K&N Cold Air Intake on '08 Ram 3500 w/6.7 Cummins

[daveinaz]

I recently put a K&N cold air intake system on our 2008 Dodge 3500 with the 6.7 Cummins in it. Just puttering around the neighborhood, I didn't really notice much difference. But over the weekend, I went for a little trip (not pulling the 5er) and accelerated like I usually do on the entrance ramp to the freeway. Before I got to the end of the ramp, about 100 feet before I could get over into the lane, I glanced down and was surprised to see that I was already going just over 75 mph!


Then I pulled the 5er around up to 55 mph and it seemed to have improvement there as well.

I don't know if the system actually gives the extra 20.63 hp or 43.35 lbs of torque, but judging by the highly scientific "seat of my pants" method, it does seem to be an improvement.

It was a pretty simple install.

[66joej]

That is interesting. Always thought from my souping up engine days the theory was "more air in needs more exhaust out" to get more power.

[daveinaz]

That is interesting. Always thought from my souping up engine days the theory was "more air in needs more exhaust out".

I know what you say was true back in the 70's when I was doing stuff like that on motorcycles. I don't know. You transfer the air intake sensors from the factory system to the K&N system, so I don't know if that makes a difference. Or maybe it just lets the turbo work better?

Who knows. Maybe the performance boost is all in my mind -- but it does sound a little better! :)

[Ken / Claudia]

Different trucks, but my results. 96 7.3 I got a bigger down pipe from turbo to under vehicle cost 200. Made to increase mpg/hp. Really not much noted except a louder exhaust, louder inside cab also. I ran that for a month or so than added the K&N cold intake around 400 if I remember right. No real noted difference, maybe if I put it on a tester before and after there was some gain.
This truck I have had the cold air intake on it maybe since 2004. Not really noted any difference.
I think better air flow is good but I am not making any vehicle exhaust louder again. I think I out grew that at 21.
No matter how good the sales pitch is on aftermarket bolt ons. I like to weigh the cost and pay back time for using those. My 96 was a waste of money on my part. This truck may have gained enough thru time to do better.

[rhagfo]

Maybe it feels better, because it cost so much. Oiled air filters are bad beans on a diesel. They may let more air in because they filter less. I would suggest getting a large paper element (AKA BHAF).

https://www.amazon.com/Cummins-Upgrade-Donaldson-B105006-DBL7349/dp/B06WRT7STP/ref=sr_1_10?ie=UTF8&qid=1548978803&sr=8-10&keywords=bhaf+air+filter

[daveinaz]

Maybe it feels better, because it cost so much. Oiled air filters are bad beans on a diesel. They may let more air in because they filter less. I would suggest getting a large paper element (AKA BHAF).

https://www.amazon.com/Cummins-Upgrade-Donaldson-B105006-DBL7349/dp/B06WRT7STP/ref=sr_1_10?ie=UTF8&qid=1548978803&sr=8-10&keywords=bhaf+air+filter

Again, it's not an oiled air filter...

[Old Mustanger]

That is interesting. Always thought from my souping up engine days the theory was "more air in needs more exhaust out" to get more power.

The cold air kits don't necessarily provide more air, the idea for most of them is to provide cooler air by relocating the air filter to an area that does not receive as much engine heated air (as in moving the filter from the engine compartment to the wheel well). Cooler air is denser so the increase in power.

[mtofell]

The cold air kits don't necessarily provide more air, the idea for most of them is to provide cooler air by relocating the air filter to an area that does not receive as much engine heated air (as in moving the filter from the engine compartment to the wheel well). Cooler air is denser so the increase in power.

From a physics standpoint this is pure snake oil. So, does a truck all of the sudden accelerate quicker on a 40 degree day versus an 80 degree day? Does it accelerate quicker first thing in the morning before the engine gets hot? I've never noticed any difference driving my trucks from temps in the teens to temps over 100. I stopped paying attention to K/N filters years ago after reading some pretty comprehensive studies totally de-bunking their effectiveness (not to mention all of the potential damage with CELs and whatnot). If what it's come to is saying the benefit is cooler intake air, it's laughable.

I'm really not trying to be a downer but I just can't resist pointing out the ridiculousness of this particular argument by the manufacturer.

[sourdough]

As I watch the thread progress I just have to add/say:....

I've added 2 aftermarket cold air intake systems in my life....what a waste. The 2nd was with all the "stuff" to increase "outflow". Increased airflow, new exhaust, chip etc. Never in my life have I spent so much, expected so much and received so little....except NOISE! Today's modern, computer controlled fuel injected engines won't give you some magic increase in power with a cold air intake. Good sales ploy but not proven out by science IMO.

