ZCar Forum banner

Status
Not open for further replies.
1 - 10 of 10 Posts

·
Registered
Joined
·
465 Posts
Discussion Starter #1
after reading all the postings in the archives about cowl induction i am thinking i might rig something up this winter but am not sure quite what i want to do i have a few questions.
1. Some one mentioned that forced air and SU's dont mix. can anyone say for sure one way or the other, will it mess up my carbs or just require a "tune up" to get correct mixtures??
2. is there anything to be gained from using as much of the cowl area as possible and funneling it into a single feed to the carbs as oposed to just cutting a hole and routing it to the carbs.
3. would i gain from blocking off part of the cowl?? like using a solid piece with a few holes cut in the top instead of the stock part with lots of holes.
4. would a scoop or something increase the effect or is the stock cowl shape good??
.
 

·
Registered
Joined
·
269 Posts
Hey, I'm guessing your talking about semi-ram air of sorts and not actual forced induction?

Ram air won't have any effect at all until you are going very fast, so if the carbs are adjusted (i'm guessing here) to make up for it the engine will be running very rich at lower speeds, and maybe right or very lean at high speeds?

The cowl would be good for a cold air intake, which is really what you want more the ram air 'cause its effective at all speeds, but I wouldn't really use it for ram air, the hole isn't big enough to be very effective.

Those are just some thoughts, I'm not sure of what air filter set up you are using, but if you are going to think about ram air you'll want to get a much better flowing air filter.
 

·
Registered
Joined
·
465 Posts
Discussion Starter #3
im not talking about ram air im talking about cowl induction where the intake air is taken from the high pressure area just in front of the windshield. this is much like ram air but effective at much lower speeds. the air is also cold like you said.
 

·
Registered
Joined
·
613 Posts
How To setup on 280zx (TONY D)

yep hes right, 240 is 100 percent right. I was thinking of setting it up on my 280zx, but that whole area is covered by a ton of things, but i am wondering how big does the intake hole have to be, and would a 180 degree bend affect the air flow to the AFM and TB to much? I might want to do this, but i need to find the right way first.

-Emir
 

·
Registered
Joined
·
241 Posts
Re: How To setup on 280zx (TONY D)

Yeah, I was thinking the same thing befor when I read about this, and how my zx has virtually no room!! I'd have to do a 180 infront of the rad support, or mabee loop around infront of the rad and back along the passenger side, not much clutter there. Is there any information as to just how much pressure is there?? I know there has been alot of areodynamic tests on the early body, but not on the zx. It would be interesting to mess around with that.

Dylan
 

·
Registered
Joined
·
613 Posts
Re: How To setup on 280zx (TONY D)

Personally i'd do the 180 loop at the AFM, much easier to do it there and less piping envolved. I have heard ( i think Tony D) that the 280zx is more aerodynamic than the prior z's. I think i would have to move a bunch of brake lines though, but i have not clue at what size should the hole in the cowl be.

-Emir
 

·
Registered
Joined
·
5,597 Posts
Re: How To setup on 280zx (TONY D)

http://www.ramairbox.com/ makes ramair boxes for V8 Like I have said before if enough of you ask about a setup for a Z both carbed and FI maybe this guy can make some up, don't know if he will but it would not hurt to ask, Right! Check out the old Chevy truck it has the box going to the cowl area. It would seem like you would want to offset to the left side and have the air pan backwards so it would be easy to hook up the hose for carbs... for the FI guys maybe he can make a 180 bend in a hard part and then add a flex hose to connect...

I want a cowl hood to vent more air out I'm not worried about a ramair box because he makes them for the V8 already and I'll run a hose to both air ducts in the fron air dam...

Z U V8ter
 

·
Registered
Joined
·
241 Posts
Re: How To setup on 280zx (TONY D)

I was just thinking of where you could run the pipe??? The m/c is really tight with the intake, and the egr and all that junk sticks up and blocks everything off, and there is little to no room vertically above the engine. Mabee with a flexible hoze could be smaked up through the maze.

Dylan
 

·
Premium Member
Joined
·
40,978 Posts
oh contrare!

the 280zx was EXTENSIVELY wind tunnel tested to improve over the 240's shortcomings! I will post more below!
 

·
Premium Member
Joined
·
40,978 Posts
OK Guys, Again...

For a stock FI motor, the challenge is getting the air under pressure to the AFM. This is a challenge. The EASIEST but not most aestetically pleasing way would be to use one of those cowl-induction hoods. You would have to mount a plate over the valve cover to seal at it's edges to the hood (like the old trans ams and camaros had...). At the frontmost portion of this hood buldge, you could easily duct to the AFM. A large buldge may not have the best affect, as the larger area you have to pressurize, the longer it takes to get the pressure equal throughout the cavity. You may want to use a large opening near the cowl area, and taper it sharply towards a duct built into the bottom of the hood that runs forward to the AFM area. Nobody said the ducting would be easy. The best teacher is experimentation. Trust me, I WILL be using this sometime next summer and will have instrumentation for speeds up to 125mph. I WILL post the results.

What am I going to do if this is not allowed in my class? I will cut the radiator height by 1/2, and install a plenum where the radiator/shroud was. The plenum will be fed from four or five NACA ducts on the leading edge of the hood. More "Ram Air" than "Cowl Induction" but I actually will be dealing with speeds in excess of 150 mph, and Scoops ARE allowed in my class, so that is the backup plan!

BTW, to add to the fray, everybody here realizes that a 1980 Chevy Impala Air Conditioner Evaporator Core will cool a N/A 280Z motor, just as well as the stock radiator, right...

velocity, core density, EAA Tech letters...
 
1 - 10 of 10 Posts
Status
Not open for further replies.
Top