With the sub-zero assist reservoir removed, and the charcoal canister moved elsewhere, it looks to me like there might be enough space for an airbox with cone filter to be fed from an NACA-style duct on the hood. This would also drastically shorten the intake from stock.

Has anyone tried this? It seems to me to be a better way of doing an ambient intake than the typical headlight mod, but there might very well be disadvantages that I haven't thought of.

 

No reason why it shouldn't work. Do it.


The only thing I can think of is possibly being more turbulent, as the air is not being pushed "into" the intake, but "against" it.

 

That would be a great spot for an air inlet.

That is where the 747 (2nd gen) GTO racing concept by Mooncraft had an inlet as shown on pg 249 of Yamaguchi's 2nd gen bible.

NACA duct on the hood toward the passenger side near base of windshield. The duct is straight sided on the side facing the center of the hood and has the swoopy NACA duct shape on the side facing the near edge of the hood as airflow is peeling off to round the corner of the A pillar here.

I have always thought it would be awsome to do a motor with relocated alternator and short race style intake and put a huge NACA duct centered in the hood with the intake box at the end for mega ram air.

 

If you don't mind making the appropriate hood scoop and cold air box, then go for it! It sounds like it has potential, though I don't know of anyone on here that's done it before.

 

I wouldn't put an airbox practically on top of the exhaust just to make the intake shorter. The stock exhaust duct is huge for the power the engine makes, so shortening it is going to gain you very little.

Anything's better than those shitty little headlight scoops...

 

I'm not doing it just to make the intake shorter. (I'm waiting for Evil Aviator to chime in and tell me why that'll make things worse.)

You mean the intake duct, yes? In any case, that's why I'm asking—I want people to tell me why it's a stupid idea...


EXACTLY.

 

I've been thinking about this for a bit, and remembered seeing this picture somewhere, took some searching... This is from Kahren's VB Garage, 2nd picture down on the left. He's always made good power with his/customers cars, although you can tell it isn't a stock setup it shows that it has been done.

https://www.rx7club.com/vbgarage.php?do=view&id=4018

 

Oops! That was a major brain fart! Yes, I meant the intake duct is huge.

It's not a stupid idea at all, I just think the stock filter location is better. There's a lot more room to fit the AFM and a decent pod filter, and it's not directly over the exhaust, both of which make it easier to fabricate an effective box or shield that keeps engine bay heat out.

IMO the intake on Kahren's car is a good example of what not to do...

 

this has the makings of a 1/2 hp mod

 

Sorry, it sounds just fine to me. It is a lot of work for small gains, if any, but it should work pretty well with a shortened intake tube and a standalone EMS. Just make sure you have a heat shield below the intake, and enough room for a filter of the appropriate size so you don't choke the engine.

Evil Aviator K&N filter rule of thumb (which hopefully isn't any more stupid than the other stupid internet guidelines, lol.):

HP = Filter Media Area sq in * 4.53

Amen.

 

I can't see why you'd need a whole new EMS just for this...

 

Maybe because (as in the pics from Kahren's VB Garage in theory's post above) he figures I won't have enough room for the AFM anymore?

BTW I'm with you on "what not to do..." Intake near the exhaust manifold with no airbox or even an obvious way for ambient air to enter = FAIL.

That is one of my main concerns. I haven't actually started measuring things to see whether I'd be able to cram an appropriately-sized cone filter and the AFM and an insulated airbox in that area of the hood; that might just kill the whole idea right there.

I just figured I'd ask and get opinions here first, because whatever weird mod idea I might have, someone somewhere out there has probably already tried it.

 

Maybe, but then Kahren's TB is much further to the right than it would be on the stock manifold, and his filter is huge, way bigger than is really necessary. I'm sure it'd all fit with a stock manifold, but I still think any gains wouldn't outweigh the hassle to make it work well. Why move the filter from an area with plenty of room and less heat to deal with, to a location that's the exact opposite?

 

You wouldn't need a standalone EMS, but it would work better with one. The AFM would take up linear space which would increase the intake tract length and make mounting more difficult, and mounting the AFM close to the manifold may cause reversion problems.