[Old Mustanger]

From a physics standpoint this is pure snake oil. So, does a truck all of the sudden accelerate quicker on a 40 degree day versus an 80 degree day? Does it accelerate quicker first thing in the morning before the engine gets hot? I've never noticed any difference driving my trucks from temps in the teens to temps over 100. I stopped paying attention to K/N filters years ago after reading some pretty comprehensive studies totally de-bunking their effectiveness (not to mention all of the potential damage with CELs and whatnot). If what it's come to is saying the benefit is cooler intake air, it's laughable.

I'm really not trying to be a downer but I just can't resist pointing out the ridiculousness of this particular argument by the manufacturer.

Didn't say they do what is advertised, just what the idea is, but I'd swear that on every 'Stang that I installed one on it made a difference. YMMV :popcorn:

[JRTJH]

Polaris Slingshot SEL models have a "specialized cold air intake"
Polaris Slingshot SL models have a "standard air intake"

The factory specs on both are exactly the same HP and torque.

The engine is a 2.4l GM 4 cylinder automotive engine. If there was "something more than talking points" to cold air intakes, I'd guess that Polaris would "talk up the improvement in performance" but they list the specs as the same for both models.

Makes me wonder about cold vs ambient vs underhood air temperature and if there's any difference in burning it in a fuel mixture in a high compression engine that "explodes the fuel/air mixture without a spark.... It's more a matter of how much air the "hot turbo vanes" can push into the engine cylinders before the valves close and detonation occurs. With an intercooler to "chill the air mixture" I wonder what a cold air intake adds to the mix ???

[lunge motorsport]

So...
A cold air intake on a engine with an exhaust driven compressor? Hmmmm.
Ok, I too ran a K&N cold air system on a small block Chevy with an aftermarket exhaust that made nice noise but didn’t do much that I could tell. It was an oiled filter that claimed the dirtier it got the better it worked. That just made me reconsider the effectiveness of the media when clean.
I won’t do it again on a street motor.

[Don_T]

I have tried both dry and wet aftermarket cold air intake systems over the years. I think they are a waste of money. I have also read that until you get over 600 HP the stock intake system works as well as the aftermarket systems.

[travelin texans]

As I watch the thread progress I just have to add/say:....

I've added 2 aftermarket cold air intake systems in my life....what a waste. The 2nd was with all the "stuff" to increase "outflow". Increased airflow, new exhaust, chip etc. Never in my life have I spent so much, expected so much and received so little....except NOISE! Today's modern, computer controlled fuel injected engines won't give you some magic increase in power with a cold air intake. Good sales ploy but not proven out by science IMO.

I've done the very same! But 20+ years ago it was cool, sounded good, rolled lots of coal, but as far as more hp/torque or better fuel economy, I never realized either. All the expensive add-ons may have increased the mileage 1-2 mpg so in 50 years or a million miles they might have paid for themselves.
Nowadays the new diesels have as much or more hp/torque than most of us would ever need along with decent mileage & will most likely increase every year with the big 3 "mines bigger" mentality.
If you want to add on cool things to your truck then have fun, but don't expect miracles in power or mileage, it's just for fun. And remember some of those add ons may void any warranty you may have.

[daveinaz]

Wow. This turned into being just as opinionated as a "best oil" or "what tire brand" thread. LOL.

I don't really care one way or the other. I just threw it out there as my experience. Never expected such intense reactions.

Ya'll have a good day.

[Ken / Claudia]

There is a difference in an opinion and experience. I gained from what you said and if you read my post you should have gained some knowledge from my experience. None of which is bad it is just different.

[daveinaz]

There is a difference in an opinion and experience. I gained from what you said and if you read my post you should have gained some knowledge from my experience. None of which is bad it is just different.

I agree. You posted your experience. Others posted their opinion.

[chuckster57]

I do have a K&N filter on my ‘94 turbo IDI and my 2004 Honda Accord. Does the filter improve performance? I can’t say because I did a bunch of upgrades at the same time. I know someone that has a K&N on his 2002 F250 7.3 PSD. He drove in dusty conditions for 3+ yrs without servicing his filter. When I did some work on it we cleaned and oiled it as directed. He called and said his truck suddenly had more power, and I personally looked at the turbo for any sign of “dusting” and found nothing.

That’s about as real as I can make it. To each their own, but if you feel it made a difference then by George it did!!

I agree these threads can get into best oil, additive, brand of truck, etc....thank you for posting YOUR experience.

[ChuckS]

It’s an option some think is great. I’ve kept mine stock. I don’t have issues with foiled MAP or MAG sensors from oil residue getting on the sensors.

For me the $300 for the cold air kit goes a long way for tranny fluid and filter, fuel filter, new differential and transfer case lube, etc.

