Cam Pros, Help me choose a cam
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From: Saskatchewan, Canada - where arguing "DA" is for the slow and weak...
Those plastic intakes dictate a lot of things around the LS world; at some point I really want to take advantage of the traditional hood clearance benefits of classic cars and run a "carb-style" EFI intake.
Camshaft Lobe Center First, for "Bspeck82" :
Your observations are correct, just a "bit" of theory improvement.
The Porsche 911S cams 256/232 @ 102 C/L. (OEM)
The intake port was a small diameter ITB AND a Full Race Open Exhaust.
The use was high RPM racing, NOT a street design. (BAJA 1970's, driver was Corkey)
I have great knowledge learned by my Camless Ford Ranger testing done for AURA on by bench in the 1990's.
We even ran this engine Two Stroke/Four Stroke.
How about a SC LS Two Stroke Camshaft ?
Would you like to try one of these Crower Cams ?
Next, a 256/242 @ 105 CL camshaft for NASCAR Racing (dirt) with the "spec" 390 CFM Carbe.
This was used by my customer Bob Cluck, he drove in the race found too much power to be of use.
Thus his Nickname "cluck-cluck" given by his fellow Irvine PD officers.
Yes, "your" answer = more overlap to allow Pressure Wave Tuning.
This style of tuning, your style, has a VOL of over 120% though the RPM range is VERY narrow.
MY answer is the LSx head am designing for Rick Mackie, two valve, NOT Poppet, free running with rotary actuators, IV area of 2.6"/EV area of 2.1", Camless.
The outside patterns are now at the Edelbrock foundry in San Jacinto.
When this head is fitted, you can test/use ALL of your ideas.
Lance
Your observations are correct, just a "bit" of theory improvement.
The Porsche 911S cams 256/232 @ 102 C/L. (OEM)
The intake port was a small diameter ITB AND a Full Race Open Exhaust.
The use was high RPM racing, NOT a street design. (BAJA 1970's, driver was Corkey)
I have great knowledge learned by my Camless Ford Ranger testing done for AURA on by bench in the 1990's.
We even ran this engine Two Stroke/Four Stroke.
How about a SC LS Two Stroke Camshaft ?
Would you like to try one of these Crower Cams ?
Next, a 256/242 @ 105 CL camshaft for NASCAR Racing (dirt) with the "spec" 390 CFM Carbe.
This was used by my customer Bob Cluck, he drove in the race found too much power to be of use.
Thus his Nickname "cluck-cluck" given by his fellow Irvine PD officers.
Yes, "your" answer = more overlap to allow Pressure Wave Tuning.
This style of tuning, your style, has a VOL of over 120% though the RPM range is VERY narrow.
MY answer is the LSx head am designing for Rick Mackie, two valve, NOT Poppet, free running with rotary actuators, IV area of 2.6"/EV area of 2.1", Camless.
The outside patterns are now at the Edelbrock foundry in San Jacinto.
When this head is fitted, you can test/use ALL of your ideas.
Lance
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Search for TR230 cam on here. It was a very popular cam back around 2002-2005 and it was a 230/224 111 cam. I believe Geoff designed that while at Thunder Racing. 5 degrees of overlap will drive nice enough and lope too.
It will definitely make a ton of midrange torque. I think it's a great cam for 6-speed cars with stock gears that don't race. So if you just want to have power off-idle to 5500 or so, it'll rock.
https://ls1tech.com/forums/generatio...o-results.html
Shows a peak of 6100... so still the harmonics of the plastic intakes dictate where you peak plus it still has an IVC in the low 40s. So it will carry all the way to about 6100 but falls off very fast after that. So it could be run with a 6200-6300 limiter.
I think people got away from it for a variety of reasons... 1 being better intakes to open up the power with the FAST intake and two being the Gen IV stuff really is exhaust limited compared to intake, so you needed more exhaust duration. And of course, the cam lobes themselves. If you could build a fast cam lobe on the intake to draw in a lot of air and could use a longer duration, lazier lobe on the exhaust, you kind of have a reverse split at .200" cam lift anyway... So you don't necessarily lose midrange power but gain a ton up top.
