Budget Intake Manifold/TB Options

[turbosax2]

I meant to say "ports", not "flange". You think it looks like 2g ports? It still looks different to me, more rounded.

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[the_mork]

2g and evo3 manifold. The Hyundai runners seem much shorter.

Hyundai manifold

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2g intake ports

Evo3 intake manifold same port size as 2g

Hyundai manifold

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Definitely looks like it will work for a 2g head and is probably a mild upgrade. There probably isn't any good way to tell how much of an upgrade it is without actually putting it on a car.


All of these photos were shamelessly stolen from the evo3 manifold thread or this one.

 

[big_d]

I did a motor swap in my first talon (1g n/t), and the motor was a G4CP (4g63 n/t equivalent). Here is a picture after I turboed that motor, notice the intake manifold. I didn't really pay too much attention to it though.

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[dsm-onster]

I've never seen head runners with mouths shaped like that. Is there a DOHC head that bolts to the 63 with ports IN BETWEEN the area of a 1g and 2g runner area? The evo runners seam to definately be shorter than all others pictured. The hyundai manifold looks shorter than the 2g manifold. . .

I think that the 2g head ports could be port matched to that hyundai manifold and do well. As mentioned, only putting it on a 2g head and running it will tell. If it does worse, then you've possibly sh!t up a 2g head by portmatching, unless porting a 2g head well will include opening up the mouth as much as that hyundai manifold needs it to be.

 

[turbosax2]

Well, here's the link in case anyone wants to pick it up. snowborder714 decided he's not going to since it wouldn't work on his car anyway.

eBay Motors: 95 hyundai sonata intake manifold 4g63, eclipse, talon (item 270312585926 end time Dec-10-08 15:21:12 PST)

 

[Zex4g63]

Well, here's the link in case anyone wants to pick it up. snowborder714 decided he's not going to since it wouldn't work on his car anyway.

eBay Motors: 95 hyundai sonata intake manifold 4g63, eclipse, talon (item 270312585926 end time Dec-10-08 15:21:12 PST)

That manifold looks like a 1g/2g one. Meaning the runners are way too long from a performance standpoint.

 

[dsm-onster]

The runners look shorter than a 2g, and a little shorter tha the 1g. There's more to a manifold than runner length. The plenum is MUCH larger than the 1g plenum. And the 1g plenum is quite a bit larger than the 2g plenum. . . You've been looking at the comparison pics right?

 

[pboglio]

Runner length matters alot more than plenum volume. 2g plenum is nearly 2x bigger in volume than the EVOIII, yet the EVO makes more horsepower due to its shorter runner diameter. Buschur attached a 4" diameter plenum to a stock EVO current gen intake manifold and lost power.

 

[DSMunknown]

^ Also noteworthy, the Evo 8 and Evo 3 manifold runners have the same general length. Between 8 and 8.5 inches. 2G runners are at 11.5.

 

[dsm-onster]

Runner length matters alot more than plenum volume. 2g plenum is nearly 2x bigger in volume than the EVOIII, yet the EVO makes more horsepower due to its shorter runner diameter. Buschur attached a 4" diameter plenum to a stock EVO current gen intake manifold and lost power.

Do you have any links to this? This is a fairly broad statement. I mean I could say that the 1g intake manifold outflows ALL SMIM manifolds based on the 2004 manifold testing. And the 1g manifold runners are longer.

I'd like to know what his setup consisted of.

I have the 2g manifold and 1g manifold in my living room here. I'm remeasuring both with a piece of coarse copper wire splitting the middle of the number one runner laying it on the driverside of the manifold. The 2g measures 14" and the 1g measures just under 13.5". . .

 

[Boostjunki84]

Do you have any links to this? This is a fairly broad statement. I mean I could say that the 1g intake manifold outflows ALL SMIM manifolds based on the 2004 manifold testing. And the 1g manifold runners are longer.

I'd like to know what his setup consisted of.

I have the 2g manifold and 1g manifold in my living room here. I'm remeasuring both with a piece of coarse copper wire splitting the middle of the number one runner laying it on the driverside of the manifold. The 2g measures 14" and the 1g measures just under 13.5". . .

