4bangerjp.com
General Forums => The Mess Hall => Topic started by: Steve-0 on November 16, 2009, 08:57:42 PM
-
Just wondering if anyone ever heard a hissing or whistling noise under the hood? I get this noise that sounds like air being restricted at about 1/3 throttle position. Doesnt matter how fast or slow I am going, but it seems like it only happens (or is loud enough to hear) at higher RPMs, like around 2500 +. It has not done anything to my performance, nothing to really worry about whatsoever, just curious to know what the heck it is. I thought it might have something to do with the cold air intake on the 4banger, but not sure. Anyone else hear that noise? Figure out what it was?
-
Just wondering if anyone ever heard a hissing or whistling noise under the hood? I get this noise that sounds like air being restricted at about 1/3 throttle position. Doesnt matter how fast or slow I am going, but it seems like it only happens (or is loud enough to hear) at higher RPMs, like around 2500 +. It has not done anything to my performance, nothing to really worry about whatsoever, just curious to know what the heck it is. I thought it might have something to do with the cold air intake on the 4banger, but not sure. Anyone else hear that noise? Figure out what it was?
do you have a high flow or cone type filter? if yes that's why you hear it.
-
Cone. I hear a whistling sound at about 1/3 throttle. Its always the same throttle position. It seems more noticeable near 2300 and above. I cant hear it below that. When I throttle past it, it almost sounds like a little blow-off valve.
-
Cone. I hear a whistling sound at about 1/3 throttle. Its always the same throttle position. It seems more noticeable near 2300 and above. I cant hear it below that. When I throttle past it, it almost sounds like a little blow-off valve.
same here, came with the cone filter and the 4.0L t/b - can't remember what position was at but somewhere in the lines of what you said. It's normal, nothing to worry about.
-
It's normal, install more aggressive tires and you may not hear it any more.
-
just turn the music up a lil more until the noise goes away :wall:
-
just turn the music up a lil more until the noise goes away :wall:
See, I like this approach better than the aggressive tires. And if your sound system is not up to par, an even BETTER approach is to go out and buy a SONY sound system, complete with head unit, speakers, amp and sub and install it in your Jeep...
-
an even BETTER approach is to go out and buy a SONY sound system, complete with head unit, speakers, amp and sub and install it in your Jeep...
maybe if you (could) set up a 4bangerjp discount your nagging would pay off more often... :pot:
-
maybe if you (could) set up a 4bangerjp discount your nagging would pay off more often... :pot:
How about 2 for the price of 2? Nah, honestly I would be happy to set you guys up, but I am in the Latin America division, so I have no contacts in Sony Electronics (US division). To those in Latin America, I can probably hook you up (I think TSD is in Chile, right? Anyone else?) with some discounts, but it's a bit harder for those in the US. Sorry!
-
Cone. I hear a whistling sound at about 1/3 throttle. Its always the same throttle position. It seems more noticeable near 2300 and above. I cant hear it below that. When I throttle past it, it almost sounds like a little blow-off valve.
i get the same thing from my AEM. i dont recall what the exact RPMs are where the sound is noticable...to be quite honest, i kind of like it.
-
Yeah, I have the 3-way speaker bar, the dash 4x6's and a 10" kicker comp. Not a raging system, but its loud enough for me, I just turn it up to drown it out, or not. Sometimes I just listen to it. I also kind of like it. Reminds me of a turbo sound effect in a way. By the way, since we are talking about intake, I was contemplating pointing my intake over to the passenger side of the engine bay area instead of down the front behind the driver side headlight. Only reason for me to do this would be to avoid water/mud puddles a bit better. Do you think its worth it?
-
I've had this happen when the clamp for the air tube on the throttle body got loose...
Dave
-
See, I like this approach better than the aggressive tires. And if your sound system is not up to par, an even BETTER approach is to go out and buy a SONY sound system, complete with head unit, speakers, amp and sub and install it in your Jeep...
I don't know about Sony :stick: but im looking forward to my DLS and Arc Audio setup thats going in my truck next summer from Audio Shoppe :dance:
-
Honestly speaking, if you plan to listen to your stereo (regardless of brand) on a Jeep with no top, you better get something with good sound power... At least (in my opinion) something with a subwoofer. Otherwise, the music will be simply drowned out.
-
I have Tuffy boxes with 6x9 and Sony Plates in the front dash holes,
and a standard Sony head unit, nothing fancy. You can hear it fine. (And my hearing is not great)
Putting money in a stereo on a vehicle without a top always seemed somehow wrong...