For example, an equivalent LSL lobe @.200 is much larger than an XE lobe @.200... so much so that you could run 6-8 degrees more duration at .050" with the XE and still end up with comparable curtain area @ .200"... so in essence, you end up with a reverse split at high lifts.
It will definitely make a ton of midrange torque. I think it's a great cam for 6-speed cars with stock gears that don't race. So if you just want to have power off-idle to 5500 or so, it'll rock.
https://ls1tech.com/forums/generatio...o-results.html
Shows a peak of 6100... so still the harmonics of the plastic intakes dictate where you peak plus it still has an IVC in the low 40s. So it will carry all the way to about 6100 but falls off very fast after that. So it could be run with a 6200-6300 limiter.
I think people got away from it for a variety of reasons... 1 being better intakes to open up the power with the FAST intake and two being the Gen IV stuff really is exhaust limited compared to intake, so you needed more exhaust duration. And of course, the cam lobes themselves. If you could build a fast cam lobe on the intake to draw in a lot of air and could use a longer duration, lazier lobe on the exhaust, you kind of have a reverse split at .200" cam lift anyway... So you don't necessarily lose midrange power but gain a ton up top.
For example, an equivalent LSL lobe @.200 is much larger than an XE lobe @.200... so much so that you could run 6-8 degrees more duration at .050" with the XE and still end up with comparable curtain area @ .200"... so in essence, you end up with a reverse split at high lifts.
This is a street car that will see the strip maybe twice a year. Its also a DD. (Did i mention its an A4?) I want to know how to make the fattest torque curve as possible, while using a stable, light and quiet valvetrain. For me, its not about making 460 hp and 444tq, dyno numbesrs honestly mean nothing to me. Its a device used to tune. Once i saw 500hp 408 sbc's putting 700hp big blocks that arrive on trailers, back on their trailers, i realized that its not big numbers that win races, but average torque that does. Sure top end is lower, but with proper gearing and stall we can take a big advantage of a smooth and fat torque curve. Right?
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First, for "Bspeck82" :
Your observations are correct, just a "bit" of theory improvement.
The Porsche 911S cams 256/232 @ 102 C/L. (OEM)
The intake port was a small diameter ITB AND a Full Race Open Exhaust.
The use was high RPM racing, NOT a street design. (BAJA 1970's, driver was Corkey)
I have great knowledge learned by my Camless Ford Ranger testing done for AURA on by bench in the 1990's.
We even ran this engine Two Stroke/Four Stroke.
How about a SC LS Two Stroke Camshaft ?
Would you like to try one of these Crower Cams ?
Next, a 256/242 @ 105 CL camshaft for NASCAR Racing (dirt) with the "spec" 390 CFM Carbe.
This was used by my customer Bob Cluck, he drove in the race found too much power to be of use.
Thus his Nickname "cluck-cluck" given by his fellow Irvine PD officers.
Yes, "your" answer = more overlap to allow Pressure Wave Tuning.
This style of tuning, your style, has a VOL of over 120% though the RPM range is VERY narrow.
MY answer is the LSx head am designing for Rick Mackie, two valve, NOT Poppet, free running with rotary actuators, IV area of 2.6"/EV area of 2.1", Camless.
The outside patterns are now at the Edelbrock foundry in San Jacinto.
When this head is fitted, you can test/use ALL of your ideas.
Lance
Your observations are correct, just a "bit" of theory improvement.
The Porsche 911S cams 256/232 @ 102 C/L. (OEM)
The intake port was a small diameter ITB AND a Full Race Open Exhaust.
The use was high RPM racing, NOT a street design. (BAJA 1970's, driver was Corkey)
I have great knowledge learned by my Camless Ford Ranger testing done for AURA on by bench in the 1990's.
We even ran this engine Two Stroke/Four Stroke.
How about a SC LS Two Stroke Camshaft ?
Would you like to try one of these Crower Cams ?
Next, a 256/242 @ 105 CL camshaft for NASCAR Racing (dirt) with the "spec" 390 CFM Carbe.
This was used by my customer Bob Cluck, he drove in the race found too much power to be of use.
Thus his Nickname "cluck-cluck" given by his fellow Irvine PD officers.
Yes, "your" answer = more overlap to allow Pressure Wave Tuning.
This style of tuning, your style, has a VOL of over 120% though the RPM range is VERY narrow.