I’ve not missed the advertised 20hp increase.

But it looks nice

https://www.knfilters.com/mobile/cold-air-intakes/cars-and-trucks/57-3057-performance-air-intake-system

[sourdough]

I agree. You posted your experience. Others posted their opinion.

Many in the thread posted their personal experiences; a few posted opinions. Either way, I don't think anyone has been "out of line", irate or ugly. Because many didn't experience your "seat of the pants" feeling of improvement doesn't mean they are attacking you - just relaying their experience. If you believe your changes netted you an improvement, real or imagined (seat of the pants vs measured), you got your money's worth it would seem and I hope you continue to realize improvement from your mods.

[daveinaz]

Many in the thread posted their personal experiences; a few posted opinions. Either way, I don't think anyone has been "out of line", irate or ugly. Because many didn't experience your "seat of the pants" feeling of improvement doesn't mean they are attacking you - just relaying their experience. If you believe your changes netted you an improvement, real or imagined (seat of the pants vs measured), you got your money's worth it would seem and I hope you continue to realize improvement from your mods.

I agree. I didn't feel like I was being attacked or that anyone was out of line, irate, or ugly. I merely stated that I was kind of surprised by the strong opinions and blanket statements my post elicited from some. (Although, considering the back and forth on some threads, I guess I shouldn't be. :) ) Some posted strong opinions (which is fine) of after market air filters who seem to have no actual experience with them.

I appreciate this forum and I'm not going to reply any more to this thread because I never intended to "start something."

How's that Frozen song go? "let it go, let it go..."

[sourdough]

I agree. I didn't feel like I was being attacked or that anyone was out of line, irate, or ugly. I merely stated that I was kind of surprised by the strong opinions and blanket statements my post elicited from some. (Although, considering the back and forth on some threads, I guess I shouldn't be. :) ) Some posted strong opinions (which is fine) of after market air filters who seem to have no actual experience with them.

I appreciate this forum and I'm not going to reply any more to this thread because I never intended to "start something."

How's that Frozen song go? "let it go, let it go..."

Dave I don't think you started anything. You brought up a topic that others wanted to share their experiences, or opinions, on. I appreciated your initial post and thoughts on the aftermarket adds. I always WANTED my aftermarket add ons to give me discernible, maybe even very noticeable, performance improvements but I never realized that. Whether the cold air intakes, chips, low restriction mufflers, new exhaust...never seemed worth the money to me in the situations I had. Now, put that low restriction exhaust behind that big block you just rebuilt with new cam, pistons, roller rockers etc. etc. and yes, it probably makes a difference (that subdued "lope" always sounded nice).

Anyway, your post is/was appreciated along with all the other comments about different experiences. I think it's a way for folks interested in that kind of thing to learn of other experiences if they are thinking of making the same kind of mod. It's one of the nice things about this forum - so much experience and so many willing to share.

[JRTJH]

If someone is looking for facts only, then regurgitation (vomiting) google web links is all the forum would be. It's the personal experiences, personal beliefs, personal opinions that make the forum a place where people can share different perspectives and all grow to a better understanding of "something I hadn't considered, thank you".....

That ability to see something "other than just the facts, mam" is what makes the forum what it is. As long as people don't start attacking people for not believing what they believe, it will work to benefit everyone.

It's not about "hey, you're wrong" as much as it is, "Hey, I didn't consider that, thanks for bringing it up".....

As always, YMMV

[Peacemkr53]

My TV (2015 RAM 6.7 TD Cummins) is computer operated. With intake and exhaust sensors the computer is mapped to compensate. So I would doubt there would be any gain. The computer would read and compensate. Now if this were a Harley forum.....that was a way different experience....LOL

[Old Mustanger]

My TV (2015 RAM 6.7 TD Cummins) is computer operated. With intake and exhaust sensors the computer is mapped to compensate. So I would doubt there would be any gain. The computer would read and compensate. Now if this were a Harley forum.....that was a way different experience....LOL
The cold air kits got real expensive when they started to have to include a flash tuner for the mapping.

[jack65]

That is interesting. Always thought from my souping up engine days the theory was "more air in needs more exhaust out" to get more power.
Yes, that is true... I have both, K&N filter system and Flowmaster exhaust system in my Ram truck with 5.7 Hemi and also notice a it gets to 75 miles in a hurry. If I'm not watching my speedometer, I also notice I'm going faster than expected with ease. My Ford Edge with 295 hp doesn't come close for comparison. (It is much lighter than the truck) I drove a stock Ram with same engine it didn't have that same kick mine does. Past experiences with five Corvettes I had over the years,
http://1-4u-computer-graphics.com/jacks-vettes.htm
I've noticed nice gains of power improving the intake & exhaust system.