I think he may be referring to the IM shootout in the May 2008 issue of DSport. According to the article, the BR modified manifold lost an average of 23.7whp and only gained 7.0whp. It also didn't even begin to make more power until 7,400 RPM.

DragSport.com - DSport Magazine - Table of Contents

EDIT: The test was performed using a 2004 EVO RS that ran a 9.65 at 151 mph using a built 2.0, BF 272 cams, BR ported head and exhaust manifold, and an HTA35R turbo.

 

[pboglio]

Do you have any links to this? This is a fairly broad statement. I mean I could say that the 1g intake manifold outflows ALL SMIM manifolds based on the 2004 manifold testing. And the 1g manifold runners are longer.

I'd like to know what his setup consisted of.

I have the 2g manifold and 1g manifold in my living room here. I'm remeasuring both with a piece of coarse copper wire splitting the middle of the number one runner laying it on the driverside of the manifold. The 2g measures 14" and the 1g measures just under 13.5". . .

Link: Intake manifold dyno tests and facts only. - Buschur Forums

The bigger plenum lost power everywhere except above 7300 rpms. Increasing the plenum along with shortening the runners further as in the EVOIII/Wilson V2 etc. design increased power bigtime.

A properly designed SMIM would blow a 1g intake manifold out of the water. Look at the dyno curves of current generation short runner manifolds against the stock EVO intake manifold in that link, the gains are huge.

 

[dsm-onster]

I forgot about those tests .

I think the alteration of the plenum shape (not volume) and the change of the runner entry caused the modified stocker to run better, not neccesarily the combination of large plenum and short runner. A confirmation of your statement would be a test with the same plenum shape used with the shorter runners with the same botched stock-like runner entry.

I know the manifolds like the JMF piece outperform the stocker. But I've not seen this as the case in the range where the stock manifold resonates, except for after 6500rpms. The stock manifold has longer runners than the evo manifold. The 272 duration cams have a valve close angle that causes the stock runner length to resonate at a 4th harmonic at 4K and a 3rd harmonic at 5.3K. The stocker has been proven to outflow all other manifolds in that range, correct?

Here is where I'm going with this. . .

At higher rpms the air velocity is MUCH higher and things like bellmouth entry and port taper become VERY important. The plenum shape is different in the Wilson modified evo manifold. All these things when done incorrectly or are absent begin to show at high rpm since the velocity is up and turbulance is magnified. A typical aftermarket SMIM takes advantage of all the little things that make a big difference at high velocity.

But, there ain't NO way a 6" runner is a length that can see a resonance at a streetable rpm. But that is a common runner length of successful SMIMs. So port tuning is not employed in a typical manifold upgrade. When resonance IS used, it performs MUCH better in the tuned rpm range vs. a smim as long as the velocity isn't high enough to ruin things with turbulance. What about a marriage of runner tuning and the componentets that reduce high flow turbulance? Since an untuned runner doesn't kill performance when all other pieces of the puzzle are used, a long runner should do just as well as a short runner as long as all the other pieces are used. Suck soda up with a 10" straw and with a 4" straw. If the diameters are the same, as soon as you fill the straw, it takes the same effort and the same flow results. Short runners appear to be used for packaging and simplicity. So, let's have the manifold employ bellmouth entry, perhaps runner taper, better plenum shape/size, and smooth surface; all these things to see the same gains up top. And then you have a runner length setup at harmonics that will work with your setup. This means a LONG runner SMIM, with all the tricks that make a short runner smim flow better up top.

It seams cutting up the stocker the right way can do most of this marriage, as shown by the tests. The stock manifold modified by wilson and all stock manifolds for the 4g63 seam to use the head runner angle well, too. Not many SMIMs are designed with that in mind. So you would have another advantage. But, the entry cannot be effectively bellmouthed. This is the only real drawback. The entry can be made better, but not best.

I'd like to see a long runner smim with bellmouth entry and good plenum shape. The long runners could wrap around just like the stocker and take advantage of good entry to the head runner (based on the head runner angle). A stock 1g intake manifold runner length with fp2 cams has THREE resonant points from 4K to 8K!!! It has a SECOND harmonic (10% signal strenght=> 20psi manifold pressure = 22psi pressure at the intake valves) at 8K.

