91.5CTDBanks

OK, I have figured out what mods I want on the truck for a while. I will have my gauges in soon. Right now I just want throttle responce and fuel economy. So I think 4" exhaust and a hard pipe from the filter to the turbo. Do I need to mod the air can? I have a new air filter in. As for the turbo, I have a 9cm housing or a complete hx35w with the 12 cm housing. What will be the best for the auto transmission? thanks

wannadiesel

The "Airflo" intake duct won't do anything for fuel economy, the stock duct is not a restriction. I (and many others) ditched the stock duct only because it kept popping off the BHAF. Some guys have "swiss cheesed" the air box. I'm not sure this is helpful from an HP standpoint, but fuel economy always gets better with warm air to the engine.

4" exhaust will help highway mileage slightly.

You don't have a 9 cm housing that fits your turbo. It's either some other size or for an HY-35.

The HX-35W will improve spoolup, and possibly in town mileage. Mileage at high speed (over 75 mph) will suffer. Depending on what you use the truck to do, this may or may not be a good idea.

The 18.5 and 16 cm housings work pretty well with the stock automatic. The torque converter doesn't let the motor lug down enough to let the 12 and 14 cm housings really shine. If high speed cruising is important, the bigger housings are a better choice.

Here's what you need to do for mileage improvement: advance the timing. The standard 1/8" bump will be fine. There's info on how to do this in the sticky.

For better throttle response, a 3200 RPM spring is without any doubt the way to go. Again, the sticky will show you how it's done.

james1

Dave:
Thanks, as always, for the wonderful advice. I never cease to be amazed.

Tell me why the bump in timing improves fuel mileage and does one lose anything by advancing the timing?

Happy Holidays!

wannadiesel

Advancing the timing increases the cylinder pressure, making the engine more efficient. Obviously you can got too far, but 1/8" advanced from stock usually works well.

You lose a little bottom end and gain a little top end.

91.5CTDBanks

As for exhaust, I have the Banks kit which is 3" to the muffler and 3.5" out to the end. Just putting a test pipe in it's place be good for my minor upgrades?

wannadiesel

Sure. The main problem with the stock exhaust is the crimp over the axle.

If you want it quiet there's nothing wrong with leaving the muffler.

91.5CTDBanks

Well, I don't want it quite now, and the bank's is a full mandrel bend over the axle.

dodgenstein

The Banks piping is good for a mildly bombed truck, but the muffler is a big restriction. When I had a Banks kit on my dually, I removed the muffler and gained 2-3 lbs of boost. I didn't like the harshness of the straight pipe, and put on a Dynomax bullet muffler. No raspiness, and no loss of boost. I have since gone larger to cool my EGT's. Beware of that first step down the bombing slope, it gets steeper and slicker very quickly!!!

91.5CTDBanks

Yea, your right about that. I have been working on my Talon now for 5 years. I can see that happening now with the Dodge......