Intake manifold runner lenght vs cam duration?
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Joined: Jul 2001
Posts: 727
From: Wolverine Lake, MI
Originally posted by engineermike
Because it makes more power.
Because it makes more power.
That is a very weak argument and is not one that would apply to many of us at all on this board.
The basics still apply Mike. A longer runner intake manifold does not go with a longer duration camshaft when you're developing a matched combination. The minute you throw rules limitations into the mix you're throwing out the "matched combination" portion of the above statement and you're building a combination that is only "optimized" for a certain rule set. With that limitation you simply can not say such a generic statement as a longer duration camshaft works better with a long runner intake manifold because it makes more power. You better qualify that statement very carefully.
For my parting comment, ever heard of "area under the curve"? Show me dyno results, as I asked Mike.
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Joined: Mar 2002
Posts: 2,743
From: Baton Rouge, LA, USA
94bird, I don't want to get into a p!ssing contest here, which happens way too often on bulletin boards.
To say that "large cams will perform poorly with long runners" is false. To say that "large cams with long runners will produce an extremely narrow powerband" is also false. Conversely, to say that "large cams and long runners produce the optimum combination" is also false, but not as bad as most people think.
According to your logic, my own combo is badly mis-matched. A stroker, as everyone knows, makes alot of low-end but isn't great on top. A centrifugal supercharger, as everyone also knows, makes alot of top-end, but not much down low. This must be a TERRIBLE combination, eh? My torque peak is way down at 3800 rpm but hp occurs at 6300 rpm. Narrow powerband? Don't think so.
I think that most board members here are pursuing maximum power. Perhaps you are the exception to that.
Mike
To say that "large cams will perform poorly with long runners" is false. To say that "large cams with long runners will produce an extremely narrow powerband" is also false. Conversely, to say that "large cams and long runners produce the optimum combination" is also false, but not as bad as most people think.
According to your logic, my own combo is badly mis-matched. A stroker, as everyone knows, makes alot of low-end but isn't great on top. A centrifugal supercharger, as everyone also knows, makes alot of top-end, but not much down low. This must be a TERRIBLE combination, eh? My torque peak is way down at 3800 rpm but hp occurs at 6300 rpm. Narrow powerband? Don't think so.
I think that most board members here are pursuing maximum power. Perhaps you are the exception to that.
Mike
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Joined: Jul 2001
Posts: 727
From: Wolverine Lake, MI
Mike, as you can obviously tell I don't agree with much you're saying here. I could dissect your last comments also, but I don't think this discussion is going anywhere. I'm sure you mean well, but I'm afraid you're misleading a lot of people on this board.
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From: In a house by the bay
So what exactly is your point here Mike?
If you're trying to buck a theory that has so much data behind it, then you really need to show your "proofs".
The only specific examples you've brought up are the TPIS vs something more akin to the LT1 intake atop an engine built for 7500 rpm. The long intake is a loser there, sorry. That intake was not designed to tune at those rpms.
Need more specifics for your point. I'm not disagreeing that a 4" runner may not be better than a 6" runner in an application turning 7k or better. We need to find the ideal tuning length and 6" may be it, but the trend is the trend and the data doesn't lie. The real question here is in finding the optimum length....
Too generalized.
You should see the dyno chart for my 383.... makes great top end power but the cylinder head/cam/intake are setup to do just that.
Yes, poorer than using the right runner length, which gets shorter as cam duration increases. More on that in a moment...
Not necessarily so false... Using a longer runner than optimal lowers the rpm at which VE peaks. It will peak somewhere around peak torque, which in turn lowers the rpm at which peak HP will be realized. The air speed through the intake is already very high and it's only a matter of time before they become too high to produce higher rpm HP. Not my theory, just regurgitating Vizard and others... but isn't that what learning is about though. 
Ou examples have revolved around the TPI long runner intake vs something more along the lines of a LT1 intake. Even if you take one of the good TPI's (not factory), at 7000 rpm or so, you are giving up a bunch of HP to produce a lower Torque peak. The whole goal behind a cam that will produce high rpm hp, is to push that rpm range higher. Torque peak goes higher as well, as it should. Using a long runner with this goal in mind just seems counterintuitive to me.
In Vizard's book How to Build Horsepower Vol II, he outlines an empirical formula for approximating runner length. It is based around factors like "effective cam duration", speed of sound at intake charge temps, rpm and the order of the positive pressure wave we are looking to utilize. Formula looks like this...
