Need Proof That More Aggressive Lobes Are Better!
05-28-2002, 06:28 PM
#82
Re: Need Proof That More Aggressive Lobes Are Better! Your timing issue is weird. My car is a 2001 and I can get 30 degrees at WOT.. My last autotap was showing 29.5 degrees and that was with the rocker arms hitting the retainers..
05-28-2002, 07:51 PM
#83
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Re: Need Proof That More Aggressive Lobes Are Better! Vince, you're a reasonable guy, I'm going to try to reason it out to ya. You shouldn't need dynos and track times as cold hard proof, if ya just reason it out.
All this car stuff, its usually about area under the curve right? Peak dynos dont matter, its average hp that matters. Peak flow #s dont matter, its mid lift flow that matters. Similar with cam lobes. Faster ramps increase the total time the valves are open, the area under the curve so to speak.
Vince, did ya know that the Thunder Racing 224 is smaller than the T1? Yup, thats right. As you know, Thunder uses a really fast ramp. Its smaller at .006", smaller advertised duration than the T1. But, its ramps are so much faster, that at .050" its bigger. Now duration at the valve seat (.006") is what really has a lot of effect on driveability and powerband. Thats how the "smaller" TR cam has better manners, lower powerband, and similar/more power all while being smaller in total duration at the seat, because it uses a fast ramp rate. Make sense? Fast ramps increase the total time the valves are open, so you can make more power with a smaller cam that drives better.
Want a real world example? Look at all the solid cams. One of the greatest advantages of a solid lifter is it can follow a more radical lobe. Duration at .050" looks huge on those, but Jason's 230 idled better than his T1 and TR224. It also made a lot more power, but the powerband didn't change much. Why's that, well its because the solid ramps are so much faster. An added benefit is that solids can rev higher, but thats a different discussion.
Idle better, same or better power, usable power that is lower in the powerband, whats not to like about fast ramps? Does it make a little more sense now?
J.
All this car stuff, its usually about area under the curve right? Peak dynos dont matter, its average hp that matters. Peak flow #s dont matter, its mid lift flow that matters. Similar with cam lobes. Faster ramps increase the total time the valves are open, the area under the curve so to speak.
Vince, did ya know that the Thunder Racing 224 is smaller than the T1? Yup, thats right. As you know, Thunder uses a really fast ramp. Its smaller at .006", smaller advertised duration than the T1. But, its ramps are so much faster, that at .050" its bigger. Now duration at the valve seat (.006") is what really has a lot of effect on driveability and powerband. Thats how the "smaller" TR cam has better manners, lower powerband, and similar/more power all while being smaller in total duration at the seat, because it uses a fast ramp rate. Make sense? Fast ramps increase the total time the valves are open, so you can make more power with a smaller cam that drives better.
Want a real world example? Look at all the solid cams. One of the greatest advantages of a solid lifter is it can follow a more radical lobe. Duration at .050" looks huge on those, but Jason's 230 idled better than his T1 and TR224. It also made a lot more power, but the powerband didn't change much. Why's that, well its because the solid ramps are so much faster. An added benefit is that solids can rev higher, but thats a different discussion.
Idle better, same or better power, usable power that is lower in the powerband, whats not to like about fast ramps? Does it make a little more sense now?
J.
05-28-2002, 08:08 PM
#84
Re: Need Proof That More Aggressive Lobes Are Better! I understand all of that. I totally agree. I really do not care about peak #'s or track times.. What I can do is read dyno graphs. I want more power under the curve and a car that idles near stock.. I just want proof that these more agressive cams ARE ACTUALLY ACCOMPLISHING THIS.. I think LS1edit has a lot to do with all the new #'s.. Not the cams..
05-28-2002, 08:26 PM
#85
Re: Need Proof That More Aggressive Lobes Are Better! Vince, I'm actually surprised with your timing. All of the '01+ cars I've seen have had no more than 26 degrees @ WOT stock. You got a ringer. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> The 11.63 @ 114 MPH was run the weekend of Super Chevy (May 17-19). I'm just as surprised as you are about the results w/ the fatter stall and steeper gears, but I'm not complaining! Jason 98 TA is going to run the same cam in his C5, and it will hopefully be up and running in the next six weeks. It'll be a stock-cid LS1 w/ forged pistons and heads/cam. He's shooting for 440-450 RWHP.
