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The Terminator
Engine/Tuning
Why do headers, ported heads, and cams show such little gains?
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<blockquote data-quote="tt335ci03cobra" data-source="post: 15586418" data-attributes="member: 68944"><p>You are all mostly forgetting that boost is a measure of restriction/pressure to occupy a space.</p><p></p><p>You may not pick up big power numbers, but you dramatically aid efficiency/longevity. Less stress, less strain.</p><p>[ATTACH=full]88406[/ATTACH] </p><p>I made 813whp with 11.75 psi and modular hardware. No coyote parts. </p><p></p><p>Mill is 9.3/1, this is on 91 octane pump gas too haha. Turbos aren't massive either, 62's on a 5.3, and the intake has 9.5" runners. It's very representative of what boosting an efficient engine does. Same with coyote numbers. It's exactly why a modular mill usually needs lots of boost to make 600-800whp compared to coyote stuff. 300-350whp na mills vs 400-450whp mills. </p><p></p><p>The heads and cams aren't going to be cheap, and you lose low end power production because you shift the power band and airflow characteristics. Air flow, velocity, and volume all have their scientific role.</p><p></p><p>My car launches like an na car and hooks damn well. Don't let the skimpy 250-300whp at 2500rpm fool you, it still has plenty of passing power and can leave a light in 2nd or 3rd gear with minimal chatter. This graph is to 7k rpm, I routinely take it to 7500, and it's flat to there/gains slightly. I'd go higher if my transmission could shift up there without feeling like I'm pulling a pole out of concrete.</p><p></p><p>Heads/cams aren't cheap, but there's no denying the science of airflow.</p><p></p><p>You could probably make 450whp with a cammed, ported head car running a stock non ported eaton on 8-9psi spinning to 7000rpm. The blower can't match much more rpm, and it'll be the thing holding it back at that point. Look what happens when 01 cobra guys with head/cam work put eatons on their cars. With stock pulley assembly's, they make 400-430whp on 6psi. It is pulled for "8.5psi" but that's because on a stock c head terminator mill, that pulley combo facilitates that resistance to flow. The sc is flowing xyz cfm. The engines ability to use that will dictate psi. This is also why 9psi from a 1.7l is much less useful for hp than 9psi from a 3.0l blower or 50mm turbo vs 76mm turbo. </p><p></p><p>Superchargers overshadow head flow by forcing it through, but do you really want to have to run 20psi to make 700whp? It's just a time bomb at that point. If you can make the same power with less boost, it's safer.</p><p></p><p>Anyways, I'm sure people will say I've got it wrong bla bla bla, I took the time to explain it. If it's over anyone's head, read up on if and figure it out with your own interpretation.</p></blockquote><p></p>
[QUOTE="tt335ci03cobra, post: 15586418, member: 68944"] You are all mostly forgetting that boost is a measure of restriction/pressure to occupy a space. You may not pick up big power numbers, but you dramatically aid efficiency/longevity. Less stress, less strain. [ATTACH=full]88406[/ATTACH] I made 813whp with 11.75 psi and modular hardware. No coyote parts. Mill is 9.3/1, this is on 91 octane pump gas too haha. Turbos aren't massive either, 62's on a 5.3, and the intake has 9.5" runners. It's very representative of what boosting an efficient engine does. Same with coyote numbers. It's exactly why a modular mill usually needs lots of boost to make 600-800whp compared to coyote stuff. 300-350whp na mills vs 400-450whp mills. The heads and cams aren't going to be cheap, and you lose low end power production because you shift the power band and airflow characteristics. Air flow, velocity, and volume all have their scientific role. My car launches like an na car and hooks damn well. Don't let the skimpy 250-300whp at 2500rpm fool you, it still has plenty of passing power and can leave a light in 2nd or 3rd gear with minimal chatter. This graph is to 7k rpm, I routinely take it to 7500, and it's flat to there/gains slightly. I'd go higher if my transmission could shift up there without feeling like I'm pulling a pole out of concrete. Heads/cams aren't cheap, but there's no denying the science of airflow. You could probably make 450whp with a cammed, ported head car running a stock non ported eaton on 8-9psi spinning to 7000rpm. The blower can't match much more rpm, and it'll be the thing holding it back at that point. Look what happens when 01 cobra guys with head/cam work put eatons on their cars. With stock pulley assembly's, they make 400-430whp on 6psi. It is pulled for "8.5psi" but that's because on a stock c head terminator mill, that pulley combo facilitates that resistance to flow. The sc is flowing xyz cfm. The engines ability to use that will dictate psi. This is also why 9psi from a 1.7l is much less useful for hp than 9psi from a 3.0l blower or 50mm turbo vs 76mm turbo. Superchargers overshadow head flow by forcing it through, but do you really want to have to run 20psi to make 700whp? It's just a time bomb at that point. If you can make the same power with less boost, it's safer. Anyways, I'm sure people will say I've got it wrong bla bla bla, I took the time to explain it. If it's over anyone's head, read up on if and figure it out with your own interpretation. [/QUOTE]
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Why do headers, ported heads, and cams show such little gains?
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