Ok i've been trying to decide what type of exhaust i want. Ground clearance isnt an issue as long as it can clear under normal driving on the road. I can't think of any time that i have ever gone over a speed bump.

Anyway i am planning on true duals, and i want to run the side pipe from the X, down the rocker and have the pipe directly even with the tire so that all of the exhaust empties out directly onto the rear tires. My drag radials hook extremely well when they are hot and i can only imagine this helping.

The piping being used will be 3". Do you know if i can directly attach bullets to pacesetter LTs, is there enough room between the body and the piping? The one concern would be if i blew my engine, oil or coolant being spray onto the tires and causing me to lose control. i am pretty sure that a dangerous ammount of oil and coolant would not reach my tires, and if it did, it wouldnt instantly lose control. i am not too sure though.

Does anyone see this as being a benifit? The hotter the tires run, the more grip they give, the longer they last right? I have 315 Nitto 555rs. It's about 20 degrees outside, and they wont grip for nothin. If it's 70 degrees out, there is no breaking them loose. I will be running an LE2 here shortly, so i will need the extra traction. i've never heard of this being done so i am going to try it. Just looking on some input. If it doesnt work out, i can always just put turn outs right before the rear wheels. I think it would help though. what do you all think?

 

One of the main products of combustion is water, so you'd be dumping water in the form of steam and some liquid water onto the tires. That sounds like a built-in burnout box to me. Perhaps that's why you don't see it done very often.

Yep, tire traction is sensitive to ambient temp. One of the things that makes "all season" tires work isn't just tread pattern for snow, it's that the rubber compound works in a large temperature range. Sticky street tires don't grip when the temps approach freezing, even on dry pavement. There's no free lunch.

 

id also want to know what the effect of the carbon monoxide dumping on to the tires would have on the chemicals in the tire and the rubber compound.

 

That's exactly what i was wondering. The water thing i had completely forgotten about though.You dont think that the pipe would run hot enough not to have water vapor? Of that it wouldnt evaporate before it reaches the tires? I really don't know, i was hoping you experts could help me out.

 

Click on link in my sig to see if this is the exhaust your talking about.I have had no problems and it sounds great.

 

Consider not only the heat, but the unburnt fuel and oil on your tires. Not good for rubber.

 

personally i wouldnt do it. the pipe wont get hot enough to get rid of the condensation,if the head gasket lets go,there is that scenario,the hotter the tire stays,the more it will wear with a specialty drag radial.

 

The water vapor is ALWAYS present in the exhaust.... doesn't matter if its hot. When the water vapor in the exhaust hits the cold air and the cold tires, it condenses. Throw in the liquid that condenses into puddles in the exhaust when you shut down, mixes with the carbon and unburned hydrocarbons from the pipes, forms a nice sludgy slime and blows out the exhaust at high flow conditions. When your producing max HP/torque, your engine runs at a richer A/F ratio, and the percentage of unburned hydrocarbons goes up dramatically. It's going to coat the tires.

Sounds like a recipe for disaster......

Also not sure about "The hotter the tires run.... the longer they last right?". The hotter they get the softer they get = increased grip and increased wear.

The long term affects of coating the tires with hydrocarbons would probably be another serious negative.

 

Exactly. I was trying to be nice about it.

As long as you are dumping the exhaust just in front of the rear wheels, how about turning it up at a 45 degree angle like the Top Fuel and Funny Car guys do to use the exhaust to create downforce on the tires. Of course, there's probably more exhaust volume and velocity on a 7000 hp engine, but every little bit helps.

So how much downforce would a 500 fwhp engine generate this way? You thermo and physics majors should be able to whip this out (no, not that!) easily. If you get stumped, ask Fred.

 

So i guess i will just turn i out before the rear wheels. Everyone has said not to do this, but one did say i shoudl try it and see what happens. You never know. I do remember the sludge now that you mention is. And it probably wouldnt be good to empty unburnt fuel onto the tires. I was thinking hot tires wear less because they spin less. Right now i break loose in 2nd, but thats because it's so cold. I'm sure that has got to be wearing alot of the tires away.

SDAKOVIC, yes thats exactly what i wanted to do. Is this your daily driver? Is there any ground clearance issues while on the road? Did you notice any increase in traction, or change in exhaust sound because of emptying on rubber?

 

I got a cutout on my i pipe right under the rear seat pointing straight at my tire. I didnt even think it was a problem. I've had it uncapped for a week or two now. Should i worry about it or not?

 

In addition to what's been well explained here, there are two more reasons you don't see side exit exhaust ahead of the rear wheels on production vehicles: Wheel corrosion and brake icing. The contaminants in exhaust happen to be pretty corrosive and over time cause pits in the the surface of the wheels exposed to the exhaust. Ford tried an early exit exhaust on their '96 trucks and shortly after production started, they issued a TSB on wheel corrosion. The fix was a new wheel and a new, rear exit exhaust. Brake icing occurs in cold climates and can be a problem in extreme conditions. Granted, most will never see this problem, but the OEMs engineer vehicles to take some extremes and they figured this problem out years ago.

 

My wheels have $4 of paint from wal-mart on them. I run 315s so I'm not sure that the exhaust would even hit the rim. I still think it would empty on the tires. I'll do turn outs cut flush with the body, and see how it works out.

 

what series flowmasters did you use?
im getting ready to swap out my dynomax bullets for some and trying to figure out what i want.
yours look pretty low profile... are they the delta force race mufflers?

 

Flow master 40 series 943043.