L = ((720 - ECD) x 0.25V x 2) / (RPM x RV) - 0.5D
L = total runner length
ECD = effective cam duration
V = speed of sound (ft/sec)
RV = order of wave
D = diameter of runner
The trend is obviously clear. For any given order of wave used, longer duration requires a shorter length runner for proper utilization of that wave.
If the long runner were beneficial at high rpm, with larger camshaft durations, we would be seeing more long runner intakes on race cars. Instead, they get used mostly on heavy sedans with mild camshaft duration like the BMW M5. They have their place but I'd bet my house that one of those TPI Stock Eliminator cars would turn better times with a shorter runner and a camshaft of similar duration, utilizing valve events better suited to the intake design.
-Mindgame
If you're trying to buck a theory that has so much data behind it, then you really need to show your "proofs".
The only specific examples you've brought up are the TPIS vs something more akin to the LT1 intake atop an engine built for 7500 rpm. The long intake is a loser there, sorry. That intake was not designed to tune at those rpms.
Need more specifics for your point. I'm not disagreeing that a 4" runner may not be better than a 6" runner in an application turning 7k or better. We need to find the ideal tuning length and 6" may be it, but the trend is the trend and the data doesn't lie. The real question here is in finding the optimum length....
Originally posted by engineermike
According to your logic, my own combo is badly mis-matched. A stroker, as everyone knows, makes alot of low-end but isn't great on top.
According to your logic, my own combo is badly mis-matched. A stroker, as everyone knows, makes alot of low-end but isn't great on top.
You should see the dyno chart for my 383.... makes great top end power but the cylinder head/cam/intake are setup to do just that.
Originally posted by engineermike
To say that "large cams will perform poorly with long runners" is false.
To say that "large cams will perform poorly with long runners" is false.
Originally posted by engineermike
To say that "large cams with long runners will produce an extremely narrow powerband" is also false.
To say that "large cams with long runners will produce an extremely narrow powerband" is also false.
Conversely, to say that "large cams and long runners produce the optimum combination" is also false, but not as bad as most people think.
In Vizard's book How to Build Horsepower Vol II, he outlines an empirical formula for approximating runner length. It is based around factors like "effective cam duration", speed of sound at intake charge temps, rpm and the order of the positive pressure wave we are looking to utilize. Formula looks like this...
L = ((720 - ECD) x 0.25V x 2) / (RPM x RV) - 0.5D
L = total runner length
ECD = effective cam duration
V = speed of sound (ft/sec)
RV = order of wave
D = diameter of runner
The trend is obviously clear. For any given order of wave used, longer duration requires a shorter length runner for proper utilization of that wave.
If the long runner were beneficial at high rpm, with larger camshaft durations, we would be seeing more long runner intakes on race cars. Instead, they get used mostly on heavy sedans with mild camshaft duration like the BMW M5. They have their place but I'd bet my house that one of those TPI Stock Eliminator cars would turn better times with a shorter runner and a camshaft of similar duration, utilizing valve events better suited to the intake design.
-Mindgame
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Joined: Mar 2002
Posts: 2,743
From: Baton Rouge, LA, USA
You guys keep pounding on and reiterating the same points that I don't disagree with.
Long runners make low end power: I AGREE!
Short runners make more top end power: I AGREE!
Very long runners with a large cam is not optimized: I AGREE!
My point is that a long duration cam with very long runners will make more power than a short duration, "matched" cam. Anyone disagree??? This is proven by data in the Stock Eliminator class that I keep refering to, especially in the TPI and Dodge Magnum 360 engines.
And. . . perhaps the long runner, big cam combo isn't so bad.
How about this: Let's build a short stroke, large bore motor using a 3" stroke and 4.155" bore. That gives us 325 cid that should make good top end. Let's "match" some large valve, large port heads to it, to also get great top end. While we're at it, add a Victor Jr. intake and a 27X @ .050" cam. Is this not a "matched" combination? You'd end up with a motor with great hp that does nothing until 5000 rpm. Add a centrifugal blower and the torque peak will come at 7500. Maybe it's not so great after all.
How about the other end of the spectrum. A stock Magnum 360. Long runners, "matched" short duration cam, small ports. Again, a very well "matched" combination, right? Except for the fact that it's a total turd. . .
