SpiralMax?

No.

If it worked, it would be in there from the factory.

--- Rich

You mean like tuned headers and K&N Filters???

Tom - Vista, CA

Tuned headers cost more than factory manifolds, and generally aren't as durable. K&N is mainly hype.

But the SpiralMax will indeed make the truck go faster...mainly due to the driver's lighter wallet.

Ken

No. At least they are honest with the "0 - NN" range. Expect 0, if not a decrease in performance due to a restriction in air flow.

Certainly do not install it between the MAF/AMF and the Throttle Body.

And when you look at their "Turbo Exhaust Product" tht promises to "lower backpressure" - keep in mind that normally aspirated engines and exhausts are designed to create backpressure.

Your money would be better spent on a K&N FilterCharger.

good luck! GTr

I thought K&N were mainly hype.

Just repeating what I heard on a newsgroup, and you know if you heard it on a newsgroup, it must be true... :>))

Tom - Vista, CA

no, not designed to "create" backpressure. the idea is to keep exhaust gases hot and moving fast. at no point is any header/manifold designed to create backpressure. if you could place a vacuum on the end of your tailpipe, your engine will make more HP. however, over scavenging the engine is a small problem......

If that's one of those spiral-vane thingies they say to put under the air filter to develop swirl in the intake, it is not going to do anything for you. Run away, do not walk.

It might make things worse to have turbulence in front of the airflow meter, since the computer needs to know how much air to get the fuel right - the turbulence could fool the EFI and make the engine go lean, and that could increase mileage a bit - right up until your engine starts doing very bad things like melting pistons...

If that kind of voodoo magic (cow magnets on the fuel lines...) actually worked, all car manufacturers would buy and install them at the factory - the Corporate Average Fuel Economy rules would see to that, every tenth of a MPG gained in a car's EPA testing is important when they look at a fleet average.

That's why they are all putting 5W30 oil in at the factory - they get a bit better fuel mileage. Nevermind the oil consumption issues when using too-thin oils in older engines, they have to push the thin stuff to get the economy gains.

-->--

Within reasonable cost levels. Today's exhaust manifolds are generally a far cry from what we grew up with. Not tuned headers, but far more efficient. Tuned headers also generally only help within a very narrow power band. What you want for pulling your sand rail up the Cajon Pass may not be the same thing Bobby Street Racer wants. You both want improved power, but at different points in the RPM band.

K&N filters? Ya... they improve performance (and ONLY at wide open throttle) by providing inferior filtration (at all throttle levels). Fine if you are racing, but vehicles are designed to go a few hundred-k before major work.

The automakers have nothing to lose if the use of these relatively inexpensive gadgets like magnets and vanes were effective. They are under orders from the government to improve fuel consumption and reduce pollutants. Improved efficiency = improved power with no additional fuel used, which helps the auto maker's fleet numbers.

I went through all of the BS back in the 70s and 80s... There's nothing that we can do ourselves to produce an improvement that is cost-effective without creating a major compromise somewhere else.

These little $50-$200 bolt-on goodies don't do anything but drain your wallet.

--- Rich

They are, but they are better than the vortex generators.

--- Rich

Maybe, maybe not. You mentioned overscavenging... a significant reduction in backpressure could get the engine into a situation where the mixture in the chamber is severely screwed up.

--- Rich

I agree, I was just playing devil's advocate...

A friend at work said he put a K&N on his pickup but couldn't really tell much difference. Then he showed me his 1983 1/2 ton with nearly

300,000 miles on the original engine. I told him that if it cleans the air that should be enough for an oldie like that... :>))

Tom - Vista, CA

You have a point. I was thinking from the POV of older carb/na engines. There's a pretty good explanation here:

GTr

Please explain. I thought all the incoming air/fuel mixture used for combustion entered the chamber after the exhaust valve closed.

There's a period of time while the exhaust valve is closing and the intake valve is opening. It's called the overlap. The idea is to use the inertia of the leaving exhaust gases to help suck in the intake charge. It works better at higher RPMs than at idle. Racing engines usually have an incredibly long overlap time, which is the main reason they don't idle smoothly and tend to be sluggish at low RPM.

Tom S

There is some overlap on the valve timing. That's why racing engines "lope", or have a very rough idle... their cam timing has a LOT of overlap. This allows the exiting exhaust flow to aid in pulling in a fresh mixture. That is also why they smell like raw gas and can't pass smog... because they are passing raw, unburned fuel and fresh air directly into the exhaust. The mixture in the cylinder is 99% fresh mixture and virtually none of the exhaust is run through the combustion cycle a second time.

Even though the piston is moving down and drawing gasses into the cylinder during the intake cycle, in a properly tuned exhaust system, the flow in the header tubes NEVER reverses... like blowing across the top of a straw to pick up a piece of tissue on the bottom, the next cylinder (still on it's exhaust stroke) is "blowing" across the end of the collector, which keeps suction on the other exhaust valves.

2-stroke engines using a tuned pipe are even more impressive. They overscavange, drawing a significant amount of fuel/air into the header, and just before the valve closes, the exhaust pulse reflected from the end of the tuned pipe returns and SLAMS the mixture back into the cylinder. Only effective in a very narrow RPM range because the pipe is tuned for peak RPM, but the effect is similar to that of a supercharger. Similar to a supercharger, running lean will result in a hole in the piston.

Street engines have more modest overlap numbers, but there is still some overlap. The exhaust helps to draw the intake charge in, which reduces the amount of suction the piston has to do, which helps efficiency. It's a fine balance between reducing the engine's "inhale effort" and re-burning enough exhaust gas to keep emissions levels down.

--- Rich

I remember riding a tricked-out Yamaha YZ-250. The thing would about rip your arms off when it hit the pipe. Of course, to match that, it had toggle-switch brakes (LOCKED -or- OFF)... :>))

Tom - Vista, CA

LOL! My boss' Q45 is in for service, and they gave him a G35 loaner. Same thing... like a truck with airbrakes.

--- Rich

the whole design of a fuel injector is TO MIX THE FUEL INTO THE AIR. spend money on better injectors, not some twisted tin....