The stock 1G intake runner length is a little under 13.5" as measured. The stock head runner length is about 3.5". Here are the lengths for the 1st through 4th harmonics from 4 to 10K rpms with FP2 cams with stock 1g intake manifold average pipe diameter. Remember to subtract about 4 inches of head runner length to get the manifold runner length:

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No doubt the stocker with no bellmouth entry and poor plenum shape is to blame for not seeing the 2nd harmonic do any good, since I've seen my g/rev fall off by this point. Interestingly, I see g/rev peak at the 5300rpm point then dip and then begin to peak up again by 6400rpms but suddenly flattens and begins to dip by 6800rpms. And I've seen this on numerous fp2 setups with the stock 1g intake manifold. With hks272s, it never even starts to rise again, it just drops a bit after the 5300rpm resonant peak and then levels off. Something is preventing the 2nd harmonic in the stocker from showing itself to be effective. I speculate that it is the same things that the typical SMIM does away with. Things that cause high turbulance when subject to high air velocity. But there's no stock like manifold that does away with those things. A wilson modified manifold seams to remedy those issues, but such isn't exactly budget-minded.

. . .Wow. sorry for the long post.

 

[turboglenn]

It seams cutting up the stocker the right way can do most of this marriage, as shown by the tests. The stock manifold modified by wilson and all stock manifolds for the 4g63 seam to use the head runner angle well, too. Not many SMIMs are designed with that in mind. So you would have another advantage. But, the entry cannot be effectively bellmouthed. This is the only real drawback. The entry can be made better, but not best.

I'd like to see a long runner smim with bellmouth entry and good plenum shape. The long runners could wrap around just like the stocker and take advantage of good entry to the head runner (based on the head runner angle). A stock 1g intake manifold runner length with fp2 cams has THREE resonant points from 4K to 8K!!! It has a SECOND harmonic (10% signal strenght=> 20psi manifold pressure = 22psi pressure at the intake valves) at 8K.

The stock 1G intake runner length is a little under 13.5" as measured. The stock head runner length is about 3.5". Here are the lengths for the 1st through 4th harmonics from 4 to 10K rpms with FP2 cams with stock 1g intake manifold average pipe diameter. Remember to subtract about 4 inches of head runner length to get the manifold runner length:

it's in the works!!! I ditched my standard run of the mill SMIM copy i was building in favor of going with runners tuned to peak at 6500 (to maybe 7500) RPM, roughly 16 to 17.5 inches long, but ging with a smaller plenum than most would relaly want to use, but it will match the volume of all 4 runners added up.

There's a book by a guy named Phillip SMith called tuning for speed and he gives a great breakdown on tuning the lenth to catch the right 2nd and 3rd harmonic

basically stating you take the number 90 the divide it by the RPM for deired peak power and then you can vary it by adding or reducing it by between 4 and 6 centiemeters extra for every 1k RPM less or more, where you want peak to occur, or just redo the math ( of course there's way more to it to make sure you get the best results in the whole power band (runner diameter for example)..velocity, plenum design etc, I still have my "notes from eading the book and my copied and slighly modded version is this, but the math is right. In that one i'm using a mix of phil's rul e of thumb and another one i read some where else on motors based in the 5 - 7k RPM range

TO get a baseline runner length, take the number 90 and divide it by the desired peak RPM in thousands, or as follws in these examples

90/rpm in thousands = length in inches

ie for 6000RPM you would come up with 90/6 = 15 inches

for 7000RPM you would come up with a runner length like this 90/7 = 12.85 inches.