Dave
-
just get one of the marine sound systems, seems to work fine on boats :lol:
the speakers are waterproof too so that's a plus
-
I'm more worried about theft,
Rockford Fosgate = Dutch for "Steal this car"
Dave
-
By the way, since we are talking about intake, I was contemplating pointing my intake over to the passenger side of the engine bay area instead of down the front behind the driver side headlight. Only reason for me to do this would be to avoid water/mud puddles a bit better. Do you think its worth it?
I never did get an answer on this. Did anyone see this?
-
I'm more worried about theft,
Rockford Fosgate = Dutch for "Steal this car"
Dave
Hmm, that's what I have in my Jeep. :lol:
-
Yea, I love those big windshield stickers proclaiming there is a good
chance of the car containing 10,000 bucks worth of audio gear. :roflol:
I usually black out the logos and labels so from outside the rig you can't
easily identify the radio. My YJ has a tuffy console that I lock when I park in the city. :guns:
Oh yea, I wouldn't worry about eth intake position unless you go lower.... :)
Dave
-
No that ones going in the truck, the jeep just has some old Alpine 4x6 type s plates and 6.5 type r speakers and Alpine amp that I had laying around from one of my other stereo builds. Its sad looking back at all the stereo stuff that I bought through the years and the money I :flush: I used to have an alpine indash moniter and dvd player, alpine and sony head units, some jbl gto 5.25's and some kenwood 6.5's, along with a cd changer and 4 channel amp all just layin in a drawer collecting dust... I have been trying to get rid of some of it so i have less crap to pack up when it comes times to move
-
ALRIGHT ALREADY! ENOUGH ABOUT THE STEREO TALK! Now, lets get back to business. So you dont think that moving my intake from behind the left headlight to the right side firewall will make a difference if I was to go get into some big ol mud puddles?
-
ALRIGHT ALREADY! ENOUGH ABOUT THE STEREO TALK! Now, lets get back to business. So you dont think that moving my intake from behind the left headlight to the right side firewall will make a difference if I was to go get into some big ol mud puddles?
why would that make a difference - i don't really see how that would help (so maybe explain in more details). I think TJs came with the airbox on the passenger side, maybe you could use one of those setups if you want to change yours
-
Would you keep it as an open filter or would you run like a tj ait filter box?
-
I'd use the air box, I don't need any more noise....
And There is no discernible power increase that I've been able to see.
I think its a CFM vs RPM thing. Our engines just don't tax the stock air box that bad,
especially if you pull the baffle out of the inlet and the air pipe depending
on the combo of parts you have.
Dave
-
I put the baffle back in. I notice a big different with and without it. It raises the power band about 300-400RPM's. Since I do most of my driving in the 'city', I figure I could use the lower torque more. It will still spin up to 4000RPM but it gets a bit more winded then before. I'm not sure if it will freely spin up to 5000RPM anymore. I've been bouncing back between using the baffle and removing it for a while.
Oh and the whistle goes away with the baffle in place.
-
Guess I need to clarify a bit more. I have cold air intake with a cone filter. The filter is set right behind the drivers side headlight and I have seen people turn the tube so it is paralell with the firewall and the filter points down behind the front passenger wheel. Reason: If I were to run into some mud puddles that splash water up into the engine bay, I wanted to keep it away from the filter. Make more sense?
-
Guess I need to clarify a bit more. I have cold air intake with a cone filter. The filter is set right behind the drivers side headlight and I have seen people turn the tube so it is paralell with the firewall and the filter points down behind the front passenger wheel. Reason: If I were to run into some mud puddles that splash water up into the engine bay, I wanted to keep it away from the filter. Make more sense?
Guess I need to clarify a bit more. I have cold air intake with a cone filter. The filter is set right behind the drivers side headlight and I have seen people turn the tube so it is paralell with the firewall and the filter points down behind the front passenger wheel. Reason: If I were to run into some mud puddles that splash water up into the engine bay, I wanted to keep it away from the filter. Make more sense?
I don't think it's a good reason to move it. When you run into water or really wet mud, you'll be pushing a bow wave. The depression will be around the front of the jeep but soon rise as it reaches the rear of the engine compartment. Moving the filter over to the passenger side will also introduce it to hot air since it has to pass over the engine. Not to mention, for every day driving, the area near the firewall will probably be a low pressure zone which collects hot air. If you're afraid of splashing then make a splash shield.
-
Just out of curiosity, but if you are willing to fab this up, why not just fab up a snorkel? I remember seing one somewhere online made with PVC pipe and a cookie can to put around a cone filter, and it looked quite nice... This way (1) the intake air will be colder (taken from a higher point, where it is less affected by the temp of the road, as well as coming from outside the engine bay), and (2) you will have less risk of hycrolocking the engine on the mud/water holes.
