Everything about Spectre Cold Air Intake

[arizona-dave]

Konig...I dont want to sound harsh here, so please take what Im saying without offense:
a) Cold Air is more dense, contains more Oxygen, and more molecules than Hoter Air...
b) Cooler Intake temperatures do not cause the engine to labor more in "increasing" the combustion temperature, the temp inside the comb chamber is dependent upon Gasoline Atomization & Amount of Gas, and its chemical reaction to the available Oxygen in the air, at over 1700 Deg F, the "work" involved in the gas "heating" up the air is far less than the increase in available oxygen to allow the gasoline to combust.
c) If you were to take in air at the same temp as combustion, you would effectively eliminate nearly all of the energy that combustion generates, Air at 1700 dwg F would be almost as thin as Exhaust (Air + Gasoline converted to Co2 * CO)...why? Because the entire purpose of adding gasoline to the mix is to EXPAND the volume of Air inside the combustion cylinder to many times its original volume, adding gasoline and spark allows this to happen, take 0.25l of air and explode it to 3 or 4 litres worth and Voila, you have a piston that moves...if the air temp going in was 1700 d F, the only additional volume of ait you would gain would be a few miligrams of of gasoline turning into maybe an ounce of CO2 and CO...or virtually nothing.

Do some research on steam engines and it will become more apparent...but in that case, the water is what increases in volume to a few times the original input...1/2 oz water can explan to a litre of vapor at 300 D F.

Well in terms of efficiency its different, higher intake temps will gain a better thermal efficiency, since if I understand it correctly, the process of combustion doesn't have to use additional energy to heat up the intake air, Ideally, I think, it would be best to run an engine at the temperature of the combustion, that way heat isn't lost to warming up the air, and heating up the engine it self, which is eventually loss thru the radiator via the coolant, but of course the engines we have now won't stand up to high temps like that.  On ecomodder they talk about warm or hot air intake, and from what I read with mixed results, some speculate on some engines, hot air can cause the computer to pull timing and stuff like that... I'm sure if they had access and the ability to alter the computers programming correctly, they could re tune it where a hot air intake would work... or maybe not, engines are complex systems lol

Colder air does build more power, because of more available oxygen in the air that can combust with the fuel, just as if you ran forced induction, or drove at a lower altitude instead of at higher elevations.

I just personally believe that some bolt ons just wont add power or efficiency significantly by themselves, sure the aftermarket intake can flow more air into the engine, but does the engine need more air? If you modded your engine, where its spinning faster, better flowing heads and all then sure it may need a better intake system, but in stock form I think the automaker who has spent millions of dollars and lot of time developing these engines would gladly put a bigger air filter in or stuff like that to improve mileage and power, (think ok a bigger filter would cost Gm $2 dollars at most more, But now the truck gets 21 mpg instead of 19, I think that would justify the extra cost ten fold) but they decided what it has now is good enough with little to gain from a different system. In my opinion I think where gain can be had, is from places where noise, vibrations, emissions, engine life and significant cost differences and stuff like that are suppressed, as a lot of people want a quiet truck or one that drives smooth and shifts smooth and all the fluffy stuff. A supercharger will definitely add power, but at the cost of reduced engine and drive-train life. Or a different muffler or not one at all, a lot more noise that may drive away a lot of customers. Emissions I can't think of one right now except lean burn mode, some gm vehicles have but is disable because of NOx emissions but heard its good for 1-2 mpg hwy; I don't think modern Catalytic converters take power but can add power, as if I understand correctly they can design them where they pull the exhaust out (think ram jet) though i'm not 100% sure if they do that. There is no free lunch.

 

[konigstigerii]

you're fine, I was actually wrong about why warm air is more efficient... I think I was thinking backwards about increasing the combustion temp, my bad lol. It actually deals with the throttling losses, google "warm air intake" or look here: http://en.wikipedia.org/wiki/Warm_air_intake (I know its Wikipedia lol) It will give you less power, as you stated with less oxygen, but gains more efficiency as the throttle has to open more to supply the same power or air, and gives less pumping losses. It seems a "warm air intake" works for some, and not for others, kinds depends on the stock system and the cars adaptability to such a modification.

I also read something about the fuel vaporizing quicker with higher intake temps too, but don't have much time to dig into that as well.