Remember: All runner length measurements should be taken from the back face of the valve to where the runner meets the plenum

Long runners are great for torque and spool based on Bernoulis pricipals of airflow. And do to his studies and discoveries, i've even been thinking of a smaller runner tubular turbo mani. but that's a differnt year in planning at least. This is why the old 5.0liter mustangs pulled so hard..they lacked top end but with a tad over 22inches of total runner length they started pulling hard right away.. I know, i know...now days rust-stangs are nothing to be eaten by a DSM, but compared to the other "factory muscle cars" of the 80's and early 90s, the mustang was one of the best "fast-teenager" cars to have right off the show room floor and had less cubic inches than most of it's counterparts from chevy

TO measure the runner length I use a piece of 1/16th 4043 aluminum TIG welding rod to measure from the heads intake gasket surface, but the rods come in 36 inch lengths so you could measure from runner entrance to valve if you wanted. IT's soft, flexible and you can use it over and over to be sure you're getting the right measurement. Some people say to use string, but that's boloney.. i can let the string coil in the vlave bowl area for a whole extra inch and not even notice if i don't have the head off and the valve partially opened or looking through the port with a light.. you can use TIG rod blind folded

Another way you can imrpoive equal airflow to all the cylinders is to put the TB in the middle and spred the center 2 runners out a tad....there's room to do this with a custom intake mani on a car with all the factory emmissions crap and what not removed and some relocation of a few things. I'm also planning to do this as well to be different thn all the other DSM SMIM's ... it will be on lthe car with my new motor and rubo late this summer or maybe even before spring if i can come up with the volumes i WANT and still make it look good.

i plan on making something that will either be great or suck... but oh well it's my free time and some old parts and aluminum tubing.. I've also got a little somethign in the works using 4 ITB's with velocity stacks that are inside a plenum and the entrnce to them set dead center in the plenum area inside. The runners on the ITB mani are going to be killer, this will be a crisp running manifold for high RPM only and will be tunable. i've built 2 for some local boosted bikes now and they've shown a great improvement over pushing through a sealed up stock airbox both seat of the pants and one even gained on teh dyno comapred to another busa with the sme makers kit on it and same boost and all.

The only thing i wish i had for the stuff i do for myself is to have some one there to brains storm with, hand a toold, filler rod or just flip the TIG to AC or change the amps for me whenneeded..but mainly conversation is what really helps... when i'm getting paid I prefer not to talk to people unless i'm designing something "one off" for them, but i ahte when un-knowing people just want to watch the whole time

These are just some things' i'm putting together base on a "street" power band and not a pure drag racing vehicle. I want the highest flattest curve i can get. that's why my ideas are a tad out of the realm of "normal performance manifolds"

I will post Dyno numbers but the setup will be far too different to accurately compare it my past dyno numbers

However, if anyone is interested, if you bring some beers and help me with the mani swap....mainly be a wrench grabber, beer getter and a second set of eyes to look for issues is all you'd do..then I WILL go back to see how much i either lose or gain from going from my slightly modded 1g to my custom one i'm building

 

[DSMunknown]

I just used solder wire and zip ties to measure the runners, especially for the longer 2G runners. In any case, I needed something that was flexible for the bends. For both the EVOs a tape measure was also able to be utilized. Interestingly enough, the Evo 8 plenum is a tad smaller than the Evo 3.

 

[pboglio]

In theory that may be true regarding a 6" runner length not being optimal, but you cannot deny that everybody who offers an aftermarket high output intake manifold uses a runner more or less about that length, including Edelbrock, HKS, etc. There is enough empirical data and dyno testing to suggest within reason, shorter is better.

It has been stated elsewhere that its a case where scrubbing losses using a severely curved and long runner vs. a short straight runner gang up and completely overshadow any pulse tuning advantage that may be occuring with the longer runners at higher rpms.

A 14" long stock runner on a 2g manifold has 3 bends before entering the intake port, and the 3rd bend is in a critically bad location right before the port. Sure radiusing the inlet of the runners is optimal, but the diameter to begin with is huge on the stock runners at the plenum side, quite massive in fact.

If you could run an optimally long straight runner with an optimally sized diameter for minimal pressure losses and a dead straight shot into the intake port, then it might perform alot better. But I don't see it practical as you have to consider packaging it against the firewall. "Scientific Design of Intake & Exhaust Systems" pretty much states this very thing. Hence you have short & straight SMIM as a practical compromise.

 

[dsm-onster]

In theory that may be true regarding a 6" runner length not being optimal, but you cannot deny that everybody who offers an aftermarket high output intake manifold uses a runner more or less about that length, including Edelbrock, HKS, etc. There is enough empirical data and dyno testing to suggest within reason, shorter is better.

