Dude, you forgot to include anything usefull about exast setups, and how just having a really high flow exaust doesn't automatically mean more power. You know, exaust scavenging, and velocity, stuff like that. It's amazing how many people don't know what equal length headers are, or why there made that way.
I couldn't really find anything "incorrect" about the writeup, exept for the fact it was confusing. (I really didn't read much of the forced induction part though). I completely understand how intake and exaust performance work, I just have a hard time explaining it also.
Although I agree with almost everyone in some way (talking about the argueing), it does get old when people start fighting. Although to be honest, when I saw this stickey, I just lauphed thinking WTF, why is this here, which is why I havn't read it until now. It would be usefull if worded so people that don't know anything about this stuff could understand better, and was more complete.
OH ya, stop creatin bitch fests guys. It's lame.
Weebel wrote:Dude, you forgot to include anything usefull about exast setups, and how just having a really high flow exaust doesn't automatically mean more power. You know, exaust scavenging, and velocity, stuff like that. It's amazing how many people don't know what equal length headers are, or why there made that way.
I couldn't really find anything "incorrect" about the writeup, exept for the fact it was confusing. (I really didn't read much of the forced induction part though). I completely understand how intake and exaust performance work, I just have a hard time explaining it also.
Although I agree with almost everyone in some way (talking about the argueing), it does get old when people start fighting. Although to be honest, when I saw this stickey, I just lauphed thinking WTF, why is this here, which is why I havn't read it until now. It would be usefull if worded so people that don't know anything about this stuff could understand better, and was more complete.
OH ya, stop creatin bitch fests guys. It's lame.
I respect what you've said
It might sound confussing because it was 5 am and I had no sleep but I was kind of writing in a run on matter. I would say something and then forget to mention something else and try to explain it. I typically don't do any type of rough drafts but I do apologize for that. Most of the people I've talked to said they understood it.
Like I said, Dave wanted to sticky it. I even told Dave to take it down but he refused to. He read it and thought it was useful cause like you said that most people don't know or understand this stuff.
Thanks for your opinion.
www.kronosperformance.com / 732-742-8837
Ya, all the problems aside.....at least your trying....wich is the point most people seem to overlook.
Weebel wrote:Ya, all the problems aside.....at least your trying....wich is the point most people seem to overlook.
Thank You
www.kronosperformance.com / 732-742-8837
THANK YOU FOR THE POST NJHK IT WAS VERY BENEFICIAL!!!, SCREW ALL THE JEALOUS FOOLS WHO CRITIZE YOU!!!!! (they just mad cuase theirs didnt get stickied and they are bored so they pick on ya)
grow up kids, and stop picking on somone whos just trying to help.
thanks again adam
DarqFire Z24 wrote:THANK YOU FOR THE POST NJHK IT WAS VERY BENEFICIAL!!!, SCREW ALL THE JEALOUS FOOLS WHO CRITIZE YOU!!!!! (they just mad cuase theirs didnt get stickied and they are bored so they pick on ya)
grow up kids, and stop picking on somone whos just trying to help.
thanks again adam
You're welcome
www.kronosperformance.com / 732-742-8837
Hey TGM.. Most of if not everything is correct, the only problem is that most people won't be able to put any of the info to use without reading a book first.
But, too answer you question, there is no point, people are / where just being pissy. If you've ever tried explaining things about this subject, it's hard ass all hell to do without confusing people. Intake and exaust flow has to be pictured visually in your head to understand it, you can't just go by general rules and math, and still fully grasp the concept. Which is why 2 people tend to argue about things like backpressure, not realizing the whole time there both trying to prove the same thing, but there just looking at it differently, which is what is happening here.
Again.... there is no point to people bashing this other than they just don't understand what he's saying, and instead of trying to simplify it, or add to things he left out, people just say "get rid of it".
As far is it's stickyworthyness? Does it really matter?
Ok, though I understand what you're saying about the resonating effect, I'm just confused as to why a smaller diameter intake runner would be preferred in a NA engine. From what I know a relatively basic concept in fluid mechanics is that higher velocity results in a lower pressure, caused by the vacuum effect most likely, which also creates more work for the engine to draw in air (kinda like sucking air through a smaller straw), which is kind of like the engine fighting itself. But by having a larger diameter intake would the mass flow rate of the intake not be increased? Combining this with the energy in the air (being compressed) plus the fuel's contribution to the overall energy of the system I think that it would result in a greater overall energy exiting the crankshaft going to the wheels, essentially reducing the resistance in the engine.