I imagine GM did a bit or research on what works well, not too warm to kill power, but not too cold to hurt efficiency

Anyways I'll have to research more, but I'm busy so until then.

 

[Z66Modder]

Here is my take on CAI and that is (at least my year) you get one from the factory. My factory box gets all its air from the ports through the fender wall. The source for that is way outside the engine compartment. The fault I see is a restrictive filter, which is why I have a K & N drop in filter. And to the guy who said he was taking out his because he found dirt in the throttle body, check your fit. I pulled my intake pipe this weekend to install my OBX catted long tube headers and it was so clean you could eat off it.

The factory system adds sound dampening with its funny design, but it also adds instant air volume past the filter for quicker throttle response. This is why I get more torque off the line  with a stock system, than a CAI. If I needed to run at 4 - 5 thousand RPMs all the time, I would have an after market CAI as it has more volume at that speed. I might look into modding the stock box to accept a Ram Air mod, but won't be going back to an aftermarket CAI any time soon

 

[2002AVA]

Again i think it goes back to your personal setup and tastes. I am running the Spectra with a 1" TBS. I am also running electric fans that give me 13 inches of clearance from the back of the radiator to the front of the Water pump. So I have a lot of room to dissipate heat. My intake tube is never to hot to touch, even after a 900 mile drive in 110* weather. I did not lose much on low end until I change my exhaust over to 2&1/2 Duals. And that was before I ever went with a CAI. I am planning on changing my exhaust down to 2&1/4 duals, to see if that helps. My gas mileage also went up from 15-16 up into the 20's.

So I am sold on the CAI. Again it is setup and tastes.

 

[PerfectReign]

Shane:  I think you also have touched on a point in that last post.  You have an '02, which had the clutch fan. I know on my 2006, I have electric fans from the factory. 

I added a CAI to my '95 Jimmy and noticed a bit of difference. However, I think that the stock box for those of us keeping the RPMs at 2200 or lower works just as well. I am emphatic about changing the filter ($10) every time I get an oil change.  IMO, that works just fine for lower RPM conditions.  Were I to add a turbo/supercharger and start running my engine at 4-5k RPMs I'd be absolutely sure to get a CAI.

(By the way, I have a K&N drop-in filter on my wife's '05 Vue which has the Honda V-6 engine and often runs up around 6-8k RPMs.)

 

[arizona-dave]

I know weve touched on this before, but will shim again...When I installed my Specre at first, I noticed better high-end freeway speed power, but Far-Reduced off the line throttle, for the first second...it was "bogging down"....when I added my Magna flow exhuast the boggin down completely disappeared and I have even better high-speed response.

I think the GM computer is pretty sophisticated with all its metering, MAF Sensor, Air Temp etc. In any even, before I did my exhaust I was ready to remove the CIA, and use a drop-in K&N in the stock filter box.

And...to be fair...if any of us really wanted tru Cold-Air intake, we would need to run Dual-Walled intake tube and have a Ram-Air intake...I think the Single-wall Aluminum tubes run fine at speed, but I know at Idle or low speed, they actually heat up and heat up the "cold" air running thru them. I actually added aluminum-backed fiberglass insulation around my CIA on my lexus...Its ugly, which is why I havnt done the AV yet...looking for a better looking insulation to put around that single-wall intake tube.

 

[konigstigerii]

z66modder, I was thinking about the same thing with the volume of air that is in the sound damping areas, and how that could effect off the line power.

And I'll probably be going back to a k&n as the acdelco paper filter seems to let this super fine dust in as well, and  in the long run the K&N will be cheaper. though I haven't noticed a difference in power with the K&N, its hard to tell with the old butt dyno, but map pressures seem unchanged except at 4500+ rpms.  I have checked my intake system fit a few times, and haven't found any leakes that dust could make it thru... though I should remind you that I do a lot, a lot of dirt road driving and the dust in the intake is extremely fine.

Btw if you do start making a ram air box for the factory set up, I would be interested in what you do, as I been pondering it myself.

on the spectre CAI after driving around, it would become way too hot I could not even touch it, whereas the stock is warm but still touchable. I do still have the clutch fan, as for me it is better suited, because if it goes bad, it stays on, electrics go, they stay off

I have a magnaflow exahust, but with the Spectre CAI I got the bogging down a lot too, but I know it was because of the CAI because my intake temps were 130+ where as my stock set up they were around 110 at most. When I bought the CAI I did a ABA test, with B being with the CAI, and noticed increased intake temps, less off line power and no change in mpg or any change in MAP readings over the stock set up with a K&N and determined it was not worth the money for me and what I use my truck for.