It has been stated elsewhere that its a case where scrubbing losses using a severely curved and long runner vs. a short straight runner gang up and completely overshadow any pulse tuning advantage that may be occuring with the longer runners at higher rpms.

A 14" long stock runner on a 2g manifold has 3 bends before entering the intake port, and the 3rd bend is in a critically bad location right before the port. Sure radiusing the inlet of the runners is optimal, but the diameter to begin with is huge on the stock runners at the plenum side, quite massive in fact.

If you could run an optimally long straight runner with an optimally sized diameter for minimal pressure losses and a dead straight shot into the intake port, then it might perform alot better. But I don't see it practical as you have to consider packaging it against the firewall. "Scientific Design of Intake & Exhaust Systems" pretty much states this very thing. Hence you have short & straight SMIM as a practical compromise.

Even the new Magnus cast intake manifold takes advantage of the evo head runner angle and is not a straight shot into the head. The last angle to the head may exhibit losses but the gains from the proper angle to the runner likely trumps it, or Marco wouldn't be offering it??? With this aspect, I'm taking the side of trusting the experts like you.

As regards the stock intake runner area, ALL SMIM runners have more area than stock. Increasing runner diameter lowers the rpm resonant point:

L = ((EVCD × 0.25 × V × 2) ÷ (rpm × RV)) - ½D
Where:
EVCD = Effective Valve Closed Duration
RV = Reflective Value
V = Pressure Wave Speed
D = Runner Diameter​

Now larger diameter will reduce signal strength, so there is a point of diminishing returns. So, I'm sure you're right as I've been stating that the typical productive SMIM doesn't employ resonance. However, your conclusion that at high rpm helmholtz resonance takes a back seat to straight runners would negate the 'snaky' design of formula one headers and even common high rpm 180* v8 header designs found on the Ford gt40 and others. I'm only looking for strong resonance (2nd harmonic) at 8K. 180* v8 headers work well at 6K and up. If Helmhotz works for exhaust gases, with it's high heat and turbulant nature of exiting the head, at high rpms, what would prevent it from being successful (return outweighs the losses) on the cold side?

Let me ask to clerify, what is considered a severly curved runner? Remove the A/C and there's lots of room

 

[pboglio]

I'm not claiming to be an expert by a mile. But exhaust headers also have an enormous amount of cylinder pressure to blast thru any minimal scrubbing losses that might occur. The intake side is quite limited in this respect as I believe the highest pressure assist from pulse tuning of an intake manifold I've heard of is around 6 psi.

I'm not stating short runner manifolds don't employ resonance. Scientific Design of Exaust and Intake systems pg 206 clearly illustrates the differences between different intake tuning lengths and finally no intake stubs whatsoever. The difference in volumetric efficiency at "high rpms" between lengths of pipes ranging from 32" to 8" is clearly an affect of pressure losses. The short runners clearly not producing as strong a resonant pulse, but neither being physically restrictive either. Now the complete lack of intake runners definitely has little to no resonant tuning affect and shows the weakest low & high rpm volumetric efficiency.

I don't believe your equations are giving you an accurate model. You'd need to add in the intake pressure losses to the resonant pressure to get a total system pressure. When you do that in a typical long runner intake manifold the "total" pressure drops off severely at high rpms. You'd benefit greatly optimizing your design using CFD at the very least. I've been tempted to purchase intake manifold resonant tuning design software in the past but I'm not as interested in it as I once was.

 

[dsm-onster]

I'm not talking about the exhaust pulses. I'm talking about the resonant reflective negative pulses (which would have a signal strength about the same as on the intake side for wach harmonic but negative) that result from the exhaust pulsing and tuned exhaust runners. Same concept, very 'curvy' runners for many high rpm applications.

I absolutely AM clearly stating that the typical SMIM does not use resonance, and why. It cannot resonate at any benenficial harmonic for the common 11second car with a typical rev limit. The resonance of a 6" runner at just the 3rd harmonic is at +9K. . . Yet the gains past 6500rpms are clear with a typical well build SMIM on an 11second car. The benefits of a common short runner SMIM are not in the runner length being very short. What's 5-6 less inches of IC piping goign to cost you in flow? Or one more bend?

