OKay, so I took my 1970 240Z out last night and got pulled over by the cops for being too loud. I had the week before had a Turbo Thrush muffler installed as the old one was punched full of rust holes. Now I'll admit that the car is loud, but I thought the new muffler had - you know - muffled that enough. I guess not.

So, I'm wondering if adding a resonator mid-pipe might make it sufficiently quieter and keep the cops off my back? I'm thinking about either this one -

Walker Exhaust 17861 Sound FX Resonator Universal : Amazon.com : Automotive

or this one-

Flowtech 50252 FlowTech Red Hots Glass Pack Mufflers

but don't want to go to the trouble and expense if a resonator isn't going to help. I just want the car to be quiet enough that the cops don't bust me. Plus I have to deal with the stupid fixit ticket.

Alternatively, does anyone have any experience with this?

Motorsport! SALE! MSA Premium Exhaust System, 70-72, 74 240Z-260Z (For Stock Manifold) - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

MSA says that it's louder than stock. Does that mean it's so loud that it'll still get me in trouble? Sigh.

Thanks in advance.

I installed one of these mid-pipe on my '78:

MagnaFlow/14 x 4 in. body polished stainless steel round muffler (14416) | Muffler | AutoZone.com

The fit was good, and it's been a good muffler. There's even more room in the tunnel area of your 240. (My transmission is a bit larger.)

I had the MSA "turbo" exhaust with Dynamax muffler. The car was loud, ground clearance was bad (it could be due to poor installation - every pipe was welded to the other instead of being connected.

I've redone the entire exhaust and I've installed a homemade glasspack in the transmission tunnel. Car is still very loud at WOT but much quieter on cruise & idle.

Just have a muffler shop add at glasspack and it will be fixed. I had Ed Hanson do my exhaust on my 73, drove it away, hated how loud it so I took it back the next day added the glasspack and I have been happy ever since.

The Police are catching on to mine too. Every time I ride through a certain area (nice long straights) the howl must be way louder coming out the tail pipe than I realize because I always meet a patrol car on my way out. I have the MSA header and 2.5" system to and this is the one I think would work best for me.

http://www.summitracing.com/parts/WLK-24215/

Hi,

Here's another option to consider: Try a 12" "Cherry Bomb" Glasspack. This unit is reversible - more noise reduction when placed in one direction as opposed to the other --> Choice.

As is, I purchased model: 87522 (on amazon) for a 2.5" pipe installation just forward to the rear wheel well - fits nicely and it works well with the Dynomax- deeper sound and no more drone.

Cheers,

George

Argh! Thank you all for your feedback, it's very helpful. Right now it looks like I don't have a straight forward route to solving my noise problem. Has anyone had any experience with the MSA Twice Pipe system?

Motorsport! SALE! Twice Pipes Exhaust, 70-72, 74, 240Z-260Z With Stock Exhaust Manifold - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

That looks like a reasonably priced option and with two glass packs it is perhaps a quieter solution to my single Turbo Thrush, which was only $23 on Amazon so I won't cry over dumping it. I'm concerned however that should it prove too still too noisy I will have a real challenge adding a second resonator or glass pack inline due to the double our trouble nature of the set up.

I just had the MSA twice pipes installed - stock manifold on a '78 280z. It was difficult to get it lined up but they did a great job - I also decided to have everything welded. It looks great and it sounds great (volume and tone) but the resonance is too much. To avoid the resonance you tend to look for the right gear and rpm (around 2900-3000) rather than the appropriate speed which can be dangerous. It's driven on sunny days in the summer so I'll live with it for awhile. Wouldn't want to have a daily commuter with this set up. I'll be taking it back in to look at installing some type of resonator but as you mentioned, it is real tight under there. It already sits real low at the 90 degree bend after the diff.

Zmonkey

The police love my Z. No matter how terrible, fast or loud I drive I have not been pulled over once.

OKay, so I took my 1970 240Z out last night and got pulled over by the cops for being too loud.

Where in LA do you live? I live in the area (OC and now D-Bar) as well and never had a problem with the po-po. I had a turbo setup for a while with no resonator and a Borla XR-1 race muffler that was over 95 db, and now my LS1 setup sets off car alarms while cruising in my neighborhood at 25 mph and 1200 rpm.

Where in LA do you live? I live in the area (OC and now D-Bar) as well and never had a problem with the po-po. I had a turbo setup for a while with no resonator and a Borla XR-1 race muffler that was over 95 db, and now my LS1 setup sets off car alarms while cruising in my neighborhood at 25 mph and 1200 rpm.

I was pulled over by a South Pasadena cop. Polite as hell, and really he was right, the car was loud. I've had a 20" resonator added to the MSA 2.5" performance exhaust and now it has a nice sound and is acceptably quiet.

What I can't figure out is how the motorcycles with open pipes don't get tagged on a regular basis. Those things are far louder than my Z ever was.

What I can't figure out is how the motorcycles with open pipes don't get tagged on a regular basis. Those things are far louder than my Z ever was.

This is what gets me!! I can drive on the highway at 75 mph with the windows up and can't even hear my OWN radio because some a-hole on a Harley thinks open pipes are cool! Why don't they get pulled over?

I've never had a problem with the police, but when my fan clutch seized I had a confused school security guard yell at me a couple times because apparently noise from the engine bay is directly proportional to car velocity. :stupid:

I have the MSA PREMIUM EXHAUST KIT installed on my 1972 240z which has a Schneider 274F Camshaft. I used to have the MSA TWICE PIPES set up and it never caused any deceleration backfire popping. Now with this one whenever i reléase the gas pedal on 2nd and 3rd gear i am experiencing a pop pop pop sound at the muffler. I even lower the mixture to 2.5 turns clockwise on both roundtop 3 screws SU Carbs and retarded the timing to 11 BTDC but it still been Heard. The kit i installed is the following:

http://www.thezstore.com/page/TZS/PROD/15-6302

and comes with an Xcelerator Turbo Muffler:

http://www.a-1performance.com/XLerator_mufflers/

This is the one i had before:

http://www.thezstore.com/page/TZS/PROD/spring02a/15-6031

Should i just consider replacing the muffler to some muffler that is more restrictive and has glasspacks?