Remove Rear Wheel Arch Liners

[SmuttyHutty]

I've done a few searches of the site but haven't really managed to come up with anything definitive.

Has anyone permanently removed the rear wheel arch liners? If so, did you just paint Waxoyl or some other underseal in lieu of the liner?

I'm thinking about doing this on the PZ. Paint with Vactan first then undersealing.

Any negatives I need to be aware of? Noise? Vibration?

[BigPete]

I removed mine and under sealed it. Imports don’t seem to have them to start with.

[SmuttyHutty]

Cheers, Pete. I might do that over the holiday before the car goes in for the spray job.

[BigPete]

Good idea, the interior is out of the grey car now

[SmuttyHutty]

Oooooo fab. Ummm....I'll Whatsapp you

[Ollie]

Removed mine last year not that Ive driven the car a lot. Goodeggbob removed his previously as well. They are meant to remove road noise I guess? But any market bar the UK that sees snow doesn't seem to have them/owners remove them because they just cause rust issues... Which makes sense. Sopping wet carpet... That gets dirt behind it basically sandpaper.

[SmuttyHutty]

Removed mine last year not that Ive driven the car a lot. Goodeggbob removed his previously as well. They are meant to remove road noise I guess? But any market bar the UK that sees snow doesn't seem to have them/owners remove them because they just cause rust issues... Which makes sense. Sopping wet carpet... That gets dirt behind it basically sandpaper.

Is it just a case of removing plastic pop studs and it comes away?

[SmuttyHutty]

Uh. Mostly. There's a few plastic nut like things that are a pain to take off. And a bung that looks like a bolt head but isn't which will just go around for days.. I also just cut a slit in them to get them past the abs wiring. Otherwise it doesn't really take long to do.

[WildMan10]

I looked at this a few years ago when optimising a turbo conversion. Liners may look simple but that’s deceptive. Designers put some effort in, not least because 25-30% of drag comes from the wheel wells.

Liners are there not just to protect the wing from stones, dirt and water, with front ones protecting the engine bay too. They also reduce drag and noise, although need to be designed carefully as they could have the opposite effect.

Personally, I’d leave those rears in. Although not as important as the front liners, I can see many good reasons why Mazda put them in rather than just treat the wing undersides, which is also the case for every production car I see.

Race cars often have them all or parts of them removed, but that is more to do with avoiding rubbing than anything else.

[Ollie]

I looked at this a few years ago when optimising a turbo conversion. Liners may look simple but that’s deceptive. Designers put some effort in, not least because 25-30% of drag comes from the wheel wells.

Liners are there not just to protect the wing from stones, dirt and water, with front ones protecting the engine bay too. They also reduce drag and noise, although need to be designed carefully as they could have the opposite effect.

Personally, I’d leave those rears in. Although not as important as the front liners, I can see many good reasons why Mazda put them in rather than just treat the wing undersides, which is also the case for every production car I see.

Race cars often have them all or parts of them removed, but that is more to do with avoiding rubbing than anything else.

Begs the question why they only came on cars in certain markets etc though for the rears. Unless I'm miss remembering.

[SmuttyHutty]

Which goes back to what BigPete was saying earlier in the thread.

Screenshot 2020-12-18 at 11.13.16.png

I am no speed freak. I hammer the car from time to time but my livelihood do not depend upon my driving - a fact of which I am eternally grateful. My interest in doing this is purely from a rust management and maintenance point of view. If those liners are hiding or causing corrosion then I want to deal with that in the most efficient manner.

However, if doing do will cause noise/vibration/discomfort then I'd rather nor do it.

Seems like it's fine to do if these cars come from overseas without the liners, though. My concern was also getting the liners out but if it is just a case of popping a few plastic rivets out and cutting the liner around the brake pipes then I am fine with that.

I've got Vactan which I'll use as a rust-converting primer and then brush a Waxoyl type product on in place of the liner. I am not going to spray because I don't want the stuff going everywhere.

Any issue about doing it in the cold?

[warpc0il]

Vactan doesn't work that well in the cold and it particularly doesn't like "condensating" conditions.



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[Ollie]

Unless the rust needs immediate tending to I'd put it as something to do for spring personally. Vactan doesn't operate below 5ish degrees. I think it says on it somewhere ideally it should be around 15 to 20 degrees for optimum drying times of an hour ish?

[SmuttyHutty]

Right-o. Spring or early summer it is. Saved me going out in the cold.

Result!

[WildMan10]

Begs the question why they only came on cars in certain markets etc though for the rears. Unless I'm miss remembering.

I don’t know about Japan, but US models all have rear liners/splash guards. Looking from the other direction, if JDM cars don’t have the rears, it begs the question of why they were fitted for the U.K. and US markets

[Donal]

It's not like they have snow in Japan...
https://www.bbc.co.uk/news/world-asia-55359771
but it is illegal to put salt on the roads.

[Ollie]

Either the JDM cars had them and they were defacto removed by owners perhaps before they got imported? Or they never had them to begin with. I remember someone mentioning before of other makes of cars in snowy markets not having material based liners/owners removing them from the cars to prevent rust.

I can understand the fronts being important. But the rears seem to me to serve no purpose beyond noise cancellation and maybe a bit of stone protection.. But imo stone protection that doesn't hide the underside of the wheel arch is going to be thousands of times better than carpet wheel liners that most owners won't check?

[350matt]

the big issue is the rear liner material gets wet and stays wet so it promotes corrosion

I've done a halfway house on mine and cut them back so they stop short of the arch edges ( where the problems begin) and then liberally sprayed the exposed metal work with underseal