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Best Sounding Exhaust For The 4.0L?

It is no longer a fix it ticket . It must be singed off at a referee station and yes you do need to pay them , if you pass there test then you get to go to court and then the court says how much you will pay plus court cost so all you need is one cop that's having a bad day and wright a modified exhaust ticket he can make you go though a lot . and yes it can work out to more then $1000 ,
 
I ran a 40 series flowmaster in the past. Sounded good but had some drone at highway speeds. If I was to dump the factory muffler on my XJ now I'd probably go with a series 50 this go round. But I'll probably just stay stock. It sounds ok and the OEM muffler looks basically new considering it's age.
 
I ran a 40 series flowmaster in the past. Sounded good but had some drone at highway speeds. If I was to dump the factory muffler on my XJ now I'd probably go with a series 50 this go round. But I'll probably just stay stock. It sounds ok and the OEM muffler looks basically new considering it's age.

To quiet the drone at highway speeds especially between 2500 and 3000 RPM I replaced the 2.5" tail pipe that came with from Rusty's Offroad with a piece of the OEM tail pipe which is about 2.125".
 
It is no longer a fix it ticket . It must be singed off at a referee station and yes you do need to pay them , if you pass there test then you get to go to court and then the court says how much you will pay plus court cost so all you need is one cop that's having a bad day and wright a modified exhaust ticket he can make you go though a lot . and yes it can work out to more then $1000 ,

This is what I've been seeing, even if the vehicle has stock exhaust a ticket can be issued if the officer "feels" that it is now warranted, forcing people to go through what you described. It looks like that not only could an officer ticket my Chrysler 200 with the less common 3.6l V-6 option since those have a factory dual tip muffler vs the single tip of the 2.4l models, but could even ticket a Tesla if the officer wants to screw with it's driver.

Kinda happy I'm in Illinois, we don't have to deal with that or the super aggressive emissions testing. Even here near Chicago, so long as it doesn't throw OBD2 codes, they don't seem to care, I haven't even seen them look for catalytic converters and check the cap pressure like they used to. We don't even have to test the remaining pre-OBD2 vehicles anymore!
 
Now in California if you cars exhaust is over 95db the cops can ticket you for modified exhaust and it is a $1000 ticket now so if you live in California it is better to keep your car quiet now .

I will believe it when they start ticketing all the muffler-less Harleys, one good biker run could support the state for weeks.
Once upon a time, noise violations were common in California. Most of that ended when Arnold became governor, he owned a lot of loud toys.
 
I will believe it when they start ticketing all the muffler-less Harleys, one good biker run could support the state for weeks.
Once upon a time, noise violations were common in California. Most of that ended when Arnold became governor, he owned a lot of loud toys.

If I read things right, motorcycles are exempt from this, as are trucks over 6000gvwr.
 
If I read things right, motorcycles are exempt from this, as are trucks over 6000gvwr.


Straight from California's auto noise regulation .

27201. For the purposes of Section 27200, the noise limit of 92 dbA shall apply to any motorcycle manufactured before 1970.
(Added by Stats. 1975, Ch. 83.)

27202. For the purposes of Section 27200, the following noise limits shall apply to any motorcycle, other than a motor-driven cycle, manufactured:
(1) After 1969, and before 1973 ........................88 dbA
(2) After 1972, and before 1975 ........................86 dbA
(3) After 1974, and before 1986 ........................83 dbA
(4) After 1985 .................................................80 dbA

27207. No motor vehicle with a gross vehicle weight rating of more than 10,000 pounds and equipped with an engine speed governor shall produce a sound level exceeding 88 dbA, measured on an open site at a distance of 50 feet from the longitudinal centerline of the vehicle, when its engine is accelerated from idle with wide open throttle to governed speed with the vehicle stationary, transmission in neutral, and clutch, if any, engaged. Test procedures for compliance with this section shall be established by the department, taking into consideration the procedures of the United States Department of Transportation.

