Headers & low end torque
#1
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Headers & low end torque
I'm farthest from an expert on making power & whatnot, but I was talking to a guy that races regularly & has several world records. He advised me to NOT install headers because of all the low end torque loss (EDIT: for a daily driver).
I tend to believe him because just doing the xpipe/muffler delete, I can tell there's torque loss there.
My point?
Well, is there a configuration that keeps the low end torque? Heads/cam/intake eventually and headers now or just all at the same time? I got a lead on some headers, but I'm wondering if I do get them, how long do I sit on them & worry about it later or what?
I'm rambling. I'm tired. Just looking at options.
I tend to believe him because just doing the xpipe/muffler delete, I can tell there's torque loss there.
My point?
Well, is there a configuration that keeps the low end torque? Heads/cam/intake eventually and headers now or just all at the same time? I got a lead on some headers, but I'm wondering if I do get them, how long do I sit on them & worry about it later or what?
I'm rambling. I'm tired. Just looking at options.
Last edited by LAYGO; 04-20-2012 at 12:31 PM. Reason: Adding clarity about the torque loss (told you I was tired)
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what does this guy own world records in? bullshit spewing?
The only thing I can figure would make sense out of what he's saying is, CTS-V dyno's like, 340/330 stock (not sure on that number), and you add headers, and get 356/338, there's 10 more hp than tq stock, but with headers, there's 18.
It doesn't make sense, but it makes more than what that guys saying. Who the **** makes power with stock exhaust manifolds?
The only thing I can figure would make sense out of what he's saying is, CTS-V dyno's like, 340/330 stock (not sure on that number), and you add headers, and get 356/338, there's 10 more hp than tq stock, but with headers, there's 18.
It doesn't make sense, but it makes more than what that guys saying. Who the **** makes power with stock exhaust manifolds?
#6
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You guys are only looking at the peak numbers. Torque off-idle and up to 2,5-3k is what this guy is referring to. Headers change the power curve and shift the power a little higher in the upper RPM's but sometimes a little lower in the lower RPM's. For normal driving, it may decrease the power in the light throttle positions, but when you get on it you'll feel the benefits of headers.
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If its really a concern get the smaller sized headers 1 3/4 instead of the 1 7/8. There seems to be multiple offerings in each size both cheap and expensive. I went with the larger 1 7/8 set with cats as its a daily driver after reading as much as I could find on the topic for a ls2. I am pleased with the results on an other wise stock ls2 375/375.
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#8
It all comes down to getting headers that are spec'd to your application, 2inch headers vs the standard 1 3/4 or 1 7/8 would mess with scavengin causing power loss on these cars.
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Yea, but I get what he was saying is that the torque at normal driving speeds is where you feel it in the lower RPM. I'm 90% sure I'll never go to a drag strip, it's just not my thing. I like going fast, but making all the power at 5k doesn't make sense to me. I'm NEVER at 5k or I should say RARELY at 5k. It's a DD. I can feel the torque loss from just the xpipe/muffer delete. If adding headers is going to drop it more, then I'm not sure I'm interested. I'd like power all across the range, even if it means being just a lil less efficient at higher RPM.
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http://www.teamplayergaming.com/cont...-minicast.html
Minicast #2: Meet SuperCarl
The interesting thing about SuperCarl is that he was in an accident & nearly lost his right hand/arm & talks about it in the podcast. It's mostly about gaming, but he does talk about drag racing. Everyone that knows him, knows he's legit. He personally told me about the records (of which I've forgotten) and he doesn't seem like a bullshitter. Just listen to him on the podcast.
Minicast #2: Meet SuperCarl
The interesting thing about SuperCarl is that he was in an accident & nearly lost his right hand/arm & talks about it in the podcast. It's mostly about gaming, but he does talk about drag racing. Everyone that knows him, knows he's legit. He personally told me about the records (of which I've forgotten) and he doesn't seem like a bullshitter. Just listen to him on the podcast.
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Header selection
Let me preface this with no I dont have dyno numbers..... yet
When increasing the flow of an exhaust system, the power range is effectively shifted, usually higher in the RPM range, Torque and HP. In my experience messing with any different vehicles, headers will provide more hp up top, regardless. Tq can suffer if the headers are too big and feed to an uinrestrictive cat back system ( x pipe, resonator delete, muffler delete, aftermarket mufflers etc.
