Anyone swapped a 2001 exhaust for a 1997 exhaust on an E350 PSD?

[Bikersmurf]

My 1997 E350 has a massive exhaust system with a CAT and a huge muffler. I picked up an exhaust from a 2001 E350. The 2001 system has a similar looking muffler but no CAT. I have no inspections to worry about, but wonder if there would be any performance advantage to one over the other.

2001 Powerstrokes are rated at 25 more hp and 50 ft/lbs more torque. Is some of this because of reduced back pressure? Would the newer exhaust be louder? Flow better? Produce better economy?

Would it be worthwhile to swap the newer exhaust in? It'd be a direct bolt in replacement.

 

[nely]

I removed my cat on my 1997 E350. Just had it cut out and a tube put in its place. I didn't notice any gains. No increase in power, no difference in EGT temps.

And as far as swapping the exhaust. I believe it will fit with a few modifications.

 

[Bikersmurf]

Interesting. So removing the CAT doesn't make much difference... Does anyone know if the mufflers are the same?

I haven't measured to be 100% sure, but the exhaust pipes appear to be the same, and they both are from E350 Crestline ambulances. The newer exhaust would likely bolt right on without any mods.

 

[landyachtcaptn]

My 99 psd RB van had no cat stock. The upgrade to 4" diamond eye exhaust definitely was an improvement. I recommend going to 4" if you are going to take the time to do the swap. I would think the way the diamond eye sections clamp together you could make it work for an ambo without modifying it if the frame length/ wheelbase is the same.

 

[nely]

Diamond eye makes the exhaust for 99 and up psd. I've read a little modifications makes them work on the the earlier years. But I'm not sure what it takes.

All I've seen that's specifically 1998 and older was hypermax cat back exhaust.

 

[Bikersmurf]

My 99 psd RB van had no cat stock. The upgrade to 4" diamond eye exhaust definitely was an improvement. I recommend going to 4" if you are going to take the time to do the swap. I would think the way the diamond eye sections clamp together you could make it work for an ambo without modifying it if the frame length/ wheelbase is the same.

What size of pipe was it originally?

I've already got 3.5"... It would have to be an impressive improvement to buy a new exhaust when I've got two complete stainless steel exhaust systems. I'm happy with the performance, but I wouldn't complain if there was an improvement in fuel economy.

 

[IdaSHO]

I removed my cat on my 1997 E350. Just had it cut out and a tube put in its place. I didn't notice any gains. No increase in power, no difference in EGT temps.

And as far as swapping the exhaust. I believe it will fit with a few modifications.

Must be a van thing.

Just putting in a cat delete on my '97 7.3 pickup dropped the egts under load by a good 200 degrees.


The biggest change came with a good aftermarket downpipe. That dropped the egts another 400 degrees under load and woke the motor up a LOT.

I dont think the E-series has the problematic OEM downpipe though. The pickup OEM downpipe is terrible.

 

[IdaSHO]

What size of pipe was it originally?

I'm happy with the performance, but I wouldn't complain if there was an improvement in fuel economy.

You wont see any noticeable change in fuel mileage.

The 7.3 cares more about RPM than anything.


Keep the revs below 2k rpm and you will see your best mileage.


Swapping to 3:55 gears was by far the best thing Ive done to mine.
I get an honest 17mpg highway with the camper loaded.

Prior to the gears (had 4;10s) it was 14mpg.

 

[nely]

It is a van thing. Our downpipe are already between 3 to 3.5 and fully round. The early PSD trucks had a smashed down pipe for body to engine clearance. Horrible pipe that's why you saw lower egt.

And I can second the gearing. My first van had 3.55 and I could pull 19mpg to Vegas all day 2wd. I didnt get to test it with the 4x stuff added.

My next van had 4.10. Holy crap, I thought my transmission wasnt shifting into od the revs where so high at 55. And that van gets consistently 15mpg.

From my research, the PSD likes 1900 rpm cruising speed.

Also if you feel your mpg is not as it should be, run a scan. I have a clogged exhaust back pressure sensor tube. It should up as an exhaust pressure sensor. Pulled it out and the tube is clogged shut. That's a common issue of low mpg in the PSD

 

[Bikersmurf]

Open highway 18mpg(US) @ 55, mostly city 14mpg(US)... It's running 4.11 gears, but at 55 RPMs are below 2K. Being an 8500 lb+ vehicle that's mostly driven below 50 mph, I don't foresee a payoff to a gear swap. It's a lot like driving a loaded truck (at the best of times).

I'm not too concerned about improving the economy, merely wanted to know if my spare exhaust would be better than what I've already got... Given it would be a direct bolt on with little cost.

 

[Bbasso]

On my E350 7.3PSD vans I've always had the muffler replaced with straight pipe. It does lower the ebp a tad and adds a 1 or 2 better mpg. But my vans never had a catalytic converter.
Since I've never pushed my vans hard or had them tuned I never bothered with egt.
since you have 2 exhausts, make a true straight pipe system.

 

[Bikersmurf]

Unfortunately, ours is a company vehicle, and we can't be pulling up to people's houses with a rig with straight pipes... Or leaving it running as a Powerstation with no mufflers. It is loud enough as it is with 10" of CAT and 30" of muffler.