mingo

iTrader: (4)

u seem to be making an air flap for something.. am i wrong?

irish44j

iTrader: (38)

pretty much on target...basically, I'm trying to combine the low-end benefits of our stock air box with the high-end benefits of a GAB...i.e. a GAB that can open and close with the flick of a switch....

I wasn't going to post the idea until I found out if it was effective in doing what I want it to do, but what the hell....

now somebody more industrious than me can do it first

BewstAdd1ct

stroke isnt an issue. you can use a lever to increase it, with force being 'F' and 'O' being objective, and V or ^ being pivot..
F__V_______O

or for a swinging door

.........\
V_F___)
........./

BewstAdd1ct

if oyu see what i mean. if not, ill take some quick pics and email them, or MSpaint some ish...


obviously, if you needed 2" of travel, and had a 1" stroke, you would make V-F ½ the distance of F-O

mingo

iTrader: (4)

i figured tha'ts what u wanted to do, some air flap for the intake since u autocross.

one thing i looked at before in the past was the stock honda airbox vacuum actuator. you can get an electrical vacuum check switch hooked up to the vacuum actuated push rod. that should work fine too =D.. or maybe you won't even need a switch, cuz once u rev it or open your throttle to a certain point that thing will just open up =D.

TAPOUT

iTrader: (5)

I have a real good idea, why don't you spring load the flap to shut, then you only need to open it. You could use a door lock type actuator, and a lever to make the required travel distance. You would also only have to worry about the opening part of the trick. and if anything failed, it would close back to stock. very simple to fabricate, and wire up. you could even be cool, and wire in a WOT switch for automatic activation when it is needed with a on/off arming switch kinda like a nitrous wiring setup.

irish44j

iTrader: (38)

that sounds like a good plan. Would the door lock actuator be strong enough to hold it open against the load of the springs?

out of curiosity, how would you rig up a WOT switch? attach it to the VIAS mechanism?

Jason, did you say you had a lock switch available? How much?

MaxBoost925

iTrader: (33)

You must have some monster project going on!

BewstAdd1ct

you could use a light duty spring, and also have gravity to assist you, i guess. you can also order actuators in different load strangths.

WOT switch would be just like nitrous, but ive got an even better idea...


if youre doing this so you can have good low end response but better high end power, dyno your car with the 'flap' in either position. match the plots against eachother and find the approximate point where the curves cross, add a window switch triggered at the corssover point, and now you have MAD VTAK y0!

Rob01ski

You'd rig it up like the nitrous guys do it, by putting it on the throttle body, since we the BEST 3.0's still have the old style more dependable and way better, throttle bodies that are cable driven not throttle by wire <--- for some reason that sounds really to me, lol.

The part that the cable ataches to by the throttle body at wot goes into a 90 degree position thus it would hit the wot switch causeing your "" SWITCH"" to activate

upstatemax

iTrader: (15)

I would use an RPM switch to open it from Summit. If you are in the middle of a race or auto-x you dont have time to manually switch it. If you can get on a dyno you can do some runs to see what is the ideal RPM to open it.

However, I dont really see the low-end gains to be that great to go through all this trouble. As I understood it, the GAB retained the most lowend of all the intake options.


I could also be wrong, but I would need a dyno sheet to shut me up.

irish44j

iTrader: (38)

hmm...just thought of a better idea.

1. the VIAS mechanism is already tuned to open at the best power-producing RPM.
2. instead of having the throttle body trigger the opening, I'm going to try to think of a way to have the airbox open up when triggered by the VIAS opening.



btw, if someone else does this before me, you better tell me how you did it

BewstAdd1ct

how do you know that the VIAS point is the best switchover point?

irish44j

iTrader: (38)

well, I mean I don't KNOW...but the VIAS opens to allow the airflow to travel faster though the IM, so it serves logic that at the moment the airflow in the IM becomes less restricted that this would be the precise time you'd want to allow more air into the IM (via the intake opening).....