So yes, if you improve both the intake and exhaust, you can expect 25 - 50 hp gains! KN is very popular with the musclecar crowd.

[mikz86ta]

Funny, just did the thermostats and hoses on our Sierra. Since access thru the passenger wheel well makes it easier job for a few of the clamps, I was in that area. In which the Duramax air intake sucks thru. While running the truck at idle doing the coolant fill process, I noticed a deep distinct lopey sound from the air getting sucked in.
I have a stock intake but a AFE filter installed. The stock filter was much more quiet.
Point is, definitely stock filters have more restriction. These diesels need air and the turbos at full spool really need the airflow. So I would not doubt you have some free horsepower on tap that was restricted before

[Trailer Trash2]

I was told that's why we have a inner cooler the turbo cools the compressed air down to enter the motor cooler for more power, I dont know where the K&N cooler is installed but if it works for you, you got your monies worth.

[Snoking]

For a real comparison one would have to do back to back dyno runs without and with the cold air intake. Everything I have learn with 3 RAM/Cummins starting in 1994, is that any gain is very minimal. It has been said on many forums for many years, the stock RAM intake and exhaust is good for up to 450HP. Now the 7.3 with the crushed down pipe between the engine and firewall was a good thing to upgrade also with the crushed bend over the rear axle on my 1993 RAM/Cummins. These are isolated issues to particular models, makes and years.

Noise always seem to make you thing you are going faster. As a kid I had a little late 40's A40 Austin with a glass pack muffler. Sounded cool but in reality was dead slow.

[mikz86ta]

Polaris Slingshot SEL models have a "specialized cold air intake"
Polaris Slingshot SL models have a "standard air intake"

The factory specs on both are exactly the same HP and torque.

The engine is a 2.4l GM 4 cylinder automotive engine. If there was "something more than talking points" to cold air intakes, I'd guess that Polaris would "talk up the improvement in performance" but they list the specs as the same for both models.

Makes me wonder about cold vs ambient vs underhood air temperature and if there's any difference in burning it in a fuel mixture in a high compression engine that "explodes the fuel/air mixture without a spark.... It's more a matter of how much air the "hot turbo vanes" can push into the engine cylinders before the valves close and detonation occurs. With an intercooler to "chill the air mixture" I wonder what a cold air intake adds to the mix ???


This is very interesting but not that odd to me that they don't give the Slingshot a higher HP rating.

My 2014 Ram was offered with some OEM Mopar dealer installed goodies. Tho, just like aftermarket, they do claim a HP increase but they don't re-issue specs for the truck. Also in 2018, if I recall, they had a Ram Sport Night package...there was Manufacturer Installed upgrades which included Mopar exhaust (made by Corsa), Mopar intake kit (made by AEM) and even it made the stock Sport Hood faux vents actually functional.
That being said, they did not show up on the window sticker or spec build sheet any HP increase over any other 5.7L Hemi. Resale, you can show these options and upgrades but even KBB does not list those items as viable options to up the resale price.
So, it's not surprising to me they didn't list any MPG or HP diffences.

[jack65]

For a real comparison one would have to do back to back dyno runs without and with the cold air intake. Everything I have learn with 3 RAM/Cummins starting in 1994, is that any gain is very minimal. It has been said on many forums for many years, the stock RAM intake and exhaust is good for up to 450HP. Now the 7.3 with the crushed down pipe between the engine and firewall was a good thing to upgrade also with the crushed bend over the rear axle on my 1993 RAM/Cummins. These are isolated issues to particular models, makes and years.

Noise always seem to make you thing you are going faster. As a kid I had a little late 40's A40 Austin with a glass pack muffler. Sounded cool but in reality was dead slow.
Don't sound like to me you've actually tried the K&N filter? Sounds like your speculating. I have, several times over the years with Corvettes and now with my truck. I have both, K&N filter system and Flowmaster exhaust system in my Ram truck with 5.7 Hemi and also notice a it gets to 75 miles in a hurry. If I'm not watching my speedometer, I also notice I'm going faster than expected with ease. My Ford Edge with 295 hp doesn't come close for comparison. (It is much lighter than the truck) I drove a friends stock Ram with same engine it didn't have that same kick mine does, nor gets to 80 mph as quickly. Past experiences with five Corvettes I had over the years,
http://1-4u-computer-graphics.com/jacks-vettes.htm
I've noticed nice gains (sometimes dramatic) of power improving the intake & exhaust system.

So yes, if you improve both the intake and exhaust, you can expect 25 - 50 hp gains! K&N is very popular with the musclecar crowd.