A certain amount of "mis-match" is beneficial to get a good spread in power. Big cam + stroker, short stroke + roots blower, small cam + centrifugal blower, etc. . . all make good combinations but would be considered mis-matched. Mindgame, your combination is "mis-matched" also, with a stroker crank + big heads/cam. I bet the stroke gives it the low-end it otherwise would have lost from the cam.
Mike
Long runners make low end power: I AGREE!
Short runners make more top end power: I AGREE!
Very long runners with a large cam is not optimized: I AGREE!
My point is that a long duration cam with very long runners will make more power than a short duration, "matched" cam. Anyone disagree??? This is proven by data in the Stock Eliminator class that I keep refering to, especially in the TPI and Dodge Magnum 360 engines.
And. . . perhaps the long runner, big cam combo isn't so bad.
How about this: Let's build a short stroke, large bore motor using a 3" stroke and 4.155" bore. That gives us 325 cid that should make good top end. Let's "match" some large valve, large port heads to it, to also get great top end. While we're at it, add a Victor Jr. intake and a 27X @ .050" cam. Is this not a "matched" combination? You'd end up with a motor with great hp that does nothing until 5000 rpm. Add a centrifugal blower and the torque peak will come at 7500. Maybe it's not so great after all.
How about the other end of the spectrum. A stock Magnum 360. Long runners, "matched" short duration cam, small ports. Again, a very well "matched" combination, right? Except for the fact that it's a total turd. . .
A certain amount of "mis-match" is beneficial to get a good spread in power. Big cam + stroker, short stroke + roots blower, small cam + centrifugal blower, etc. . . all make good combinations but would be considered mis-matched. Mindgame, your combination is "mis-matched" also, with a stroker crank + big heads/cam. I bet the stroke gives it the low-end it otherwise would have lost from the cam.
Mike
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Joined: Jul 2001
Posts: 727
From: Wolverine Lake, MI
OK Mike, let me first point out that your assumption that stroking an engine is only done to increase the low end torque is false. I held my tongue when you originally mentioned it, but you just keep on saying it.
It's true that for the same cubic inches a larger bore engine can use a larger valve since the larger bore will shroud the valves less. It's also true that a shorter stroke engine will have less piston speed at a given rpm. A shorter stroke engine also gives the opportunity to run a longer rod. However, if you chose not to take advantage of those opportunities, and built the larger bore / short stroke engine for a lower rpm range, you could make VERY comparable power / torque curves.
Your big cam / long runner intake manifold theory is equally as flawed. Mindgame and I both have asked you many times for dyno sheets (proof) of your theory and you won't produce them. You see, when you have a theory that bucks a generally accepted theory based on physics and dyno / racing experience you should provide proof of your theory if you expect it to be accepted. That's just the way it works. Where's the beef?
It's true that for the same cubic inches a larger bore engine can use a larger valve since the larger bore will shroud the valves less. It's also true that a shorter stroke engine will have less piston speed at a given rpm. A shorter stroke engine also gives the opportunity to run a longer rod. However, if you chose not to take advantage of those opportunities, and built the larger bore / short stroke engine for a lower rpm range, you could make VERY comparable power / torque curves.
Your big cam / long runner intake manifold theory is equally as flawed. Mindgame and I both have asked you many times for dyno sheets (proof) of your theory and you won't produce them. You see, when you have a theory that bucks a generally accepted theory based on physics and dyno / racing experience you should provide proof of your theory if you expect it to be accepted. That's just the way it works. Where's the beef?
Thread Starter
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Joined: Jun 2002
Posts: 1,817
From: O-Town
I don't claim to know much on this subject, but I am having to agree with Mike on some things. I am building a 351 with a long runner intake. I have talked to a few guys that have something similar and are running low 11s with 3300+lbs race weight. One guy I talked to had FTI spec out his cam and his best run was 11.4s with 3405 race weight. He says it is his daily and said that his cam specs are in the neighborhood of 240/245 on a 112. I would think a cam of this size would be mismatched, but the only problem is that this cam was speced out by FTI, not some shelf cam.
Just a thought.
Just a thought.
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Joined: Mar 2002
Posts: 2,743
From: Baton Rouge, LA, USA
Originally posted by 94bird
OK Mike, let me first point out that your assumption that stroking an engine is only done to increase the low end torque is false. I held my tongue when you originally mentioned it, but you just keep on saying it.
