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No I didn't, but no velocity stack comes with the admin intake. I did lots of research into them and the benefits were obvious to me. Plenty of other independent dyno testing on velocity stacks out there, so I decided to just stick with it.
They're using a filter that funnels airflow smoother than a traditional flat bottom filter. So not a proper velocity stack, but still a design that eliminates turbulent airflow at the filter level (you get some stagnant, turbulent airflow pocket with a flat bottom filter).
Are you using their filter + velocity stack? Or your own, flat bottom filter + v stack?
I mean it's a 3.5" intake, how much airflow acceleration do you really need over stock...? I would think Moncef tried to tack on a v stack to one of his prototypes, but I could be mistaken.
Any kind of filter with a built-in stack is not going to compare to a proper 6" stack, you should know that the bigger the pipe the slower the air flow so the more you can speed it up the better.
Any kind of filter with a built-in stack is not going to compare to a proper 6" stack, you should know that the bigger the pipe the slower the air flow so the more you can speed it up the better.
*yep, with the caveat that saturation does happen.
Where is that dynamic pressure saturation point in the air intake velocity range (0-325 ft/s)?
They're using a filter that funnels airflow smoother than a traditional flat bottom filter. So not a proper velocity stack, but still a design that eliminates turbulent airflow at the filter level (you get some stagnant, turbulent airflow pocket with a flat bottom filter).
Are you using their filter + velocity stack? Or your own, flat bottom filter + v stack?
I mean it's a 3.5" intake, how much airflow acceleration do you really need over stock...? I would think Moncef tried to tack on a v stack to one of his prototypes, but I could be mistaken.
I picked up my own standard 6" composite stack and flat bottom filter to adapt to the intake tube.
It's interesting to see you used a flex tube (?) that fits into the OEM intake point (square with rounded corners)... given that it's a tube and round by design, there's a loss in surface area at the intake point (for colder air anyway) that you would think gets fully compensated by the custom intake here, one that sports a thick v stack. The aim of trumpet shaped intake tubes is to make the airflow as laminar as possible - but it's only beneficial, especially with that Kinetix Velocity's 6500+ RPM potential, if it's big diameter AND laminar all the way. The tube is not smooth and by design induces turbulence into your airflow; the flat bottom filter accumulates a small amount of turbulence near that bottom as air gets sucked in (think of somebody in the merge lane being blocked by everybody i.e. every single particle)... so those are I believe two question marks in a full-on laminar flow design, which a big v stack is made to achieve. My $0.02.
It's interesting to see you used a flex tube (?) that fits into the OEM intake point (square with rounded corners)... given that it's a tube and round by design, there's a loss in surface area at the intake point (for colder air anyway) that you would think gets fully compensated by the custom intake here, one that sports a thick v stack. The aim of trumpet shaped intake tubes is to make the airflow as laminar as possible - but it's only beneficial, especially with that Kinetix Velocity's 6500+ RPM potential, if it's big diameter AND laminar all the way. The tube is not smooth and by design induces turbulence into your airflow; the flat bottom filter accumulates a small amount of turbulence near that bottom as air gets sucked in (think of somebody in the merge lane being blocked by everybody i.e. every single particle)... so those are I believe two question marks in a full-on laminar flow design, which a big v stack is made to achieve. My $0.02.
Not sure I get what all you're trying to articulate here, but the flex tube you see is 3in. race ducting from Pegasus racing that's attached to a composite inlet that's molded to a vent on my front bumper. The goal is merely to dump ambient air around my filter element while at speed and lower my intake temps, not try to smooth air flow that early in the intake process. The inside of the admin intake is smooth, so not sure what you're talking about. If you're talking about the flex tube, it doesn't matter if it's not smooth for the purpose I'm using it for. I count on the stack at the inlet to smooth my airflow.
