Exhaust exit location

redchev · December 15, 2003

Living in Wisconsin I have to put up long winters and alot of salt and snowy conditions. The back window on my topper gets so covered with dirt and mist I can't see through it after 50 miles. I was wondering if my exhaust exiting out the back has anything to do with it. I dont remember this problem with my old blazer with exhaust out the sides.

AZ-Z71 · December 15, 2003

Hopefully not or you got some serious smoking going on there

Tucson_02Silverado · December 16, 2003

Some of it depends on the amount of air that will flow down the window then straight back. The more vertically flat the rear is, the more it'll be hit by aero back swirl. Don't really know how to explain it other that visulize the side of the truck. Then right in back is like an ocean wave with the crest (top) curling back towards your topper window and the bottom coming to the back of the truck from your rear wheels (road grime). There are some topper "wings" like on some SUV's and station wagons of ago that are available. They direct air from the top and if adjusted/designed right will push that "crest" of road grime farther down and out from the rear window.

That's also why it's not good to have the rear window open, the exhaust gets sucked into the interior.

sdtahoe · December 16, 2003

Some of it depends on the amount of air that will flow down the window then straight back.

I had a compact pickup with a topper and lived on a gravel road and I could almost never see out the back. My current Tahoe is about the same after a couple of blocks on sloppy road the back windows are dirty.

I had a '88 S-10 Blazer and that wasn't as bad as it had a "wing" over the rear window to deflect air over the window and help keep it clean. You may want to chack with some topper places and see if they have a wing for you topper that will help keep the window clear.

Shaners · December 16, 2003

Mine is the same way...

You could add the air deflector like was already mentioned, and it should help some of your problems... However it could cause some interference from the extra height when parking in the garage. (I know I wouldn't have the extra height to put my truck in my garage with a deflector on it)