YES or NO?
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From: the third rock from the sun!
YES or NO? Is this cam a good choice for a turbo application?
230/224 .569/.563 111LSA for an A4 with tuning. I'm not real worried about idle qualities if that's the only problem.
I need to know quickly so I can go ahead and get it and hopefully install it in a couple weeks.
Thanks,
Papa Ferret
230/224 .569/.563 111LSA for an A4 with tuning. I'm not real worried about idle qualities if that's the only problem.
I need to know quickly so I can go ahead and get it and hopefully install it in a couple weeks.
Thanks,
Papa Ferret
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From: Raleigh, NC
Re: YES or NO? Yes, except I think you SHOULD worry about the idle qualities with an 111 LSA in an A4. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
That being said, I think you have the right idea with the duration and lift. Sure you don't want a 114 or even a 116 LSA? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
That being said, I think you have the right idea with the duration and lift. Sure you don't want a 114 or even a 116 LSA? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
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From: Raleigh, NC
Re: YES or NO? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JAS:
<strong>No</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Some reasoning or comments on your judgement might be helpful... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
<strong>No</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Some reasoning or comments on your judgement might be helpful... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Staging Lane
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From: ST. Louis MO.
Re: YES or NO? It looks like a good choice exept for the LSA, for a turbo it would be better to go with a larger seperation angle not just for idle but to keep the exhaust from backing up and diluting your air /fuel charge under boost.
I'd go with a 114-118 LSA depending on the boost you want to run.
I'd go with a 114-118 LSA depending on the boost you want to run.
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From: the third rock from the sun!
Re: YES or NO? Well, to those who think 114 LSA, is that from experience or simply a generally known reliable number?
I know 112 for M6s and 114 for A4s is constantly repeated on here but if I'm not mistaken, Rob Raymer has an auto, albeit not a 4L60E, and he has said that he leans towards the 112 LSA.
SO....is a 111 just out of the question without major problems and if so, would a 112 or 113 be enough to overcome those problems with the average tune?
WS6underPRESSURE...Could you elaborate a little more about diluting the A/F mix? I'm guessing you mean that the exhaust gases won't evacuate quick enough. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Is there a simple equation to figure out how much overlap a cam has and how the cylinder charge will react? Is there any amount of vacuum effect on the exhaust from a turbo?
Help me out guys! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
I know 112 for M6s and 114 for A4s is constantly repeated on here but if I'm not mistaken, Rob Raymer has an auto, albeit not a 4L60E, and he has said that he leans towards the 112 LSA.
SO....is a 111 just out of the question without major problems and if so, would a 112 or 113 be enough to overcome those problems with the average tune?
WS6underPRESSURE...Could you elaborate a little more about diluting the A/F mix? I'm guessing you mean that the exhaust gases won't evacuate quick enough. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Is there a simple equation to figure out how much overlap a cam has and how the cylinder charge will react? Is there any amount of vacuum effect on the exhaust from a turbo?
Help me out guys! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
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From: the third rock from the sun!
Re: YES or NO? Oh yeah, for what it's worth I'm looking in the 7lb range. As cheap and reliable as I can go a first. 6.0 ported heads with a matched Holley and forged pistons. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
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From: the third rock from the sun!
Re: YES or NO? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by EvilTwistedTwins:
<strong>I myself like single dur/lift cams for turbo cars</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well I had originally looked at the TR224 with similar lift. I don't think I'd be far off either way but the reverse split 230/224 LOOKS to be the same if not a little better on N/A cars and seemed, by popular thought, to be setup for turbos more.
<strong>I myself like single dur/lift cams for turbo cars</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well I had originally looked at the TR224 with similar lift. I don't think I'd be far off either way but the reverse split 230/224 LOOKS to be the same if not a little better on N/A cars and seemed, by popular thought, to be setup for turbos more.
Staging Lane
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From: ST. Louis MO.
Re: YES or NO? Out of all the power adders the turbo is the only one that when supplying boost will almost always have more exhaust back pressure than boost supplyed to the intake, as much as a factor of 2X or more.
When you have a large duration and large valve overlap cam you run into trouble with exhaust back pressure when on boost, the exhaust trys to flow back into the combustion chamber and with a large overlap back into the intake, to prevent this you need to get the exhaust valve closed sooner and use less overlap, the higher the boost you run the bigger the problem.
The size of the turbine housing has the biggest effect on this back pressure, the smaller the housing the higher the pressure and the faster the turbo will spool up. If you go with a large housing the back pressure is less, the turbo will have a longer spool up time but you can use a cam with more duration and a smaller LSA and it will work well.
When picking a cam you have to look at the turbo system, the boost you plan on running and what rpm you want to see your peak power.
Hope the info. helps <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
When you have a large duration and large valve overlap cam you run into trouble with exhaust back pressure when on boost, the exhaust trys to flow back into the combustion chamber and with a large overlap back into the intake, to prevent this you need to get the exhaust valve closed sooner and use less overlap, the higher the boost you run the bigger the problem.