I'm sure you are way over thinking this scenario. All I can tell you is I've been around these cars for 12 years and the velocity stacked intakes are always better. My past car dynoed significantly higher with one than other cars with more mods than mine, enough that Sound Performance was questioning if I was hiding what my mods were lol. Everything I say is from experience and I am also a mechanic and do all my work so I know a thing or two about what I'm talking about. If you have a need to prove us all wrong then by all means let's see what you can do =)
Not sure I get what all you're trying to articulate here, but the flex tube you see is 3in. race ducting from Pegasus racing that's attached to a composite inlet that's molded to a vent on my front bumper. The goal is merely to dump ambient air around my filter element while at speed and lower my intake temps, not try to smooth air flow that early in the intake process. The inside of the admin intake is smooth, so not sure what you're talking about. If you're talking about the flex tube, it doesn't matter if it's not smooth for the purpose I'm using it for. I count on the stack at the inlet to smooth my airflow.
What I'm trying to articulate when it comes to doing your own R&D (vs. relying on OEM or aftermarket companies that have a dyno in the shop) is that different intake tube lengths and diameters should probably be tested & dyno results documented, if you want optimal results. At that point, you are likely -or should be- dealing with other airflow improvements (closer to the intake valves, so port & polish and optimally sized TB). So really, who the hell knows what kind of car the 4" LMT intake was R&D'ed on, for instance... and that's why it becomes even more of a crapshoot if you start modifying their product. Since you drastically changed the airflow specs of the AT intake by cutting it off and playing with velocity and pressure, did you use modelling and simulation to design your custom intake? If you did, did you model it all the way down to the intake runners? (like a race team would)
What's the volumetric efficiency (VE) of a VQ35DE anyway? Did you guys ask Nissan?
A couple quotes from old car/engineering forums, since v stacks were alive and well 15 years ago... I don't know how far you'd have to go back in dragster history not to see trumpet intake pipes.
"This formula for pipe sizing is from Grape Ape Racing (found it in my "How to Tune and Modify Engine Management Systems" book by Motorbooks Workshop):
Diameter = Square root of (cubic inch displacement of motor x volumetric efficiency x rpm) all divided by (velocity of air [ft/sec] x 1130). Velocity should stay under 180 ft/sec for optimal power.
Also according to Grape Ape, a 13" pipe should give a boost around 6k. Shortening by 1.7" will increase the optimal powerband by 1k (so an 11.3" length will be good at 7k), and vice-versa: adding 1.7" will lower the powerband by 1k (14.7" will be good at 5k, 16.4" better at 4k), etc.
If the length of the intake does not match the cams, headers, you may see no gain from a velocity stack alone, or might even see a dip somewhere in your powerband. If you have the wrong intake, or are pulling air from the wrong place nothing will help."
"Velocity stacks are like a wing on a jet plane, it helps to cut the air and allow for smoother entry of the air. All in all, a smooth intake, and smooth walls early in the intake manifold, and a properly scored end of the manifold will do its job a lot more efficiently. I believe the stock air box is a really poor design on most cars, due to the irregular curvature of the box, its more like a coffin. A nice curved pipe would be the best, trying to avoid sharp curves is really beneficial.
Yes turbulence is good for certain reasons, but that does not mean its going to be helpful thought out a tube, the best way to increase air flow velocity is by having the least restriction available. And a dryer hose is definitely a pathetic use of a intake tube in my opinion. If laminar did not matter then all you would have is engine chocking to death trying to breath properly, but its nostrils are clogged. You can maximize atomization by putting the turbulent surface in a key area, such as closer to the combustion chamber. There is no need for soo much turbulence in a intake tube!!!!!! "
" As far as a velocity stack, the more you increase the velocity, the lower the pressure of the stream. That's how the jets on a lot of carbs work, the venturi effect (more velocity => less pressure) sucks the fuel out of the jets in to the air stream, which at that point (late in the intake) is turbulent to assist atomization. If you have any sort of forced induction, including ram-air at speed, then a velocity stack seems to be counterproductive on the surface. Unless you're just on an odd quest for sonic flow into your engine, and you'd have to get lower than .536atm inside the engine for that. However if you are simply running a CAI or SR, then you want that velocity high, but not too high, so that the engine isn't working as hard to get in the air and you don't lose performance due to less dense air. If you want it to move quickly simply to reduce heat transfer from the wall of the pipe, then go to Home Depot and buy some pipe insulation... "
This is a pretty good dyno comparison of a K&N dyno against 6" velocity stack. I've scheduled a dyno tune at Z1 for effectively the same thing.