If you guys know me, there is no way in hell I'm going to dyno anything, so "guesstimating" is going to be the way I'll do it.....that, and just trying to be logical.

BewstAdd1ct

lol, okay...


the VIAS is specifically tuned for the length and shape of the runners, so i doubt that the point will be the same... but maybe

irish44j

iTrader: (38)

perhaps....but it's as good a theory as any

upstatemax

iTrader: (15)

The VIAS point is pretty high about 5100RPMS (some have dropped it about 4900). I would think that 4-4500 and your engine is looking for more air. I thought the VIAS just changed the runners so that the air runs more efficiantly into the engine, not so much that it lets "more" air in.

BewstAdd1ct

theory?!


upstate, the runners change the effective runner length for intake manifold pulse tuning, esentially creating a ram effect and a positive pressure wave timed to enter the cylinder as the intake valve opens...

irish44j

iTrader: (38)

right....it essentially increases the airflow velocity into the engine. But when you increase airflow velocity the air is going through faster (duh), and therefore I would think it would be helpful to allow a higher volume of air in, or at very least allow a higher airflow velocity all the way through the intake and TB.

just a guess though...I'm no induction expert.

BewstAdd1ct

no, if it were restricting flow, then why put it in in the first place...


it adjusts the runner length so the resonant frequency matches the engine speed. i can fully explain this if you like

irish44j

iTrader: (38)

the same reason that there is a compressed "kink" in the OEM b-pipe on the maxima. If maximum airflow is achieved with the OEM intake box, why do people put on aftermarket intakes?

I realize that...but as a by-product it is bound to increase airflow, due to the shorter distance being traveled, it is bound to increase the velocity. I know it's not WHY the VIAS is there...but it could be a by-product.

upstatemax

iTrader: (15)

I agree, I just think that you would benefit from the increased airflow earlier than 5100rpms. The VIAS is there to "maximize" the use of the air comming in at top end. there is nothing saying that more air earlier on wont help.

The only real way to tell is to set one up and try it at different points. If you do it let us know.

irish44j

iTrader: (38)

will do. I'll be sitting in a hotel for the next week on travel for work, so I'll have alot of time to brainstorm

BewstAdd1ct

is maximum airflow acheived with the OEM box? if it is, then your answer is sound/looks. i guess.

the kink in the b-pipe, youre talking about for the clearance for the tunnel bracing, right?

irish44j

iTrader: (38)

I don't think it is...the stock airbox restricts the flow for better low-end....which is more important than high-end for the "average" driver. Just a guess though......really, I have no idea, but it's worth messing with IMo...

yes...which totally puzzles me, considering my full-width frankencar bpipe clears the tunnel bracing just fine

I know it's not the same idea as the intake, but it's just one of those cost-cutting measures or oversights that EVERY OEM car has someplace on it

GBAUER

iTrader: (2)

MMMuuuhhhh-huuuuummmmm!!!!

Sorry, just had to clear my throat a bit...



What? I don't get any credit? BTW: I think I've thunk up another option that you may want to consider....

irish44j

iTrader: (38)

of course, credit to George....did you say that when we were talking? Didn't remember you saying it, but maybe you did. There was a hottie walking across the street while I was on the phone with you,so my attention was divided....I really don't remember a single thing you said except "2-car garage"

MrGone

iTrader: (30)

what kind of forces are you looking at? if it is going to lift something too heavy you will have to get heavy duty servos, or even then they might not be powerful enough. Also most RC car and truck servo's run at 4.8 or 6v.


the CDROM "motor" idea wont work, it is not the right type of motor, unless you want to use a gear drive and not a hinge style like you would with a servo.

MrGone

iTrader: (30)

I just read part of the second page and got to the part where you want to make a flap kind of thing on the stock air box. I think a RC servo would be able to do that without a problem. Would actually work quite well.

