MONZTER Posted February 21, 2008 Author Share Posted February 21, 2008 now thats looking better, and the pressure drop is much lower than the HKS. getting closer Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted February 21, 2008 Share Posted February 21, 2008 Excellent results on that one!!! The flow appears to be much more evenly distributed. Looks awesome !! Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 21, 2008 Share Posted February 21, 2008 This is frightening, my series of smaller holes on the bottom of my diffuser plate on the 'Home Made HKS Knockoff Plenum' took that same approach! Like I said, I never actually got to hold the thing in my hand, so I could only guess what HKS did inside the box to diffuse the air after it's hitting the baffle/diffuser plate...I figured best I could do was drill a series of holes equal to or greater than the cross sectional area of the feeding pipe from the compressor! That looks pretty good! I think the key is to diffuse it through that series of smaller holes. I think the HKS Plenum I have can be easily modified to work that way as well... Quote Link to comment Share on other sites More sharing options...
TimZ Posted February 21, 2008 Share Posted February 21, 2008 So I took Monday and Tuesday off and took the family to Palm Springs. We stopped at the WWII airplane museum. Some really beautiful stuff in there. Anyway, I was checking out all of the intakes and air scoops on the planes. One thing they all had in common was the inlets for the radiators. All of them had a deep honeycomb "grill" that acted as flow straightners to the turbulent air. Hmm this gives me an idea. Jeff That is a nice museum - I took my family there about a year and a half ago. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted February 21, 2008 Share Posted February 21, 2008 How would it work if instead of the air coming in from the bottom it came in looking directly into the intake? The velocity of the air would add to the intake pressure and should increase the charge to the cylinder. Now after your modeling of the 4x4 box, I think I am going to add a diffuser pipe down the center of it with a 1-1/2" hole looking at each carb throat. I too vote for this post to become a sticky. Quote Link to comment Share on other sites More sharing options...
MONZTER Posted February 21, 2008 Author Share Posted February 21, 2008 How would it work if instead of the air coming in from the bottom it came in looking directly into the intake? The velocity of the air would add to the intake pressure and should increase the charge to the cylinder. Now after your modeling of the 4x4 box, I think I am going to add a diffuser pipe down the center of it with a 1-1/2" hole looking at each carb throat. I too vote for this post to become a sticky. I don’t know what you mean about the air coming directly into the intake? Part of the design of the air going into the bottom is that it works with the cone to distribute the air evenly. Typically as velocity goes up, pressure drops. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted February 21, 2008 Share Posted February 21, 2008 You have a pressure drop when going through any change of diameter. To get from the first chamber to the second chamber there is a restriction area. The ramp in and out will cause friction and create a pressure drop. The air going through the vent section should have a much higher velocity. Having this point at the intake ports should force air into the intake ports, it would be like using cowl induction uses the pressure at the base of the windshield to add air to a carb. From my fluids class years ago, this seams right. Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 21, 2008 Share Posted February 21, 2008 My box had the air coming in from the fenderwell side, with a diffuser plate that went lengthways, kind of like the SK Comp Turbo box you had pictured earlier. You would vent from the inlet side of the diffuser, while the carb throats would draw from behind the diffuser plate. Like I said, I drilled holes at the bottom of the diffuser plate to let the air flow underneath it, and diffuse through the little (er, 3/8" 10mm, but LOTS of em!) holes to the main chamber on the carburettor side. This box worked REALLY well compared to the straight 2X4 plenum bolted to the front of the carbs that I later (stupidly) changed to...and I thought it was some sort of 'upgrade'! LOL I wonder how atrocious the flow is in a 2X4 straight box...yeech! Anyway, my box the air entered the center of the plenum through a single hole (the HKS box shows that maybe 2, 2" holes are better) pointing at the diffuser plate that was angled around 60 degrees inside the plenum which was 2.5 to 3" deep (as I recall, it's 2200 miles away right now). On the bottom of the diffuser plate, about 1/4 of the way from the bottom of the box (which I believe was 5 or 6" tall, and roughly 24 or 28" long) the diffuser bent toward the front of the box---it was bolted with a 1/4" stiffener at the top and bottom to the removable front cover, and there was a flange about 3/8" wide on the box where I used like a million M6-1.0 stainless steel metric bolts to hold it together under the tremendous pressures I was planning to run (yeh...) I believe in this instance, a photo would be worth 1000 words. I think blowing air directly at the carb throats will cause problems, I'd place a segregated baffle in there at least. The whole idea of the box is to allow residence time and let diffuse pressure fill the cavity so the air going down the throats is evenly distributed and without much velocity other than what the engine is calling for at WOT. i might be wrong on that, but it doesn't seem like directly blowing the pressurized air down the carb throats will be too advantageous. The air in the vent section has slightly higher pressure due to the size holes, as you want higher pressure in the vent section to enrichen the mix through raising the fuel level in the jet well (pressure differential greater than what normally would be there from the venturi effect). This is why the HKS box enrichens under boost with much smaller jets, letting you run 350 HP to the rear wheels and still get 17mpg in daily beat the heck out of it driving down Carbon Canyon twice daily back and forth from Corona to Brea.... Remember MonZster is designing a plenum for EFI ITB's and his goals will NOT be the same as someone running Carburettors. The carb guys will want the difference in pressures to allow for the float bowl air pressure to be slightly higher, and therefore you MUST have SOME restriction to flow before the main plenum area the carb throats draw from. What may be possible is using the EFI plenum, and like your box is set up SHO, running that Carb Vent Line from the super-high pressure inlet piping red-zone just before the box (or at the elbow where pressure 'backs up') that would probably allow sufficient pressure differential that would allow you do 'dial in' the differenital using those variable orifices we talked about some time...(er, valves in the lines to the float bowl covers I think). Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 21, 2008 Share Posted February 21, 2008 blah blah blah blah blah blah, and hit an "L" Shaped baffle plate that directed it to the floor of the plenum, where it diffused through a seried of holes drilled in the 'foot' of the "L". blah blah blah blah, blah blah blah blah... Ohh, post five. LOL I'm repeating myself. Argh! Quote Link to comment Share on other sites More sharing options...
