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Discussion Starter #1
Ok, so i put a flowmaster super 10 series exhaust on my truck with a 3'' tailpipe. it hangs down a little lower than stock because of a problem with the hanger. Now ever since i replaced it, i get a crazy amount of fumes into the truck with the rear window down, is there anything i can do to fix this? maybe an exhaust tip that sticks out a little past the body?
 

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The stock exhaust exits behind out the side behind the rear wheels. Ford did that so the exhaust fumes wouldn't be sucked back in the rear window. If your exhaust is straight out the back, it WILL be sucked back in through the rear window.
 

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yo,
This is by Ford in 96 Owner's Guide;
Guarding Against Exhaust Fumes Carbon monoxide, although colorless and odorless, is present in exhaust fumes. Take precautions to avoid its dangerous effects.
"...Make sure your Bronco’s tailgate window is closed when your truck is running to prevent exhaust fumes from being drawn in. If you must have the tailgate window open, adjust your air control system to force outside air into the front of your truck. If your Bronco has outside air control vents, open them fully. Have the exhaust and body ventilation systems checked whenever:
your vehicle is raised for service
the sound of the exhaust system changes
your vehicle has been damaged in a collision

Improve your ventilation by keeping all air inlet vents clear of snow, leaves, and other debris.

If the engine is idling while you are stopped in an open area for long periods of time, open the windows at least one inch (2.5 cm). Also, adjust the heating or air conditioning to bring in outside air.
HEATING — Set fan speed at MEDIUM or HIGH, the function selector knob on VENT,
FLOOR, MIX, or the DEFROST symbol and the temperature control knob on any desired position.
AIR CONDITIONING — Set the fan speed at MEDIUM or HIGH, the function selector knob on NORM or VENT and the temperature control knob on any desired position..."

Also check;
rusted out floor pan
floor pan plugs missing; Many plugs and grommets are used in the floorpan and dash panel. The floorpan plugs seal the various access holes. If any plugs are missing or improperly installed, a dust or water leak may result. This also applies to the grommets used on the dash panel. When dust or water leaks are evident, these plugs and grommets should be checked for proper installation.

quarter panel wheelhouse inner panel rusted out into cargo area; seat & seat belt belt bolts missing with holes in pan;

Underbody Heat Deflectors bolt missing

Body Sealant deteriorated @;
floorpan
quarter wheelhouse inner panel and quarter wheelhouse outer panel
dash panel
running boards
door openings
roof side drip rail
Check weatherstrip @ floor pan where bottom of tailgate meets it; air, fumes and water can be sucked-in through a bad ws.

Liquid Butyl Sealer

Liquid Butyl Sealer C9AZ-19554-B (Black) or equivalent meeting Ford specification ESB-M4G162-A does not run, is fast drying, and remains semi-elastic. The sealer can be used for seam sealing in such areas as the floorpan, wheelhouse, dash panel, running board, door openings and drip rails. It can also be used to seal outside moulding clip holes, and for windshield and rear window installation.


Caulking Cord

Caulking Cord D6AZ-19560-A or equivalent meeting Ford specification ESB-M4G32-A has a plastic base with a filler, is heavy bodied, and is commonly known as perma-gum. It is used on spot-weld holes, around mounting clips and between two surfaces not sealed by a gasket.


Weatherstrip Adhesive

Weatherstrip Adhesive E8AZ-19552-A or equivalent meeting Ford specification ESB-M2G14-A is a quick-drying, strong adhesive designed to hold weatherstripping to doors, bodies, cowl ventilators and the surrounding metal. Windows and windshields that are set in rubber can be effectively sealed against leakage by flowing adhesive into affected areas.

Clean all grease, dirt and old sealer from surfaces, and wash the surfaces thoroughly with a cloth moistened with a suitable commercial cleaner. For best results, apply a medium coat of adhesive to both surfaces, allow it to dry until tacky and then press both surfaces firmly together.


Silicone Lubricant

Silicone Lubricant C0AZ-19553-AA (jelly) or equivalent meeting Ford specification ESR-M13P4-A is to be used on the door and window weatherstrips. It is recommended that silicone lubricant be applied to the weatherstrips at every lubrication period. Its use makes the doors easier to close, avoids weatherstrip squeaks, retards weatherstrip wear due to chafing between the door glass upper frame and the weatherstrip, and helps to retain door window alignment by reducing friction between the glass frame and rubber weatherstrip.

Dust and Water Leaks
After trim removal has revealed the location of leaks, seal these leaks, and road test the vehicle on a dusty road to make sure all leaks are sealed. Dust entry is usually indicated by a pointed shaft of dust or silt at the point of entrance. After the road test, check for indications of a dust pattern around the door openings, cowl panel, and cowl side panel.

Sometimes leaks can be located by putting bright lights under the vehicle, with the above components removed, and checking the interior of the body at joints and weld lines. The light will show through where leaks exist
 

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Discussion Starter #5
I used the 15003 tailpipe from magnaflow, it exits right behind the rear tire on a 90 degree angle, like the 92-96 stock style tailpipe
 

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I have the same problem.My tail pipe is behind my rear tire and I get fumes as soon as I start to drive. Removing the roof seems to stop it well.lol
I have been considering a spoiler or something to direct the air flow down past the rear window but no one has ever said whether or not they actually work.Some here have the stock spoilers and I wonder if they ever get fumes in the back window while driving with it down.
 