 

[arizona-dave]

Yeah, the Bogging down at first was unbearable....and I really think the single-wall aluminum tube gets way to hot...and we all know Aluminum is an Excellend conductor of heat, thus any air going thru the tube will heat up.

As for Ram-Air...I think Id need to buy a diff hood...that hole near the fender is small, and its not in the direct stream of the air...but, its a wish-list to do.

I cleaned my MAF sensor the other day....I have a tad bit better throttle response, but not the nite/day diff that some people claimed, but if it was dirty is was barely...so I didnt expect a big change....I was actually surprised how clean it was after 79,000 miles.

z66modder, I was thinking about the same thing with the volume of air that is in the sound damping areas, and how that could effect off the line power.

And I'll probably be going back to a k&n as the acdelco paper filter seems to let this super fine dust in as well, and  in the long run the K&N will be cheaper. though I haven't noticed a difference in power with the K&N, its hard to tell with the old butt dyno, but map pressures seem unchanged except at 4500+ rpms.  I have checked my intake system fit a few times, and haven't found any leakes that dust could make it thru... though I should remind you that I do a lot, a lot of dirt road driving and the dust in the intake is extremely fine.

Btw if you do start making a ram air box for the factory set up, I would be interested in what you do, as I been pondering it myself.

on the spectre CAI after driving around, it would become way too hot I could not even touch it, whereas the stock is warm but still touchable. I do still have the clutch fan, as for me it is better suited, because if it goes bad, it stays on, electrics go, they stay off

I have a magnaflow exahust, but with the Spectre CAI I got the bogging down a lot too, but I know it was because of the CAI because my intake temps were 130+ where as my stock set up they were around 110 at most. When I bought the CAI I did a ABA test, with B being with the CAI, and noticed increased intake temps, less off line power and no change in mpg or any change in MAP readings over the stock set up with a K&N and determined it was not worth the money for me and what I use my truck for.

 

[Z66Modder]

I know weve touched on this before, but will shim again...When I installed my Specre at first, I noticed better high-end freeway speed power, but Far-Reduced off the line throttle, for the first second...it was "bogging down"....when I added my Magna flow exhuast the boggin down completely disappeared and I have even better high-speed response.

I already had the exhaust modded when i did my test, maybe with my headers it might be different, just don't know? 

And...to be fair...if any of us really wanted tru Cold-Air intake, we would need to run Dual-Walled intake tube and have a Ram-Air intake...I think the Single-wall Aluminum tubes run fine at speed, but I know at Idle or low speed, they actually heat up and heat up the "cold" air running thru them. I actually added aluminum-backed fiberglass insulation around my CIA on my lexus...Its ugly, which is why I havnt done the AV yet...looking for a better looking insulation to put around that single-wall intake tube.

 
What about that fibercloth wrap they use on water heaters that looks like a cotton blanket, would that be better? Maybe it could be cut to fit and secured with tiewraps or SS tie wire?
[/quote]

 

[konigstigerii]

If I were to make a cold air intake tube, I would make something like this: outside would be a somewhat thin layer of polished aluminum or something white with a low absorptivity (wouldn't absorb much heat from radiation) then a layer of some kind of insulation, the more the better, then something for the inside tube like aluminum or plastic.

For something simple, just get a high gloss white paint (or any lighter color since you can't get much worse than black lol) and paint you plastic tube

Or get some foam tape, cover the tube, the use some aluminum foil tape, and the cover the plastic or aluminum tube

many possibilities

 

[txyank1]

I just sat here and read thru this whole thread and I'd like to make a few thoughts based on my experiences related to the things mentioned here. I apologize for the fact that I have not tried a Spectre CAI. But I've used the Stock, Pro Cold and Airaid in all possible combinations.
*The Airaid tube made the most noticeable power difference. The filters, and boxes etc. just added more noise. Nice noise though.
* Greatest performance add was in the 40-60 mph range.
* Several 3700mi round trips to NY using all the various setups netted all the same avg MPG. (21.4) This was with an 05 and 06 both 2wd w/3.42 gears and stock exhaust.
* Every modern, computer-controlled vehicle I've driven (99% GM's) since '99 bog off the line if you floor it. With the exception being my Daughter's '98 500+ HP Lingenfelter 'Vette. No bog there.
* Every vehicle I've driven in the past 50 years, but especially my GM's, act like they have 50 more HP on cool damp mornings.