 

Uh-huh...see, that's what I'm talking about. I knew you'd come through for me!

Really, the major goal here was to move the filter/airbox somewhere where I could have a cone filter with an intake that isn't a "shitty little headlight scoop."

If I'm going to need a standalone or face possible airflow problems, then it's not worth it, and I'll stick with stock. I just have an N/A, after all.

 

I thought about doing something like that but mine is my daily driver and if it's raining what's to stop water from pouring down on to the filter and getting sucked up into the motor?

 

Doh! LOL

Well, the stock intake works just fine for a stock NA engine, so you may be better off just leaving it as-is. There may very well be no reversion problems with relocating the AFM, as I am just speculating without actual experience, although it is possible in theory. However, I don' t really see much point in going through all that trouble if your engine does not need more air than the stock intake can efficiently provide.

As for the standalone EMS, if you have a good local tuner, it WILL increase engine performance on an NA. The peak HP will be about the same, but the power band will really open up, the gas mileage will increase, throttle response will be better, idle will be better, and nasty things like the 3800 rpm hesitation will be eliminated. I think it is unfortunate that this forum makes it sound like a standalone EMS is only for turbocharged cars. Anyway, an EMS, installation, and tuning are expensive and time-consuming, so I understand why most people do not choose this modification.

 

Since you "only" have a NA there is a ton of unused space in the nose of the car for your intake.

Not only is this area removed from exhaust manifold heatsoak issues but -purely from a practical fabricating standpoint- you needn't hack up the hood and figure out an effective intake scoop.
Looking at the underside of the hood (assuming you were to use the stocker), there is a lot of bracing in the area you propose.
Cutting that away to incorporate an intake might severely compromise the integrity of the hinge mount at the very least.

Still and all, it's an interesting idea- I admit to gazing speculatively at that area myself...- and could probably be done.
The question would be is it better or just different?

 

you already get the most performance out of sticking a round filter/intake over the stock setup... relocating it wont gain any more then going with an intake setup.. this is like trying to reinvent the wheel wihtout forced induction. I wouldnt spend too much time doin this on a stock motor/stock efi

 

There is a guy Eric on the board and he calculated thats there is fractions of a hp difference by changing the length of piping.

 

I already have a corksport intake lying around, it's a straight piece rather then the stock curved piece. I was thinking of attaching the AFM right to that piece and a cone filter right to the AFM, seems like enough room.

For air intake a NACA duct like this http://img.auctiva.com/imgdata/5/4/9...1625287_tp.jpg could be used. It'd be neat to try anyways to see if anything could come from it.

Of course some heat wrap and a heat shield would be fabbed up to...

 

I have my pod filter in the stock location, separated from the engine bay with a fairly well sealed heat shield. Air is drawn in through two holes cut in the sheetmetal in front of and beside the filter.

 

Although Kanren's intake setup may not appear to be the best thing, that engine (stock ports) made more power than any other stock engine I've ever seen and most then many streetports. It was somewhere around 185 rwhp or so. That's pretty impressive. It may not be perfect but something about it works quite well.

 

I routed two ducts from the nose of the car between the the radiator and to the filter. Had to take out the exhaust piping that went to the air pump though, but it was long gone anyway. It keeps cool air in as long as I'm moving. If I stop and pop the hood after going highway speeds filter is cool as can be. never built a cold air box so if I sit too long everything heats up. Here a pic of when I just had one hose but you can get the idea.

 

I'm sure it worked pretty well on the dyno, with the bonnet up and big fan blowing air into the room, but that's not even close to real-world conditions. No doubt out on the road it'd lose some of power due to the hotter intake temps, and would probably lose a noticeable chunk of power after sitting stationary for a few minutes, at a red light say. The rest of the set-up is impressive, but there's definitely some potential extra performance being lost because of the intake.

Those two ducts will be doing very little. They're way too small and are far more restrictive than the other source of air for the intake; the whole engine bay! The only way an intake will effectively provide ambient air is if it's much harder for engine bay air to enter the intake than it is for ambient air. In your case it's the exact opposite.