remember the ram air thread from a week or two ago?

well i've got my vortec headed 305 powered 86 Camaro up and running and made this air intake setup:

it's a stock air cleaner housing from an 84 Z/28 with a snorkel i pirated from a late 70's Chevy air cleaner housing put on the front of it with self tapping screws, hooked up to the stock scoop setup that was hooked up to the V6 that the car originally had with some poorly fitting dryer duct that i need to figure out how to seal up tighter to the scoop. you can see where the stock Z/28 scoop was attached on the side where i screwed a pieced of sheetmetal over the hole... i made a coroplast airbox in front of the radiator to jam all the air from my custom made grille insert (made from a piece of expanded aluminum that was sold as a device to keep leaves out of gutters on houses) thru the radiator and into the air intake setup.

here's a closeup of the grille.. it looks race ready, eh? and it was only like $1.99..

all the air to cool the engine and feed the carb goes thru here. the license plate isn't really blocking off anything since the bumper brace is closed off in the middle.

side note: coroplast is awesome.. i'd recommend everyone use it for invisible aero stuff, and the 1/2" long philips head self tapping screws i used to put most of the rest of the car together work just fine to hold it in place..

anyways, i don't have any real mpg or performance numbers from this setup yet since i just got it hooked up sunday and have only put 50 miles on it so far.. but the carb was cold to the touch after a 15 mile trip down the interstate at 75mph with air temps around 85 degrees, while the intake manifold was too hot too touch for more than a second or two.. it seemed like it needed less throttle input with this setup yesterday than it did on the same stretch of interstate with the stock snorkel on the air cleaner not hooked up to anything on saturday, but i didn't keep track of which way the wind was coming from or how hard it was blowing. i do know that the ambient air temps were about 10 degrees warmer on monday than saturday.

anyways, the first tank of gas i ran thru this thing on 300 miles of shakedown runs on friday and saturday netted me a 19.9mpg average with a LOT of idle time for things like carb tuning and my co-pilot playing the role of tourist and wanting to stop to take pictures of everything.. i'm hoping for much better than that now that the carb is mostly sorted out, the ram air is hooked up, and i don't have a woman with me that wants to stop and take a picture of every freakin thing she sees on the side of the road.. 30mpg is my goal for this thing..

Very cool.
What's it like living with a mid 80's camaro? When they haven't been beaten absolutely to death they're pretty cheap and they seem like fun.

Cool!

Do you have more things planned to get to 30 mpg?

What's your rear axle ratio?

The duct work looks like what my friend did to his Pulsar. His went down to the bumper to create a "cold ram air" intake. It really didn't change a damn thing. Looks like yours will be pulling in slightly cooler air which is a plus.

RossD wrote: Cool! Do you have more things planned to get to 30 mpg? What's your rear axle ratio?

i'm mostly down to tuning and driving nice now..

also, i need to figure out a starting issue- it cranks over really awesome when cold and when i first shut it off, but after it sits a while it barely cranks over. since the cables are all brand new 4 gauge from NAPA and it's an 800cca battery, it's either the header heat soaking the starter or a weak starter. it was a starter that i had sitting on a shelf in the barn, and i obviously took it out of something in the past for some reason. i tried moving the ground wire from the intake manifold down to the front of the block today, maybe that will help.

3.42 gears, 225/60/16 tires, 700r4 trans. engine is an L69 305 out of an 86 Caprice with 906 vortec heads and a tiny little cam. i still need to get the torque converter clutch wired in to drop the cruise rpm's a few hundred, which will put me right around 2000 at 70mph. speedo reads 5mph fast at any speed and kinda flutters around a bit, but the odometer is dead on with interstate mile markers.

as far as how it is to live with- it drives nice, the seats are comfy, and it's not too much of a rattle trap for a $400 car that is missing about 1/4 of it's interior panels.. it would be better if it didn't have those silly T-tops that leak and cause the body to flex, but there is no other dead weight wasted on silly things like AC or power windows or things like that on this particular car so it should weigh around 3200 pounds. adding the tilt steering column made it much easier for my fat ass to get in and out of it, but i still kinda fall into and climb out of it.

i don't know why GM didn't build all the carbureted and TBI V8 Camaros with this style of air intake- the parts were already engineered in the wind tunnel and on dynos for the MPFI V6 and V8 cars and it would have been a simple matter of moving the scoop on the air cleaner to point forward like i did.

I like the homemade ram air setup

I had a 85 Impala with a 305 4bbl/700r4/3.42 G80 posi that would get 25mpg on the highway.

I think 30mpg highway for your camaro is possible.

Aren't carbs usually cold to the touch anyhow due to the fuel atomization? Can't say I've ever fondled one after a run, but that was my understanding.

Here's the intake setup we're using on our V8 Miatas now. Looks a lot like novaderrik's.