OK Mike, let me first point out that your assumption that stroking an engine is only done to increase the low end torque is false. I held my tongue when you originally mentioned it, but you just keep on saying it.
Originally posted by 94bird
Your big cam / long runner intake manifold theory is equally as flawed. Mindgame and I both have asked you many times for dyno sheets (proof) of your theory and you won't produce them. You see, when you have a theory that bucks a generally accepted theory based on physics and dyno / racing experience you should provide proof of your theory if you expect it to be accepted. That's just the way it works. Where's the beef?
Your big cam / long runner intake manifold theory is equally as flawed. Mindgame and I both have asked you many times for dyno sheets (proof) of your theory and you won't produce them. You see, when you have a theory that bucks a generally accepted theory based on physics and dyno / racing experience you should provide proof of your theory if you expect it to be accepted. That's just the way it works. Where's the beef?
If their engines are so horribly mis-matched, you should call them up and let them know that they need smaller cams that are better matched to the TPI and Magnum long runner intakes so they can start running some good numbers. I'm sure they'll really appreciate your input.
Mike
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Joined: Oct 2001
Posts: 1,517
From: Engineerland
mike in this 355/383 test they used the same cam and top end, and they also used the exact same camshaft. lets think about that for a second, few problems with a test like that. the optimal valve timing for a 383 is a touch different than the ones for a 355. also cylinder head cross sectional area also needs ot be increased for the larger motor since the longer stroke creates higher piston velocities. runner length should probably also change a little bit because the 383 can take advantage of more camshaft. i mean even given the same static compression the 383 can still handle more cam to make the exact same dcr.
given all that you've just proved everyone elses point. that the better matched engine will make more power. the 383 made more torque yeah thats exactly right given the same ivc the effective stroke is longer. do tpi motors make more power with a huge camshaft well yeah if it can move the air in and out at the rpms its meant to be run in but thats as simple as same tq at higher rpm = more hp. at the same time though put a proper intake on it like a super victor or some other manifold for high rpm use and i bet it stomps the tpi into the ground. i think what everyone is trying to say is its more important to build the right engine as best you can, not crutch some horrible intake choice. because lets face it how many of the questions here or on any board are for stock eliminator engines?
given all that you've just proved everyone elses point. that the better matched engine will make more power. the 383 made more torque yeah thats exactly right given the same ivc the effective stroke is longer. do tpi motors make more power with a huge camshaft well yeah if it can move the air in and out at the rpms its meant to be run in but thats as simple as same tq at higher rpm = more hp. at the same time though put a proper intake on it like a super victor or some other manifold for high rpm use and i bet it stomps the tpi into the ground. i think what everyone is trying to say is its more important to build the right engine as best you can, not crutch some horrible intake choice. because lets face it how many of the questions here or on any board are for stock eliminator engines?
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Posts: 2,985
From: In a house by the bay
Originally posted by engineermike
I've seen back-to-back dyno tests of a 383 versus a 355, same cam, heads, intake, everything. The 383 made 38 ftlb more torque at low rpm, but only 5 hp more up top. At very high rpm, the 355 actually made more hp and torque.
I've seen back-to-back dyno tests of a 383 versus a 355, same cam, heads, intake, everything. The 383 made 38 ftlb more torque at low rpm, but only 5 hp more up top. At very high rpm, the 355 actually made more hp and torque.
383
460 lbs-ft and 436 hp @5500 rpm
350
407 lbs-ft and 410 hp @6500 rpm
http://www.superchevy-web.com/tech/0310sc_edelbrock/
Sure, turn the 350 to 7000 rpm and it makes more hp than the 383 but it's a moot point cause the 383 can turn more revs too.
As I keep saying, THE PROOF IS IN THE STOCK ELIMINATOR CLASS!!!
If their engines are so horribly mis-matched, you should call them up and let them know that they need smaller cams that are better matched to the TPI and Magnum long runner intakes so they can start running some good numbers. I'm sure they'll really appreciate your input.
Mike
Mike
I think a better measure of the subject would come in comparing classes where there are no limitation on intake design.
-Mindgame
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Joined: Mar 2002
Posts: 2,743
From: Baton Rouge, LA, USA
You guys are seriously not getting what I'm saying. You still reiterate points that I have not and will not disagree with.
I'll quote myself so I don't have to type this again.