Perhaps you're right about 8K resonance with a curved long runner (the only way to fit in runners that are tuned to the 2nd harmonic). What I'm proposing is to build an intake manifold tuned for the 2nd harmonic at 8000rpms anyway. This will give a 3rd harmonic at 5300rpms like the stocker. And have all the flow techniqes employed by the high rpm successsful SMIMs. So midrange performance of the stocker with less flow restriction and less turbulance, and probably with a little less scrubbing loss if you can get a larger radius curvature in there. Though scrubbing loss may negate the signal strength at 8K since it is several times weaker than the the boost but at 8K the flow is several times faster, I doubt the scrubbing losses would affect overall power/flow itself in higher rpms, considering a curve in the manifold would be the same as a curve in an intercooler pipe. Perhaps the 8K resonant point cannot be beneficial. But having afew more inches runner is the same as having a few more inches intercooler piping, if you're not concerned about resonance. The result? a manifold that performs as a well as the stocker at midrange and equally as well as the typical SMIM at 8K. I'm drawing up an intake manifold design that I'd like to test. . . I'd like to see what happens.

 

[turboglenn]

I'm not talking about the exhaust pulses. I'm talking about the resonant reflective negative pulses (which would have a signal strength about the same as on the intake side for wach harmonic but negative) that result from the exhaust pulsing and tuned exhaust runners. Same concept, very 'curvy' runners for many high rpm applications.

I absolutely AM clearly stating that the typical SMIM does not use resonance, and why. It cannot resonate at any benenficial harmonic for the common 11second car with a typical rev limit. The resonance of a 6" runner at just the 3rd harmonic is at +9K. . . Yet the gains past 6500rpms are clear with a typical well build SMIM on an 11second car. The benefits of a common short runner SMIM are not in the runner length being very short. What's 5-6 less inches of IC piping goign to cost you in flow? Or one more bend?

Perhaps you're right about 8K resonance with a curved long runner (the only way to fit in runners that are tuned to the 2nd harmonic). What I'm proposing is to build an intake manifold tuned for the 2nd harmonic at 8000rpms anyway. This will give a 3rd harmonic at 5300rpms like the stocker. And have all the flow techniqes employed by the high rpm successsful SMIMs. So midrange performance of the stocker with less flow restriction and less turbulance, and probably with a little less scrubbing loss if you can get a larger radius curvature in there. Though scrubbing loss may negate the signal strength at 8K since it is several times weaker than the the boost but at 8K the flow is several times faster, I doubt the scrubbing losses would affect overall power/flow itself in higher rpms, considering a curve in the manifold would be the same as a curve in an intercooler pipe. Perhaps the 8K resonant point cannot be beneficial. But having afew more inches runner is the same as having a few more inches intercooler piping, if you're not concerned about resonance. The result? a manifold that performs as a well as the stocker at midrange and equally as well as the typical SMIM at 8K. I'm drawing up an intake manifold design that I'd like to test. . . I'd like to see what happens.

If you'd like to work together on this SMIM let me know, i've got some ideas, but you seem to have more knowledge than I do. THe one thing i do have is access to all the fab equipment needed to build it. PM or call me, I"m just about finished with the dirtbike roject i'm working on (built xr250 motor destroked to 238, 13.5:1 CR, crower cam ) and i'm shoving it in a CR85 frame with out changin the frame geometry.. i should have it finished in another week and free to play around with my manifold again or work on something in a collaborative effoirt wih you. Of course you would get a manifold out of the deal and so would i, but unless you're wanting to i have no plans on "producing" them for sale in the public market..just something for myself is all i'm after and like i said, it would be great to collaborate with another person for bouncing ideas, and things like that.. If you don't have my number still PM me and i'll shoot it o ya

 

[dsm-onster]

I'd like to. I sent you a PM. Can you make flanges, too? There's a few websites that have premade Al plenums and radiused entries. . .

 

[pboglio]

"I doubt the scrubbing losses would affect overall power/flow itself in higher rpms". This not correct at all. "Internal Combustion Engine Fundamentals", pg 217 clearly shows the different affects that 1) charge heating 2)frictional flow losses 3) choked flow in the intake valves 4) induction ram effect 5) intake (pulse) tuning all have on intake manifold performance.

