james@cjperformance Posted January 14, 2013 Share Posted January 14, 2013 so after we have started the first stages of development for our inlets, im lloking for peoples opinions on inlet design. i found a thread that was done by an evo specialist about different types of inlet and the design of the inside etc so it seems from this guys findings that velocity stacks dont really work but decrease power and torque thread is here its quite a good read http://highboostforum.com/forum/showthread.php/20866-Intake-manifold-dyno-tests-and-facts-only goes rather in depth as to what the inside of an inlet is like and how one should be made for optimal flow. all of the runs were done on the sam car, engine, spec the only difference being the inlet. thoughts, discuss Quote Link to post Share on other sites
Azz Posted January 14, 2013 Share Posted January 14, 2013 Velocity stacks still looks the dogs, can't understand how they would be worse tho, your chaging the turbo inlet to a larger diameter so letting in more air and at a greater speed due to going from say 3" to 2" forced induction ect...So its hard to see where that's not a better thing Quote Link to post Share on other sites
james@cjperformance Posted January 14, 2013 Author Share Posted January 14, 2013 I meant stacks in the intake plenum dude stacks on the turbo then yeah they serve a purpose, just cant see the purpose in an inlet :S Quote Link to post Share on other sites
mattyD Posted January 14, 2013 Share Posted January 14, 2013 haha, digs at someone me thinks Quote Link to post Share on other sites
Lew91 Posted January 14, 2013 Share Posted January 14, 2013 Just read this, Seems like good stuff. http://m.miataturbo.net/showthread.php?t=42877&page=10&styleid=21 Quote Link to post Share on other sites
morgey Posted January 14, 2013 Share Posted January 14, 2013 I know this is based on n/a applications but theres some good theory behind it, that if going to the extent of R and D probably would be worth looking into. http://www.emeraldm3d.com/articles/emr-adj-length-intake/ Quote Link to post Share on other sites
james@cjperformance Posted January 14, 2013 Author Share Posted January 14, 2013 haha, digs at someone me thinks No digs dude, just genrally interested in it hence the topic, ther is not alot of info on inlets at all in general, plenty of thoey ehind it but not alot of practice Quote Link to post Share on other sites
mattyD Posted January 14, 2013 Share Posted January 14, 2013 No digs dude, just genrally interested in it hence the topic, ther is not alot of info on inlets at all in general, plenty of thoey ehind it but not alot of practice Lol, im only messing mate The link above pretty much gives you the answer Quote Link to post Share on other sites
Driver Posted January 14, 2013 Share Posted January 14, 2013 I know of a tuner who makes inlets who made 2 inlets exactly the same. One with and one without. With the map adjusted to suit the VS inlet had a better/smoother torque curve and peak figures were improved noticeably. Without a map the difference was negligible IIRC. Quote Link to post Share on other sites
james@cjperformance Posted January 14, 2013 Author Share Posted January 14, 2013 Lol, im only messing mate The link above pretty much gives you the answer which link? Quote Link to post Share on other sites
mattyD Posted January 14, 2013 Share Posted January 14, 2013 Both of them mate, but if you have time have a read of the emerald one Quote Link to post Share on other sites
Addymk2 Posted January 15, 2013 Share Posted January 15, 2013 (edited) Difficult to explain but... Personally I don't see the point in having the velocity stacks protruding into the intake manifolds actual chamber. That's only going to cause the fast moving pressurised air to hit a solid object and become turbulent. If the stack was built into the base etc so the top of the stack was flush with the base of the chamber, makes much more sense.___________\ / _\. /_\. /__. < bad_________________. _. __. __. < good. \. /. \. /. \. /If you do feel like using my design, remember to add a 4th stack. Cheers.Edit: automatically deletes my spaces but you get he gist. Edited January 15, 2013 by Addymk2 Quote Link to post Share on other sites
james@cjperformance Posted January 15, 2013 Author Share Posted January 15, 2013 Difficult to explain but... Personally I don't see the point in having the velocity stacks protruding into the intake manifolds actual chamber. That's only going to cause the fast moving pressurised air to hit a solid object and become turbulent. If the stack was built into the base etc so the top of the stack was flush with the base of the chamber, makes much more sense.___________\ / _\. /_\. /__. < bad_________________. _. __. __. < good. \. /. \. /. \. /If you do feel like using my design, remember to add a 4th stack. Cheers.Edit: automatically deletes my spaces but you get he gist.exactly what i thought dude to be honest. i would see them as more of a restriction if positioned protruding out of the intake runners but like you say if they were flush on the inside it would be alot better Quote Link to post Share on other sites