If you were to rig it using a WOT switch just run it off the throttle body (could probably grab the signal from the stocker). A better way would be to use a RPM switch because you can have it switch over at the most effective point. Think of it, if you use an WOT switch and you go WOT at 3000rpm the flap is going to open at 3000rpm and stay open until you lift, but say you would be making more power with the flap closed until 4000rpm. You aren't going to go partial throttle until 4000RPM then go WOT because the gains from the "flapper" wont be enough to justify it lol.

to properly setup a window switch with that design you would want 2 dyno's. One run with the flap open, and one run with the flap closed. You overlay the two graphs and find the crossover point and that is where you want the flap to open . again that would be the most effective way.

IMHO It would be wise to build the flap part and dyno before you invest in all the electronics/etc because you might find the gains aren't enough to justify the cost/work

woosh

Irish,

If I understand you correctly the same mechanism that is used on those older style flip up headlights is kinda what you're looking for?

irish44j

iTrader: (38)

yeah, that had been mentioned before...like the old covers on an old LeBaron or something.

irish44j

iTrader: (38)

true, but I'd rather spend $50 on a mod that might or might not work rather than spend $50 + $50 in dyno fees to "prove it". I really couldn't care less about dynos, and will likely never feel the urge to get one. The butt dyno is enough for me.

As to justifying the cost/work... ....I'm just doing this for fun, not because I think it's going to yield any kind of significant gains. I'm kind of tired of spending large amounts of time/money on the maxima and would rather save my money to get my classics out of storage and work on them (they're so much more fun to work on and drive)...these cheap, silly projects are just something to kill time until I see some other "real" mod I really want to get/can afford

MrGone

iTrader: (30)

well the reason to dyno would be to set it up properly, but I see what you mean.


I learned dumping money on the small stuff makes it take longer to get the big stuff though

irish44j

iTrader: (38)

heh, time is something I have. It'll be another year or two before I can sell this townhouse and buy something with a 2-car garage....which is when the work on the classics will begin again and the maxima modding will all but stop

MrGone

iTrader: (30)

what are the classics?

irish44j

iTrader: (38)

my 1970 GT6s.....

which used to (and will again) look like this:



but currently look like this (partway through rebuild 7 years ago, but had to put it away for a while since I have no garage)...the other one was acquired more recently, but I don't have a pic of it on hand.

MrGone

iTrader: (30)

I <3 those wheels on that kind of car


look like a bunch of fun

irish44j

iTrader: (38)

you'd love em for racing....they only weigh (as I recall) 9.5 lbs

hehe, 14 x 6"

DrKlop

iTrader: (3)

Maybe it was discussed before (did not read the whole thread – too long) but here’s what came to my head:

You know those shift lights some people install on their race cars… The light turns on at a specific RPM which can be set at any time. So, if somehow, you could get this shift light to activate the motor which opens the flap, it would solve all the problems of deciding at what RPM it’s best to open the airbox. After that you can just drive around and tune for optimal performance.


Besides, it will make it much easier to readjust the RPM it should open at in case you install some other performance mod.

GBAUER

iTrader: (2)

Irish: I've been doing a lot more thinking about it and I really think that the 4200 RPM or so when the secondary opens IS the best point to have your modified GAB open up. This is because the point where torque drops and HP kicks in happens to be the same point that Nissan decided to open up the "secondary" (for lack of a better term) on the intake. In order to get more torque, the engine reqires less air (sorta like an InJen losing low-end power: too much air). That majical point where the Hp curve crosses the torque curve is the same point where the engine begins to benefit most from more air. The switch we talked about on the seconday would, as far as I can figure, be the best, cheapest (mr. Home Depot) way to do what you want to.

Now, that said, I'll be ordering springs from Corey at some point in the near future. as of Saturday, I'll have a two car garage with a heater. Want to do it there?

(I'll keep my no-low-end-power Injen though. It's sparkly!).