MY answer is the LSx head am designing for Rick Mackie, two valve, NOT Poppet, free running with rotary actuators, IV area of 2.6"/EV area of 2.1", Camless.
The outside patterns are now at the Edelbrock foundry in San Jacinto.
When this head is fitted, you can test/use ALL of your ideas.
Lance
This is a street car that will see the strip maybe twice a year. Its also a DD. (Did i mention its an A4?) I want to know how to make the fattest torque curve as possible, while using a stable, light and quiet valvetrain. For me, its not about making 460 hp and 444tq, dyno numbesrs honestly mean nothing to me. Its a device used to tune. Once i saw 500hp 408 sbc's putting 700hp big blocks that arrive on trailers, back on their trailers, i realized that its not big numbers that win races, but average torque that does. Sure top end is lower, but with proper gearing and stall we can take a big advantage of a smooth and fat torque curve. Right?
The other factor is RPM. I find that the ability to stretch the gears - especially after gearing the rear - does more for the car than the peak numbers too. That of course goes back to stability and weight of the valvetrain. but if you choose a cam for torque, and someone else chooses a cam for RPM, I'd bet the higher RPM will win, because the actual torque at the wheels will be higher. You'll be in second while he's still in first, and then on up the gear range. And think about this... those 700hp big blocks had FAR more torque than the 500HP 408's. torque didn't win those races.
But most of the time, I see the smoother, flatter torque curves revving better anyway.
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I agree with almost everything you said here. Honestly, I think valvetrain stability is the absolute foremost concern. And removing weight from the valvetrain has tremendous benefit, as does removing rotational weight like moving to a lighter clutch. Where I've seen quite alot of lower HP cars beat higher HP cars was due to rotational weight reduction.
The other factor is RPM. I find that the ability to stretch the gears - especially after gearing the rear - does more for the car than the peak numbers too. That of course goes back to stability and weight of the valvetrain. but if you choose a cam for torque, and someone else chooses a cam for RPM, I'd bet the higher RPM will win, because the actual torque at the wheels will be higher. You'll be in second while he's still in first, and then on up the gear range. And think about this... those 700hp big blocks had FAR more torque than the 500HP 408's. torque didn't win those races.
But most of the time, I see the smoother, flatter torque curves revving better anyway.
The other factor is RPM. I find that the ability to stretch the gears - especially after gearing the rear - does more for the car than the peak numbers too. That of course goes back to stability and weight of the valvetrain. but if you choose a cam for torque, and someone else chooses a cam for RPM, I'd bet the higher RPM will win, because the actual torque at the wheels will be higher. You'll be in second while he's still in first, and then on up the gear range. And think about this... those 700hp big blocks had FAR more torque than the 500HP 408's. torque didn't win those races.
But most of the time, I see the smoother, flatter torque curves revving better anyway.
I don't know of any shelf Comp reverse split cams. If you do custom, go Cam Motion all the way. Comp still uses old lathes to cut custom cams. But for "shelf grinds" they use their digital CNC equipment. So the CNC stuff is dead nuts... and they did change how they were making the cams so they don't turn into ugly decorations in your garage.
But Kip can cut any lobe you want. If you tell him you want to do a reverse grind, he may have some ideas for lobe combinations. I'd probably do an EPS lobe on the intake, and one of his milder exhaust lobes on the exhaust. You could also call Geoff @ EPS and see what he'd do using the Cam Motion cores.
But Kip can cut any lobe you want. If you tell him you want to do a reverse grind, he may have some ideas for lobe combinations. I'd probably do an EPS lobe on the intake, and one of his milder exhaust lobes on the exhaust. You could also call Geoff @ EPS and see what he'd do using the Cam Motion cores.
Took me a minute: here is a good cam also (395/395 to the wheels) in a 6L through an A4... but in a 6L.
https://ls1tech.com/forums/dynamomet...-only-lq9.html
https://ls1tech.com/forums/dynamomet...-only-lq9.html
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I wonder why we dont see many off he shelf reverse grinds. What I do see is 222/226 grinds on a 113ish Lsa. This goves IVC of 42-44 and EVO of 46-48. Seems like with stock like heads these can give great results. Nice midrange, smooth power curve and peaks at 6200. Carries it far enough to retain power to the shift points. Also only has -2 overlap at .050. With the right tuning amd exhaust it could be quite tame. But gives just enough overlap near seat that it has no reversion into the intake but can pull clean air into the cylinder. I guess the lobes dictate the difference in performance of these cams as well.