I'm not trying to pick apart your post, but maybe you know something that I don't that might clear my doubts and I might be able to put it all together.
^^^ basically... the more velocity there is.... the less turbulence there is.
Lets say that the intake on a given engine if open (free flow) just enough for maximum flow and would be pointless to open it up any more. If you where to widen the runners any more... you would start to experience more air turbulence in the runners which in turn would decrease the amount of air that is able to efficiently enter the engine.
Just because you can breath in faster.. doesn't mean your getting more air.
So basically you don't want a runner that has any more area than the combination of intake ports so you don't get any flow 'eddies' at the entrance to the cylinder?
^^^^
sort of.... but it's a little more complicated than that ... you get the idea though..
You wan't enough vaccum in the intake for the air to pull istelf into the engine smoothly.
This is a streatch but sometimes it helps to look at it this way...
imahine that your engine is sucking water through the intake.... if it's too small of a diameter, ar shaped in a way that deverts flow too much. and the water starts to swirl or back up on itself.. you will get less water through it..
On ther other side... even if the inside of the intake is smooth without any sharp angles... if the diameter of the runners is too wide.. you will get air pockets and the water wont be able to be sucked through efficiantly because there isn't enough vaccum to pull all that water through that big of an opening smoothly.
Air acts differently than water.... but thats the similest way that I can think of explaining it... you just need to think of air as something tangeble that you can see.
Ya, it could get really complicated lol... you'd have to take into account the density of the air, mean velocity of the air, length of the flow, and the viscosity of the air, in order to obtain a reynolds number below that which would keep you in the laminar flow region and not turbulent flow. Not to mention any pressure drops and changes in velocities that result from bends or sharp corners like you said.
But I really don't want to attempt to try to make it that complicated lol. for the extra... 5 hp you might get from sizing your intake to the exact size, if that much.
^^^^ thats the problem.... if the engine ran at the same RPM with the throttle open the same amount all the time it would be worth it... but since there are so many variables to consider... you just have to do your "best guess" for max flow at whatever rpm most your horsepowers is being made.
^^^ This is why i was considering making a variable exhaust vlave for a school project once.
your exhaust pipe is the same type of idea that you were all just talking about. there are fomulas and tests that can be conducted to determine what is the ideal size of pipe you would need. exhausts and intakes are sized like this in theory too i would assume, but like you said, the final size is based upon an average size or where the maximum flow is needed, etc.
in my theory, if you sized the pipe for absolute maximum flow that the engine is capable of outputing (could also be sized larger for future considerations), then maximum flow would be met (obviously). then, a valve or diaphragm could be made to vary the size of the pipe for how much exhasut gasses would be flowing out and a d/p cell (with some adjustments of course) could be used to adjust the opening of the vlave.
voila! you now have a variable exhaust that should work for maximum power and flow at all rpm.
it was just an idea i never went through with, but sounds pretty good in theory.
1997 RedR - ZedR
^^^ that actually works (although prbably a little differently than your talking about doing it)
Some cars have done it but the only one I can think of for sure is on Suzuki GSXR 1000 mototrcycles (don't know if they do it anymore though). They used a computer controlled butterfly valve in the exaust to alter backpressure for optimum power throughout the powerband. A problem with crotch rockets has been that all the "real" power comes on really high in the rpms and that was thier way to try and help the problem.
Although that wouldn't work for designing an intake.......
Don't the new Z06 Corvette's have something like that? Or is that just for controlling exhaust noise? I think there are butterfly valves on the exhaust controlled by the vacuum system, but they're positioned after the mufflers.I thought of using this idea for quieting the exhaust, only i wouldn't make it variable, just adjustable. But I have doubts whether that would do anything at all.
After reading the topic post and getting tired of the arguments I just wanna give my 2 cents
I learned quite alot from NJHK's post. One thing it reminded me of is yamaha's genesis engine.
The engine uses 5 valves per cylinder (3 in. 2 ex. I think
) but the thing I'm gettin at is the 3 intake valves have a smaller area than if there was 2. This means more velocity for the same amount of volume. Just think, why is the R1 and R6 so popular?
The R1 and R6 are so popular for 2 reaons...