Flaminsam Posted January 15, 2013 Share Posted January 15, 2013 Bit off topic here but surely if your pressurising the inlet the flow would pretty much stay the same? Surely only a 4e can move a certain ammount of air fuel mixture? The way I understood it if your running say 1bar of boost the engine in effect becomes a 2.6l? I thought to improve flow on a turbocharged enngine you had to make the exhaust flow better as the inlet is already taking in as much as the engine can take? Any one want to give some devine inspiration as I think velocity stacks on anything other than a n/a are pretty pointless? Quote Link to post Share on other sites
Ricky@Race-Tech Posted January 15, 2013 Share Posted January 15, 2013 so after we have started the first stages of development for our inlets, im lloking for peoples opinions on inlet design. i found a thread that was done by an evo specialist about different types of inlet and the design of the inside etc so it seems from this guys findings that velocity stacks dont really work but decrease power and torque thread is here its quite a good read http://highboostforum.com/forum/showthread.php/20866-Intake-manifold-dyno-tests-and-facts-only goes rather in depth as to what the inside of an inlet is like and how one should be made for optimal flow. all of the runs were done on the sam car, engine, spec the only difference being the inlet. thoughts, discuss I'll keep this brief as i'm just in the middle of mapping a car. (500hp one) The guy on the forum makes his own intakes. Velocity stacks are difficult to make and use correctly. As you have found. Look at the "better intakes" I.e. high end £2000+ stuff. Or f1... F1 turbo era etc you will find them. Velocity stacks still looks the dogs, can't understand how they would be worse tho, your chaging the turbo inlet to a larger diameter so letting in more air and at a greater speed due to going from say 3" to 2" forced induction ect... So its hard to see where that's not a better thing It does seem simple at first, there are more indepth advantages also. I meant stacks in the intake plenum dude stacks on the turbo then yeah they serve a purpose, just cant see the purpose in an inlet :S I'm not sure how you can see an advantage on a turbo, but not on an intake? The principle is exactly the same. Difficult to explain but... Personally I don't see the point in having the velocity stacks protruding into the intake manifolds actual chamber. That's only going to cause the fast moving pressurised air to hit a solid object and become turbulent. If the stack was built into the base etc so the top of the stack was flush with the base of the chamber, makes much more sense. __________ _\ / _\. /_\. /__. < bad _______________ __. _. __. __. < good. \. /. \. /. \. / If you do feel like using my design, remember to add a 4th stack. Cheers. Edit: automatically deletes my spaces but you get he gist. I also looked at this. However the protrusion is the most important part. Think of it like this, in your way, the air has a 180 degree plain in which to be sucked in. With protrusion it has 270 degrees approx. This is more for balance at lower speeds and to improve spool. exactly what i thought dude to be honest. i would see them as more of a restriction if positioned protruding out of the intake runners but like you say if they were flush on the inside it would be alot better Do some reading on fluid dynamics, you will soon see the advantages. Our cheaper intakes have flush velocity stacks like you mention, its just CNC machined into the plenum plate, like on the miata thread. Bit off topic here but surely if your pressurising the inlet the flow would pretty much stay the same? Surely only a 4e can move a certain ammount of air fuel mixture? The way I understood it if your running say 1bar of boost the engine in effect becomes a 2.6l? I thought to improve flow on a turbocharged engine you had to make the exhaust flow better as the inlet is already taking in as much as the engine can take? Any one want to give some devine inspiration as I think velocity stacks on anything other than a n/a are pretty pointless? Exactly, the pressure makes no/very little difference. People think you are double flow to double power, this would be nice, but you can't, so you have to increase pressure. A lot of my flow analysis is on the other PC. But here is some on a very early design before we angled them. It's not the best to show this as most of it is high flow testing. But you can see much of the airflow comes from below the level of the stack. The reason they protrude. Quote Link to post Share on other sites
