04-07-2021, 06:37 PM | #29 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
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I've built a few cars from the ground-up and owned a shop. Then got an engineering degree and used Ricardo Wave to design manifolds as one of my projects. Older log-style manifolds were really bad, well worth replacing as the entire goal was to lower costs, even at the expense of fuel economy and performance. Now fuel economy is such a big deal it's going to be MUCH harder to improve on a stock manifold unless you make significant changes to the motor, like a different cam or forced induction. IMO, unless you are making those major changes I'd definitely leave it stock. In many ways the emphasis on fuel economy pushed a lot of the massive improvements we've seen in performance vehicles, as many of the things that make power also increase efficiency. I honestly wouldn't be surprised to learn that pre-emission era vehicles used to be purposefully designed to waste fuel, then when emissions standards became a thing those requirements were often at odds with fuel economy and performance because technology wasn't developed to adequately meet emissions, so you had bodges like obstructing intake and exhaust ports in weird ways (TBI injected motors), which massively handicapped the motor. In these cases you could do mods and get significant increases in both economy and performance, and while it may not strictly meet emissions it could be argued that car ran so much better with the mods that it's well worth it.
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04-07-2021, 06:39 PM | #30 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
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An LT1 that doesn't get driven on track and is mostly stock definitely does not need one though.
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04-07-2021, 07:46 PM | #31 | |
Drives: 2011 Camaro SS Join Date: Jul 2019
Location: Parts unknown
Posts: 820
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EPS CUSTOM GRIND CAM....K@N CAI....VMAX PTB.....FRANKENSTEIN STAGE 2 HEADS ...1 7/8 STAINLESS POWER CATTED LONGTUBE HEADERS...CORSA XTREME 3 INCH CATBACK.....CIRCLE D 3800 Pro Series stall...391 gears.....Ported/modded GPI intake .Forgestar drag pack with Mickey Thompson ET street drag radials AGP PERFORMANCE DYNO TUNED. 463 WHP 428 FTLBS TORQUE.
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04-07-2021, 09:15 PM | #32 |
Drives: like an old lady Join Date: Jun 2012
Location: indiana
Posts: 2,394
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fwiw i've raced a few bolt on manifold cars. i'm sure it wasn't *just the headers but they got drug either way.
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2016+ camaro: everyone’s first car
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04-07-2021, 10:38 PM | #33 |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,196
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So I did a test. Keep in mind all I changed was the header dimensions and these header/manifold dimensions are all from my best guess and crude measurements. If anyone has detailed exhaust measurements that would be really helpful. Also keep in mind I am not simulating cats or mufflers or exhaust pipe restriction after the manifolds, I will work on trying to simulate this though.
The modified header dimensions are from what I could measure on my Kooks 1-7/8 headers, they are not equal length but I averaged the primary length to 28 inches so probably 28 inches +/-5 inches. The simulation assumes they are equal length. This is on a stock engine, stock cam, stock heads, stock intake, etc: This is on what I intend my new setup to be but I used the GMPP LT1 Hot Cam 228/236 .577/.577 110-ICL 116.5-LSA, stock LT2 intake, TSP PRC ported stock heads milled with thinner gasket (12.95:1 compression), 95mm ported TB: I am working on simulating the mufflers and cats, but I have to switch the solver in the software to a less accurate solver. I also would like to add I hate headers too, with how expensive they are it just makes it worse that after you put it on you have extremely bad sound quality where you can hear ticking everywhere and exhaust pulses from up under the car along with a hacked up exhaust you can't put back to stock and an horrible smell and your car now sounds like a old 90s beat up work van with an exhaust leak and blown exhaust manifold gaskets. |
04-08-2021, 07:38 AM | #34 |
Drives: 2013 C6Z06 Join Date: Nov 2016
Location: PA
Posts: 1,577
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100%
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Old Ride: 2016 Callaway SC630 Camaro SS
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04-08-2021, 08:10 AM | #35 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,764
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Not surprised with the results. Factory headers with cat delete pipes are a pretty good setup. Most gains I have seen are those moving to cat less headers. There was a member that picked up 19whp on a 650-700whp supercharged car coming from stock headers and cat deletes to cat less headers.
