VAP
04-10-2003, 10:01 AM
<center><img src="http://pictureposter.audiworld.com/711/flaredie1.jpg"></center><p>
I'm expecting my 2-stage flaring die back from the hardening shop this afternoon. All the dies have now been hardened to Rockwell 65 (drill bits are in the Rockwell 58-60 range). So these pieces will be hard, hard, hard... I mean "harder 'n Chinese arithmetic to an english teacher!" Should provide a lifetime of flaring aluminum tubing without so much as a surface scratch or flaw.
The first pic is of the initial flare: Die 1 has been hardened to the above spec then an industrail Teflon coating applied to help prevent marring/scratching of the aluminum tube inner wall. This die will be used to put the initial flare in the aluminum tubing after it has been annealed. That process will likely cause some measure of work-hardening which will then likely require a second annealing to be able to accomodate the second flaring process which will be a two-stage angle below the intakes initial flaring mentioned above.
Die 2 I'll pick up this afternoon. It is the two-stage die I mentioned above. It will create a tapered angle just inside the wide-mouth inlet and roll the first-stage flairing into a more rounded shape. This die will be hardened to the same spec as die 1.
Last week I made up a plastic prototype of the aluminum MAF inlet then heated it and forcing it over the protype dies I made, heat-formed it into the shape I'm going to use for this. After a few corrections and reshaping the dies I was able to create some incredibly dramatic improvements over the original "airhorn" tape MAF inlet. You'll see the results below.
When done, the aluminum MAF inlet will be a true velocity stack MAF inlet with all the features that qualify it as such:
1. Greater volumetric efficiency and resultant theoretic torque increase
2. Boundary layer turbulence and distortions far smoother than a simple simple angled "horn flare"
3. Smoother air stability thru MAF than stock airbox outlet or airhorn design
4. Higher velocity of filtered air thru velocity stack allowing more air to replace it sooner.
5. Velocity stack actually creates more of a "scavenging affect" in that it helps pull air behind it into MAF/induction tract. This can only be improved or enhanced with velocity. Simple volume increases or larger surface area filter media cannot accomplish the same effect.
6. Simple bell-mouth flair flows 12% more air thru the airbox lid than stock design at 400CFM. New velocity stack inlet flows 28% more air at 300 CFM!! Thats a whopping 134% increase over the stock airbox at 25% LESS CFM!! (tested with new stock paper panel filter and airbox intact from grill inlet to airbox outlet).**
7. Allows for stock airbox and paper filter to be retained and a simple 2-3 minute installation with only a screwdriver to unclip airbox lid. Slightly higher gains should be expected with a good aftermarket panel filter.
**(note)
Stock MAF* is the bottle-neck of the entire induction tract and even tho flow-rates upstream of it can be improved and enhanced it doesn't mean that those enhancements can or will materialize at the cylinder on compression stroke or on a dyno bei it of the conventional or "butt". Those results should be verified or not very shortly. I use this example for comparison purposes only.
* (note)
Results of induction tract measurements.
MAF I.D. 2.995"
MAF I.D. minus sampling tube housing and cast cross-housing insert equals a net diameter of 2.248" for air to flow thru (even less if sharp/perpendicular angles and obstruction dynamics are factored in)
Induction hose I.D. at stock plenum intake port 2.361" (smallest diameter just ahead of external clamp) measured inside hose.
Throttle body flange I.D. 3.12"
Secondary bore: 2.110"
Primary bore: (stock) .940"
Ironic the throttle body (IN STOCK FORM!!) and counting for the butterflies and shaft (again IN STOCK FORM) mass @WOT is capable of flowing almost 30% more air than the MAF housing and 17% more than the induction hose!! Dems de facts!
I'll fix the induction hose soon but until/if some measure of MAF flow improvement comes along or someone finds an alternative we're gonna be stifled by diminished flows thru the MAF. I know some have already done some MAF surgery "sampling tube-ectomies" and re-calibration but they are a bit cryptic and secretive... preferring to say they've done it but unable/unwilling to discuss specs/results. Has anyone done that willing to openly share what "exacrtly" was done, how it was done and the empirical or dyno proven results along with fuel/air ratio samplings at various RPM's?? Without some data other than "britches barometer" it's a little risky for any kind of "one-size-fits-all application.