I dyno'd last year with Z1 m-spec race intake, K&N cylinder filter, as well as non-revup DE lower plenum. I have installed Z1's "high flow intake" filter, which is a 6" velocity stack and K&N style cone filter. After the initial install of the velocity stack, I felt gains everywhere, more or less confirming the results of this test.
He's obviously not going to see the light lol, thinking that most companies do all this outrageous R&D and dyno pulls when making a product is silly to say the least. The 350Z's air box is a better design than a lot out there, there is a reason that a LOT of JDM tuning companies that use a modified stock box with a larger tube... That being said I only know 2 companies selling products for these cars that actually do such research, that is Motordyne and Tomei. All their research is well documented and there are multiple dynos and prototype pics to prove that.
The simple fact that he doesn't get that the DUCT is simply a means to provide colder, denser air to the intake and not part of it is baffling, I'm looking forward to your results Jello though I don't think I would ever put a oiled filter on my car, which would make that modification impossible for my to do =)
Hi all, Is the LMT 4 " intake pipe worth the bucks on an 05 Stillen stage 4 VQ35DE motor?.My mechanic suggested to upgrade from my existing 3".
Got aem W.I, custom pullies for the SC and an uprev tune.
Need to retune next month after a couple of diff size pullies were added..got tge NWP big bore 75mm T.B as well...Worth adding the LMT intake too?
What are the hood spacers that come with the kit?
Any pics?
Anyone used the intake wirh their Stillen?
Tks all
What I'm trying to articulate when it comes to doing your own R&D (vs. relying on OEM or aftermarket companies that have a dyno in the shop) is that different intake tube lengths and diameters should probably be tested & dyno results documented, if you want optimal results. At that point, you are likely -or should be- dealing with other airflow improvements (closer to the intake valves, so port & polish and optimally sized TB). So really, who the hell knows what kind of car the 4" LMT intake was R&D'ed on, for instance... and that's why it becomes even more of a crapshoot if you start modifying their product. Since you drastically changed the airflow specs of the AT intake by cutting it off and playing with velocity and pressure, did you use modelling and simulation to design your custom intake? If you did, did you model it all the way down to the intake runners? (like a race team would)
What's the volumetric efficiency (VE) of a VQ35DE anyway? Did you guys ask Nissan?
A couple quotes from old car/engineering forums, since v stacks were alive and well 15 years ago... I don't know how far you'd have to go back in dragster history not to see trumpet intake pipes.
"This formula for pipe sizing is from Grape Ape Racing (found it in my "How to Tune and Modify Engine Management Systems" book by Motorbooks Workshop):
Diameter = Square root of (cubic inch displacement of motor x volumetric efficiency x rpm) all divided by (velocity of air [ft/sec] x 1130). Velocity should stay under 180 ft/sec for optimal power.
Also according to Grape Ape, a 13" pipe should give a boost around 6k. Shortening by 1.7" will increase the optimal powerband by 1k (so an 11.3" length will be good at 7k), and vice-versa: adding 1.7" will lower the powerband by 1k (14.7" will be good at 5k, 16.4" better at 4k), etc.
If the length of the intake does not match the cams, headers, you may see no gain from a velocity stack alone, or might even see a dip somewhere in your powerband. If you have the wrong intake, or are pulling air from the wrong place nothing will help."
"Velocity stacks are like a wing on a jet plane, it helps to cut the air and allow for smoother entry of the air. All in all, a smooth intake, and smooth walls early in the intake manifold, and a properly scored end of the manifold will do its job a lot more efficiently. I believe the stock air box is a really poor design on most cars, due to the irregular curvature of the box, its more like a coffin. A nice curved pipe would be the best, trying to avoid sharp curves is really beneficial.
