Floor tar repair/ restoration Options

[TonyA]

Thanks for all the suggestions. I want to see what the AA kit looks like and I also like the lizard skin stuff. I may purchase both and compare. It won't go to waste always making something.

[914_teener]

Just curious....those interiors look beautiful.

Why not dampen the firewall (inside behind the backpad) the the foreward wheel wells and front bulkhead? Those are two next largest resonant metal panels.

With regard to "sound absorbtion" and "resonance", two different things.

I've worked on a couple of projects in my career where both were concerns.

Sound absorbtion uses different ways to "disrupt" the sound waves.

Sound resonance damping is what you guys are talking about. It's the actual transfer of the sound energy to the metal panels. Like a shock absorber on a car.

Sound absorbtion is a sort of vodoo science...really cool stuff almost like quantum physics applied.

Curious about the comaprison since the only differnece I see from the layered product is the layered composition and buytl....other than that....it's the same stuff in layers of foil with sticky Avery crap on the backside.

[bbrock]

Why not dampen the firewall (inside behind the backpad)

I actually did that. I still use the stock rubber sheet on the interior of the firewall but added a layer of foil faced (constrained layer) butyl on the engine side that is hidden beneath a sound absorption mat made of modern materials.

Curious about the comaprison since the only differnece I see from the layered product is the layered composition and buytl....other than that....it's the same stuff in layers of foil with sticky Avery crap on the backside.

I don't know how accurate this is, but what I've read about the modern foil-faced butyl stuff is that the butyl adds mass to reduce the vibration of a panel and also absorbs the energy of sound waves moving through it. As waves propagate from the panel through the butyl, the foil reflects some of the waves back through the butyl to further dampen the energy so less "escapes"through the mat to travel to our ears. Seemed reasonable to me when I read it anyway.

I've also seen rules of thumb about the percentage of a panel's surface that should be treated to achieve sound dampening. I'm not sure of the physics involved but seems there are diminishing returns beyond a certain level of treatment. The stuff is kind of spendy so optimizing for biggest bang for the buck makes sense.

Of course, the shape and size of a panel has a huge difference in how much they vibrate and resonate sounds. Like @Superhawk996 said, it gets really complicated and is way beyond my comprehension. Treating the large flat surfaces makes the most difference. Of course, if money is no object and you aren't worried about weight, I suppose covering all the panels with sound dampener might make the quietest car and some people do just that.

Another area that makes a huge difference is inside the door skins. I don't remember if early doors had tar added but the heavy late doors did. A strip or two of sound mat inside the doors makes an enormous difference. I cringe every time I watch a video of someone shutting a 914 door and hearing that tinny ring that makes the car seem much more cheaply built than they were.

[mepstein]

Thanks for all the suggestions. I want to see what the AA kit looks like and I also like the lizard skin stuff. I may purchase both and compare. It won't go to waste always making something.

Tony - I’m painting my 912 in a couple months so if you want to try lizard skin, you can either buy the kit with the gun and I’ll buy it from you when you are done or I’ll buy the kit and you can use it whenever you want. We’ll talk.

[zoomCat]

In addition to the floor and sills the factory put tar on the front firewall. Here’s what I found in a 70 six. George sells these as well.

[mepstein]

The shop where I used to work was getting good feedback from the lizard skin. That’s certainly not the same thing as a real study and maybe it’s like the butt dyno. You feel what you want to feel and hear what you want to hear. I figure if it’s not enough, I can add more of the modern sheet style product.

Besides sheet metal, I’ve found a lot of noise comes from induction, exhaust and tires. Years ago, I went from a stock 1.7 (FI, oem exhaust and standard tires) to a hot 2.0 with carbs, aftermarket monza exhaust and yoko A008 tires. The increase in noise was shocking. Each piece- induction, exhaust and tires could be heard individually and at different times.

My 914 used to be my daily driver and trips over an hour or two became a little less fun. Now I have driving options and if it bothers me, noise canceling ear buds work wonders. I use them on my indoor bike trainer, power tools and lawn mower. They make exterior noise disappear.

[Mikey914]

I just happen to like the sound of all 3!

[Garland]

we sell an exact cut factory duplicate floor pan tar kit designed from original factory pieces we had for years. six pieces, just heat and beat to install


b914556110kt

What does everyone use to repair floor tar sound deadening material. I have some popping up very little rust the cause of course. I am removing a small amount to good sound completely rust free areas and want to restore that to like new appearance. Any suggestions?

I order the kit today, I did my Build off 73 in FatMat, and EZ Cool. But in the 72 I’m going with a stock build and installing George’s kit. I’ll share the install when the weather warms up a bit.
Here’s 2 pictures of the 73 build off floor, and then the silver 72 floor, waiting fo the kit.

[zoomCat]

You can get pretty good decibel meter apps for phones now. It would be very interesting to see results for various treatments, particularly if some care was taken with the experiment design.

I don’t have a running car at the moment, so I’m no help.

[bbrock]

You can get pretty good decibel meter apps for phones now. It would be very interesting to see results for various treatments, particularly if some care was taken with the experiment design.

I don’t have a running car at the moment, so I’m no help.