27204.the purposes of Section 27200, the following noise limits shall apply to any motor vehicle within the specified manufacturer’s gross vehicle weight rating and date of manufacture:
GVWR—Pounds Date of Manufacture Noise Limit—dbA
Over 6,000 after 1967 and before 1973 88
Over 6,000 after 1972 and before 1975 86
Over 6,000 after 1974 and before 1978 83
Over 8,500 after 1977 and before 1982 83
Over 6,000 but not over 8,500 after 1977 80
Over 8,500 but not over 10,000 after 1981 80
Over 10,000 after 1981 and before 1988 83
Over 10,000 after 1987 80
 
Now in California if you cars exhaust is over 95db the cops can ticket you for modified exhaust and it is a $1000 ticket now so if you live in California it is better to keep your car quiet now .

95dB is so insanely loud, you deserve a ticket. My open wastegate/no muffler 250whp out of 2.0Ls of fury racecar RACED at Laguna Seca on a noise controlled weekend (92dB limit, granted, I short-shifted the noise station just to make sure). The law states:

(b) For the purposes of exhaust systems installed on motor vehicles with a manufacturer’s gross vehicle weight rating of less than 6,000 pounds, other than motorcycles, a sound level of 95 dbA or less, when tested in accordance with Society of Automotive Engineers Standard J1169 May 1998, complies with this section. Motor vehicle exhaust systems or parts thereof include, but are not limited to, nonoriginal exhaust equipment.

J1169 is a stationary test at idle. If you're making more than 95dB at idle you deserve not only a ticket, but also a slap from momma for being disrespectful to those around you. :D
 
No that's not loud most people can talk at about 50db and they check it 20 inches from the end of the exhaust at 3000 to 5000 rpm . It would be loud if they checked it at 50 yards or so .

You should check out J1169. At one time, it was 75% of rated peak HP RPM, but my understanding is that has since been amended back to idle (or some other relatively low RPM) because many cars did not allow the engine to rev that high when stationary. The test on stationary vehicles is done at 3M, up to 45* offset from the exhaust outlet. Even if you were to still be required to rev to 75% of the HP peak's RPM, that's 3400 on a Jeep, which is about where it shifts when I'm driving around at normal acceleration. Since it's stationary, there is no load on the engine, so 3400rpm during this test will be quieter than when you're driving.

The decibel scale is logarithmic and doubles every 3dB. 95dB has 30 times the sound intensity/energy that a measurement of 50dB does. 95dB has twice the sound intensity my no muffler/no cat/divorced wastegate racecar did at 5000-ish RPM racing at Laguna Seca. 95dB is four times as loud as a lawnmower at full tilt and about the same volume of a leadblower strapped to your back (which requires hearing protection for any operator doing it for work).

Why you'd want to drive around with an exhaust that loud just cruising around is beyond me. No excuse to exceed those sound levels in any vehicle cruising around, let alone on a Jeep 4.0 with it's teensy tiny cam and tractor-like maximum RPM.
 
I was just saying that you mite want to stay on the quiet side because they are starting to go after loud cars , and some cars with OE exhaust systems that won't pass the test the California bar does , they have there own test that California came up with and most newer cars with a auto trans will not free rev over 2500 to 3000 rpm but that's California .
 
I was just saying that you mite want to stay on the quiet side because they are starting to go after loud cars , and some cars with OE exhaust systems that won't pass the test the California bar does , they have there own test that California came up with and most newer cars with a auto trans will not free rev over 2500 to 3000 rpm but that's California .

Per the CVC, it's J1169, which has since been modified (but can't confirm since I'm no longer an SAE member) to idle (again, I believe) due to new cars not allowing free-revving to 75% of peak HP.
 
You must get 5mpg! My "driving normal" shifts at about 2200-2300 RPM and i only get around 16 average...

12-ish...

Maybe not EVERY time I accelerate it's rolling to 3400RPM, but it's not uncoming. I live in the foothills and my rollers are about 100lbs a corner... :D

Either way, no XJ should be over 95dB under normal operating (which includes WOT).
 
Didn't read through all of this but I am about to do my 92 xj exhaust and I have now ordered a high flow cat cheapie off ebay (Izumi) and a jones exhaust max flow muffler which was all of 40 bucks shipped off ebay. I was gonna do magnaflow as I am going for a deep but not too loud sound with no drone. Ive had flows and they drone without a doubt. My tj has a magnaflow and it just sounds great! Granted it has a turn down but the xj will go all the way out. I need it to be deep and grumbly not loud and annoying. After much research I found the jones muffler to be almost exactly like a magnaflow so I am looking forward to getting it done. If anybody wants to know how it sounds I will see about giving an update. ---------------Kyle
 
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