The size of the turbine housing has the biggest effect on this back pressure, the smaller the housing the higher the pressure and the faster the turbo will spool up. If you go with a large housing the back pressure is less, the turbo will have a longer spool up time but you can use a cam with more duration and a smaller LSA and it will work well.
When picking a cam you have to look at the turbo system, the boost you plan on running and what rpm you want to see your peak power.
Hope the info. helps <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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From: the third rock from the sun!
Re: YES or NO? Aaaargggh! <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> Don't have time to post what I want. Got to go to work. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
I need your guys help to get this all straightened out. Soooo much information out there and everyone adds a different twist to it. <img border="0" alt="[fight]" title="" src="graemlins/gr_punch.gif" /> <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
Oh well, gotta go make some cam/turbo money. <img border="0" alt="[pimp]" title="" src="graemlins/gr_pimp.gif" />
I need your guys help to get this all straightened out. Soooo much information out there and everyone adds a different twist to it. <img border="0" alt="[fight]" title="" src="graemlins/gr_punch.gif" /> <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
Oh well, gotta go make some cam/turbo money. <img border="0" alt="[pimp]" title="" src="graemlins/gr_pimp.gif" />
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From: the third rock from the sun!
Re: YES or NO? Okay guys, I had kinda gotten the impression that a split pattern with larger exh. was best for a SC and that a reverse split was better suited for a turbo. However, they both work on forcing air into the chamber but the source behind that force is different. And, it makes since that they both need to evacuate the exhuast quickly to keep from diluting the A/F mix and to avoid unnecessary work on the blower/turbine to fill the chamber.
SO...I would think that I "should" need a cam with AT LEAST as much exh. duration as int. duration. The cam should at least have fast exh. ramp rates to close the valve as quick as possible to keep the exh. flush out. And, the lobe separation should be wider to also help avoid dilution more than worry about its affect on idle. Am I just missing the boat here or what?
I talked to Paul at TR and he said definitely not on the 230/224. I also talked to my local dyno guy who felt the same way. I trust his judgement even more since he's been into turbos for a while BUT he's not real familiar with LS1s. He even suggested staying with the stock cam but that AIN'T gonna happen.
Z00 and y2khawk...What gains are you expecting from the reverse split over a normal split pattern??
WS6underPRESSURE...In the realm of turbos, what size would the PTE T-63 and the T-76 Qtrim be considered...big, small? At a conservative 7lbs, I think I could dust about anything on the street around here until I could afford some forged parts and then see how 10lbs feels.
Help the dummy out! <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
Andy
<small>[ May 18, 2002, 02:43 PM: Message edited by: WEASEL ]</small>
SO...I would think that I "should" need a cam with AT LEAST as much exh. duration as int. duration. The cam should at least have fast exh. ramp rates to close the valve as quick as possible to keep the exh. flush out. And, the lobe separation should be wider to also help avoid dilution more than worry about its affect on idle. Am I just missing the boat here or what?
I talked to Paul at TR and he said definitely not on the 230/224. I also talked to my local dyno guy who felt the same way. I trust his judgement even more since he's been into turbos for a while BUT he's not real familiar with LS1s. He even suggested staying with the stock cam but that AIN'T gonna happen.
Z00 and y2khawk...What gains are you expecting from the reverse split over a normal split pattern??
WS6underPRESSURE...In the realm of turbos, what size would the PTE T-63 and the T-76 Qtrim be considered...big, small? At a conservative 7lbs, I think I could dust about anything on the street around here until I could afford some forged parts and then see how 10lbs feels.
Help the dummy out! <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
Andy
<small>[ May 18, 2002, 02:43 PM: Message edited by: WEASEL ]</small>
Staging Lane
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From: ST. Louis MO.
Re: YES or NO? I'm not familiar with the T-63, the T-76 is on the large side when it comes to street turbos but is a good match when it comes to the ls1.
When looking at the exhaust back pressure I was talking about turbine housing A/R ratio, for a set size turbo there are usually several A/R ratios turbine housings. When you pick a turbo, you pick the compressor side to match your air flow and pressure needs, and picking the turbine housing will determine how fast and what rpm your boost comes in.
All of your decisions affect what the ideal cam for your set is, most cams will work, but only a few cams will give you the max. HP for the amount of boost you want to run.
Good luck with your setup. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
When looking at the exhaust back pressure I was talking about turbine housing A/R ratio, for a set size turbo there are usually several A/R ratios turbine housings. When you pick a turbo, you pick the compressor side to match your air flow and pressure needs, and picking the turbine housing will determine how fast and what rpm your boost comes in.
All of your decisions affect what the ideal cam for your set is, most cams will work, but only a few cams will give you the max. HP for the amount of boost you want to run.
Good luck with your setup. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />