OP
I can tell you this. I don't care what folks want to run. It's their choice, not mine. I would have posted the results if there was no gain.
Does a cold air intake add power on a 4.0?
- Thread starter Jezza
- Start date
I can tell you this. I don't care what folks want to run. It's their choice, not mine. I would have posted the results if there was no gain.
With that math removing the filter (or going to the windstar filter) would take you to nearly 300 hp
Only if this is used too.
OP
Ya got me. That would work too. Looks like a Windstar airbox as well.
That comment from the engineer doesn't even track. At how many inches of mercury? There is no such thing as "flows enough" as a blanket statement. "It is not a meaningful restriction even at redline" or "a 4.0 doesn't pull enough air to be able to take advantage of an upgraded intake" would be accurate. Same kind of thing applies to Amazon cooling fan's CFM ratings.
Honestly, I think what he was saying is what we are; it flows enough not to matter for a factory 4.0 and bolting on an intake isn't going to have any appreciable difference for the driver. I think you interpreted it differently than he meant it. I'll bet if he was in this thread, he would agree with us and point to Jezza's dyno results as proof. With all due respect, I think you are putting your own spin on what he said. And remember, I said with all due respect.
You really think Jeep's senior most engineer doesn't know what he's talking about? And he said that to me personally during a lengthy phone conversation. This is also the same guy who came up with the Rubicon model... he's known as the father of the Rubicon.
I don't and I never said he didn't. I said I think you are interpreting what he said in the way you wish to make it jive with how you view things, and no mountain of evidence seems to sway you otherwise.
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And name dropping the Rubicon moves my needle zero on the matter of 4.0 intake science.
Your claim of "name dropping" is pure bullshit, it's called citing your sources. As Jeep's senior most engineer before recently retiring Jim Repp knows WTF he is talking about. He in fact said it was specifically designed to have no restrictions at even WOT and redline rpms. That is opposed to some air intakes having been designed designed to be restrictive. Anyone wanting the truth would be far better off trusting what he confirmed over your claims.
Argumentum ad verecundiam is the highflautin name for that.
As an anecdotal observation , if the factory air cleaner truly flowed EVERYTHING the 4.0 could use , then Jezza's dyno test could not show ANY horsepower or Torque improvement at all. Everything else is opinion , no matter what their education or vocation is / was.
While it's true that you're not going to set the world on fire with an additional 8 horsepower. Over 4% improvement improvement with minor intake changes , is something that absolutely can't happen if the stock air cleaner was able to flow everything the 242 could ever dream of using.
While it's true that you're not going to set the world on fire with an additional 8 horsepower. Over 4% improvement improvement with minor intake changes , is something that absolutely can't happen if the stock air cleaner was able to flow everything the 242 could ever dream of using.
Dynos are precise but they can also show any result the operator or entity paying for it wants.
For an example...
https://www.google.com/amp/s/www.motortrend.com/news/0612phr-dyno-accuracy-testing/amp/
For an example...
https://www.google.com/amp/s/www.motortrend.com/news/0612phr-dyno-accuracy-testing/amp/
OP
Absolutely 100% untrue. Did you even watch the video. No one changed the fan or lowered the tire pressure. The laptop had coolant temp and intake temp up the whole time.
Brianj5600
TJ Expert
Brianj5600
TJ Expert
Surely you are not questioning Jezza's results.
Such a particularly contentious topic on this forum - even if you take the filtration piece out of the conversation-. Seems like ever since that one guy said "if you like your doctor, you can keep your doctor" people dont trust people like they used too.. but there a few science laws that support the OP findings that seemed to be over looked in the dialogue.
- Cooler air holds more oxygen particles. Think we all learned that in basic physical science class. Now the number that sticks in my head as a rule of thumb formula is .9% for every 10 degree drop the engine see.(its not a linear law but for our discussion close enough) If you have a ducted true CAI and not just a cone filter under the hood and can achieve a 20-30 degree drop of ambient at the engine- its a gain across the whole curve- about 2-3HP at 2500ish rpms(approx 100hp at the flywheel) and 3.5-5.5hp at peak hp on paper.
- Now if the CAI enlarges the pipe- well that opens discussion farther- My observation is the throttle body is 60mm, when I cut the cross section of the straw between the airbox and the throttle body its 50mm ID, the air horn is 42mm ID. Which begs the question -what is sized appropriately- the 60mm throttle body or the 42 mm air horn? But moving on from that observation - changing sizes from a 50mm pipe to a 76mm pipe straw has another science/engineering findings. It just less restrictive- moving from a 50mm to 76 mm pipe is like 2.5 times more flow- dont get hung up on the unnecessary CFM argument but is simply means that atmospheric pressure has less to over come pushing air into the engine. So if I presume that the factory throttle body is correctly sized, then keeping the throttle body that as the constraint would beneficial , more oxygen -yes?
My question is. If the manufacture thought they could get more hp and torque by putting on a less restrictive air intake why did they not do it? Cost? Emissions? Lord knows Mopar likes to brag about hp and being able to drive like an idiot.
Can we talks about oils and filters now?
Can we talks about oils and filters now?
Head Lice
TJ Addict
Would it not stand to reason then . . . . that the cold air systems tested by Jezza wouldn't produce more hp/tq if the OEM system is 'the best it can be' as supported by Jim Repp?
Saying he was Jeep's senior engineer applies. Lauding him as the guy who invented the Rubicon model does not. The Rubicon is the (unrelated) name you are dropping, not his.
But it's not his word we are questioning. It's yours. And I am not saying you are lying and made the conversation up. I'm saying you have a preconceived notion of how you think things work and interpreted what he said the way you wanted to hear it. You even just said yourself he "confirmed" it.
He absolutely is. He clearly stated as much earlier in the thread and is trying to do it again.
When presented with actual reasoning and first hand experience, he scoffed and pointed to "this guy I talked to" as proof (across all discussions on this subject, not just this thread). When presented with actual proof and numbers, he blows off the numbers and says they are being fudged. And all of this for what?
We are all in agreement (I think) that most TJ owners are wasting their time/money installing an aftermarket intake and could be potentially dangerous (potential water intake + inferior filtering). Bolting an intake on is going to do zero to help push your under geared rig on 33s up a hill in 5th gear. The how and the why are important though because different people have different builds and want different things. If somebody wants that 5hp @ 4500rpm, that's their business. Just because somebody wants to build their TJ a way you wouldn't, doesn't make them wrong. Unless angry eyes or 20s. Then they are wrong.
So, next you'll tell me that Kamala isn't the best VP in history, the border isn't secure and the economy isn't doing great??? CNN and MSNBC told me so.
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