Cold Air Intake
- Thread starter Cheeto928
- Start date
Nothing off the shelf works. Folks have built their own Ford Winstar intakes for a little bump in power.
What he said....waste of money....OEM Jeep one is just as good as anything.
Oh ok. My intake box has a hole in it from something a long time ago, dont know what it was though.
How about a pic? If that hole is on the forward side, its probably for the OEM "trumpet."
The flanged item in the top middle of this item.
https://www.ebay.com/itm/2839160865...pid=5337789113&customid=&toolid=10001&mkevt=1
The flanged item in the top middle of this item.
https://www.ebay.com/itm/2839160865...pid=5337789113&customid=&toolid=10001&mkevt=1
When I got my 05 TJRU the PO had put on a CAI. Luckily he kept the old air box and the very first thing I did was to get rid of the CAI and go OEM.
CAI only have a limited increase in HP at 5000 rpm. Look at their data if they publish it. Only benefit, if you call it that, on a TJ is an increase in noise.
Plenty of other upgrades to spend your money on.
CAI only have a limited increase in HP at 5000 rpm. Look at their data if they publish it. Only benefit, if you call it that, on a TJ is an increase in noise.
Plenty of other upgrades to spend your money on.
KennethS
TJ Expert
I removed that inlet "snorkel" on mine a long time ago. I had multiple 90s era V-8 engines with that inlet snorkel that reportedly was a noise reduction device that as a side feature also restricted air flow. Removing it made a noticeable difference in power on the V-8 vehicles, but no idea if the Jeep breathes better without it.
As others stated....my experience (one 05 TJ I bought had it on there) was that it did nothing other than provide a different noise/sound. No noticeable anything.
The brand doesn't matter so much in terms of the hardware, but the filters from K&N are terrible for a 4.0. S&B and AFE and some others publish the filtration results for their media and they're much, much better than K&N while flowing much better than stock. Dry media filters generally do better than oiled filters in dusty conditions.
This is from a thread here from a TJ that had almost 350,000 miles on the odometer running K&N;
That's alot of miles, but VERY bad.
Oxcart Jeep Channel has done dyno tests on both the underhood style and windstar cowl intake style. In both situations there is nothing between the stock filter box and the CAI until you reach about 3300rpm and then the CAI starts to make more power. In both cases, there is about +9hp peak at the wheels. Trouble is, we don't tend to hang around 3500-4500rpm with these 4.0Ls.
View: https://youtu.be/Q1JXc6Rqbow?si=og0zX5Lu8bGAOzuo&t=402
View: https://youtu.be/Q5AhnJKux_0?si=O4GArIfqwTPLQATR&t=1551
I see you have a 6-speed manual. Assuming you are wanting to get a bit more power pulling up to Eisenhower tunnel with a stock-ish tire/gear combo - you'll get nothing in 5th gear. In your 4th gear a CAI will just start to help a little around 55mph.
This is from a thread here from a TJ that had almost 350,000 miles on the odometer running K&N;
That's alot of miles, but VERY bad.
Oxcart Jeep Channel has done dyno tests on both the underhood style and windstar cowl intake style. In both situations there is nothing between the stock filter box and the CAI until you reach about 3300rpm and then the CAI starts to make more power. In both cases, there is about +9hp peak at the wheels. Trouble is, we don't tend to hang around 3500-4500rpm with these 4.0Ls.
View: https://youtu.be/Q1JXc6Rqbow?si=og0zX5Lu8bGAOzuo&t=402
View: https://youtu.be/Q5AhnJKux_0?si=O4GArIfqwTPLQATR&t=1551
I see you have a 6-speed manual. Assuming you are wanting to get a bit more power pulling up to Eisenhower tunnel with a stock-ish tire/gear combo - you'll get nothing in 5th gear. In your 4th gear a CAI will just start to help a little around 55mph.
Bernoulli says it is very likely beneficial to have the intake horn.
IMO the only way to get more air through the intake manifold is by adding some form of forced air such as a turbo or blower and increasing fuel flow. 9hp isn’t much of a difference. I’m sure the AC compressor robs HP and I don’t see any difference climbing the grades around me with the AC on or off on my 05 6sp. Fully loaded and pulling my teardrop I can maintain 55mph on long steep grades with proper shift management. I do have a 7% 4 mile grade that I’m only able to maintain 45mph at the top portion.
But then you lose the satisfaction of tearing apart strange things you don't understand. It has everything to do with propping up a charade of freedom and individualism.
Tray Burge
TJ Addict
Yeah, I hear sucking hot air right off the top of your engine plus the sticker makes huge gains too.
But seriously OP, if you want more power the cheapest and best thing you can do is re-gear it.
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You can also increase the intake potential of the system with a larger displacement, more intake valve lift/duration, or a better flowing head. The Jeep 4.0L is hardly a masterclass in specific power output for it's displacement and is easily outclassed by more clever engines even at smaller displacements.
The AC in a 4.0L has been measured to pull 5-10hp. If you are below 2500rpm, that could be as much as 10% of the hp produced at WOT. If you're not at WOT without the AC, then you're compensating for it with more throttle input. Or the Jeep PCM is smart enough to trim AC load under high engine load.
Either because of the size of the air filter or turbulence in the design, the stock intake absolutely creates restriction at high rpm. Unusually so in a car of this era. If they did not, we wouldn't see consistent increases in the 9whp range in tests.