It replaced this.

Much, MUCH cooler intake air. We were seeing some pretty high temps due to the previous filter location. Ram air wasn't the goal, we just wanted to dump some intake temps. And it works. On the dyno I don't expect we'll see much difference because that's usually a fairly ideal scenario for air temps.

BTW, the car in those pictures got 28 mpg on his drive from Colorado to Ontario, Canada. No attempts at aero work, and possibly with the top down a fair bit of the trip.

Last summer I drove my Camaro to work and I averaged 19-20 mpg on the highway at 75mph. That's a bone stock '83 LG4 with no a/c, stock 700-r4, 3.23 limited slip rear with 235/60r15 tires.

I'm sure 25-27 mpg is doable, not sure about 30 unless you start taking weight out, and adding aero devices and etc

TIGMOTORSPORTS wrote: I like the homemade ram air setup I had a 85 Impala with a 305 4bbl/700r4/3.42 G80 posi that would get 25mpg on the highway. I think 30mpg highway for your camaro is possible.

the 4 door 86 Caprice the 305 came out of had a 700r4 and 2.56 gears and it would get an honest and repeatable 28mpg with the cruise set at 75 and the AC blowing cold, and it would average 26 in my normal everyday driving.

the engine now has better heads and better exhaust and is in a car that is at least 800 pounds lighter without an AC compressor and AIR pump running off the engine and a smaller aero cross section with the deeper gears that put it right around that 2000 rpm sweet spot where small blocks cruise the best with mild cams.

Keith wrote: Aren't carbs usually cold to the touch anyhow due to the fuel atomization? Can't say I've ever fondled one after a run, but that was my understanding. Here's the intake setup we're using on our V8 Miatas now. Looks a lot like novaderrik's. It replaced this. Much, MUCH cooler intake air. We were seeing some pretty high temps due to the previous filter location. Ram air wasn't the goal, we just wanted to dump some intake temps. And it works. On the dyno I don't expect we'll see much difference because that's usually a fairly ideal scenario for air temps. BTW, the car in those pictures got 28 mpg on his drive from Colorado to Ontario, Canada. No attempts at aero work, and possibly with the top down a fair bit of the trip.

carbs aren't generally very cool to the touch unless you run a cold air intake of some sort- this one is downright cold after going down the interstate for a few miles.. i'm betting that it will be like the 76 Monte Carlo that i had 20 years ago after i put my first home made dual snorkel ram air setup on it that picked up air from the top of the radiator. there would be water running off the outside of the carb like a glass of ice water on a humid 90 degree day- that car got 30mpg, so this Camaro should, too, unless something is terribly wrong or i forgot how to tune a carb.....

Wouldn't colder air reduce your gas mileage? Denser charge, less throttle, more pumping losses.

My idea...

If you picked up hot air you could reduce the density of the air by a large percentage, essentially making your engine seem smaller, which should use less fuel when cruising.

Put a valve on it like the carb heat on an aircraft engine, so you can turn it off when you want power.

Keith: What intake is that on the Miata? I want to run an over the radiator intake on the LS RX-7 and have been toying with C5 or Camaro intake and modifying it.

B430, have you been reading your Smokey Yunick books?

Greg, it's an LS7 intake from a current Z06. Easy enough to find used. The LS3 Corvette intake looks almost identical with a resonance chamber plugged into the side. We looked at a couple of aftermarket ones but this one was just a little thinner and gave us the hood clearance we needed. The best part is that, since we're using LS3 engines, it fits like factory right down to the MAF insert. We use an LS9 filter because it's less restrictive than the LS3/LS7 ones and pops right in.

Here are a few more pics showing how it fits in the car.

On the NB, it sits a bit higher so it's not quite in the airstream. I've changed the one in my own car (shown here) to an Attack Blue filter which also moves it up a bit and out of the bug strike zone.

No, but I have heard about it. Can't be debated that colder air = more power, thus more fuel. Hot air does the opposite.

A gas engine is more efficient at higher power settings, so in theory if you can reduce the power the engine produces at full throttle to that needed to maintain cruising speed it should be more efficient.

Don't know that the gain would really be worth it, but my point was more that a ram air/cold air system would not reduce fuel consumption.