I'm expecting my 2-stage flaring die back from the hardening shop this afternoon. All the dies have now been hardened to Rockwell 65 (drill bits are in the Rockwell 58-60 range). So these pieces will be hard, hard, hard... I mean "harder 'n Chinese arithmetic to an english teacher!" Should provide a lifetime of flaring aluminum tubing without so much as a surface scratch or flaw.
The first pic is of the initial flare: Die 1 has been hardened to the above spec then an industrail Teflon coating applied to help prevent marring/scratching of the aluminum tube inner wall. This die will be used to put the initial flare in the aluminum tubing after it has been annealed. That process will likely cause some measure of work-hardening which will then likely require a second annealing to be able to accomodate the second flaring process which will be a two-stage angle below the intakes initial flaring mentioned above.
Die 2 I'll pick up this afternoon. It is the two-stage die I mentioned above. It will create a tapered angle just inside the wide-mouth inlet and roll the first-stage flairing into a more rounded shape. This die will be hardened to the same spec as die 1.
Last week I made up a plastic prototype of the aluminum MAF inlet then heated it and forcing it over the protype dies I made, heat-formed it into the shape I'm going to use for this. After a few corrections and reshaping the dies I was able to create some incredibly dramatic improvements over the original "airhorn" tape MAF inlet. You'll see the results below.
When done, the aluminum MAF inlet will be a true velocity stack MAF inlet with all the features that qualify it as such:
1. Greater volumetric efficiency and resultant theoretic torque increase
2. Boundary layer turbulence and distortions far smoother than a simple simple angled "horn flare"
3. Smoother air stability thru MAF than stock airbox outlet or airhorn design
4. Higher velocity of filtered air thru velocity stack allowing more air to replace it sooner.
5. Velocity stack actually creates more of a "scavenging affect" in that it helps pull air behind it into MAF/induction tract. This can only be improved or enhanced with velocity. Simple volume increases or larger surface area filter media cannot accomplish the same effect.
6. Simple bell-mouth flair flows 12% more air thru the airbox lid than stock design at 400CFM. New velocity stack inlet flows 28% more air at 300 CFM!! Thats a whopping 134% increase over the stock airbox at 25% LESS CFM!! (tested with new stock paper panel filter and airbox intact from grill inlet to airbox outlet).**
7. Allows for stock airbox and paper filter to be retained and a simple 2-3 minute installation with only a screwdriver to unclip airbox lid. Slightly higher gains should be expected with a good aftermarket panel filter.
**(note)
Stock MAF* is the bottle-neck of the entire induction tract and even tho flow-rates upstream of it can be improved and enhanced it doesn't mean that those enhancements can or will materialize at the cylinder on compression stroke or on a dyno bei it of the conventional or "butt". Those results should be verified or not very shortly. I use this example for comparison purposes only.
* (note)
Results of induction tract measurements.
MAF I.D. 2.995"
MAF I.D. minus sampling tube housing and cast cross-housing insert equals a net diameter of 2.248" for air to flow thru (even less if sharp/perpendicular angles and obstruction dynamics are factored in)
Induction hose I.D. at stock plenum intake port 2.361" (smallest diameter just ahead of external clamp) measured inside hose.
Throttle body flange I.D. 3.12"
Secondary bore: 2.110"
Primary bore: (stock) .940"
Ironic the throttle body (IN STOCK FORM!!) and counting for the butterflies and shaft (again IN STOCK FORM) mass @WOT is capable of flowing almost 30% more air than the MAF housing and 17% more than the induction hose!! Dems de facts!
I'll fix the induction hose soon but until/if some measure of MAF flow improvement comes along or someone finds an alternative we're gonna be stifled by diminished flows thru the MAF. I know some have already done some MAF surgery "sampling tube-ectomies" and re-calibration but they are a bit cryptic and secretive... preferring to say they've done it but unable/unwilling to discuss specs/results. Has anyone done that willing to openly share what "exacrtly" was done, how it was done and the empirical or dyno proven results along with fuel/air ratio samplings at various RPM's?? Without some data other than "britches barometer" it's a little risky for any kind of "one-size-fits-all application.