The engine bays of the era were nowhere near as compromised for space and the power output nowhere near as high as cars today. Designers generally had no problem creating an air filter design that could keep up with the airflow potential. Aftermarket intakes of the era rarely achieved more than 2-5hp in independent testing, generally within the margin of error.
The regear does change where you are on the power curve at a specific speed in a specific gear. It does not produce a single hp at the crank. You're still limited to 190 crank hp minus the driveline losses.
Dollar for dollar, this is the highest hp/$ option for a TJ 4.0L. (Assembly + properly sized injectors + tuning required)
https://www.cleggengine.com/jeep-4-0-stroker-kits/stage-2-jeep-stroker-kit-4-6l-8-8-1c-r.html
Which isn't to say regearing isn't also a prudent investment.
If that were true, dynos would produce the best result in 1st gear, but they produce their best result in the 1:1 gear.
HP = Torque(ft-lbs) x rpm /5252 - you see higher torque but not higher whp with higher ratio gearing on a dyno and can actually lose a bit due to inertial losses in the engine. You're increasing the wheel torque, but decreasing the wheel rpm for a given engine rpm and specific point on that power curve.
Yes you will accelerate from 0-x faster assuming you're not losing time with gear shifts, but the gearing only benefits when it is usable for your application.
I'm on a 65mph 2 lane highway and come up on an RV lumbering along at 45mph with oncoming traffic, and I want to pass, I have to start my pull at 45mph. Generally to pass successfully in a short window on our busy CO mountain highways, you're going to hit about 80-85mph as you're merging back into your lane.
I have 4.56 gears with an NV3550 and 32.6" actual diameter tires.
If I'm in 4th gear I'll start the pull at 2115rpm, the engine is at about 180 ft-lbs and 75hp. It will finish the pull at 3760rpm at about 230 ft-lbs and 165hp.
If I'm in 3rd gear I'll start the pull at a more favorable 2940rpm nearing about 235 ft-lbs torque and 135hp but I'll hit max hp at 4500rpm at 70mph before completing the pass and have to shift to 4th or roll past the peak HP to redline at 5200, losing some acceleration either way.
Changing to 4.88 gears helps the case for the 4th gear acceleration (2263rpm-4024rpm) or (200ft-lbs/80hp - 225ft-lbs/175hp), but makes the 3rd gear scenario worse because you roll past 4500rpm at only 65mph and will definitely need to shift mid-pass.
The fastest accelerating scenario for this pass with my tire size is actually 3rd gear in a Rubicon's stock 4.10 ratio as you enter at 2645rpm, higher than the 4.88 in 4th and exit the pass in the same gear at 4700rpm just beyond peak hp. And in THAT specific scenario - the CAI/Windstar actually does provide a tangible benefit.
For alot of other drivability reasons the higher ratio gears are better all around with the 4.0L and I'm not suggesting otherwise, but we have 3, 4, 5 or 6 gears as a system.
In EEs example it added .015g or 4.8% avg to 2nd gear acceleration and the times were faster. Forced induction, stroker or V-8 adding 100 ft-lbs+ everywhere on that curve is going to produce a fundamentally different level of acceleration.
HP = Torque(ft-lbs) x rpm /5252 - you see higher torque but not higher whp with higher ratio gearing on a dyno and can actually lose a bit due to inertial losses in the engine. You're increasing the wheel torque, but decreasing the wheel rpm for a given engine rpm and specific point on that power curve.
Yes you will accelerate from 0-x faster assuming you're not losing time with gear shifts, but the gearing only benefits when it is usable for your application.
I'm on a 65mph 2 lane highway and come up on an RV lumbering along at 45mph with oncoming traffic, and I want to pass, I have to start my pull at 45mph. Generally to pass successfully in a short window on our busy CO mountain highways, you're going to hit about 80-85mph as you're merging back into your lane.
I have 4.56 gears with an NV3550 and 32.6" actual diameter tires.
If I'm in 4th gear I'll start the pull at 2115rpm, the engine is at about 180 ft-lbs and 75hp. It will finish the pull at 3760rpm at about 230 ft-lbs and 165hp.
If I'm in 3rd gear I'll start the pull at a more favorable 2940rpm nearing about 235 ft-lbs torque and 135hp but I'll hit max hp at 4500rpm at 70mph before completing the pass and have to shift to 4th or roll past the peak HP to redline at 5200, losing some acceleration either way.
Changing to 4.88 gears helps the case for the 4th gear acceleration (2263rpm-4024rpm) or (200ft-lbs/80hp - 225ft-lbs/175hp), but makes the 3rd gear scenario worse because you roll past 4500rpm at only 65mph and will definitely need to shift mid-pass.
The fastest accelerating scenario for this pass with my tire size is actually 3rd gear in a Rubicon's stock 4.10 ratio as you enter at 2645rpm, higher than the 4.88 in 4th and exit the pass in the same gear at 4700rpm just beyond peak hp. And in THAT specific scenario - the CAI/Windstar actually does provide a tangible benefit.
For alot of other drivability reasons the higher ratio gears are better all around with the 4.0L and I'm not suggesting otherwise, but we have 3, 4, 5 or 6 gears as a system.
In EEs example it added .015g or 4.8% avg to 2nd gear acceleration and the times were faster. Forced induction, stroker or V-8 adding 100 ft-lbs+ everywhere on that curve is going to produce a fundamentally different level of acceleration.
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It sucks all the hot air out of the engine compartment, so the engine runs cooler!
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