Wednesday, February 5, 2020

DIY Second Layer Door Seals and Gaskets

One of the items that was recommended by Amazon's "others who bought this, also bought" feature was Basenor door seals kit for the Model 3 to reduce wind noise, etc. So I ordered one, and after a quick assessment, I promptly returned them. I don't like writing negative reviews, but these were badly designed and would have been a waste of time and money. I made a quick video about the problem to warn others:


Since the bug to improve the door seals had bit me, I started to do some research and started looking for other seals. Nothing decent existed on the market. I ended up using my GT-R as a model for where additional door seals ought to be placed. Besides sound, good seals should keep water and road debris out, so the door jambs stay cleaner. Therefore, my test bed has been checking how much dirty rain water and car-wash water ends up in the door jambs over time. Since air is a fluid too, this is as scientific as I can get given the cost/effort of this mod, as opposed to sound measuring equipment.

After using the seals for a good month - driving through rain, snow & slush and going through the car wash 3 times - I can say that it is almost as good as it will get. I have add one additional seal section to perfect it. I cannot scientifically test the road noise, but on a recent 286 mile trip from/to home,. I noticed the car was much quieter in terms of whistling/wind noises. 

Because the GT-R was designed to cut through air, it has some interesting and rather visible seals outside the doors and along the hood gap. Based on these patterns and the desire to only purchase seals with genuine 3M adhesive (and not some Universal knock-off), I ended up with ~33ft/10m of these two seals 1. B-shape seal(not D), and 2. Z-shape seal for my DIY project. 
B-shape and Z-shape seals
So I manufactured a second layer of door seals for all 4 doors by combing the seals as follows:


The technique is rather simple:

1. Clean the surface of the door with a soft cloth e.g. microfiber and some rubbing alcohol.
2. Dry fit the seal and cut it to length, an extra 1" doesn't hurt to trim later.
3. Either perform instillation on a hot day so the body of the car is > 80 F, or simply use a hair dryer to warn up matching sections both the seal and the door and adhere the seal to that section and slowly work a few inches at a time.
4. Do not stretch the gasket when applying it, that will make it peel off immediately.
5. Do not peel the entire backing off the 3M sticky tape. Instead work section at time, peeling a few inches at a time.
6. Trim excess and any notches and then run the dryer one more time along the seal a few inches at a time. Once a section is warm then press down firmly for 10-15 seconds, warming each section and pressing it firmly.
7. Move on to the next section or door.

For the front doors:

First run the B seal and note where it ends, look at how it lines up against rear door lip and realize that adding any more seal to the front door would be a complete waste as it does not have a metal lip to close up against.

Front door outside seals don't need to go all the way to the bottom
For the bottom of the front doors, Z-seal is used. The trick here is to remove the tape backing from three or four small sections along the seal, then line up the seal and close the door.  Next look at the bottom gap between the front door and frame to ensure that the Z seal was flush against the bottom of the frame, without either the folding over or leaving an opening. Adjust the height of the Z seal and then finally adhere all of it. It takes a few attempts to get right but remember not to let the sticky tape get dirty or on and off more than once. Final heating & pressing ensure good adhesion.

The notches are important, they allow water to drain from inside the door. You don't want it to build up inside or around the seal. If it builds up around the seal then in winter it can expand as ice and buckle the door or frame.
Front door bottom seals lined to close gap and notch cut out
The last section of the front door was the most important and I think it contributes the most for cutting out wind noise and sealing it up helps a lot/ It is also hard to adhere here since it has to be done behind the door hinges and cable looms. Take your time on this one and really work inch by inch. The door edge provides a good guide from making the Z-shape flush against thedoor edge.

Front door front edge door seal, slow and steady for a good result.
If done correctly, upon closing the front door the gaps should be filled by the gasket such that they simply appear black and not the typical body color with light shining through.
Hard to see but good sealing gasket on front.
The same should apply to the bottom of the doors a nice seal.
The gap is filled nicely, without gasket folding over or leaving a gap.
For the rear door, the B gasket should be used as follows along the outer edge of the door, almost to the bottom part that the door edge that becomes horizontal. 

The smaller section of the of the B gasket on top was added later on after a few car washes when I realized that some water was still coming into the door jam area and could see the trail. This is the "later modification" I referred to earlier..
Out edge of the rear doors with B-style
The bottom edge of the rear door, repeat the same lining-up procedure and note where the B & Z gaskets meet and where the other Z -gasket from the B-pillar meet. A few mm gap is okay for drainage.
Additional seals on the bottom of the rear doors
The B-pillar (pillar between front and rear doors) side of the rear door seal is much easier to apply with the rear door closed and from the front door side. Notice the extend to which the metal lip of the rear door runs (yellow mark), this is why it is pointless to put B-style seal along the entire edge of the front door as stated earlier.
Easier to apply the rear door B-pillar side seal with rear door closed and front door open
The rear door front edge/B-pillar side seal makes the most impact to wind noise and letting in dirty road water, etc. (yup I know that the stock seal against the finisher if not correct in the below picture,  I had recently removed trim to defog a side camera)
Front side of rear door fitted with Z-style seals
I also tried both the B-style and D-style seals on the front trunk (frunk). Both on the extreme outer edge and on the next inner edge that closes against the plastic trim piece, but neither did anything. After a wash the frunk trim edge was equally wet with the seals. Still exploring this one. Might need a larger D seal. I have had more luck, adjusting the entire frunk using the 2 rubber grommets on either side so that it closes slightly below the bumper edge, therefore not sucking in water when driving through rain.. The goal is the same cleaner inside and less rain water, etc. on the frunk inner section and trim.
Using seals makes no difference to the frunk.
Overall, I am pretty happy with this. The front doors close with the same effort, the rear doors require maybe 5% more effort. I added the top piece to the rear doors just today to see what happens as I could see whatever run down. If you look carefully at the pictures above the outside of the car had a decent amount of salt spray from the roads, but the insides of the doors were much cleaner. Coupled with the mud-guards that I installed, I am pretty happy with this mod for keeping the door jambs clean of road spray.

This mod does require patience and technique to install it properly but the results are good. Even if the sound just went down by a few dB, I am happier that everything is cleaner.

Ciao for now!