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I have the same problem.My tail pipe is behind my rear tire and I get fumes as soon as I start to drive. Removing the roof seems to stop it well.lol
I have been considering a spoiler or something to direct the air flow down past the rear window but no one has ever said whether or not they actually work.Some here have the stock spoilers and I wonder if they ever get fumes in the back window while driving with it down.
yo Northernguy,
I had the EGR spolier mounted on camper top and it didn't help one bit.
 

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I have them dumping out the back side behind tires and i don't get any fumes. But i have 7" of lift. Would that matter?
yo,
Probably due to aerodyanmics;
let's se if we can get it into Roush's wind tunnel... prob not though; they would charge too much.
Here is an interesting article on Drag Reduction on SUVs and Trucks by Wake Control
excerpt; "...Road vehicles such as SUVs or pickup trucks are described as bluff bodies. When the air flow passes over the road vehicles the flow will separate at the rear of the vehicle, forming a large low pressure turbulent wake region behind the vehicle..."

This large low pressure area is the fume issue



\ an \ article on Fundamental investigation of road vehicle aerodynamics
excerpt; "...An interesting feature of the flow is the strong downwash in the
symmetry plane of the model, which inhibits theformation of a mean recirculating region behind the tailgate..."

I know that F1 cars created more downforce by using a blown diffuser that diverted fumes to the aerodynamic undercar diffuser, but all that was banned for this year, so further R&D is shot.


Ford has done a lot for the Focus http://social.ford.com/our-articles/suvs/explorer/fuel-economy-secrets-how-ford-does-it/
 

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The further you get it away the better. You need to have it angled downward a little bit so the exhaust is forced down. By the time it curves back up your either past, when driving, or it rises up away from the vehicle enough to go up and over instead of into the windows when parked. The stock one sticks out further on top and is cut away at an angle on the bottom, not a straight vertical cut. It only sticks out a few inches past the lower rocker panel behind the (RR) back tire! :thumbup -Kevin-
 

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let me put it this way. years ago when I bought my rig it had stock exhaust, the first thing I did was have it removed and replaced with duals routed out at an angle from the rear bumper..rear window down and it would suck fumes in the cab..had them removed and re-run to come straight out the back..what a mistake..it was even worse..finally went back to the stock configuration, with a single outlet just after the rear tire and I don't have any problems, and I run a soft top all year long..

particularly with duals (at least in my experience) and the rear window down you get an even more pronounced venturi effect that draws the fumes back into the vehicle..
 

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So it seems the way to go is have them run out and dump in front of the rear tires right? I am planning on getting mine run soon and sure am glad I saw this or they would have been straight out the back!
 

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The further you get it away the better. You need to have it angled downward a little bit so the exhaust is forced down. By the time it curves back up your either past, when driving, or it rises up away from the vehicle enough to go up and over instead of into the windows when parked. The stock one sticks out further on top and is cut away at an angle on the bottom, not a straight vertical cut. It only sticks out a few inches past the lower rocker panel behind the (RR) back tire! :thumbup -Kevin-
I have been thinking about putting an angle on my tail pipe as well to see what happen.

I had the stock exhaust and never really had a problem then i changed my exhaust to 3" a nd it was fine when i first put it on, i could smell it a little more but not bad. Now i smell it coming in my passenger window, going to have to check for another leak somewhere,
 

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Side step it
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So it seems the way to go is have them run out and dump in front of the rear tires right? I am planning on getting mine run soon and sure am glad I saw this or they would have been straight out the back!
No, behind the rear tire, about even between the end of the bumper and the back of the tire. The pipe is at more of a 45 deg angle at the bend than a 90 deg one and the Chrome tip is slightly pointing down. If another truck was parked next to you, your tip would be pointing at the end of his bumper instead of directly between the tire and the bumper. Your tip comes out between the two but points slightly backwards so the exhaust will go "out & down" and "curve around" the back of your truck before it starts to rise and go into your side windows (if they're taken out) or get "sucked into" the tailgate one if it's down.....:thumbup -Kevin-
 

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No, behind the rear tire, about even between the end of the bumper and the back of the tire. The pipe is at more of a 45 deg angle at the bend than a 90 deg one and the Chrome tip is slightly pointing down. If another truck was parked next to you, your tip would be pointing at the end of his bumper instead of directly between the tire and the bumper. Your tip comes out between the two but points slightly backwards so the exhaust will go "out & down" and "curve around" the back of your truck before it starts to rise and go into your side windows (if they're taken out) or get "sucked into" the tailgate one if it's down.....:thumbup -Kevin-
Great Tip!
Thanks
 

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Discussion Starter #20
My exhaust is pointing a little bit upwards because the dumbass mechanic clamped it like that, that could be the cause of the fumes?
 
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