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[Z06] Against the grain

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Old 04-13-2018, 07:03 PM
  #61  
Pb82 Ronin
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I wonder (just thinking out loud here) if the "dip" is caused by timing being pulled by the ECU because of the frequencies of the exhaust pulses mimicking knock at that RPM with certain header design or primary length. Only way to really tell is data-logging. It's such an interesting phenomenon though...hopefully the community (myself included) will study it further.
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Old 04-14-2018, 02:27 PM
  #62  
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I’ve only seen one dyno graph that did not have that dip in that range. He is running the dreaded Pfadt tri y headers.

So, I retuned on the vararam yesterday. Weather was worse. 3200DA and 80% humidity. Peak numbers dropped again to 604whp and 518wtq but the powerband is smoother overall. We revved the car out to 7400 and the band started to fall off around 7200.

Hoping to head to the track on Friday if the weather holds up.

My last dyno(with the Mamo MSD) was done in January cold weather. Just for a reference.
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Old 04-15-2018, 11:13 AM
  #63  
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Originally Posted by jayyyw View Post
Peak numbers dropped again to 604whp and 518wtq but the powerband is smoother overall. We revved the car out to 7400 and the band started to fall off around 7200.
Can you share your cam specs? The answer is there.
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Old 04-15-2018, 11:14 AM
  #64  
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248/260 .656/.656 111+3lsa
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Old 04-15-2018, 12:09 PM
  #65  
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What's the consensus on the 285cc PRC head for naturally aspirated stuff? I've never really been a fan of them but I may have an opportunity for a swap. I'd have them angle milled for 13.5 compression, roughly.
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Old 04-16-2018, 11:54 AM
  #66  
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Originally Posted by jayyyw View Post
248/260 .656/.656 111+3lsa
Your intake events are similar to mine.

IO is only .5* difference but I close the intake 1.5* later.

My runner lenght is a bit longer than the Hi-Ram, so for my application and what I want the car to do, my IVC is about right.

With the Hi-Ram ~6.3" runners I would have chossen a cam with an IVC of around 55-56*, while keeping the same IVO and a CR of about 12.5 effectively moving your band peak about ~200RPMs.

Edit.

IVC selection is critical and very much influenced by runner length.

FYSA. My overlap is 27* vs your 32*

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Old 04-16-2018, 11:59 AM
  #67  
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Originally Posted by Pb82 Ronin View Post
I wonder (just thinking out loud here) if the "dip" is caused by timing being pulled by the ECU because of the frequencies of the exhaust pulses mimicking knock at that RPM with certain header design or primary length. Only way to really tell is data-logging. It's such an interesting phenomenon though...hopefully the community (myself included) will study it further.
When compared to my old 1 7/8 Hinson headers, I do have the same dip with the AHR 2"
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Old 04-16-2018, 12:46 PM
  #68  
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Originally Posted by Da Z06 View Post
Your intake events are similar to mine.

IO is only .5* difference but I close the intake 1.5* later.

My runner lenght is a bit longer than the Hi-Ram, so for my application and what I want the car to do, my IVC is about right.

With the Hi-Ram ~6.3" runners I would have chossen a cam with an IVC of around 55-56*, while keeping the same IVO and a CR of about 12.5 effectively moving your band peak about ~200RPMs.

Edit.

IVC selection is critical and very much influenced by runner length.

FYSA. My overlap is 27* vs your 32*
I don't know the science behind the madness. I basically closed my eyes and chose my camshaft. There was really no information on it when I opted for it so I decided to give it a try. It's a TSP off the shelf grind. It's definitely not ideal for this situation.

I did have Pat G spec me out a cam for my previous setup and decided against running it. Don't remember what the specs were. It just seemed only slightly larger than the BTR 3 I was running and didn't think it was worth the effort to swap, at the time.
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Old 04-16-2018, 12:56 PM
  #69  
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Originally Posted by jayyyw View Post
248/260 .656/.656 111+3lsa
LS7R from TSP?
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Old 04-16-2018, 02:53 PM
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Originally Posted by Pb82 Ronin View Post
LS7R from TSP?
Yes, the new cam.
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Old 04-16-2018, 03:40 PM
  #71  
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Why not forced induction? rear mount turbo works great on V8 engines. There is a 2k rwhp vette with twin rear mounted oil-less cartridges on here somewhere.

Many folks are making 800-1000rwhp with a stock 6.0L truck engine and single turbo. It kills me when those $1200 engines make 1k hp and the vette guys are throwing 5k-10k into N/A parts just to touch 600.
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Old 04-16-2018, 04:01 PM
  #72  
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Different strokes for different folks.

At this point, I'd have to change many things around. Not to mention, still being on the stock bottom end isn't the best option.

I love the raw power on N/A. The powerband is hard to beat. You need almost 100whp more in a boosted application just to edge out a well done N/A Z06. Plus, the ability to trap 145+mph plus without a power adder is amazing.