Maybe you'll read and pay attention this time:
I hate pointing out the obvious, but the Edelbrock 383 made 58 ftlb more at 2500, but only 7 ftlb more at 6500 rpm. How is that much difference from the dyno test I saw? I'm sorry, was someone trying to disprove my statement that strokers are biased towards low-end?
And here's a big shocker for everyone, I AGREE that replacing a
TPI intake with a shorter runner will make more power. But, then again, that's true regardless of cam size. . .
Mike
I'll quote myself so I don't have to type this again.
Maybe you'll read and pay attention this time:
Originally posted by engineermike
You guys keep pounding on and reiterating the same points that I don't disagree with.
Long runners make low end power: I AGREE!
Short runners make more top end power: I AGREE!
Very long runners with a large cam is not optimized: I AGREE!
My point is that a long duration cam with very long runners will make more power than a short duration, "matched" cam. Anyone disagree??? This is proven by data in the Stock Eliminator class that I keep refering to, especially in the TPI and Dodge Magnum 360 engines.
You guys keep pounding on and reiterating the same points that I don't disagree with.
Long runners make low end power: I AGREE!
Short runners make more top end power: I AGREE!
Very long runners with a large cam is not optimized: I AGREE!
My point is that a long duration cam with very long runners will make more power than a short duration, "matched" cam. Anyone disagree??? This is proven by data in the Stock Eliminator class that I keep refering to, especially in the TPI and Dodge Magnum 360 engines.
And here's a big shocker for everyone, I AGREE that replacing a
TPI intake with a shorter runner will make more power. But, then again, that's true regardless of cam size. . .
Mike
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Joined: Jan 2002
Posts: 348
From: Jonesboro, GA, USA
After a few posts, it is agreed that you more or less agree with the rest of them. But no matter how many examples you give of guys running big cams for racing, this guy wants a daily drivable combo. Not a lopey *** cam that makes 5 more horses at a higher rpm than another smaller cam.
I would have to agree with what Bret has suggested for you to do. If you cannot afford it, then I would try and stay within the optimal camshaft area. As I can say I've experienced in several of my cars before.. running too much cam may lead to a little more power.. but in a car below 6500rpm that needs to be daily driven.
The benefits of that few extra peak hp on a daily driver ain't worth it. I know from experience, unfortunately
Good Luck,
Josh
I would have to agree with what Bret has suggested for you to do. If you cannot afford it, then I would try and stay within the optimal camshaft area. As I can say I've experienced in several of my cars before.. running too much cam may lead to a little more power.. but in a car below 6500rpm that needs to be daily driven.
The benefits of that few extra peak hp on a daily driver ain't worth it. I know from experience, unfortunately
Good Luck,
Josh
Thread Starter
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Joined: Jun 2002
Posts: 1,817
From: O-Town
Originally posted by dist0rtion_69
I would have to agree with what Bret has suggested for you to do. If you cannot afford it, then I would try and stay within the optimal camshaft area.
I would have to agree with what Bret has suggested for you to do. If you cannot afford it, then I would try and stay within the optimal camshaft area.
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Joined: Jan 2002
Posts: 348
From: Jonesboro, GA, USA
True.. I meant the solution more in general though.. I'd much rather see you change the intake out to match your combo if you plan on using a larger cam. You'll be much happier with the car. I have learned this from personal experience. Running a manifold designed with low end torque still might make more power with a larger cam than a smaller cam. I don't think thats really the issue. The issue is.. you could make more/the same power with the proper intake manifold with a smaller cam and have better overall drivability as well as make the power at a lower rpm.
But if your like me.. you don't always have the money to redo the whole combo. So its not a bad idea to go ahead and do the cam you will want in the future, and you can always upgrade the intake manifold later. I ran a 240/246 with a performer rpm and vortec heads for the longest before this latest upgrade to afrs and a victor jr hehe. Needless to say it was more bark than bite but it still pulled harder than the 230/236 cam that was in it before.. It still benefitted from more duration, despite the low rpm manifold design. To say that an upgrade woke the motor up though would be an understatement
Good Luck with whatever it is you decide to do,
Josh
But if your like me.. you don't always have the money to redo the whole combo. So its not a bad idea to go ahead and do the cam you will want in the future, and you can always upgrade the intake manifold later. I ran a 240/246 with a performer rpm and vortec heads for the longest before this latest upgrade to afrs and a victor jr
hehe. Needless to say it was more bark than bite but it still pulled harder than the 230/236 cam that was in it before.. It still benefitted from more duration, despite the low rpm manifold design. To say that an upgrade woke the motor up though would be an understatement Good Luck with whatever it is you decide to do,
Josh
Last edited by dist0rtion_69; Jul 12, 2004 at 06:40 AM.
