CHOPacabra not choppin
Thread Starter
Registered User
Joined: Apr 2024
Posts: 5
Likes: 1
CHOPacabra not choppin So I recently built my first LS and got it tuned.
In park 80% of the time I can't even tell it's cammed.
I specifically chose this cam because it was a mild cam for a daily with a great sound. I went with a well known mail tuner, and when I asked about this my question was completely ignored.
The idle at operating temp is set to 800 rpm. Could this be the "problem"?
Specs:
Cam - TSP "CHOPacabra" 214/222 .550/.550 108 LSA 106 ICL
5.3 Iron Block bored out to 3.903
2" long tubes
3" exhaust with flow master super 44
cold air intake
Stock stroke with forged internals
Stock 779 heads i believe
Stock intake
I mean, there's hardly any chop, and when there is it's only for a split second then goes away. It's nothing like any video I've watched with the same cam. This may sound trivial to some, but I wanted my daily to sound a certain way. If it's not the RPMs maybe it's the extra displacement?
In park 80% of the time I can't even tell it's cammed.
I specifically chose this cam because it was a mild cam for a daily with a great sound. I went with a well known mail tuner, and when I asked about this my question was completely ignored.
The idle at operating temp is set to 800 rpm. Could this be the "problem"?
Specs:
Cam - TSP "CHOPacabra" 214/222 .550/.550 108 LSA 106 ICL
5.3 Iron Block bored out to 3.903
2" long tubes
3" exhaust with flow master super 44
cold air intake
Stock stroke with forged internals
Stock 779 heads i believe
Stock intake
I mean, there's hardly any chop, and when there is it's only for a split second then goes away. It's nothing like any video I've watched with the same cam. This may sound trivial to some, but I wanted my daily to sound a certain way. If it's not the RPMs maybe it's the extra displacement?
Last edited by Carlo; Apr 5, 2024 at 12:41 AM. Reason: Title
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,615
From: Central Cal.
Set the idle at 650RPM. It will chop more but will not be as responsive.
Buying a cam just for sound is counterproductive and shortsighted.
Does the engine make power the way you like? If so, quit complaining.
Keep in mind, "chop" is an intermittent miss. The less it does that, the better it's running at that RPM.
Normally if I hear a cam that chops, it darn well better make some serious power higher up. If not the engine and its owner are posers.
Buying a cam just for sound is counterproductive and shortsighted.
Does the engine make power the way you like? If so, quit complaining.
Keep in mind, "chop" is an intermittent miss. The less it does that, the better it's running at that RPM.
Normally if I hear a cam that chops, it darn well better make some serious power higher up. If not the engine and its owner are posers.
Thread Starter
Registered User
Joined: Apr 2024
Posts: 5
Likes: 1
Set the idle at 650RPM. It will chop more but will not be as responsive.
Buying a cam just for sound is counterproductive and shortsighted.
Does the engine make power the way you like? If so, quit complaining.
Keep in mind, "chop" is an intermittent miss. The less it does that, the better it's running at that RPM.
Normally if I hear a cam that chops, it darn well better make some serious power higher up. If not the engine and its owner are posers.
Buying a cam just for sound is counterproductive and shortsighted.
Does the engine make power the way you like? If so, quit complaining.
Keep in mind, "chop" is an intermittent miss. The less it does that, the better it's running at that RPM.
Normally if I hear a cam that chops, it darn well better make some serious power higher up. If not the engine and its owner are posers.
That makes sense.
I mean, I have almost zero chop. I don't want anything crazy, but I'd like to hear my cam. It's called the CHOPacabara for a reason.
Sound was definitely part of the reason, but not the only reason. It's a great mild cam for a daily. I also plan to add some type of forced induction when the transmission goes out. That's why I did the forged internals and brass trunions. Everything was planned.
I will try to slowly decrease the idle by 50 until I notice a difference in responsiveness. I definitely don't want to sacrifice performance for sound. I am however very fond of the sound.
Can I just -50 rpm for the whole idle in park map? Would that mess with anything else, or are there any other maps I'd need to change as well?
TECH Enthusiast
Joined: Jul 2018
Posts: 635
Likes: 329
From: Missouri
is that a headers into y-pipe single then single 44 muffler, that will take some chop out. just did a forged lq4 370 (about 11.1) with that cam and headers / speed eng true duals dumped and it chops pretty good. and like said above lower idle more chop.
