things in mind, and working towards the ideal balance of reliability, durability, overall flow, and balance between runners (or reduction of imbalance). Yes, they could have been further ported, especially in the collector area, but it would have been at the expense of balance between the runners. Ideally, all runners would be completely identical in flow, but in the real world that is not possible. The improvement in balance, and ultimate flow, was quite impressive though when you look at the flowbench data posted above.
2. C7 exhaust components are not interchangeable with C6 components, but they are just as workable in their own right. This shop has also done C6 exhaust manifolds for another CorvetteForum member and the results should be about the same since the manifolds are similar in design.
3. Both cast iron and stainless steel manifolds are good candidates for porting (and ceramic coating). Stainless steel does have advantages, such as lower weight, higher strength (better durability), and lack or surface rust (all at a higher material cost of course, which is why you see it on the Z06 but not the base models). SS does take more time and effort to port than cast iron, but it can be done regardless.
4. The stock LT1 intake manifold is a bit more of a challenge since it is plastic rather than a cast metal, but I do have one being worked on so we can find those benefits and areas for improvement first hand. I don't have a hard timeline yet, but you can expect similar flowbench and dyno data in the somewhat near future (I'd guess sometime during late Q1 2015).
5. It's tough to say on the stock tune compatibility until I actually get the car on the dyno. In theory, keeping with the stock design, the MAF should be able to compensate for the increase in airflow. I won't commit to anything one way or the other though until I actually see the AFR readings on the dyno, and how the fuel-trims are affected on the street. I am confident no check engine lights or error codes will be created though. It is safe to say, the more modifications you make, the better candidate you are for a customer tune. Luckily there is no shortage of competent tuners available on CorvetteForum, both local dyno tuners and remote email tuners.
#78
Le Mans Master
Thread Starter
My guess is Chevy uses cast stainless steel for the LT4 exhaust manifolds; probably will be a good upgrade for the LT1 once the Z06 guys start ditching them in favor of stainless steel tubular headers. That would be another good test for the future...ported LT1 manifolds vs. ported LT4 manifolds
1. Cost - new LT4 manifolds are ~$400 each vs. $75 each for the LT1's
2. Similarity in design (as shown below).
2014 LT1 (Stingray & Z51) cast iron exhaust manifold:
2015 LT4 (Z06) cast stainless steel exhaust manifold:
Unless I stumble upon a used set for cheap, I probably won't bother. It was worth a thought though!
#79
Heat Shiels
Looks to me like from the photos the stainless steel manifolds have the bolt holes for the C7 heat shields. Is that correct?
Thank you very much for the excellent work and sharing it.
Thank you very much for the excellent work and sharing it.
#80
Le Mans Master
Thread Starter
You're welcome!