JALVORD_2003_68

As you may well know i have a set of dual weber tipo carbs, i was wondering if anyone makes a cold air system for K&N type filters?

REVHED

I doubt it. You'll probably have to make your own if you want cold air.

I'm considering making one for my IDA setup but I'll lose the awesome induction note. Also, the performance increase is debatable as you can't optimize the carb jetting for all temperature conditions.

JALVORD_2003_68

wouldn't it be helpful because the carbs wouldn't be sucking hot air from the engine compartment?

REVHED

There's no doubt it will help. It's just hard to say to what extent though.

Directfreak

iTrader: (2)

He's right. Why don't you put it on the DYNO before and after the modification to settle this once and for all?

- I am kidding.

PaulFitzwarryne

You get a one per cent increase in power for every 11 degrees F ou decrease the temperature. With a good fan and radiator you will be very lucky to get more than a five degree drop on the open road. Thus, the increase in power will be minimal. The engine may be hot but the air rushing past has little time to gain temperature and become less dense.

With a turbo its a different story, an intercooler does have a noticeable difference.

WackyRotary

Cold air intake on a non-turbo car is MOSTLY a waste of time. Not 100% worthless, but so near it would be a well in the realm of phsycologicial increase in power....

RotoHusker

Heat shield between the intake and exhaust manifolds ???

82streetracer

iTrader: (1)

I see alot of the members on this forum with a cold air setup with the stock airbox. This is not the way to go. There is a valve in the air box that routes hot airfrom the exhaust manifold if intake air temp gets to low. When I first got my car I removed this valve. Now I am running a edelbrock Proflow air cleaner

Edelbrock Proflow Aircleaner

i saw a noticable improvement when I installed it and I got A little bit of intake roar.

REVHED

Actually, that's a great idea. That's exactly one of the things dyno's are useful for amongst many others.

Defprun

I took off that exhaust thing as well, and cut a hole out of my aircleaner (the side away from the exhaust manifold) just to get more air. I know less cold air is better than more hot air, but I'm thinking about running both. I actually felt a small difference! It actually opens the vacc secondaries quicker...

Not to worry though, i plan on running some kind of ram-air system later. I'll even see about carbon fiber...but would these ends justify the means? Who gives a crap! They're 7s I wanna go fast.

Manntis

A so called cold air intake a.k.a. airbox also keeps larger particles away from your filter. See that black crap building up in lumps around your engine compartment? See all that road grime?

Ever see any of that INSIDE a factory airbox or 'cold air' box?

Aha...

Bass

Actually, this "valve" is a coiled dual metal ribbon that reacts to the temperature of the engine block as it travels to the airbox through induction. It's intent is to use the warm air passing over the exhaust manifold to bring the engine up to operating temperature faster. Once the engine reaches operating temperature, it closes off the warm air route - switching to the snorkel, and won't open again until you have a cold engine. The temperature of the intake air should be as low as possible (such as what can be taken in through a cold air ram) as colder air is denser air - and denser air has more oxygen molecules - and more oxygen molecules means a bigger BANG! at ignition. Also, with the ram air intake out in front of the radiator, you get alot of intake roar and better acceleration. In stock form, the end of the snorkel points away from the radiator in an attempt to get the coolest air possible without increasing noise. The cold air ram set-up gets much colder air as it is subject to wind chill and a higher velocity.

Defprun

Yeah, but all that road grime helps the K&N work better!

85RX7GS

iTrader: (1)

Does Edelbrock make anything for the stock air canister and carb on a 12A?

PaulFitzwarryne

I am still not convinced that a 'cold air' box works on a NA Sterling is taking some temp measurements as given on another recent thread on the same subject. My readings on air temp while driving were surprising low.

Perhaps more important is the flow of air as the stock snorkle is apparently restrictive. REVHED on his Nikki widened it while others have taken a more simple approach of drilling holes in the air filter box. Pineapplle Racing suggests this, presumably taking into account the temperature of the air.

Bass

I once saw an episode of "On The Road Again" where a guy out on the East Coast would take your food order and then he would place your hamburger, fries and whatever else, wrap them in tinfoil and place them in the engine compartment. He would then drive around for a few minutes ; open the hood and voila! Your meal is served. It's gotta be hot under that hood.
Just some food for thought!

82streetracer

iTrader: (1)

I didnt know thats how that flap worked, mine was always closed so I removed it.

The edelbrock also looks really cool under the hood.

PaulFitzwarryne

I do not disute the engine and header are relatively hot thus you can fry an egg. The qustion is the air temperature that flows past. Turn an oven ring full on then feel the temp say a foot above it, then turn a range hood or fan on.

Bass

Yes, but that stove top ring is trying to heat the air in the entire room. In that given scenerio, the heated air is constantly rising and mixing with the cooler air. Think about how that oven below works - through heat induction of the air that is contained within the oven itself. The elements in the oven don't actually create anymore heat than the rings on the stove top. It's the closed and restricted air space that allows it to reach higher temperatures. An open oven is a better replica of the engine compartment than that of the stove top rings.

PaulFitzwarryne

OK its an oven, but its fan forced! The rad fan is forcing vast quantities of new air into the engine bay each minute. the air temperature is far more dependent on the heat transfer from the radiator than the engine block. The temperature of the air exitting the bay and going into the snorkle is well under 2 degrees different from the temperature measured after the fan.

If your engine is running too hot the heat loss is mainly from the cooling system. Thus, the critical factor is the increase in temperature as the flows across the core.

I agree adding a cold box will not have any negative impact and looks cool. Do it yourself and its no cost even if its no measurable improvement!

Manntis

Air in the engine compartment does circulate, but not at gale-force blasts from front to rear through the entire engine compartment as is being implied in certain thread responses. Where is it going to go? The hot air is contained on top by the hood, on either side by frame and strut towers, behind by the firewall, in front by the wall of air trying to ram its way into the engine compartment.

Air coming through the rad typically spins through the fan then drops down and out the bottom of the car. The low pressure air whipping past under the car makes friends rather nicely with this other heavy, colder air while the top half of the engine compartment, where most people locate those huge conical filters, traps all the dirty, hot air.

An airbox, in contrast, creates a physical and thermal barrier between this hot layer of engine compartment air and the cold air being pushed in (nothing is truly "sucked" - gasses push from high to low pressure even with engine vacuum) from the outside.

Air thus entering an airbox flows through so rapidly it doesn't have time to sit and soak up heat through the walls of it's airbox before taking the guided tour of the inside of the combustion chamber.

Air being gathered from the hot layer in the top half of an engine compartment, on the other hand, does have time to sit there and get cranky, losing PPM of oxygen before being invited in.

On another note, if the engine is running too hot it's due to the engine-heated coolant not being pumped away from the hot engine block and replaced with cooler, er, coolant.

JALVORD_2003_68

Do you think that will fit on my set-up?

PaulFitzwarryne

If the carb is sucking in air at say 350cfm, them surely it scavanges the top of the engine bay every 3 seconds? Or is my recollection of the basic data faulty? What is the flow potential of a pair of Weber sidedraught 45s?

This flow requirements at high rpm is why so many people think the stock snorkle is too restrictive on a modified Nikki .

Manntis

The air in the top of the engine bay gets hot.

Rather than debate this, go for a spin to get the engine to operating temperatures. Pull over. Pop the hood. Lift it just high enough to slide your hand in beside the intake manifold.

Then go buy an airbox.