My personal opinion is if you have great expectations of increases in MPG and HP you're going to be disappointed and they aren't worth the money. On the other hand they look cool and sound good! (Fortunately I bought all mine used from Members here.)

All in all a good thread with lots of good input 

 

[PerfectReign]

I think I found a nice CAI that might add a little hp...

 

[arizona-dave]

Ur Getting 21.4 Mpg ? Holy crap!!! Iv got 3.73 but 4WD Option, leave it in 2WD, cant get over 17.5 even when pussy fottin it. Does ur Gas up there not contain Ethanol?

I just sat here and read thru this whole thread and I'd like to make a few thoughts based on my experiences related to the things mentioned here. I apologize for the fact that I have not tried a Spectre CAI. But I've used the Stock, Pro Cold and Airaid in all possible combinations.
*The Airaid tube made the most noticeable power difference. The filters, and boxes etc. just added more noise. Nice noise though.
* Greatest performance add was in the 40-60 mph range.
* Several 3700mi round trips to NY using all the various setups netted all the same avg MPG. (21.4) This was with an 05 and 06 both 2wd w/3.42 gears and stock exhaust.
* Every modern, computer-controlled vehicle I've driven (99% GM's) since '99 bog off the line if you floor it. With the exception being my Daughter's '98 500+ HP Lingenfelter 'Vette. No bog there.
* Every vehicle I've driven in the past 50 years, but especially my GM's, act like they have 50 more HP on cool damp mornings.

My personal opinion is if you have great expectations of increases in MPG and HP you're going to be disappointed and they aren't worth the money. On the other hand they look cool and sound good! (Fortunately I bought all mine used from Members here.)

All in all a good thread with lots of good input   

 

[konigstigerii]

Ur Getting 21.4 Mpg ? Holy crap!!! Iv got 3.73 but 4WD Option, leave it in 2WD, cant get over 17.5 even when pussy fottin it. Does ur Gas up there not contain Ethanol?

17.5 hwy? or combined? On my avy, 04 with 3.73, but I have 285/70/R17 tires, and Hwy I've gotten anywhere from 19 to high 22s under normal conditions (not towing, cross/tail/head wind etc.) Usually I seem to get 21 driving around 70 mph. I'm unsure if the gas here has ethanol, its costco gas, which is always filled up with tesoro tankers. City well not so good, my average is usually 15 maybe 16 if i'm easy. And yes my DIC is accurate, checked it a few times, exactly correct, and my computer is adjusted correctly for the bigger tires. Only performance mod is the diablo tuner

 

[txyank1]

My 21.4 includes gas bought in TX, AR, TN, PA and NY. All has at least 10% Ethanol. I buy cheapest, I don't use any one brand. And some of my best mileage has been on gas from the non-brand-name stations. I get around 14-14.5 city. City was better on my '03 with the 3.73 gears but seldom hit 20 on the highway.

 

[arizona-dave]

Maybe my tires are stealing MPG? BF Goodrich A/T 265/70 R 18. Who knows.

Ive gotten 19 MPG Highway 70 Mph, never more...also, the 4WD diff and extra drive train I think steal a little even when disengaged....not sure.

 

[konigstigerii]

Maybe my tires are stealing MPG? BF Goodrich A/T 265/70 R 18. Who knows.

Ive gotten 19 MPG Highway 70 Mph, never more...also, the 4WD diff and extra drive train I think steal a little even when disengaged....not sure.

We have about the same size tires, and gear ratio, but I seem to get 21 ish at 70, sometimes better. Wonder if elevation plays a part, me being in utah, elev. around 4000 feet, where the air is thinner and less air drag? and also possibly more engine efficiency because of thinner air with the throttling losses.

What modifications do you have? I just have the diablo tuner, fresh tune up and all synthetics (engine and diffs) Also I have stock ride height as well. 