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05-28-2002, 08:53 PM
#87
Re: Need Proof That More Aggressive Lobes Are Better! oh ok No, I didn't know that. I should've looked closer at the sig. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> He really squeezed some timing out of your setup! I'm actually happy w/ 26.5 degrees because that'll give me "room to play" when racing in the extreme summer heat on pump gas. I would like to get it back on the dyno to see if the added degree of timing really shows up as anything significant. I'll probably take it to the next local dyno day.
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05-29-2002, 10:10 AM
#88
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Re: Need Proof That More Aggressive Lobes Are Better! Trevor, I would think you would see an improvement at 29 degrees of timing. That is the MINIMUM you should be running.
savvy?
savvy?
05-29-2002, 11:50 AM
#89
Re: Need Proof That More Aggressive Lobes Are Better! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Raughammer:
<strong>Trevor, I would think you would see an improvement at 29 degrees of timing. That is the MINIMUM you should be running.
savvy?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I understand that a few more degrees of timing may net some more HP, but I'll play with that once I have LS1 Edit. I don't want to send my PCM back and forth umpteen times trying to get my timing exactly where I want it. I know of a few cars, "Just Me" included, that had optimum timing at 28 degrees. Anything past that showed no gain or a slight loss in power.
<strong>Trevor, I would think you would see an improvement at 29 degrees of timing. That is the MINIMUM you should be running.
savvy?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I understand that a few more degrees of timing may net some more HP, but I'll play with that once I have LS1 Edit. I don't want to send my PCM back and forth umpteen times trying to get my timing exactly where I want it. I know of a few cars, "Just Me" included, that had optimum timing at 28 degrees. Anything past that showed no gain or a slight loss in power.
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05-29-2002, 01:47 PM
#92
Re: Need Proof That More Aggressive Lobes Are Better! even though i am only a lowly hotcam user, i make most power at a full 30 degrees of timing and i get zero KR. this is autotaping with LS1 edit too. i have even thought about going with more timing.
05-30-2002, 01:28 PM
#94
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Re: Need Proof That More Aggressive Lobes Are Better! Guy's, you may not be getting all the duration you paid for. With high spring pressures and fast ramp rates, oil can be forced out of the hydraulic roller lifter, resulting in lost duration and a noisy valvetrain.
I would like to see some dyno numbers with some of these XE-R lobes used with a properly designed rev kit. This would allow lower valvespring pressures to be used.
I would like to see some dyno numbers with some of these XE-R lobes used with a properly designed rev kit. This would allow lower valvespring pressures to be used.
05-30-2002, 01:34 PM
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Re: Need Proof That More Aggressive Lobes Are Better! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
<strong>If aggressive cam lobes are so badass for performance (hype?) then how come the manufacturers didn't just skip the less aggressive lobe patterns and start with the "badass" ones?
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well 1st of all, they try to - the new LS6 cam, for example.
But they generally don't because there's no way the springs and valves would be able to take that beating for 100,000 miles.
I remember last summer tons of guys were having 941 Comp Cam springs break. It was all guys with the real aggressive lobe cams. And I think install problems were some of it (guys not calling comp and getting their specs on how to set up the springs). I just ran the little comp 212/218 cam with all comp valvetrain for a year with 0 problems. I called comp to get their exact reccomendations for install height on the springs and such and followed them to the t.
<strong>If aggressive cam lobes are so badass for performance (hype?) then how come the manufacturers didn't just skip the less aggressive lobe patterns and start with the "badass" ones?
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well 1st of all, they try to - the new LS6 cam, for example.
But they generally don't because there's no way the springs and valves would be able to take that beating for 100,000 miles.
I remember last summer tons of guys were having 941 Comp Cam springs break. It was all guys with the real aggressive lobe cams. And I think install problems were some of it (guys not calling comp and getting their specs on how to set up the springs). I just ran the little comp 212/218 cam with all comp valvetrain for a year with 0 problems. I called comp to get their exact reccomendations for install height on the springs and such and followed them to the t.
05-30-2002, 01:35 PM
#96
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Re: Need Proof That More Aggressive Lobes Are Better! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
Thats because your compression is higher Terry.. You would have issues if you ran more timing.. Back to the topic..
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">It's 11.3:1. Isn't that what we all run?
Thats because your compression is higher Terry.. You would have issues if you ran more timing.. Back to the topic..
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">It's 11.3:1. Isn't that what we all run?
05-31-2002, 05:22 PM
#97
Re: Need Proof That More Aggressive Lobes Are Better! Not everybody is running 11.3:1 Terry.. Some are higher and some are lower.. Just depends on what you want.. I keep getting in theory stuff.. Any real proof that the new more aggressive lobes are better. I think ls1edit is the new horsepower culprit.