That siad, with out a blower or pushing serious cubes, say 400+, the 1 3/4 would be a better selection for a balance of hp gains and minimizing tq loss. Even with a blower, tq should be higher, and hp might suffer just a bit, but without chasing 1/10th at a drag strip, it will give a better seat of the pants feel.
I for instance am running Kooks 1 3/4 headers, hi flo cats and stock resonator and mufflers. This setup will allow the flow up top to get HP, but also keeps some back pressure to keep the lower RPM range more responsive, albeit not as good as stock manifolds with an otherwise stock motor, and i mean stock, no head work, donkey dick thumper cam, blower, stock ls9, which is not stock for these cars, you get the point.
It does come down to personal preference when modifying cat back systems, I prefer not to since mine is a DD and i dont want it to be loud. Keep in mind that noisy cars attract attention, good and bad.
As far as your particular set up, unless you are really in love with the x pipe/muffler delete, consider re-installing atleast one. The factory resonator from my understanding has a internal x pipe. That with headers might put you closer to a sweet spot for what you want.
Your cam selection will have alot more to do with tq and hp range than the exhaust system, but they have to be matched for best results. Who ever helps you with cam selection should ask what exhaust you have or will have and use that to pick specs for your car.
Just my.02
Again, just my .02
When increasing the flow of an exhaust system, the power range is effectively shifted, usually higher in the RPM range, Torque and HP. In my experience messing with any different vehicles, headers will provide more hp up top, regardless. Tq can suffer if the headers are too big and feed to an uinrestrictive cat back system ( x pipe, resonator delete, muffler delete, aftermarket mufflers etc.
That siad, with out a blower or pushing serious cubes, say 400+, the 1 3/4 would be a better selection for a balance of hp gains and minimizing tq loss. Even with a blower, tq should be higher, and hp might suffer just a bit, but without chasing 1/10th at a drag strip, it will give a better seat of the pants feel.
I for instance am running Kooks 1 3/4 headers, hi flo cats and stock resonator and mufflers. This setup will allow the flow up top to get HP, but also keeps some back pressure to keep the lower RPM range more responsive, albeit not as good as stock manifolds with an otherwise stock motor, and i mean stock, no head work, donkey dick thumper cam, blower, stock ls9, which is not stock for these cars, you get the point.
It does come down to personal preference when modifying cat back systems, I prefer not to since mine is a DD and i dont want it to be loud. Keep in mind that noisy cars attract attention, good and bad.
As far as your particular set up, unless you are really in love with the x pipe/muffler delete, consider re-installing atleast one. The factory resonator from my understanding has a internal x pipe. That with headers might put you closer to a sweet spot for what you want.
Your cam selection will have alot more to do with tq and hp range than the exhaust system, but they have to be matched for best results. Who ever helps you with cam selection should ask what exhaust you have or will have and use that to pick specs for your car.
Just my.02
Again, just my .02
Last edited by slowlaneblues06; 04-20-2012 at 12:38 PM.
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You guys are only looking at the peak numbers. Torque off-idle and up to 2,5-3k is what this guy is referring to. Headers change the power curve and shift the power a little higher in the upper RPM's but sometimes a little lower in the lower RPM's. For normal driving, it may decrease the power in the light throttle positions, but when you get on it you'll feel the benefits of headers.
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Ok, this is from CTSV_510s car (with MP112). Is the fainter line the torque? That's seems pretty flat, but is that because of the Maggie? Someone have a sheet w/o a blower?
#19
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With a tune you won't notice any torque loss down low. At worst you won't gain any but certainly not lose any. You most likely noticed a loss after the x-pipe and muffler delete because it's not tuned for the increased flow. I've tuned the same car before and after headers and the difference down low was amazing after the proper tune. I've seen this on several vehicles.
#20
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With a tune you won't notice any torque loss down low. At worst you won't gain any but certainly not lose any. You most likely noticed a loss after the x-pipe and muffler delete because it's not tuned for the increased flow. I've tuned the same car before and after headers and the difference down low was amazing after the proper tune. I've seen this on several vehicles.