 

[2002AVA]

My mileage has been better since I moved from Pocatello, Idaho,(5300 feet). I am now at 2000 feet and am getting 18, but I am in the mountains and drive up and down grades all the time. When I do drive in the San Joaquin valley, I get 22 doing 65mph. I figured it was because I have more air in the throttle so I require less fuel. I also noticed that running 265/70/17 or 285/70/17, my mileage does not change much. That is why I am going back to 33' tires.

 

[konigstigerii]

My mileage has been better since I moved from Pocatello, Idaho,(5300 feet). I am now at 2000 feet and am getting 18, but I am in the mountains and drive up and down grades all the time. When I do drive in the San Joaquin valley, I get 22 doing 65mph. I figured it was because I have more air in the throttle so I require less fuel. I also noticed that running 265/70/17 or 285/70/17, my mileage does not change much. That is why I am going back to 33' tires.

Like said before, I'll get about 21 at about 70 mph right now. With the K&N and stock box (not really sure it actually makes a difference yet) and with the air hot, 95+ outside, on a straight away, no grades, I've seen high 22s-to 23 average. This doesn't count off or on ramps, just from one point to another already at speed. Typically if I count on and off ramps, its been about 21 for about a 7 mile freeway drive, long as I don't race around

The hills can play a big part, as well if it cold, as there maybe different grades of gas for winter or summer blends.

btw I believe if you were getting more air, you would also be using more fuel, as the computer tries to keep the air-fuel ratio the same, unless you figured out a way to enable lean cruise mode then you must share how to But this kinda goes back to the warm (or thin) air letting the engine be more efficient, requiring you to open the throttle more and in turn loose less in pumping and throttling losses, this of course would be counter productive, if say, the air was too thin, and you engine could not produce just enough torque and power to maintain a speed, which would cause it to unlock the torque converter, then go into 3rd gear if it was really lacking power. Also the thinner the air, less air drag, and seeing how our trucks aren't exactly the best, this also plays a significant part I believe.

 

[2002AVA]

Maybe it is just the fact that I am not using a clutch fan anymore. This would take a lot of torque off the engine freeing it up for other uses. I also know by my records for the past 6 years that I get an average of 2mpg better in Cali than anyplace else I have been. I have driven in Milwaukee, Chicago, both Dakotas, Montana, Utah, Idaho, Washington, Oregon, Neveda and Arizona. All though my records show Arizona was 20 Average. When I use to drive from Pocatello Idaho to SLC, Utah I would average 19.7. Driving across 80 from Wells to Reno I get 18.6 from Reno to Coarsegold, Ca I get 22.3.
I have a Spectra CAI, Hypertech tuner, FM40 with dual pipes. I change my plugs every 30k and my wires every 60k, I am using MSD 8.5mm. I also use only synthetics. My worse mileage is 9.6, and that was towing a 5000lbs trailer through the mountains. I had previously got 13 pulling the trailer from Pocatello to Reno. I also have 163k on my 2002.

 

[konigstigerii]

Maybe it is just the fact that I am not using a clutch fan anymore. This would take a lot of torque off the engine freeing it up for other uses. I also know by my records for the past 6 years that I get an average of 2mpg better in Cali than anyplace else I have been. I have driven in Milwaukee, Chicago, both Dakotas, Montana, Utah, Idaho, Washington, Oregon, Neveda and Arizona. All though my records show Arizona was 20 Average. When I use to drive from Pocatello Idaho to SLC, Utah I would average 19.7. Driving across 80 from Wells to Reno I get 18.6 from Reno to Coarsegold, Ca I get 22.3.
I have a Spectra CAI, Hypertech tuner, FM40 with dual pipes. I change my plugs every 30k and my wires every 60k, I am using MSD 8.5mm. I also use only synthetics. My worse mileage is 9.6, and that was towing a 5000lbs trailer through the mountains. I had previously got 13 pulling the trailer from Pocatello to Reno. I also have 163k on my 2002.

