Well, I just placed an order with Geno's garage, ordered me a 4/2 filter kit and a muffler elimiation kit. Going to be ordering an Aero 4040XL, put an offer in Ebay for $210.00 w/ free shipping, so we will see what happens. Plan is to removed the muffler and place the aero at the very begining of the elimiation pipe. Any requests to what info you want from what setup?

I am thinking of just putting the elimiation kit in, and driving it that way for a little bit, quarter to half a tank worth of driving. Then fill up, add the aero and try again. My truck is all stock, so it should give a good indication of what just the exhaust can do.

I am going to try and get sound clips of all three setups, stock, no muffler, and then aero. Will try to get in cab noise and outside noise. Then, write up what my thoughts are.

If there are any other suggestions of what info to get, just let me know and I will do my best.

 

if your going to do any kind of mileage test... pick a route that can keep you at hiway speeds for at least 25 miles 1 way... more would be better.

 

My route to work is 35 miles and all but 4 is freeway miles.So I should be able to do a pretty close comparison. Probably one week straight piped and one week with the aero. I drove the truck this week, so I should have a good idea of what stock will be for the route.

 

Let us also know about the bottom end torque results of both set-ups as I am also going to do one or the other.

 

im sailin in the same ship as sonny

 

You know, I may be a little confused and don't mean to get off topic, but I jsut don't see how removing the muffler or straight piping is hurting low end torque. TD's don't need backpressure like a gasser to assist scavenging, it hurts the spooling.

I know that too big or too open of an exhaust on a non-turbo'd gasser hurts it, because it doesn't scavenge properly and most exahust mod's here are only effective on the top end.

Here's what I'm "thinking" and I'd like to see dyno numbers as butt dyno's can be deceiving....

I don't think you're losing low end torque, just getting a bigger gain in the top end. HP / TQ gain is much easier felt than a loss is.

The mileage loss I can see, as you are getting more air flow.

I'm just having a hard time believing that increasinga TD'sefficiency would hurt power in any part of the RPM range.

 

I agree completely. With a turbo in the exhaust stream the only thing back presure will do is slow the turbo down. Also mathmatically you will gain more torque than horsepower on these trucks with anything you do (hp = (torque x RPM)/5252) because you don't want to rev them past 5,252 RPM.

I guess I should introduce myself. I picked up my new 06 2500 4X4 on monday and love it. You guys have a great forum here and I look forward to learning from you guys on how this oil burning stuff works.

 

cumminalong-

thats a great point and something I have wondered. I am newer to diesels in the fact I have never owned one and the same applies to the turbo. I was under the impression that the turbo creates however much back pressure it needs, and if it's too much, the wastegate opens. Since the turbo relies in part on the exhaust side of things, how would opening up the exhaust hurt.

Mine opinion on what is felt (supposed loss in low end) is hard to explain, but I will try my best. This is an odd analagy, but we'll try it anyways. It's like using a straw. Like today, the straw for my pop (thatsMN for soda) from Taco bell was smaller than the straw from McDonalds yesterday. Well, if you blow through the two straws the pressureyou feel in your head (motor)will be different. You will feel more pressure when blowing through the smaller straw asopposed to blowing through the larger straw. (the less pressure in you melon relates to the "loss" feeling inlow end.) While you are expending the same amount ofair, the larger starw (exhaust) allows that process to happen faster and easier.To try and relate that to exhaust goes like this....when you step on the throttle with restrictive exhaust, you can feel/sense the pressure on the motors based the noise of the motor and the feel of the pedal. When you step on it with a less restricitve exhaust, you don't feel/sense that pressure on the motor, thus thinking you lost your low end torque. When in (my) reality the motors making more power easier and as cummingalong said, getting you to the bigger gain on the top end faster.

I am working on finding a dyno place around herebecuase you've got me thinking nowabout what the actual numbers would be.

Well....thats my Socrates take on the whole thing. Not sure if it made sense or not, but my mind doesn't work in very complicated ways, hence the analogy to the straw.

Thanks for wasting the last 10 minutes of your life with me....Fell free to chime in with your thoughts, comments, or degrading remarks about my intelligence. It's ok, I can take it.

 

the wastegate opens up to slow the turbine impeller down so it doesnt over spin and sling the compressor apart. Diesel do need a little pack pressure, however not as much as gassers. The back pressure is there mainly to keep a little hot exhaustin the cylinders to assist is the conbustion of the next power stroke. However this mainly applies to start-up and cold operations. Once the engine warms up it doesnt need it, but it is there.

backpressure before the turbo only spins the turbo faster since the drive pressure is higher. backpressure after the turbo slows the turbo down.

 

That's a GREAT analogy chewy, but why then does everyone recomend AGAINST a 5" exhaust over a 4" if your theory is correct ??