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Posts: 2,985
From: In a house by the bay
Mike,
You've backed out of many of the over-generalized statements you made at the beginning of this thread. To the point that it has become difficult understanding just WHAT your point here has been.
We went through IVC and tuning using your Hot Cam example and according to you... "tuning for the first wave". Which btw, would make for a very impractical runner length. So, I presented Mr Vizard's formula which doesn't agree with your reasoning.
Like any successful debate, a point is made, then a counter point is made to hold the other position. Nothing personal, we're all just trying to let each other know WHY we hold the opinions we do. Been pretty civil too.
From what I've digested so far, your only point worth standing on is..... a larger cam in an engine with very long intake runners will make more power?
I might agree with that to a degree. If peak power is your only measure of engine performance. I believe the hp falloff after peak torque would be rather quick to say the least.
The original TPI manifold, originally designed for the 305 ci motor but used on both the 305 and 350, is a good example. Made prodigious torque even on the L98 350 ci engine but really fell on its face with attempts to turn higher rpm.
Either way, in light of this conversation, comments like, "I think that most board members here are pursuing maximum power. Perhaps you are the exception to that", don't seem to coincide with your point. Which is.... larger camshafts make more power, even if not properly matched to the engine architecture.
Peak power... maybe, but not near optimal in any case.
Don't feel this conversation is going anywhere fast.
mastdriver,
If you can't afford on of the intakes mentioned then that takes care of that. You'll have to explore your other options.
As for your example... a friends car running 11's, that's commendable. Don't measure what is perhaps closer to "optimum" with track ET's. Your friend may never know that another intake could bump his times considerably and may never even care as long as he can show 11 second time slips to his friends. Point being, the cars that you should look at are those going the fastest within a set of rules.
For the mustang crowd, you have the supercharged guys going really fast with stock "type" intakes. Alot of the choice is going to come down to transmission and gearing but for the NA crowd... most of them have switched over to short runner tunnel ram type intakes or carb-type single planes.
Good luck.
-Mindgame
You've backed out of many of the over-generalized statements you made at the beginning of this thread. To the point that it has become difficult understanding just WHAT your point here has been.
We went through IVC and tuning using your Hot Cam example and according to you... "tuning for the first wave". Which btw, would make for a very impractical runner length. So, I presented Mr Vizard's formula which doesn't agree with your reasoning.
Like any successful debate, a point is made, then a counter point is made to hold the other position. Nothing personal, we're all just trying to let each other know WHY we hold the opinions we do. Been pretty civil too.
From what I've digested so far, your only point worth standing on is..... a larger cam in an engine with very long intake runners will make more power?
I might agree with that to a degree. If peak power is your only measure of engine performance. I believe the hp falloff after peak torque would be rather quick to say the least.
The original TPI manifold, originally designed for the 305 ci motor but used on both the 305 and 350, is a good example. Made prodigious torque even on the L98 350 ci engine but really fell on its face with attempts to turn higher rpm.
Either way, in light of this conversation, comments like, "I think that most board members here are pursuing maximum power. Perhaps you are the exception to that", don't seem to coincide with your point. Which is.... larger camshafts make more power, even if not properly matched to the engine architecture.
Peak power... maybe, but not near optimal in any case.
Don't feel this conversation is going anywhere fast.
mastdriver,
If you can't afford on of the intakes mentioned then that takes care of that. You'll have to explore your other options.
As for your example... a friends car running 11's, that's commendable. Don't measure what is perhaps closer to "optimum" with track ET's. Your friend may never know that another intake could bump his times considerably and may never even care as long as he can show 11 second time slips to his friends. Point being, the cars that you should look at are those going the fastest within a set of rules.
For the mustang crowd, you have the supercharged guys going really fast with stock "type" intakes. Alot of the choice is going to come down to transmission and gearing but for the NA crowd... most of them have switched over to short runner tunnel ram type intakes or carb-type single planes.
Good luck.
-Mindgame