ro55ifumi Posted January 15, 2013 Share Posted January 15, 2013 ^^^^Quality input Ricky Cheers John Quote Link to post Share on other sites
turbo Grant Posted January 15, 2013 Share Posted January 15, 2013 I've got stacks in mine Quote Link to post Share on other sites
pick1 Posted January 15, 2013 Share Posted January 15, 2013 This is turning into a good topic to read Quote Link to post Share on other sites
Flaminsam Posted January 15, 2013 Share Posted January 15, 2013 Not sure if any one is aware of the range rover v8? On the n/a engine the inlet or plenum uses velocity stacks. On the supercharged v8 the velocity stacks are removed. The reason is Because of the forced induction. Quote Link to post Share on other sites
morgey Posted January 15, 2013 Share Posted January 15, 2013 N/a loves v/stacks and they sound soo good Quote Link to post Share on other sites
Ricky@Race-Tech Posted January 15, 2013 Share Posted January 15, 2013 Not sure if any one is aware of the range rover v8? On the n/a engine the inlet or plenum uses velocity stacks. On the supercharged v8 the velocity stacks are removed. The reason is Because of the forced induction. I'm not up on Rover's to be honest. But there will be more to it than that, probably room/cost. As said before. It doesn't matter if the pressure is 1 bar or 10 bar the same basic principles apply. An n/a engine effectively has 1 bar of boost, (atmospheric), at 2 bar, (what would normally be seen the 1 bar of boost) if the flow is the same the power output will double. I dare say the rover V8 supercharged is far less efficient than the n/a engine. Quote Link to post Share on other sites
mattyD Posted January 15, 2013 Share Posted January 15, 2013 Ricky, any chance you can post pictures of your standard and race spec inlet to show how they differ? Quote Link to post Share on other sites
Addymk2 Posted January 15, 2013 Share Posted January 15, 2013 On the other hand Ricky, as seen on the Emerald site, the length of the stacks was tested on the software. When on the dyno the car performed in a different manner to how the system expected the stacks to perform. Which, IMO means that the software can only be referred to as a rough guestimate as to the speed with which the air is entering the chamber. The only real way to find out would be to dyno the same car back to back with the different inlet manifolds. A back to back dyno of the standard and race spec inlet manifolds would be ideal aslong as they utilised the same throttle body etc. Quote Link to post Share on other sites
shorty Posted January 15, 2013 Share Posted January 15, 2013 my inlet also uses stacks and mine is the same make as the one wepr sold a little while ago, and sacha had good results from it. i also belive zisco use stacks. tbh alot of flowtesting and money goes into inlet r and d as far as i understand it. its not as simple as building a box with stacks in and welding some runners on. quite a science to air flow/pressure. Quote Link to post Share on other sites
Ricky@Race-Tech Posted January 15, 2013 Share Posted January 15, 2013 There are viarables of course. But you can work backwards to know the exact airflow. I also have a velocity probe, so know exact gas speeds and where. This backs up my data, and from this, I can work out using the X sectional area of the pipe and the speed an exact volume also if required. I have made 3 versions of our Race Spec intakes.This all costs money, time and effort. Most of which goes without being noticed. And the guy in china polishing cheap aluminium gets credit for making untested crap products selling for £100.Back to back testing is pretty much useless also. You have to remap. I don't know if you saw recently 30hp change in power from back to back testing oils.On the other hand Ricky, as seen on the Emerald site, the length of the stacks was tested on the software. When on the dyno the car performed in a different manner to how the system expected the stacks to perform. Which, IMO means that the software can only be referred to as a rough guestimate as to the speed with which the air is entering the chamber. The only real way to find out would be to dyno the same car back to back with the different inlet manifolds. A back to back dyno of the standard and race spec inlet manifolds would be ideal aslong as they utilised the same throttle body etc. Quote Link to post Share on other sites
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