xB / xA Sheet Metal Intake Manifold..
For those of you that say make it rounder...As WR stated, the whole back side of this is rounded...and this could be part of the problem! If you look at other sheet metal intakes, MOST are square shaped with very sharp corners compared to this one. I have noticed that they also taper off towards the last runner. Also, for more power, they are running shorter runner lengths.
Actually, a more rounded plenum makes for better power and response. Most aftermarket intake manifolds are a square shaped design purely because of the ease and cost of construction. The rounder and smoother the transitions are on the inner walls of the manifold, the better power you can expect.
Originally Posted by WeaponR_Ray
Actually, a more rounded plenum makes for better power and response. Most aftermarket intake manifolds are a square shaped design purely because of the ease and cost of construction. The rounder and smoother the transitions are on the inner walls of the manifold, the better power you can expect.
make the main part a little longer. it lookes like it was too short and the last runner had to be put in a different angle....
keep the spacing and angles the same for all the runners (mostly a cosmetic thing i know, but when you show your car this makes it just that much better.)
taper the main part as it moves away from the TB. this should help keep the velocity even to all the runners.
Originally Posted by macdaddy
none of us here have studied air theory,
there are plenty of engineers here.
airflow inide a confined space is not that hard to understand.
it is just a matter of a vacuum or pressure application.
I would think that in order to tune the intake to perform better at higher rpm, you should shorten the length of the runners. I have a taurus sho and one of the main tricks of the engine is the intake. It has two intake runners to each piston; a longer one that is open 0-3999 rpm; and a shorter secondary that is open at 4000-redline rpm. From what I have read, the intake charge goes into the cylinder when the valve is open. When the valve shuts, a pulse wave is reflected back up the runner till it hits the first major stop and then travels back down the runner. This pulse is traveling at the speed of sound, approximately. To "tune" the intake is to make the runner a certain length so that at the desired rpm, the pulse is slamming back into the valve just as it opens. Since this is the case, the length of an intake runner can only be optimum at one rpm. From the pictures of the intake, it looks like the runners are longer than stock, so I would expect that the optimum rpm for this intake to be lower than stock, hence, you would lose some mid and top end from stock. I would think that the trick for this engine is to make it the optimum runner length for maximum hp at around 3500-4000 since this is where the VVTi stuff starts to happen, or so Ive read. Also, this is where my xA is in the rpm range at 80 mph, hehe.
Ive also read that this is same thing with exhaust tuning (length from valve to cat or first major stop in header or manifold), but Im not sure about this.
Ive not had my stock xA intake off to look at it, but it looks to me that the runners are all different lengths, which would mean that the cylinders all have different optimum rpms, but I could be very wrong about this.
No, Im not an engineer, this is just stuff Ive read. Could be wrong.
Ive also read that this is same thing with exhaust tuning (length from valve to cat or first major stop in header or manifold), but Im not sure about this.
Ive not had my stock xA intake off to look at it, but it looks to me that the runners are all different lengths, which would mean that the cylinders all have different optimum rpms, but I could be very wrong about this.
No, Im not an engineer, this is just stuff Ive read. Could be wrong.
Originally Posted by dgHotLava
Originally Posted by macdaddy
none of us here have studied air theory,
there are plenty of engineers here.
airflow inide a confined space is not that hard to understand.
it is just a matter of a vacuum or pressure application.
well, i shouldn't have said none of us, but guessing at what will make it better isn't a good idea. your ideas are good, but some of the other ones were a little dodgy.
Originally Posted by macdaddy
none of us here have studied air theory, which brings me to my question, did you guys hire a HVAC engineer for the design of the intake, or is it being produced on a trial and error basis?
Yeah, I'm an engineer.
Originally Posted by WeaponR_Ray
Actually, a more rounded plenum makes for better power and response. Most aftermarket intake manifolds are a square shaped design purely because of the ease and cost of construction. The rounder and smoother the transitions are on the inner walls of the manifold, the better power you can expect.
^^^ ANY "sheetmetal" intake is not cast... it's "sheetmetal". Hence the name. I think they were reffering to the sharp corners that I had mentioned in an earlier post.
The ones you speak of are 'cast' for faster easier production.
The ones you speak of are 'cast' for faster easier production.
I haven't seen the inside of the stock manifold yet, but I wonder about the consequences of replacing plastic with metal. I have read about heat transfer issues from the engine to the incoming fuel/air, but that has mainly been regarding FI.
Will the heat transfer matter with NA?
For the FI people, will it matter for them?
Will the weather drastically affect performance (i.e. summer versus winter temperatures)?
Maybe some cooling fins are in order ;)
Will the heat transfer matter with NA?
For the FI people, will it matter for them?
Will the weather drastically affect performance (i.e. summer versus winter temperatures)?
Maybe some cooling fins are in order ;)
Originally Posted by x_rayted711
^^^ ANY "sheetmetal" intake is not cast... it's "sheetmetal". Hence the name. I think they were reffering to the sharp corners that I had mentioned in an earlier post.
The ones you speak of are 'cast' for faster easier production.
The ones you speak of are 'cast' for faster easier production.
i understand that but he had said most aftermarket intake manifolds. most aftermarket intake manifolds seem to be cast. as to why i referred to them lol