B430 wrote: No, but I have heard about it. Can't be debated that colder air = more power, thus more fuel. Hot air does the opposite. A gas engine is more efficient at higher power settings, so in theory if you can reduce the power the engine produces at full throttle to that needed to maintain cruising speed it should be more efficient. Don't know that the gain would really be worth it, but my point was more that a ram air/cold air system would not reduce fuel consumption.

cooler air does work to get extra mileage.. i've documented it on many cars.. the trick is to ram as much cool air into the carb as you can, then feed it into a nice and hot intake manifold.. i don't know what manner of alchemy is involved, but it works. probably has something to do with the extra oxygen being able to more efficiently utilize the fuel or something like that. i do know that you can run less ignition timing with a good ram air/cold air setup so the engine isn't "fighting" itself as hard as it squeezes the air/fuel mixture on the compression stroke. in the case of my Camaro, i had to back off the distributor a few degrees after hooking up the ram air due to audible detonation at part throttle, but it seems to cruise down the interstate better now with my foot just barely pushing the pedal down.

i have thought about trying to make a ram air setup that routes the air over the exhaust to get it nice and warm before ramming it into the carb (similar to Smokey's adiabatic engine but without the turbocharger), but routing everything to get minimum restriction would be a nightmare and keeping the gas in the carb from wanting to boil would be a trick, especially at low speeds and after engine shutdown...

I've been thinking of running some plastic tubing from my front bumper to the "frying pan" filter housing. The car had something like that stock, but the CAI hose had disintegrated and then I removed the CAI/HAI switching box it ran to (HAI is the last thing I need in this climate).

I noticed it feels a little more powerful when it's cold and rainy, and I'm sure there's lots of potential to drop intake temps.

In reply to novaderrik:

Maybe it depends on the car, but I seem to get much better mileage when the temperatures outside are warmer. at least 3-4mpg better in the summer months than in the winter. And I've definately heard of hypermilers using warm air intakes.

maybe theres a point of diminishing returns there somewhere in either direction (powwwwar! vs MPG), and an ideal IAT......

of course I am dealing with relatively new fuel injected car, not carb'd

Here's a hypermiler trying to do proper testing of a hot air intake system:

http://www.gassavers.org/showthread.php?t=12006

It makes sense that you'd get better economy with less dense intake air and lower pumping losses - we see that here at altitude. You also see it with a turbocharger, as there's basically less intake restriction at cruise. But I'm usually looking for power, so I'll take my air as cold as possible

failboat wrote: In reply to novaderrik: Maybe it depends on the car, but I seem to get much better mileage when the temperatures outside are warmer. at least 3-4mpg better in the summer months than in the winter. And I've definately heard of hypermilers using warm air intakes. maybe theres a point of diminishing returns there somewhere in either direction (powwwwar! vs MPG), and an ideal IAT...... of course I am dealing with relatively new fuel injected car, not carb'd

The reason in general MPG are worse in winter is the fuel mix changes (depending on your location) and it takes your car longer to warm up to optimum temps in colder weather. So in that time it takes to warm up the motor is dumping all kinds of extra fuel.

I would think that a hypermiler would want the motor as hot as possible without detonation or going over the oil breakdown/too thin to do it's job temperature. And then sustain the temps at that point as long as they can. This might be harder to do with a fun car that is going to see more spikes in temperature from say spirited driving.

an update on this ram air setup.. it has it's own little quirks..

it apparently works really well, since the carb is almost ice cold after an interstate drive of a few miles on 90 degree days despite sitting on top of a hot intake manifold . water was running off the outside of the carb the other day when it was 95 degrees out. the downside to this is that it screws with the calibration of the idle circuit after slowing down- the car wants to idle at 1500-2000 rpm while the carb is cold, but after a few minutes of heat soaking into the carb from the intake, it settles down to a nice 700 rpm idle in park and 500 in gear. i checked the choke, and it's wide open and the fast idle is kicked off. i wonder if there is an icing problem in a passage or something weird like that?

it's a very repeatable problem- drive down the road a few miles after letting the carb heat soak, and it does the same thing.. never had this happen before in other cars, but i don't think i've ever rammed this much cool air at a carb, either. i think i now know why GM didn't use this setup on the carbureted cars and instead just put a small scoop on top of the radiator support on either side of the radiator- the carb still got cool air, but not so much of it to cause carb problems.

i wish i had a pressure sensor of some sort to put inside the air cleaner, as well as a temp probe.. could be some interesting stuff to learn here..

regarding fuel mileage: each tank gets a little better- the lowest was 16mpg, the last tank was 22mpg. i've put probably 1000 miles on the car over the last couple of weeks, but i haven't been able to just drive it without having to sort out some problem that involved idle time or repeated test drives.. but i'm still getting the new car/new engine bugs worked out, and i think that once i get it dialed in and don't have to berkeley around fixing weird problems i should be at least into the high 20's, with 30mpg being my ultimate goal. i think there's a few mpg's to be found once i get the torque converter to lock up without popping the fuse. my current lack of a garage and the daily rain storms have kinda slowed me down on things like that..

i did swap in a better starter last weekend that allowed me to pull the timing ahead to where the engine runs a bit better, but i haven't really played with it all that much, what with the rain and all..

Seems as if cold air has an advantage since just about every car made today and before take intake air from the outside.

In reply to iceracer:

But they also have stuff like hot coolant running through the throttle and so on.