How Air "Works"

[Phoenix7]

are you going to put AIT sensors before and after the IC? Heat-wrapping the pipes?

[Dr-Rotor]

Not sure If I will go to those extremes.

[Phoenix7]

well, how else would you monitor IC efficiency?

I'd monitor temps after the IC to see if the IC is damaged, clogged, or whatever.

If the temps go up before the IC then you can isolate problems before the IC, after the IC and before the manifold. Seems like a little overkill but it'd help diagnose possible issues?

I don't know which is more efficient though. FMIC or VMIC. VMIC wins based on number of bends but how well can you create vacuum at the hood area to draw the air out of the IC? Adding a fan would help but more draw on the electrical system.

With FMIC you know air will go though no matter the speed and, when mated to the dual oil coolers and vents, you can create ducting to the underside of the car, which you know for sure will create enough vacuum to pull the hot air out.



I just don't trust aftermarket hoods. All my conversations over the years end up with people claiming that the D-MAX hood (the hood I think seems to be the most efficient) is pure BS marketing because of low pressure areas of the hood and so forth.

They throw in some weird looking diagram that's supposed to "clearly show" the low pressure areas and call it a day. I don't see it but that's because I hit a knowledge wall.

I'd like to know of a way to test the aerodynamics of the rx7's with different hoods and front ends to figure out the best way to use the pressure around the car to draw hot air out.

My favorite image is this one because I see potential for great heat expulsion:




All this to keep the IC pipes as cool as possible to have the most dense air possible.

[Dr-Rotor]

The reason why I said that I might not put temp sensors in is because the WI will drop the temp no matter what.

Besides that you have given me an idea...you spoke of a vent under the car that would suck the hot air out as the under side of the car has low pressure. This gives me the idea to put a reverse vent in the undertray just below the back of the radiator. This would draw the hot air out as it would create a sort of vacum from the high speed low pressure air underneath.

Im not sure of the hood your talking about but mine sure as hell blows air right out. I blocked the front scoop, attached some streemers to each vent & went for a blast around the track. Every streemer was near vertical from the force of the air passing through them....if it had been a low pressure area they would have been sucked in. Right?

Anyway...I will be redesiging my IC setup & I will be doing a few tests with a reverse scoop in the undertray in the next year or so.

As I said before with mounting the IC ferther inside to create an air ram effect, I recon the reverse scoop will aide in the removal & suction of more air through both IC & Rad.

[memski]

Here's an old pic of my setup, have been thinking more recently of trying to vmount the ic, more to reduce pipe volume than aid rad temps. Greddy elbow was modified and the piping is 3" all round.

[Dr-Rotor]

That looks fairly straight on both sides & the first pipe off the turbo is not as harsh a bend as some that I have seen. Nice setup.

Whats the reason for trying to reduce the pipe volume? Is that so the air wont have to go as far to get to the throttle? I dont think it matters all that much because the air travels so fast anyway....Your setup would have less pipe as it is now than mine dose & I dont have any issues with spool up or response.

Try just moving the IC into the bay right in front of the Rad, seperate the 2 with some firm rubber or foam all the way round to seal them off & keep the pipeing as is. It will be slightly shorter, less brakets than a V-mount & the pipe length would be pretty much the same as some V-mount setups. If you realy like V-mounts by all mean change it to what you want.

[FC3S Murray]

After reading this thread, my IC set-up makes me very sad. So many bends!

I have been brain storming lately on how to fabricate some sort of ducting to force air through my IC, oil cooler and radiator.

My Air temps are already cool with the amount of heat insulation and expulsion I have fabricated/added to the exhaust and LIM and ducting to my TID. I get a reading in the TB elbow of 30 degrees C when the ambient air temp is 65-70 degrees F AFTER WOT tuning. Never really budges after that.

My water temps don't exceed 80 degrees C BUT my Oil temps always stabalize at 170 ish F cruising and I would love to get them at about 160.


My boost response is very good granted the lenth of piping and my 62-1 set-up BUT I could imagine it would be even better with some smart refinements.

Any ideas on ducting??

[RETed]

Interesting thread...

I dunno why the original poster gave up after the initial flurry, but one of the big things that wasn't touched upon is resonance or Helmhotz[sp?] tuning?
Mazda did mess around with it a lot on the stock induction systems, and having only two combustion chambers, this effect does get magnafied.
This type of tuning is actually counter to the statement about air being a liquid; in this case, the air(flow) is a wave.

As for the replies about pipes, layout, etc...
Placement of the heat exchanger (the IC) is primary.
The placement and paths of the IC pipes are secondary - i.e. just make them fit.
FMIC are popular due to the fact that you're placing the heat exchanger in the most efficient position - where the ambient airflow is highest and most pressurize, i.e. - the front bumper facing forward.
I, personally, don't like all that V-mount crap, cause it's a compromise design - yes, you get short and more direct pipes, but ambient airflow is compromised, usually.
Not many of us measure this efficiency over the entier IC system - pressure in versus pressure out - and dialing most boost is the easy answer to overcome "poor" efficiency numbers...
Running more boost is usually easier than rerouting IC piping...in most cases...


-Ted