Now If you have to run cats then headers with high flow cats definitely gains over completely stock exhaust. As mentioned by another member, cat less headers or cat delete stock headers passes emissions with Ethanol fuels. I believe most would run Ethanol fuel if it was available. So perhaps instead of giving people shit for wanting to modify exhausts to make more power you should be asking our government why are we continuing to run all of this expensive emission equipment to clean up shit pump fuel? Clean burning fuels have been around for years that would not require catalyst to pass emissions.
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2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
04-08-2021, 09:43 AM | #36 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
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Quote:
The 1st sim looks pretty accurate but the 2nd... 600 hp would put it +50 whp over a ZL1, seems a little optimistic?
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04-08-2021, 10:05 AM | #37 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,196
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04-08-2021, 10:10 AM | #38 | |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,196
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I have been able to get somewhat close to the stock LT1 SAE power rating, the peak power and torque is usually about 500 rpm or so lower than what it should be. Problem is I can't simulate a continuous phasing of the camshaft, but I can run it in its factory calibrated 8-10 degrees retard position at high rpms and get closer to the SAE LT1 rating, but I have to run different simulations. If you were using Ricardo Wave that should be way more accurate than what I am using, that's a high dollar expensive industry only software? |
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04-08-2021, 10:46 AM | #39 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
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I got a grant to use Wave while in school, that was about 12 yrs ago so I can only imagine how good it is now! Even back then you could take a manifold in CAD, run fluid dynamics sim and then feed that info to Wave. Of course you can start out with a generic manifold and specify only the dimensions, then run sims to optimize it before making a CAD model, this is mostly what I did with it as I was more interested in theory than making a production part, although it was used for the school's FSAE car. It was slow going back then, every virtual experiment took the computer overnight to crunch the numbers, I bet my current computer would do it in seconds.
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04-08-2021, 11:09 AM | #40 |
Drives: 2021 LT1 6spd Join Date: Nov 2020
Location: Arlington, VA
Posts: 763
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So can someone help me understand what changing to a ported intake manifold or to the LT2 or MSD IM does? Is it similar to the Ported Throttle Body where it allows more airflow, or are there further differences?
Trying to understand what mods are cost effective and street legal, lol.
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Current: 2021 LT1 Camaro, 6spd, Crush, Corsa NPP, GMPP CAI, Soler Performance Throttle controller
Previous: 1997 V6 Camaro, 5spd, Black |
04-08-2021, 12:20 PM | #41 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,837
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Quote:
You used to be able to build a whole new motor that would likely double the hp of the stock motor a few decades ago, these days people are spending similar money on cam, heads, etc. to get 10-20% more power, and in the process losing warranty and making the car incapable of passing emissions. IMO, you're better off buying a ZL1 if you want more power, and if you have a ZL1 and want more power you got to think about spending 6-figures on your car and what else you could get for that cash, like a 911 Turbo S that can do the 1/4 in low 10s stock, with warranty and reasonable resale value. Your cost of ownership is likely to be less than a modded ZL1 in the end. Modifying modern cars is going down a path of diminishing returns and mostly not worth it, imo.
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04-08-2021, 12:24 PM | #42 | |
Drives: 2021 LT1 6spd Join Date: Nov 2020
Location: Arlington, VA
Posts: 763
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I've definitely noticed most mods appear to be either looks/sound-based with small benefits or wildly expensive. Why I'm keeping it somewhat simple, it is a daily driver after-all, just looking down the road for post-warranty and when I might have a second car. Apologies, not purposefully derailing just trying to customize my car to a reasonable degree.
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Current: 2021 LT1 Camaro, 6spd, Crush, Corsa NPP, GMPP CAI, Soler Performance Throttle controller
Previous: 1997 V6 Camaro, 5spd, Black |
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