bernb6

I was constantly irritated by the noise after I added Numeric cables to my daily driver Cayman S. The installation was initially done by a pro shop in the area and they carefully reused the original gasket at the firewall, though they had to slice open each sleeve for the larger diameter Numeric cables. In spite of reusing the original gasket, the noise was a problem.

I've seen other references/complaints re the noise but no solutions. Some people are bothered, many aren't. In the end, the solid metal-to-metal connections brings high frequency noise into the cabin. So I did two things.

With some automotive acoustic dampening material (e.g. SAMPLER PACK** NEW GTMAT 6sqft (3'PRO+3'ULTRA+ROLLER) Sound Deadener Deadening), I wrapped the gasket surrounding the cables at the firewall. I kept the self-adhesive sound mat off the removable panel but tried to fully cover the gasket, top and bottom, its baseplate, and onto and between each cable. Any airgap will let in noise.

Just this seemed to reduce the Numeric noise by half.

The second part was a lot more work and required removing the console: see https://rennlist.com/forums/997-foru...-1-of-5-a.html for a great write up on this. I encased the rear of the shifter cage and above the cable inlet in sound mat, covering as much of the air gaps as possible. To ensure the everything was removable, I first used high quality cloth tape on anything the self adhesive sound mat would contact. I used a portion of a plastic bin as a support structure to keep the mat safely off any moving cable surface. I was careful to go through all gears in a test drive to ensure no problem before replacing the console.

Doing both these areas has brought the noise level pretty much back to OEM level.

I'd still like to find a way to treat the area under the shift boot but could not think of a way that wouldn't impede shifting yet still be effective.

Bern

ottobon100

You "MacGyver'ed" it. Great job. That noise would certainly bug me. Looks like Numeric would address this somehow. Certainly has me thinking that if the day comes if I would want to go with Numeric or stock.

bernb6

As a close, I probably could have skipped/avoided the work McGyver stuff in the console if I had first installed 3/8" ID silicone hose over the cables inside the engine compartment. That seems to keep the cables from picking up frequencies in the first place.
Bern

altonj

The noise one gets from a numeric cable is the same as one gets in a GT3 from the installation of Porsche Cup Car cables. It bugs some, but not others. There really is no way for Numeric to address the issue. It is a factor of the cable ends which is critical to their durability and functionality.

Cheers

Cman21

I used 7/16 fuel line to cover the cables to reduce the noise. I split the fuel line and zip tied them in place. The sound levels in the car are the same as the factory cables.

Cman21

BoulderGeek

This is very helpful.

I have a new-to-me Cayman S with 10 years on the OEM cables. I am going to install Numeric cables (which I have) along with an Ebay *& M type SSK.

I already have 10 feet of 15/32" silicone vacuum tubing to encase the lines in, but I like the approaches that this write-up presents, as well.

jdavis8361

New guy here who is considering the hose solution to the Numeric noise but who is confused as to whether he should buy hose with a 3/8" or a 7/16" or a 15/32" inside diameter.

All three sizes are mentioned in different posts. Is one size preferable to the others? Does it really matter, being as how they're all pretty close?

Also, three types of hose are mentioned. Does the type of hose matter?

Thanks in advance for your opinions.

jD

jdavis8361

I bought 10 feet of 7/16" black fuel line and zip-tied about 4-1/2 ft. onto each of my cables. I put it on only the cables in the engine compartment because removing the center console is too much of an undertaking.



While driving down to the gym I listened hard for the noise and if it's not 100% gone, it's at least 95% gone and I'm happy with the improvement.


jD

bernb6

The 3/8" hose is a little small and will leave an open slit. The 7/16" is a little big - the hose I had would not close tightly after being slit. I just put the 7/16" over the slit in the 3/8". Ideal would be 13/16" but generally not available.

moe01325

After reading your how-to, I also ordered some sound deadening and added it to the cables at the firewall. Definately reduced the noise a lot! I would say nearly back to OEM levels. did not add anything to the shifter directly - I have the full Numeric Shifter block and actually like the mechanical sounds from it.

Thanks a lot!

cavediver32043

I used the KISS principle. Studied where the cables route over the engine and make contact. The amount of engine vibes creating sound resonance are picked up and transmitted by cable contact points. Simply narrowed down the culprit points; mainly on top of engine and insulated those 2 points with HD foam pipe insulation WALA!! back to OM sound of old. Took a whole hour inclusive of top firewall removal and install. I did this 3 years ago.....

juvenescence

I used 10mm silicone tubing (ID 10 x OD 16mm), approx 3m of it to wrap both cables before they got installed. I honestly can't really hear a difference compared to the OEM cables. Maybe if it was dead quiet and I was around the 3-3.8K RPM range I could hear a slight higher-pitched whine? Could've been in my head though, cause I can't hear it normally while driving.

Wanderer

This is what I did for cables. A bit extreme but there is no noise. There are plastic washers that dampen vibrations. They worked for a while but a better washer will be needed long term. Rifle shifts for sure. Very nice and very smooth.