Crazy Plenum Update - More Sillyness Finding Power
11-26-2009, 08:20 AM
#22
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I have a very good idea as to what happened and what was not workable on it, as it was my money and my time that was lost (substantial amounts of both). I made a decision to abandon the ITB's for a variety of reasons, as I posted in my own build thread several times. I went in a different direction, and that is exactly where I am going to leave it.
12-29-2009, 06:54 AM
#27
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Are you still running MAF or is this using MAP? Even if it's MAP, wouldn't you have a lot of uncontrolled air coming in the engine? It would probably work at high RPM, but can it idle at a reasonable rpm? Anyways, this is definitely interesting stuff.
Edit: read the old thread, alot of the questions answered. So with this new manifold will the engine idle with the hole open, or do you still have to seal it when the rpm is low?
Edit: read the old thread, alot of the questions answered. So with this new manifold will the engine idle with the hole open, or do you still have to seal it when the rpm is low?
Last edited by S12 driver; 12-29-2009 at 06:59 AM.
12-29-2009, 06:55 AM
#28
I'm Working on it guys.
Got a 90mm LS2/7 throttle body that I can use and if it makes good power with a custom plenum we're working on, perhaps I will try to find a way to bring it to market. We know the stock intake is only good for 280whp at which point it starts to become a 15-30hp restriction, so if the demand is there for power this is a good product to bring to market!
Got a 90mm LS2/7 throttle body that I can use and if it makes good power with a custom plenum we're working on, perhaps I will try to find a way to bring it to market. We know the stock intake is only good for 280whp at which point it starts to become a 15-30hp restriction, so if the demand is there for power this is a good product to bring to market!
12-29-2009, 09:10 AM
#29
I'm Working on it guys.
Got a 90mm LS2/7 throttle body that I can use and if it makes good power with a custom plenum we're working on, perhaps I will try to find a way to bring it to market. We know the stock intake is only good for 280whp at which point it starts to become a 15-30hp restriction, so if the demand is there for power this is a good product to bring to market!
Got a 90mm LS2/7 throttle body that I can use and if it makes good power with a custom plenum we're working on, perhaps I will try to find a way to bring it to market. We know the stock intake is only good for 280whp at which point it starts to become a 15-30hp restriction, so if the demand is there for power this is a good product to bring to market!
12-31-2009, 10:19 PM
#30
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Anyone here familiar with a box style manifold? Basically velocity stacks and a creative simple plenum. Sort of like the E60 M5 setup with or without the twin filters.
01-20-2010, 10:07 AM
#36
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I thought he was planning on using the stock lower plenum. It looks a bit tall for strut bars, although I could be wrong.
What is your reasoning for the seemingly small volume where it splits into L and R banks? Is it to speed up the air so it can sufficiently feed the front 2 cylinders? If not, will this plenum fix the 2 front cyl starvation issue that's present in the DE engines without a spacer?
Lastly, why not design an entirely new plenum rather than refining an existing one? Cost issue? Time issue?
What is your reasoning for the seemingly small volume where it splits into L and R banks? Is it to speed up the air so it can sufficiently feed the front 2 cylinders? If not, will this plenum fix the 2 front cyl starvation issue that's present in the DE engines without a spacer?
Lastly, why not design an entirely new plenum rather than refining an existing one? Cost issue? Time issue?
01-20-2010, 11:18 AM
#39
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plenums, cams and exhaust manifolds all go hand in hand in hand - when you start getting into the upper echelons of power, as on say Fontana's car, or a 380rsc, etc, it becomes impossible to just mix and match -they all must be spec'd to work together
01-21-2010, 07:44 AM
#40
Hey guys, thanks for all the comments! It sure is interesting isn't it?
Jason from Carbotron did the flow analysis. The volume is really getting up there so we tried to remove it wherever possible. Jason concluded from some CFD tests that the majority of the flow parts to each bank at the elbow and a ton doesn't flow through the center section of the plenum, so some volume removal was OK there. Of course this is just what a computer is telling us based on the data we've fed IT. We won't know if it's actually working until the wideband goes way lean on throttle and I say HOT DAMN! TIME TO ADD FUEL SHES WORKIN!
The fontana car is incredible. Note how low and far back the engine is. Inner brake/battery sheet metal? Not there anymore. Now go draw a line across your engine where their strut tower bar is. You'll find you are mighty close to the time chain cover if not directly on it! Incredible really. It's inspiration for sure.