Frictional losses represent the 2nd largest factor in why the volumetric efficiency drops off severely at higher rpms, aside from choked flow in the intake valves. Doubling the length of the intake runner alone doubles the frictional loss. Throw in nearly 3 bends totalling almost 270* and the flow losses go up significantly. I don't care what happens in the intercooler pipes, the intake runners are significantly smaller in diameter and there is a little more complexity in terms of multiphysics going on in this region. This isn't even debateable, the research on this subject has been done 50 years ago and published extensively.

This is why the SMIM are kicking the crap out of the long runner manifolds at high rpms, no bends and half the runner length are enough to greatly reduce frictional losses. The pulse tuning pressure assist is clearly lower in the shorter runner manifold, as "Scientific Design of Exhaust and Intake Systems" illustrates, but it is most definitely still there helping out.

 

[dsm-onster]

I've done a long route and a short route IC piping setup. Zero difference in peakflow and the hertz curve. About 5 more 90s and 2 more 45s. What's the difference at the intake manifold?

The magnitude of scrubbing loss goes down as air pressure goes up. Hense, reducing bends on an intake pipe to the compressor yields alot better results than the piping coming from the compressor. There's a great paper about this written by an engineer hired by GM to tackle the Duramax Diesel overheating issue. The reason for the overheating was because of precompressor scrubbing losses. I can email it to you if you'd like to see it. It's a good read and covers alot of turbocharging "nuances".

SMIMs are "kicking the crap" out of stock manifolds because of plenum shape, radiused entry, and tapered runners. Some now are employing better runner to head angle, which the stock 1g intake provides.

Pulse tuning does NOT help a car with an 8000rpm rev limit and a SMIM. As I mentioned, the weaker 3rd harmonic of the typical SMIM runner is at over 9K.

BTW, this is a gread discussion .

 

[pboglio]

DSM-onster:

PM that article, I'll like to read it. Getting back to the discussion.

I think we agree that SMIM employ all tricks necessary to reduce pressure losses and make things aerodynamically efficient within the manifold, no secret there.

We disagree on whether there is pulse tuning at 8000 rpms or whatever rpms on a short runner manifold. I think there still is, though its going to be weaker in the shorter runner manifold than the longer runner manifold. My point is with the long runner manifold you won't make it to 8000 rpms without volumetric efficiency dropping off the cliff. VE is a combination of ALL tuning phenomenon, both positive and negative. At the end of the day its VE that counts, not the pulse "tuned" rpm.

The Helmholtz formula your counting on does not tell you what happens outside the tuning rpm, yet clearly on the dyno brake tests shows there is still a tuned affect outside this "tuned rpm". Its not like zero tuned intake pressure assist, then BAM, +6psi in the intake manifold at 5000 & 8000 rpms or whatever, then nothing again. Your taking a "snap" shot of a movie and attempting to draw large conclusion from it. The graphs you plotted illustrates this.

For example, you know what is going on at every rpm using DIFFERENT tuned lengths, but you DON'T know what is going on at ALL rpms using a SINGLE tuned length, not using the formula you stated. I'm aware of advanced wave simulation software for designing intake manifolds that could do what I just described but I have zero experience with it.

 

[turboglenn]

I'd like to. I sent you a PM. Can you make flanges, too? There's a few websites that have premade Al plenums and radiused entries. . .

Yea, i have access to both plasma and waterjet cutting styles. I also have access to a large CNC mill now as well. ( it pays to network)

SOrry i haven't gotten back to you yet on that PM

Does anyone remember what thread had the link to the manifold "lego" set that let you snap together bends and kind of pre-test your fit before cutting the pipe? IT was demonstreated on a 5cyl header build in the video that was linked.. I want to buy them for my SMIM build which I'm hoping dsm-onster and i can work closely in a collaborative effort on coming up with a unique manifold for at least teh 2 of us to test over teh next year or so.

I might even be moving to langley AFB here in the next few months and be sure i'll have ALL my fab equipment with me when i move.. I'll leave everything else behind to take my motorcycles and fab stuff if i have to