M&K ?'s

[81 911 SC]

For those that have M&K mufflers, specifically 2in/out mufflers, how much and where do you see resonance in your mufflers? I am sure Ben will be able to chime in. I know I can not eliminate it but I am hoping it will be less than my GHL due to the increased muffler size over the GHL.

[rfuerst911sc]

Mine is around 2000-2300 or so. I ended up purchasing one of Bens caps and I cap the passenger side outlet when I drive on the street. When I autocross,DE or just want to work off some anger I uncap the passenger side and let her rip ! When it's capped there is no resonance. In my opinion this is the perfect setup as you can control the noise/resonance with a simple 1 bolt cap.

[DW SD]

I have the dual outlet version II. It has zero resonance, though it is loud. It won't wake the dead, but it is loud. It does not drone or resonate.

My dual outlet version I did drone / resonate. So he made some changes that worked, between the two versions.

Doug

[72 four door]

Ok my set up is the ssi and 1 out on a 3.0 it does drone and resonate up to to 3000 rpm . My muffler also was blowing out fiberglass so maybe i got a reject not sure.

[Steve 82SC]

My previous set-up was stock heat exchangers, cat, and a 1-in-1-out GHL....absolutely no resonance at any rpm. When I changed to SSI's and a M&K, I get a resonance at 2300 rpm. Twenty-five rpms north or south of 2300, there's no resonance. Ben offered to alleviate the situation, but I've been too busy and really don't find it that annoying at this point to make it a priority.

Steve

[81 911 SC]

Thanks for the responses fellas. I ordered my M&K this morning and will be putting the GHL up for sale on the board once the M&K comes in and is installed.

[mb911]

Originally posted by 72 four door
Ok my set up is the ssi and 1 out on a 3.0 it does drone and resonate up to to 3000 rpm . My muffler also was blowing out fiberglass so maybe i got a reject not sure.

No was not a reject. we tried some packing material in them but it failed to capture so we stopped using it.

To coment on drone think about this for a second

What tire diameter?
what RPM range do you cruise at?
What compression level do you have?
What cam shaft is being used?
What induction is being used?
What gear ratio is being used?

ALL OF THESE ARE DIRECTLY RELATED.

If you "lug the engine" in some way you will get a drone of sorts. some people are more to be concerned then others. So drone is subjective to the individual. If you cruise at say 2600-3000 you will usually have no issues.

Quick story. I just drove a customers car with a 3.2,ssi, and one of our earlier 2 in 1 outs. To me it was rather quiet. It sounded good , No droning could be detected just sounded pure "european "

Also while my car was still NA I used a 2in 2 out on that and could hold a conversation with my son(4 at the time) in the back seat. we were not yelling or rasing our voices. So as I said it all depends on what the person wants and what they expect for noise levels..

I hope this helps

[81 911 SC]

It does and to answer your questions:

245/45/16 rear tires
around town I would say the rpm range is anywhere from 2k-3k
The motor is a stock 3.0 with 40MM PMO carbs and no changes were made to gear ratios on the 915.

[mb911]

you currently have the 2 in 2 out ghl? Then there won't be a huge difference between the 2 except the sound quality

[81 911 SC]

I do have the 2in 2out ghl however what I noticed is the difference in size of the muffler between yours and the ghl. The ghl is very small with very large tips where as yours looks to be more in size with the dansk mufflers.

[mb911]

yeah ours is more like the traditional 911 muffler (increased volume of exhaust gasses )

to answer though the droning is all up to the drivers habbits etc..

[petevb]

I guess I've probably got a V1, because my dual outlet resonates pretty badly right at 3k and a little above. Perhaps a cap or a V2 version is in order, as it's loud. What are the options if I'd like it quieter?

[mb911]

you can cap it very easily and it will drop down quite a bit