-
I wouldnt be fabing anything, just turning the intake tube. But thats not a good idea. A splash guard is exactly what I was thinking. Probably can bolt it up right at the airbox support brackets.
-
I put the baffle back in. I notice a big different with and without it. It raises the power band about 300-400RPM's. Since I do most of my driving in the 'city', I figure I could use the lower torque more. It will still spin up to 4000RPM but it gets a bit more winded then before. I'm not sure if it will freely spin up to 5000RPM anymore. I've been bouncing back between using the baffle and removing it for a while.
Oh and the whistle goes away with the baffle in place.
Jeffy, I was thinking about starting a new post, but since you were talking about it, I will just ask. Does yours easily rev up to 5000 RPM? I was thinking 4300 RPM was about as high as it gets for the 4banger? Mine seems like thats about all she will push without sounding like it is about to blow up. Plus she looses a bit of power after 4000RPM. The powerband drops from there I believe.
-
Jeffy, I was thinking about starting a new post, but since you were talking about it, I will just ask. Does yours easily rev up to 5000 RPM? I was thinking 4300 RPM was about as high as it gets for the 4banger? Mine seems like thats about all she will push without sounding like it is about to blow up. Plus she looses a bit of power after 4000RPM. The powerband drops from there I believe.
you should be able to get close to 6000 rpm. the max power is rated at 5250rpm after which the power drops - if you can't go over 4000 then it's either you are running out of fuel or air (oxygen) - your hot air from the engine bay will have an impact but not that dramatic as you won't be able to rev the engine (unless of course there's some big time bottleneck on your intake) - could be fuel or maybe spark related (if it start misfiring) or maybe a combination (fuel+air) which in turns can have the effect you described (power dropping past 4000rpm). I never had probs getting mine up in the revs, not that i really wanted to though, just needed a bit more push at times.
-
Jeffy, I was thinking about starting a new post, but since you were talking about it, I will just ask. Does yours easily rev up to 5000 RPM? I was thinking 4300 RPM was about as high as it gets for the 4banger? Mine seems like thats about all she will push without sounding like it is about to blow up. Plus she looses a bit of power after 4000RPM. The powerband drops from there I believe.
Mine will if I remove the venturi and the baffle on the front of the stock box. The nice thing about the box is that it's easier to tune by then to futz around with tube dia. and lengths. The 2.5L seems to struggle at higher RPM's because it isn't able to get enough air. Problem is you need to keep the air speed up as you increase the flow. Basically, it's like the big water pipe vs. a small one. The larger pipe will have more volume but lower pressure. The key is to tune it so you get higher volume but still keep the pressure high as well. This is where tuning comes into play.
At higher RPM's the engine is struggling since most cars are designed for every day driving and most people aren't going to be reving that high. So they tune the engine for lower RPM's. This locks the performance at higher RPM's though. You can really feel it on a stock engine as you try to climb over 4000RPM. You'll hit a wall where, the engine will seem to not make any more power and it's tough to rev higher. That's the engine struggling for more air and tries to compensate by reducing the fuel.
If I remove the baffle and the venturi, I'm able to rev up to 5000RPM's and over. The engine makes more power higher up but this is at the cost of lower end performance. I usually have to rev to 3100RPM's for the power to really start to kick in. This gets old fast when driving around town though as by the time I hit the powerband and shift, I have to start slowing down for traffic again. Currently, I have it where the power kicks in around 2700RPM so I have some power at 2500RPM and I'm not lunging as much.
There are a lot of other factors to consider as well. In short, there is a thing called a pulse-wave which the engine creates as it pulls air into the cylinders. You get a 1,3,2,4 then a pause for 3 strokes then it repeats. The pulse wave is created as it is drawn into the beginning of the intake when it hits the closed valves it then bounced back. What you want to do, on the intake side is to make sure the pulse passes the air filter before the intake stroke starts. When that happens the wave then reenters the intake. You want this to coincide with the intake stroke so it naturally supercharges the intake, at a smaller scale.
This also works in reverse with the exhaust. This is often referred to exhaust scavenging. If you time it right the pulse will hit the exhaust valves right as they are opening. The pulse will then reverse and help suck the exhaust out of the cylinders. This also helps pull the air into the cylinder as the intake valves are open as well.
It takes a lot of tweaking to find what works for you.
-
:eek: I think I will just stick with what I've got. I have no reason to mess with the power band. Actually, I think my 4banger hauls ass. I was just wondering about the revs, it does seem like the pressure in the intake may be the culprit as I have a large and long cold air intake tube. But I am not worried about it. Just need to get that stuttering issue figured out.