I tried several of those apps and finally bought a decibel meter after getting weird results from the phone. It seems we are limited by the sensitivity range of the mics on phones. The phone would read too loud or too quiet compared with the meter over various frequencies and only agreed in a relatively narrow band. I gave up on trusting the phone as a decibel meter. This was an android phone. Not sure if iPhones do any better.

[zoomCat]

NIOSH prefers the iPhone, consistent hardware apparently allows for better calibration.
https://www.cdc.gov/niosh/topics/noise/app.html

“iOS devices share common hardware and software architecture that is optimized for audio applications. Therefore, we have been able to verify that the NIOSH SLM app will perform as expected on any iOS device. On the other hand, the Android device marketplace is fragmented among many manufacturers with different requirements and specifications for microphones, audio/signal processing chips, and software tools. As a result, testing and verification of the accuracy and functionality of an Android-based app in our laboratory is not currently possible. “

You can get pretty good decibel meter apps for phones now. It would be very interesting to see results for various treatments, particularly if some care was taken with the experiment design.

I don’t have a running car at the moment, so I’m no help.

I tried several of those apps and finally bought a decibel meter after getting weird results from the phone. It seems we are limited by the sensitivity range of the mics on phones. The phone would read too loud or too quiet compared with the meter over various frequencies and only agreed in a relatively narrow band. I gave up on trusting the phone as a decibel meter. This was an android phone. Not sure if iPhones do any better.

[Garland]

Well here’s how it went on the install.
Almost 3 years later, and speaking with George, and his team, again.

“ we sell an exact cut factory duplicate floor pan tar kit designed from original factory pieces we had for years. six pieces, just heat and beat to install”

Just a few of many concerns, after inquiring, ordering, and then receiving these:
They are to large, every corner would have to be cut, and all sides trimmed. I fitted, starting with alignment to the seat brackets. The center console piece, is to small of a cut to clear the access tunnel door. Along with the large winged notch for the seat belt hole. Notice the shifter cut out. In places on comparison with factory, the material is too short.
In hoping this is a one off kit, when I inquired, I was now told by AA,

“ it will require trimming to install”


Be aware these are not “exact cut factory duplicate” not able to “ just heat and beat to install”
I honestly, would not have purchased these if I was informed of the facts. I have not, and may not installed these, there back sitting on the shelf.

[burton73]

What PMB used on my 6

Best Bob B

[Superhawk996]

To be fair the wording on their site is “Custom made for the 914; cut into 6 pieces for an excellent fit on the floor pan.”

But I certainly wouldn’t call that excellent either (IMG:style_emoticons/default/chair.gif)

Appreciate the post though - it truly is a shame that people have to spend good money to find out that marketing trumps fit, finish, and function quite often and AA isn’t alone in this.

Ah . . Now I see the “exact” fit comment back on page one. (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/blowup.gif)

[Garland]

[quote name='dr914@autoatlanta.com' date='Dec 22 2022, 11:05 AM' post='3046788']
we sell an exact cut factory duplicate floor pan tar kit designed from original factory pieces we had for years. six pieces, just heat and beat to install


b914556110kt


To be fair, spoke with George, and his install guy. I did not just order from the wording on the site. To be fair!

[Superhawk996]

[quote name='Garland' date='Sep 22 2025, 01:24 PM' post='3225291']
[quote name='dr914@autoatlanta.com' date='Dec 22 2022, 11:05 AM' post='3046788']
we sell an exact cut factory duplicate floor pan tar kit designed from original factory pieces we had for years. six pieces, just heat and beat to install


b914556110kt


To be fair, spoke with George, and his install guy. I did not just order from the wording on the site. To be fair!
[/quote]
See above - was correcting as you posted - yeah I’d be pissed too.

[mepstein]

To be fair the wording on their site is “Custom made for the 914; cut into 6 pieces for an excellent fit on the floor pan.”

But I certainly wouldn’t call that excellent either (IMG:style_emoticons/default/chair.gif)

Appreciate the post though - it truly is a shame that people have to spend good money to find out that marketing trumps fit, finish, and function quite often and AA isn’t alone in this.

Ah . . Now I see the “exact fit comment back on page one. (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/blowup.gif)

George will say whatever you want to hear to make a sale. It’s always been that way.

[Superhawk996]

To be fair the wording on their site is “Custom made for the 914; cut into 6 pieces for an excellent fit on the floor pan.”

But I certainly wouldn’t call that excellent either (IMG:style_emoticons/default/chair.gif)

Appreciate the post though - it truly is a shame that people have to spend good money to find out that marketing trumps fit, finish, and function quite often and AA isn’t alone in this.

Ah . . Now I see the “exact fit comment back on page one. (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/blowup.gif)

George will say whatever you want to hear to make a sale. It’s always been that way.

Oh trust me . . . I’ve been in the 914 game since the 80s. (IMG:style_emoticons/default/lol-2.gif)

I guess the point of my post was to commiserate with Garland and to say that AA isn’t alone in this behavior even though it truly isn’t right.

I appreciate Garland posting the truth and wish more people would show when parts aren’t as advertised vs money paid. Same as the discussion the other day about 914Rubber bushings that don’t fit, seals that don’t fit, etc.

I try to appreciate our vendors but no one likes getting screwed.

[Geezer914]

Under the car and fenders I used bed liner.