Noddle Posted February 22, 2008 Share Posted February 22, 2008 So I took Monday and Tuesday off and took the family to Palm Springs. We stopped at the WWII airplane museum. Some really beautiful stuff in there. Anyway, I was checking out all of the intakes and air scoops on the planes. One thing they all had in common was the inlets for the radiators. All of them had a deep honeycomb "grill" that acted as flow straightners to the turbulent air. Hmm this gives me an idea. Jeff Have you ever watch mythbusters when they play with high speed "wind/air", they cut boxes of straws in half and direct the "wind/air" through them, something to do with reducing turbulence. Nigel Quote Link to comment Share on other sites More sharing options...
MONZTER Posted February 26, 2008 Author Share Posted February 26, 2008 Ron asked if I would run a test on his revised plenum. I thought it would be interesting to compare his revised design with his old design. I also thought it would be interesting to compare this single throttle open plenum design to what I am trying to do, as well as the HKS. Here is a link to Rons old results and pictures below of his new design http://forums.hybridz.org/showthread.php?t=117607 Picture of his old design Some pictures of his new design - 5 psi 20 psi As usual, click on the picture for a bigger view. Looking for comments, and yes Ron gave me permission to post his results, thanks Ron:D Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted February 26, 2008 Share Posted February 26, 2008 Have you ever watch mythbusters when they play with high speed "wind/air", they cut boxes of straws in half and direct the "wind/air" through them, something to do with reducing turbulence.Nigel I remember that. They did it with their home made wind tunnel experiment. I think the idea was that the air from the fan swirled and had tons of turbulence, but if they forced the air from the fan to funnel into tons and tons of straws, the air would evenly distribute itself. so instead of swirling the air would get funnel, sorted,then exit pretty evenly. Much like with the plenum with the many slots monzter came up with. it's sort of like if you took a ton of straws, and blew through all them. No matter how twisted and curvy they are up to the point where they came from, when they exit, they'll all exit straight. I guess it's a form of ducting? Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted February 27, 2008 Share Posted February 27, 2008 i wonder how my manifold would perform... hmm Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted February 27, 2008 Share Posted February 27, 2008 when you going to put that on proxlamus??? Quote Link to comment Share on other sites More sharing options...
Globerunner513 Posted March 5, 2008 Share Posted March 5, 2008 This whole thread is really intriguing to me. Looks like some real progress is being made. Awesome! Quote Link to comment Share on other sites More sharing options...
texis30O Posted March 5, 2008 Share Posted March 5, 2008 but what I want to konw is if anyone is going to make an of these in numbers for others to purchase? Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 6, 2008 Author Share Posted March 6, 2008 Just a little update. Been working non stop on the design trying to get it perfect. I have the flow really balanced out nicely between all runners. Now I am just looking at pressure drop, and total flow. I should be posting some final results of this design as well as all the other designs tested in my research. As far as making a quantity of these! It was never my intention to make any more than 1 for myself, but provide the information to the group to use it in the creation of their own designs. I am not really into the idea of using the forum as a sales tool as much as I am into it as a fantastic knowledge base. Quote Link to comment Share on other sites More sharing options...
Accurate Injection Posted March 6, 2008 Share Posted March 6, 2008 Excellent Work! Kevin Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 6, 2008 Share Posted March 6, 2008 Jeff, if the HKS Type 2 was to have a series of holes bored in the wall separating the upper plenum from the lower plenum, what kind of flow icrease/improvement would there be? Reason I'm asking is the Type 2 will be going on those HKS ITB's, and I really have no need for the restriction in the upper plenum...but would like a better flowing 'period correct' looking piece when I install it on my 73. I'm thinking I can access the wall with a drill bit through the carb openings, and then enlarge the holes by hand with a right angle die grinder. Yes, I could use the Type 1 in the application, but the Type 2 is what HKS was hawking for the ITB's when they came out. Thanks! Quote Link to comment Share on other sites More sharing options...
MONZTER Posted March 6, 2008 Author Share Posted March 6, 2008 Jeff, if the HKS Type 2 was to have a series of holes bored in the wall separating the upper plenum from the lower plenum, what kind of flow icrease/improvement would there be?Reason I'm asking is the Type 2 will be going on those HKS ITB's, and I really have no need for the restriction in the upper plenum...but would like a better flowing 'period correct' looking piece when I install it on my 73. I'm thinking I can access the wall with a drill bit through the carb openings, and then enlarge the holes by hand with a right angle die grinder. Yes, I could use the Type 1 in the application, but the Type 2 is what HKS was hawking for the ITB's when they came out. Thanks! Tony, I'll add some holes in the divider floor, but I dont think that is the only restriction point. I think it may also be between the seperate elbow part and the main plenum (lots of room for enlargement). I will do a little work to figure it out for you. Jeff Quote Link to comment Share on other sites More sharing options...
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