Electrics can help, after all chevy did start putting them in in 05, and during freeway driving you don't really need a fan anyways.  But There is a lot of other factors that can play into mileage at different locations, such as air pressure, humidity, temp, and stuff like that... For you mileage trips you list, is that both ways or just one way? Change in elevation plays a part, I could probably get 50 mpg from park city utah to salt lake going down Parleys Canyon lol But I know one mod that can help you don't have listed, would be underdrive pulleys (or harmonic balancer if you will) I put them on my S10, and I could feel a difference, more so than anything, although my mpg calculations were absent because after I added a roof rack, so I can't comment on the mpg improvements. And I didn't really notice any decrease in the accessories that were underdriven either, its still one mod I'm contemplating for the Avy.

 

[2002AVA]

The ,mileage was for both ways, using pocatello as a hub. The trips to Milwaukee I did 8 times each way. SLC I have done more times then I can count, use to go to all the GTG's when I still lived in Idaho. But you are right, driving habits is probably the biggest factor in mileage. My wife's 93 Civic is a perfect example. her best mileage is 36 mine is 41, doing the same trip. I keep my tires at 40lbs when rated to 44lbs. When they are rating at 65lbs I run around 55lbs. I try to never go above 2000rpm, and I use cruise control even at 25mph. I also plan my braking as much as possible so I am not slamming or braking hard. Since my AC does no effect my MPG I don't worry about that. And I do not drive with the windows down above 35mph. I try to keep the Av waxed and clean, sometimes easier said then done.
Now when I break all my rules and drive harder my mileage suffers. I took the family off roading a couple weeks back down to the Merced River. When I was taking highways 41 &49 to get to the US Forest service road. I had to lock down into 4Lo and climb rocks and such. I also Baja'd the smoother parts of the dirt road in 4Hi. My mileage dropped to 13.2, and I never got much above 55 on the hard pavement. But I had so much fun I really did not care.

 

[PerfectReign]

@Shane - When you drive down from coarsegold (beautiful area, BTW!  seen any tarantulas yet?) to the valley, do you end up getting too many bugs in your intake, which drops your mileage?

j/k

 

[2002AVA]

No, but I have built a filter under the filter to keep them out. I used a chunk of swamp cooler padding and mounted it under the filter covering the hole. I just cleaned my filter and all the was in it was dust. The filter I installed needed to be cleaned, it did have a nice collection of bus on it, but only the underside. I can take some pics if you want to see what I did.

 

[tomfrojr]

Alright, I just finished reading this entire thread on the Spectre intake and saw many different topics brought up.  I like many who have already posted here have been searching for a year or more on which intake to purchase for my Avalanche and decided to go with the Spectre primarily because of cost.  The quality is good I would say that it is as good as any of the more expensive ones on the market.  Installation was fairly easy especially since I have never done a full blown install ever.  I checked the install today after putting it on yesterday afternoon and noticed everything was still tight even after driving around for half a day.  I felt the aluminum tube after driving and noticed it was hot to the touch but I have been driving around town with stop lights and temps around the lower eighties.
So far I like the $114 I spent on it and do not think I will Need to buy anything else except for maybe a K&N air filter or any filter that is shorter than the one that came with the kit.  The filter I feel is pointless being as long as it is because there is no use.  I will though be adding some filter material at the bottom of the heat shield because I know it is easy for water and debris to be sent through the void and could be a potential problem since I do plan to use this truck off road.
I feel that the gains around town are negligible because there is no need to drive fast and it is also illegal to speed heh.  I have not romped on the gas pedal because there is no need but I am sure the hesitation that people have noticed is common to most all vehicles since there is so much air brought into the engine that it cannot atomize it fast enough for it to not hesitate.  I recently within the past 10000 miles or so did change the spark plugs to Bosch platinum 4's and the wires with OE replacements but plan on going with MSD's when money is available again.  So I have not noticed any of this hesitation, I think that the real benefits are to be found by driving on the highway.  While passing or climbing hills the additional air will help the engine perform better.
I do have planned within the next 2 weeks to replace my exhaust because my factory muffler is finally going out on me not to bad since it has not been replaced in 111000 miles.  The exhaust I am going with is a true dual setup with Dynomax mufflers.  I chose these because the FM sound terrible to me I really dislike the tinny sound that they have all the time.  I do allot of highway driving so minimizing cabin drone is important.
WOW I am rambling on here but what I was really meaning to say was that so far the Spectre CAI has been a good purchase and aside from what others have said I will not be putting my stock air box on again because it looks gaudy and the new look of my engine bay is nice.