Yes turbulence is good for certain reasons, but that does not mean its going to be helpful thought out a tube, the best way to increase air flow velocity is by having the least restriction available. And a dryer hose is definitely a pathetic use of a intake tube in my opinion. If laminar did not matter then all you would have is engine chocking to death trying to breath properly, but its nostrils are clogged. You can maximize atomization by putting the turbulent surface in a key area, such as closer to the combustion chamber. There is no need for soo much turbulence in a intake tube!!!!!! "
" As far as a velocity stack, the more you increase the velocity, the lower the pressure of the stream. That's how the jets on a lot of carbs work, the venturi effect (more velocity => less pressure) sucks the fuel out of the jets in to the air stream, which at that point (late in the intake) is turbulent to assist atomization. If you have any sort of forced induction, including ram-air at speed, then a velocity stack seems to be counterproductive on the surface. Unless you're just on an odd quest for sonic flow into your engine, and you'd have to get lower than .536atm inside the engine for that. However if you are simply running a CAI or SR, then you want that velocity high, but not too high, so that the engine isn't working as hard to get in the air and you don't lose performance due to less dense air. If you want it to move quickly simply to reduce heat transfer from the wall of the pipe, then go to Home Depot and buy some pipe insulation... "
Again, not a dryer hose. Tried telling you this, but I'll try again. The hose you see is 3in. race ducting from Pegasus racing. It is NOT a part of my intake tract. I.e. there is no direct vacuum from the engine applied to that piece of ducting. It is only there to drop my intake temperatures, which I have measured via the torque pro app. I went from a +50 degree over ambient intake temp at interstate speed down to a +4 degree over ambient with the ducting. It works.
Also, all the big words and internet research of "did you guys ask Nissan?" is basically pointless. No, I did not do any modeling all the way down to the intake runners. Also, by your logic, all intakes on the market for the VQ35DE are designed and only should be run on factory cams. There are too many unknowns to put everything into a cookie cutter formula for your average tuner/performance manufacturer. It is usually trial by error methods and trying different things that people discover what works for their setup.
In the weeds thinking and over-analyzing like this usually leaves guys like you doing nothing and guys like me making 304whp on a stock block DE.
Can I optimize things and continue to make adjustments and improvements? Sure. But there's not a chance in the world that I'm going to do an in depth engineering analysis if I want to run different headers and/or a different cam profile in the future.
Bottom line is this: I did my research, saw dyno results from Z1 by adding velocity stacks to their intakes, and decided to give it a shot on my setup. It performed the way I wanted. Is it better than if I hadn't put the velocity stack on it? I believe so, but that may only be unique to my individual setup. It may not do the same on a non-cammed car.
Hi all, Is the LMT 4 " intake pipe worth the bucks on an 05 Stillen stage 4 VQ35DE motor?.My mechanic suggested to upgrade from my existing 3".
Got aem W.I, custom pullies for the SC and an uprev tune.
Need to retune next month after a couple of diff size pullies were added..got tge NWP big bore 75mm T.B as well...Worth adding the LMT intake too?
What are the hood spacers that come with the kit?
Any pics?
Anyone used the intake wirh their Stillen?
Tks all
I would say no, you could just make your own for a fraction of the price.
You can't refer to what Nissan's potential intentions, design/engineering strategies etc in order to make your Nissan faster. A mass produced vehicle has way more limitations to adhere to from a cost and regulatory standpoint than a tuned street car.
You can't refer to what Nissan's potential intentions, design/engineering strategies etc in order to make your Nissan faster. A mass produced vehicle has way more limitations to adhere to from a cost and regulatory standpoint than a tuned street car.
While the conversation is going on, can you articulate on what caused the decision to not incorporate a velocity stack to your intakes? Really curious about that =)
02-13-2018, 05:51 AM