The idea behind this plenum is to see how much of the ~30whp we can get back from the open plenum test, and when the stock intake manifold/lower plenum runs out of steam. We can then try the revup and see if at higher RPM the shorter and larger runners start to out perform the non-revup.
Remember guys, this is a stock engine. Stock compression. Stock rods. Stock Crank. Stock heads. All that's done to it are Nismo cams. Once we figure out what makes the most power and why, we can figure out how to bring it to market at a reasonable cost for the guys that want to have fun at the track, drag racing, etc. Making it applicable to street cars might be a bit more difficult, especially with the 90mm throttle body. But we'll see!
I might test this plenum/TB in the next few days and find surprisingly it makes no power. But it's research and development. I'm learning, which is great, and its fun as hell.
The plenum is actually quite simple, the idea is to just offer the runners an open area of air to breathe from that is unrestricted by other cylinders, by the walls of the plenum, or by a restriction into the plenum. Once that goal is reached and you have a good baseline, you can work on streamlining and flow analysis to keep velocity up in the plenum, and try to effectively ram air into the cylinders, as well as a whole bunch of other stuff that is WAY above my head. The less volume the plenum has (on a single throttle body engine) the more responsive the throttle will be. This is another reason you want to remove as much plenum volume as possible.
That may prove to be a very real issue on this plenum at low engine speeds, since we are placing the throttle body somewhat down the line (because of space restraints).
Anyways, I'm getting a bit ahead of myself. I'll keep you all updated!
As far as the front strut brace, I've been running without one for the last 2 seasons and I'll have to do a back to back test to see if I notice a difference. I believe the factory chassis was stiff enough for the grip I was making previously. But now with real slicks and more aero I'm sure it'll become a requirement. But I can just make a strut brace around the engine. Or through it? Lol.
It's a compromise, I'm not willing to lose 5hp for a strut tower bar of which I cannot measure the gains. If I start seeing spot welds shearing, well i'll know I was wrong!!!
Jason from Carbotron did the flow analysis. The volume is really getting up there so we tried to remove it wherever possible. Jason concluded from some CFD tests that the majority of the flow parts to each bank at the elbow and a ton doesn't flow through the center section of the plenum, so some volume removal was OK there. Of course this is just what a computer is telling us based on the data we've fed IT. We won't know if it's actually working until the wideband goes way lean on throttle and I say HOT DAMN! TIME TO ADD FUEL SHES WORKIN!
The fontana car is incredible. Note how low and far back the engine is. Inner brake/battery sheet metal? Not there anymore. Now go draw a line across your engine where their strut tower bar is. You'll find you are mighty close to the time chain cover if not directly on it! Incredible really. It's inspiration for sure.
The idea behind this plenum is to see how much of the ~30whp we can get back from the open plenum test, and when the stock intake manifold/lower plenum runs out of steam. We can then try the revup and see if at higher RPM the shorter and larger runners start to out perform the non-revup.
Remember guys, this is a stock engine. Stock compression. Stock rods. Stock Crank. Stock heads. All that's done to it are Nismo cams. Once we figure out what makes the most power and why, we can figure out how to bring it to market at a reasonable cost for the guys that want to have fun at the track, drag racing, etc. Making it applicable to street cars might be a bit more difficult, especially with the 90mm throttle body. But we'll see!
I might test this plenum/TB in the next few days and find surprisingly it makes no power. But it's research and development. I'm learning, which is great, and its fun as hell.
The plenum is actually quite simple, the idea is to just offer the runners an open area of air to breathe from that is unrestricted by other cylinders, by the walls of the plenum, or by a restriction into the plenum. Once that goal is reached and you have a good baseline, you can work on streamlining and flow analysis to keep velocity up in the plenum, and try to effectively ram air into the cylinders, as well as a whole bunch of other stuff that is WAY above my head. The less volume the plenum has (on a single throttle body engine) the more responsive the throttle will be. This is another reason you want to remove as much plenum volume as possible.
That may prove to be a very real issue on this plenum at low engine speeds, since we are placing the throttle body somewhat down the line (because of space restraints).
Anyways, I'm getting a bit ahead of myself. I'll keep you all updated!
As far as the front strut brace, I've been running without one for the last 2 seasons and I'll have to do a back to back test to see if I notice a difference. I believe the factory chassis was stiff enough for the grip I was making previously. But now with real slicks and more aero I'm sure it'll become a requirement. But I can just make a strut brace around the engine. Or through it? Lol.
It's a compromise, I'm not willing to lose 5hp for a strut tower bar of which I cannot measure the gains. If I start seeing spot welds shearing, well i'll know I was wrong!!!
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