They had far more torque on the very top end of their powerband. Off the line they were dogs. I know this 408 runs a 3200 stall and 3.73 auburn gears in a 10 bolt corp. It has a torque curve that looks almost linear, like the curve of a well thrown football or a bullet. It doesnt stop pulling.
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Ha pretty much i guess. I think more and more people are focusing on big dyno numbers. I blame marketing. Look up l cam comparisons and you end up with (usually superchevy and hotrod) saying oh this cam makes 500hp! This one only makes 440. Lets adjust fuel and timing and wow 7000 rpm 550 hp! Meanwhile they forget to mention that the stock bottom end cant handle that. It idles like crap and you need to rev it to 5 grand to pass up a prius. (okay exaggeration but you know what i mean) oh and run a 4000 stall. Goodbye 22 mpg hello 12 mpg.
Ha pretty much i guess. I think more and more people are focusing on big dyno numbers. I blame marketing. Look up l cam comparisons and you end up with (usually superchevy and hotrod) saying oh this cam makes 500hp! This one only makes 440. Lets adjust fuel and timing and wow 7000 rpm 550 hp! Meanwhile they forget to mention that the stock bottom end cant handle that. It idles like crap and you need to rev it to 5 grand to pass up a prius. (okay exaggeration but you know what i mean) oh and run a 4000 stall. Goodbye 22 mpg hello 12 mpg.
Way I see it, a certain displacement engine will make a certain torque number and no more without power adders. So, a 346 is really not going to make much more than 430-440 lbs torque unless FI or nitrous. At that point, stretching RPM helps. But if you're making 500/380, you definitely benefit more from improving torque curve than from continuiing to stretch the RPM range
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LOL, I found a happy medium at 16!
Way I see it, a certain displacement engine will make a certain torque number and no more without power adders. So, a 346 is really not going to make much more than 430-440 lbs torque unless FI or nitrous. At that point, stretching RPM helps. But if you're making 500/380, you definitely benefit more from improving torque curve than from continuiing to stretch the RPM range
Way I see it, a certain displacement engine will make a certain torque number and no more without power adders. So, a 346 is really not going to make much more than 430-440 lbs torque unless FI or nitrous. At that point, stretching RPM helps. But if you're making 500/380, you definitely benefit more from improving torque curve than from continuiing to stretch the RPM range
Hm so a single pattern cam or a reverse split would work well in an ls1 with ls6 intake and ported milled 241s or 243s? I remember, when tuning technology...well...sucked, we had the "big" 22X/22X cams running hard through all the gears, making mid 11 second passes all day with boltons. Before everyone had a Fast intake and AFR heads. Im in that position, I cant justify three grand on heads and 1200 on a intake/TB. I want to make power but make it in a smart way. Under the curve is where its at. I want as much torque, not peak mind you but average torque, as possible. I dont really care what happens to horsepower since im there for only 1/6 of the powerband.
This is a street car that will see the strip maybe twice a year. Its also a DD. (Did i mention its an A4?) I want to know how to make the fattest torque curve as possible, while using a stable, light and quiet valvetrain. For me, its not about making 460 hp and 444tq, dyno numbesrs honestly mean nothing to me. Its a device used to tune. Once i saw 500hp 408 sbc's putting 700hp big blocks that arrive on trailers, back on their trailers, i realized that its not big numbers that win races, but average torque that does. Sure top end is lower, but with proper gearing and stall we can take a big advantage of a smooth and fat torque curve. Right?
This is a street car that will see the strip maybe twice a year. Its also a DD. (Did i mention its an A4?) I want to know how to make the fattest torque curve as possible, while using a stable, light and quiet valvetrain. For me, its not about making 460 hp and 444tq, dyno numbesrs honestly mean nothing to me. Its a device used to tune. Once i saw 500hp 408 sbc's putting 700hp big blocks that arrive on trailers, back on their trailers, i realized that its not big numbers that win races, but average torque that does. Sure top end is lower, but with proper gearing and stall we can take a big advantage of a smooth and fat torque curve. Right?