NovaDiemen aero engine cover question

[JRMarchand]

Hey guys, I just finished modifying the original engine cover, it took me 7 months to mend it back together Over these months I went back and forth with a few people about making a new lower engine cover. I'm just sharing some pictures because I need help deciding how to introduce air into the engine. The airbox does not have an airfilter at the moment but i am working on the options. Van Diemens have side cooling naca ducts that could be used to route a couple of air charge hoses straight to the box. The other option I can see is a charge tube on the back side of the airbox that goes to a filter box just between the rear shock mounts. I have see this setup on the newer DP grand am cars but I dont know how efficient that setup is. Got this far and I'm super tired and need a little bit of help. Next weekend I am racing at Michigan Speedway and need to wrap things up. Thank you for your advise, regards

ps, the second picture has a square of black tape in the area where the air filter box would fit.

[Brett Lane]

Hey Juan,

Great idea, but not sure those NACA ducts will give you enough air for the intake. I tried a NACA duct on a C sport project 15 years ago and it just didn't work. Nothing works better than an intake where you are "ramming" air.

My opinion, the engine cover and intake Jay and Mike have done is the best way to go for now.

Another way would be a FC kind of "snorkel" intake with an air box designed to take air from the side. K&N makes all kinds of flat filters that can be adapted for that.

Either way, my admiration for being innovative- that is what this class is all about.

Brett

[JRMarchand]

Brett, when you tried using the naca ducts, did you made a cover over the naca duct so that it draws more air into the charge hose? Kinda like a ram air scoop but on the side, like the swift ff has for the radiator. I can't believe how good the car looks, the only problem is that it has not been tested. I've heard about the citation, Nixon's car, that it fed the airbox using the sidepods, that car has a low cover. Idk but this has been great fun.

[Jnovak]

Juan, the box itself is way too small. NACA ducts will not be enough.

[JRMarchand]

Jay thank you, this is hard, designing or building something and making it work . This airbox I made has more available volume than the factory k5 box, I do.nt know what that says. But these are stock bikes engines and the airbox that was in my car was fine until I cut the engine cover. Main goal is to have a slicker car, its a NovaVD so it already handles, and with a Citation diffuser under it who knows I hope I have enough tme to get to MIS and enjoy the weekend.

I wouldn't just use the naca duct guys? It needs to be thought out, I have little brain power left , I'll take some pictures of the progress or lack of and hopefully completion before Friday.

[Jnovak]

The box needs more height over the air horns. A NACA duct will not pressurize the air box.

[JRMarchand]

I changed the velocity stack a while back you see, how much ceiling you want above the stacks to hit the sweet spot. I'll post a picture of how I would use the idea of an inverted ram air opening and using the Vd naca openings as the real estate area for the charge tubes. I can only say, this is fun.

[Brett Lane]

Juan-

No, I didn't try that. It was the biggest one I could find- Over a foot from top to bottom. It was on my RT-5 with the Honda B16. It was just not getting enough air by itself, and ran real flat.

[JohnPaul]

not 100% sure but Brandon Dixon designed his (now JR's) Citation with a single duct intake similar to the one pictured through one of the sidepods (not sure of the diameter). I specifically asked if the thought it was "enough" air flow, he seemed to think it worked just fine. As far as the airbox he used the stock gsxr one.

[JRMarchand]

JP, I heard the system in Dixons car was/is pretty awesome. That car used to have a snorkel over the driver's head with a fabricated air box.

I am almost done making some molds to make air intake scoops over the vd naca holes. I really wonder how Dixon's citation routes the air to the box and is it a hose or rectangular formed plastic duct within the sidepod like in some atlantics. I almost thought it could be possible to have an opening that draws air from under the car so to speak, like a hole on the sidepod floor.

[nulrich]

Listen to Jay, he knows this car well.

When we had a Van Diemen F2000 car in the wind tunnel we tried taping over the NACA ducts near the engine to see if it would reduce drag. Glenn Phillips was watching during the run and noticed the tape was bulging outward.

We did a run with the smoke wand and smoke flowed OUT of the NACA ducts. Not a good place for an air intake.

If you want to take advantage of ram air affect you want an opening in a high pressure area with clean flow. That means a forward facing opening like a high intake above the roll hoop (or in the roll hoop) or inside a sidepod (possibly, depending on the inlet and duct design). The rear sides or top of the engine cover are a bad choice, because the flow is turbulent and trying to converge after being disturbed by the front of the car and the cockpit opening.

Of course, you may not want to use ram air affect. Not sure what the current thinking is for F1000. As I said in the beginning, listen to Jay.

Nathan

[JRMarchand]

Nathan, I totally hear what you are saying, I should've let Jay and LRP sort this out for me, I saw that a lot of cars have a lower rear lid than my car did, I only intended to trim bodywork off the car, I really messed up a good design, sorry Jay. Thank you Nathan I love your work.

Now I have to move forward and accept that my car is not as good as it once was. Before we put one final ax on this. would these air inlet covers, one on each side should feed air to the box, is there a chance here, come on fellas, give me something, I have to wrap this up and go drive, MIS Mid O and June sprints all in a row. If I make these air inlet covers i might be able to catch some air, just my uneducated opinion. I'll look back at this post in 20 years and see how stubborn I am, agreed.

is there any chance for the inverted ram air inlets , one on each side??

[JRMarchand]

The more i look at these green horns,reminds me of a ram air device, looks like a mini sidepod and has a nice venturi shape, what gives?, I wonder what the air going around the cockpit looks like, certainly turbulent.

[JRMarchand]

i decided to make inverted ram air scoops, found an inexpensive way with fiberglass and green crayola paper, i will have to blend it in to the bodywork, so what, fiberglass is my friend

wondering if two ram air scoops would be too much, i made them aero so what you think, just under 20 inches long and with a nice nice shape, it should bring the air home, we'll see.

this is the first time that I've made things with fiberglass, it is really like art, its awesome, i'm not scared of it, next i'm gonna make a new style shock cover. the weather is perfect for making parts.

[Brett Lane]

Go ahead and try it. If it doesn't work, go home. And start over....

That's the only way you'll know for sure.

[Brett Lane]

The more i look at these green horns,reminds me of a ram air device, looks like a mini sidepod and has a nice venturi shape, what gives?, I wonder what the air going around the cockpit looks like, certainly turbulent.

Based in what Nulrich said, I think the air pressure is lower around the sides and above the sidepods than the "ambient" pressure on the other side of the body work due to the velocity of the passing air(V/P).

This is probably why the NACA ducts don't work...

[JRMarchand]

Brett you are right. I will have to test it and see what the numbers say. I'm kinda going rogue on this one, but I have to finish and go drive it and haul the mail as fast as I can.

Ram air will be there, not optimal, but ok good we shall see. I'm happy to finally be making progress good or bad.

[Brett Lane]

Good luck- I know you'll sort it out.