100% totally in your tune. Yes, the idle is too high, but as you lower the idle, your oil pressure will drop also fwiw. So when it sounds absolutely killer at 550, but you now have 15psi of oil pressure…it’s tempting to keep dropping idle if your looking for chop. You might have to mess with your idle air values also. How does the vehicle run?
Thread Starter
Registered User
Joined: Apr 2024
Posts: 5
Likes: 1
I think I'll attempt to lower idle a little and see if i loose any performance.
Thread Starter
Registered User
Joined: Apr 2024
Posts: 5
Likes: 1
100% totally in your tune. Yes, the idle is too high, but as you lower the idle, your oil pressure will drop also fwiw. So when it sounds absolutely killer at 550, but you now have 15psi of oil pressure…it’s tempting to keep dropping idle if your looking for chop. You might have to mess with your idle air values also. How does the vehicle run?
Trending Topics
TECH Fanatic
Joined: May 2016
Posts: 1,292
Likes: 436
From: St. Louis
Less spark advance at idle sounds meaner as well so don't get to low with the idle just yet. You got to get the fueling and idle airflow in the ballpark first before You can play with the timing and work on your vacuum, the strongest idle is going to be different for every setup but it should be tuned to maximize the vacuum at the given idle rpm so that is what you want or at least you will once you get bored chasing sound. Stock LS1 M6 800rpm idle, the A4 is 550 in drive and 650 park.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Registered User
Joined: Apr 2024
Posts: 5
Likes: 1
Less spark advance at idle sounds meaner as well so don't get to low with the idle just yet. You got to get the fueling and idle airflow in the ballpark first before You can play with the timing and work on your vacuum, the strongest idle is going to be different for every setup but it should be tuned to maximize the vacuum at the given idle rpm so that is what you want or at least you will once you get bored chasing sound. Stock LS1 M6 800rpm idle, the A4 is 550 in drive and 650 park.
I also have hydraulic breaks, that would probably help with the vacuum situation right?
Yah, I have zero experience tuning. I know how to drop the idle 50 for the idle base map based on temp. I'm afraid if I do that something else may become off, and I don't know what to look for.
I'll either have to do a deep drive and learn more about tuning, or pay someone who knows what i want in advance.
TECH Enthusiast
Joined: May 2008
Posts: 642
Likes: 572
From: Carnation, WA
If you have HP Tuners, learn how to use it. All a normal dyno tuner will do for you is make your tune safe for the engine at WOT … which is a good thing after you just dropped a bunch of money on it. Driveability, which will determine your satisfaction day to day, takes waayyy too long for the dyno tuner to iron out. I’ve got almost 400 tunes on my engine since it came off the dyno… it runs 1000% better, but I had to do it myself.
If you have HP Tuners, learn how to use it. All a normal dyno tuner will do for you is make your tune safe for the engine at WOT … which is a good thing after you just dropped a bunch of money on it. Driveability, which will determine your satisfaction day to day, takes waayyy too long for the dyno tuner to iron out. I’ve got almost 400 tunes on my engine since it came off the dyno… it runs 1000% better, but I had to do it myself.
TECH Fanatic
Joined: Jul 2022
Posts: 1,032
Likes: 389
From: Alaska
Stock idle on my samples of 2002, 2003 and 2004 Tahoe 5.3 ( were) set at 525 RPM. You want your cam to sound shitty, turn the idle down a bit. Also, they all sound RATTIER with the cats removed, tending toward a nasty ricer rasp sound. If you really want it to stagger a bit split the exhaust, totally separate the Left and Right banks, and use DIFFERENT mufflers on each side, say a long cherry bomb Glass Pack on left side and a FlowMaster on the right, You'll get some wicked exhaust stagger and still run pretty well.
Whatever you end up with,, make sure your high octane, low octane and closed throttle idle timing tables all have the SAME value(s) in the idle portion of the maps.
I like to run 32 degrees down the lowest RPM column, as a built in stall saver, which will be handy when you have intentionally set your idle too low, and mis-tune the engine to run poorly at idle.
Please, I hope not to have offended, all information is offered with intent to help achieve your goal
Good luck, and have fun.
Whatever you end up with,, make sure your high octane, low octane and closed throttle idle timing tables all have the SAME value(s) in the idle portion of the maps.
I like to run 32 degrees down the lowest RPM column, as a built in stall saver, which will be handy when you have intentionally set your idle too low, and mis-tune the engine to run poorly at idle.
Please, I hope not to have offended, all information is offered with intent to help achieve your goal
Good luck, and have fun.