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Old 04-16-2018, 05:43 PM
  #73  
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Originally Posted by jayyyw View Post
What's the consensus on the 285cc PRC head for naturally aspirated stuff? I've never really been a fan of them but I may have an opportunity for a swap. I'd have them angle milled for 13.5 compression, roughly.
We are about to find out, I ended up deciding to Mill mine .030. I was going to do boost but I love NA. My cam is also close to yours, 248/262 and lift is 65x for both, not sure of exact number and I forgot LSA lol. I have it somewhere lol. They flow 416-417 CFM at .700 lift so maybe 400-405 at .650 lift. My compression will be 11.8 to 1 or 12 to 1, 13.5 would be dope.

Originally Posted by jayyyw View Post
Different strokes for different folks.

At this point, I'd have to change many things around. Not to mention, still being on the stock bottom end isn't the best option.

I love the raw power on N/A. The powerband is hard to beat. You need almost 100whp more in a boosted application just to edge out a well done N/A Z06. Plus, the ability to trap 145+mph plus without a power adder is amazing.
More than 100 rwhp on some platforms, it is crazy how these cars move out. Shoot if I trap 145 when my Z is done I would be happy as all get out haha.
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Old 04-16-2018, 06:03 PM
  #74  
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Originally Posted by Innovate View Post

We are about to find out, I ended up deciding to Mill mine .030. I was going to do boost but I love NA. My cam is also close to yours, 248/262 and lift is 65x for both, not sure of exact number and I forgot LSA lol. I have it somewhere lol. They flow 416-417 CFM at .700 lift so maybe 400-405 at .650 lift. My compression will be 11.8 to 1 or 12 to 1, 13.5 would be dope.


More than 100 rwhp on some platforms, it is crazy how these cars move out. Shoot if I trap 145 when my Z is done I would be happy as all get out haha.
I was speaking mainly about vette to vette, na to boost. Weight plays a huge role as well for the other platforms.

145 is more of a ***** out super max effort setup. Most likely need a 3.90 or 4.11 gear.

I look forward to your results after your build. Who spec'd your cam?
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Old 04-16-2018, 06:07 PM
  #75  
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Originally Posted by jayyyw View Post
Different strokes for different folks.

At this point, I'd have to change many things around. Not to mention, still being on the stock bottom end isn't the best option.

I love the raw power on N/A. The powerband is hard to beat. You need almost 100whp more in a boosted application just to edge out a well done N/A Z06. Plus, the ability to trap 145+mph plus without a power adder is amazing.
I agree everyone ask me the same question and I tell them the same thing. My tuner makes 350 rwhp more than me he's stick I'm auto with a 4k stall and he always tells me hown instant the torque is in my car compared to his.
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Old 04-16-2018, 07:00 PM
  #76  
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Originally Posted by Pelan View Post
I agree everyone ask me the same question and I tell them the same thing. My tuner makes 350 rwhp more than me he's stick I'm auto with a 4k stall and he always tells me hown instant the torque is in my car compared to his.
Just can't beat it! I eventually want to go turbo but I want to have as much fun as I can N/A. Much more satisfying beating people and having them think you're boosted or spraying.
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Old 04-16-2018, 08:38 PM
  #77  
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Originally Posted by jayyyw View Post
I was speaking mainly about vette to vette, na to boost. Weight plays a huge role as well for the other platforms.

145 is more of a ***** out super max effort setup. Most likely need a 3.90 or 4.11 gear.

I look forward to your results after your build. Who spec'd your cam?
Ah I got you, a boosted Z usually needs more then another 100 rwhp to outrun an NA Z? Ah I got you, 145 did seem a tad stout lol.

Tick Performance in NC, it is their new Polluter cam for the LS7, I think I am the second person with one. They think it would match what I want well without going really high lift. I was thinking higher lift to use these heads more but did not want the increased valvetrain wear.
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Old 04-16-2018, 09:37 PM
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I'm running a 249/262 .675/.652 with 12.4:1 and the car is a blast to drive. I should be at the track within 4-5 weeks.

Speaking of which, I'm ready to see jayyyw trap in the 140s.
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Old 04-16-2018, 11:20 PM
  #79  
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power actually described distance. So 400 horsepower always moves the same amount of weight the same distance. There is absolutely no way to have the same amount of horsepower and move on object farther than the other.

I believe what you mean to say is that, poorly contrived combinations tend not to hold the engine in their respective powerbands as well as properly contrived combination would. But this holds equally true for poor N/A setups as it does FI
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Old 04-16-2018, 11:49 PM
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Originally Posted by Turbo2L View Post
I'm running a 249/262 .675/.652 with 12.4:1 and the car is a blast to drive. I should be at the track within 4-5 weeks.

Speaking of which, I'm ready to see jayyyw trap in the 140s.
How does your car like the extra lift with .675? I thought about a higher lift cam but valvetrain wear deterred me. I guess that extra lift is good for a few horsepower?
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