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tired of exhaust coming through rear window.

V

vortec

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fort worth, texas
i know this has been addressed before, but i have a new question about it. obviously, the problem is exhaust blowing, or sucking, into the cab when the rear window is down. does this happen with the tailgate off, too? it seems like that might allow the pressure to equalize and not suck that nasty cloud in.

any other suggestions? since my conensor coil has a big hole in it (stupid po), and it's 100+ degrees outside, driving around with the windows up is like being in a huge oven.
 
I have seen some with a fan mounted on the spare tire bracket. I think it is for when it rains but might help. My mechanic said put extension tips on my exhaust and point them down wards to just out from body. Haven't tried it yet have to many other things going.
 
I used to have that problem. I permanently removed the hardtop, put on a truck tailgate, and havent smelled a fume since. With the top off, their is no suction in thru the rear window. Not a fix if your keeping your hard top, but a softop with the sides rolled up works really well...also, try putting your vent fan on to blow some air back towards the window...others say it helps, I say it helps in a minimal kinda way...
 
nice maturity, there, fireman. haha. it's a single driver's side exit. stock location, afaik. i'd like to upgrade to duals at some point, so if i hit a huge uneven rut in the mud, one side may sink all the way, but i'd still have a pipe that wasn't underwater.

i do the front down, rear up, (no, not that, perverts. my windows!) most of the time, lately. it's less smelly and headache-inducing, but it causes more drag and it's more fun to have the back one down, too, brain damage aside.

my vent works better than the ac, but is wimpy. fixing that is on my to-do list. you know how it goes. i like the fan idea. i tried a small one up front to blow the stuff off of me, but i like the idea of blowing it back out better. maybe i can use some junkyard radiator fans or something. my dad is about to trade in his taurus in on a new car. maybe the dealership won't notice the missing radiator fan. :D
 
The problem is that there's a region of recirculating flow behind the Blazer. Think of it as an eddy in a river. Due to its box-like shape, a region of relatively strong low pressure develops behind (and inside) the vehicle, and air (and the mixed-in exhaust) very easily gets inside (pic A).

Opening the front and side windows would lessen this effect, but proabably not enough to totally eliminate the fumes. Don't know if your hardtop has opening side windows.

Removing the top would get rid of the fumes, as the aft recirculation region would stay below the level of the tailgate. But maybe it rains where you live.

A huge fan that added pressure behind the Blazer would work, but it would be a monster, and would have to draw air from somewhere.

You could add panels that extended aft and taper down from the sides, top and bottom of the Blazer, but you'd look like a retard. But you would also get better gas mileage.

A solution that might work and be easy enough would be to extend some sort of plate out horizontally from the top of the tailgate (pic B). It would prolly have to stick out a couple feet to work, though. Maybe you could put a sink in it and have a wet bar back there for tailgating.

If you're really bored you can check out this report on lowering drag of boxy vehicles, which has images of the recirculaiton region: eed.llnl.gov/aerodrag/pdf/aiaa_llnl_rm.pdf

I must be bored.
 

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The fans I have seen back on trie brace are just the 12 v school bus type (do they still have them). If I lower my rear window about 2 inches and open the vent wings and windows I am ok. But I am not in TEXAS...
 
as far as exiting behind the door, on a blazer, i don't think that's legal in texas, since it's not past the passenger compartment. it's fine for pickups, as long as it is behind the cab.

and maybe i should clarify the weather situation a little, since i just have "texas" on there. that could mean a lot of different environments. it's the dallas/fort worth area. not as bad a college station, where i was for a few years (105 and 80% humidity is rough). we've been in the low 100s for a long time, now, and very little rain, so i could pop more than i do. might be the way i go, short-term. too bad soft tops cost as much as my engine.
 
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1985_K5_Silverado said:
Perhaps that little roof wing (you see them installed in some of the old dealer brochure pics) would help.
Click to expand...
if you`re talking about the spoiler on the back of the cap, it doesnt do much
 
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