Not to discern Tree25?? but here is my cold air. I got the heater ducting from a local hardware store () pm me if you want to know where. It only cost $5.99 too, but cant say where. Any way, its an easy mod if you have the tooling. I was able to leave the overfill in the stock location. Its a 3" duct.

 

next

 

and last, sorry it took so long, learning how to bypass server to do what I want. Muhahahahaha

 

nice job. How much cooler does your car run?

 

The looks like it will work well!

 

you might want to put a filter on that so you dont clog up the filter you have on the carb with dirt and dibre(sp)

 

how could i go about making a cold air kit for a weber 45 dcoe? the intake just sits right on top of the block (not the coolest air)

 

nice setup

 

why the hell cant you say where? that sounds pretty dumb, i was at HOME DEPOT the other day and i saw that **** for the exact same price you stated ($5.99) so whats the big secret

 

I ran a cold air intake on my car (not the Rx-7) simply by taking my breather off and going to autozone. I picked up a 2 1/2 to 3" adaptor clamped it to the top of the carb and ran PVC pipe down to a cone filter. The carbs on the Rx-7 are most likely a bit bigger, measure it sometime and try it out (most likely 3"), not really any power gains, but sounds cool and cleans up the engine bay.

 

Gregs, you would have to read Tree25is' thread cold air intake with pics thread to know where that came from. Didnt notice the car running cooler, did notice that when stopped in traffic it seems to breath better. Would say a minimal hp increase, just looks cooler. Was hoping to get a little ram air effect as well. It definately is cooler than engine bay, major icing probs with the onset of winter, then I remembered I had the hot air duct taped off. When summer hits I'm going to remove or have the flapper in a closed position, cant do it now though.

 

For all of us that just like to look and not click...







I think I stumbled upon the reason why you're not seeing as dramatic increase as you were hoping for. The square hole that is in the air cleaner base itself (where the air cleaner horn is spot-welded to...) has dimensions that essentially are equal to a tube with a 4" ID. Anything less than that diameter tube and you are keeping the significant airflow restriction that the air cleaner horn represents, even though your cold air tube is larger than that horn. FYI for all the CAI gliterati out derrrr...

 

Ok, and now for something completely different.


J/k

Mario your in the right track, that would help also. Its the plastic flapper thats causing the restriction. Trust me, my flowbench doesnt lie.

 

Your set up will actually hurt your carburetor performance. With you trying to ram air into a carburetor you are forcing air in, which works fine for fuel injection.
I tried a simular setup when running PRO7 and saw my lap times drop, so I turned the air inlet to the left (across the car) and my times went up.
Another problem with your setup you will pull in a lot of the dirt and water into the intake tube.

I agree the fresh air is what the engine needs, but the carburetor will need to pull it in, not to be forced in. Very hard to duplicate on the dyno machine, but repeated testing at the track showed to me that forcing air in was not helping.

John

 

Cool will do, that would be easy enough.

 

Alot of hot air is better than a little cold.

 

Gotta argu that! There is a trade off somewhere since cold air is more dense than hot - what is the trade off, lot of factors, altitude, humidity etc. Im still perplexed on what Mar3 said (thanks for the pic post info) about area coming to be 4" ID, this is a 3" duct and it fit perfect, and the snorkle end is like 2.5. Now I know the dynamics of tubes with divergent vs convergent design (jet engine mechanic 12yrs USAF) and that design will create pressure increase/velocity decrease at the expansion point, but this is all on the theory of air being pushed and in this case its being pulled [edit]feel its the same-only change I ever heard of was at supersonic speed the theories are reversed[edit], further conveluted by the air cleaner assy and air filter itself. Now in perspective, this is a car and the total increase I could be getting is minute at best, I'm not making a living on this, so its just fun to tinker.

 

Have you ever seen a fast car with duct work from a home improvement store hanging out the front of it? I'd suggest buying a mushroom filter from eBay, taking off the air breather assembly and clamp the mushroom to the top of the carburetor.

 

That would be the best (air flow wise) I agree! And yes I have seen super fast cars with a duct hangin out the front. Skylines, Sylvias, 180 sx's, Hachi Roku's, you name it. You know, the place where the "Rice" comes from, the elusive j-spec cars. Seen a really cool MR-2 with a periscope duct on it too!

 

What he's sayin is the OTHER end of the metal snorkel is close to what a 4" duct will fit. I suggest you remove the black plastic flapper, then test it again. If you dont like it, put it back on. What I do is cut the metal snorkel right in front of the hole where the plastic flapper axle goes theu. Then a 4" duct will fit nicely over the snorkel.

 

Yea, look under the hoods of cars at the road course near you. Just cause its doesnt make it fast.

 

Trust me Im not bling blingen, its a Home Depot project. Damn I said the forbidden word again-oops. Its all subject. Now I understand the 4" - he should have just said top of carb. But yeah, bling bling dont make it fast.

 

ghetto fabulous

id try it, but with my hoods rust holes and the dremel work ive done to the airbox, i dont need it