#1. Yamaha has some of the best finincing you cand find when it comes to taking a loan out on a new bike and they don't cost much
#2. The R6 is the most nimble crotch rocket on the market wich = more fun (and more crashes.... just ask some of my friends)
90% of the people that buy an R1 or R6 don't have a clue about the inner workings of the engine.....
by the way... for those that are wondering....
R1 = Yamaha YZFR1 (1000 cc's) and R6 = Yamaha YZFR6 (600 cc's).... in case your in the market.
Andrew Bell wrote:Ok, though I understand what you're saying about the resonating effect, I'm just confused as to why a smaller diameter intake runner would be preferred in a NA engine. From what I know a relatively basic concept in fluid mechanics is that higher velocity results in a lower pressure, caused by the vacuum effect most likely, which also creates more work for the engine to draw in air (kinda like sucking air through a smaller straw), which is kind of like the engine fighting itself. But by having a larger diameter intake would the mass flow rate of the intake not be increased? Combining this with the energy in the air (being compressed) plus the fuel's contribution to the overall energy of the system I think that it would result in a greater overall energy exiting the crankshaft going to the wheels, essentially reducing the resistance in the engine.
I'm not trying to pick apart your post, but maybe you know something that I don't that might clear my doubts and I might be able to put it all together.
you are correct in the fact that higher velocities lower pressure. but lower pressure actually means LESS work because it has less mass than that of high pressure. and the engine is working to SUCK IN that air.
and u cant really compare straw sizes and ur lungs. the capacity of ur lungs is probably more than 2.4L and ur comparing that with straws LOL. what if u had a straw intake (way too undersized)? Instead try breathing FAST with ur mouth WIDE OPEN and then try with it partially open. the results will be totally different. Ever see a track runner breathing with their mouth as wide open as possible? I HAVEN'T.
Air velocity vs. Air pressure for a given cross-sectional area ISNT a linear relationship. It can only travel so fast (approaching the speed of sound).
Mike Witton wrote:After reading the topic post and getting tired of the arguments I just wanna give my 2 cents
I learned quite alot from NJHK's post. One thing it reminded me of is yamaha's genesis engine.
The engine uses 5 valves per cylinder (3 in. 2 ex. I think ) but the thing I'm gettin at is the 3 intake valves have a smaller area than if there was 2. This means more velocity for the same amount of volume. Just think, why is the R1 and R6 so popular?
ur thinking of area on the wrong plane. valves do not slide out of the way or open like a butterfly valve (this would be horizontal plane area or valve diameter). The fact is that valves open on a vertical plane and the opening boundaries are cylindrical shells. When you observe surface area of these cylindrical shells u will notice that 3 intake valves in fact DO have more area than 2.
i would also like to add this simple equation that helps to explain velocity and flow:
Volumetric Flow = Velocity x Cross sectional surface area
Cubic feet/min = feet/min x feet^2
also a decrease in velocity increases pressure and vice versa.
This is why many race cars have megaphone style collectors. Because when the cross sectional area is a known number and then increases to infinity instantly (open header collector to open air) velocity goes to 0 (see equation), because velocity and cross sectional area have an inverse relationship. When the velocity goes to 0 there is an increase in pressure (good old backpressure) that the oncoming exhaust pulses have to "fight" through causing turbulence.
On the intake side its more about laminar flow.
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EFFICIENCY DETECTIVE
Fast cars. I respect them ALL. Brand elitism is for fanbois and benchracers
daily: 99 civic Si
deceased: 95 cavy '00 LD9 auto swap (vandalized)
So by putting a high flow cat and having a 4 inch exhaust tip without putting performance headers ect screw up the scavenge effect and create that build up in the exhaust system?
I didnt know about any of it and i think i learned a little but i really dont understand it and dont see why people are b!tc(-)ing why dont you post stuff that will help people like me understand it better
haha, i love how people think they are the majority on this site.
"what about the lifter thread for the OHV guys that includes SlowOleJ's LN2/LT1 hybrid lifter how-to? What about the threads like that, that just get thrown by the wayside"
because the VAST majority of jbody owners picked up the hobby from owning a car. and DONT know all the ins and outs of cars so these stickys help. and since the majority of people benefit from it it is a sticky, but since the minority is working with how to's for lifters on a hybrid, that can be tossed to the wayside and you can use that "search" function all you vets are so keen on telling us noobs to use to find that information.
get a clue.
in the meantime, i will read over this helpful thread cause i wanna learn!
-Keep it Cavy-