I can't fully understand why people in cold climates get rid of their Exhaust Backpressure Valves. I understand there is the desire to increase exhaust flow and simplify maintenance on the truck, but this one seems short-sighted to me... unless I'm missing something.

It was 7 degrees F yesterday, and I fired Stinky up for the first time since last Saturday (Stinky's all "Woohoo! Road trip!"-n-stuff). He wasn't plugged in, he was just shivering under an inch of fresh powder in the snot-freezing cold. I cycled the glow plugs twice for safety and Started Stinky right up in Warm-up tune. A few seconds pass and the tach shows about 900 RPM, the Exhaust Back Pressure gauge is swung to the right, The EGTs bounce to 400 degrees F and eventually reach 500 degrees F while idling (normal EGTs at idle when warm is 200-300 F... sensor on manifold). My Engine Oil Temp started climbing quickly. Between the Oil cooler and the coolant's close proximity to the exhaust temperatures, the coolant warms for defrost to work in a few minutes.

Have you ever walked in out of the cold while somebody was baking or oven-broiling? You want to be the first to offer to open the oven for them when needed. Well, the EBPV is like the oven "preheat" ****. It gets the engine to operating temperature much faster, as well as the coolant- which heats the cabin and makes the defroster... well... defrost sooner. These are all good things.

Engine braking is managed in custom tunes with the EBPV, you just need a transmission equipped to handle this. Braking down a hill while towing... without wearing down the pads/rotors? Have you priced the rear brakes on these rigs? This is a good thing on so many levels.

I mentioned my warm-up tune - I have a use for it that is not as common: That backpressure puts an artificial load on the engine. I have discovered many hidden secrets about the engine that would never reveal themselves, were it not for a little load on the engine while I'm under the hood. I officially declare this another good thing.

With all the good the EBPV does... particularly in cold climates near the mountains - I can't help but point this out before the next driver deletes this delightful device... or a brother backs this behavior by a buddy in Bismark.

 

I got rid of mine because I did the math, and it takes up a full 21% of the cross-sectional area of the exhaust outlet. It also must create a massive amount of turbulence, and turbulence causes more drag. The truck could have been ordered from Ford without it, so it isn't required or necessary. Mine had never closed regardless of the temperature, and I get heat within a couple miles anyhow.

As far as using it as an engine retarder goes, if the backpressure exceeds 40 psi or so, you can start lifting exhaust valves on adjacent cylinders, even if the springs aren't weak. That introduces the possibility of piston-valve contact. So, as far as I'm concerned, its disadvantages outweigh its advantages.

If it had been designed better, with less restriction, I may not have gone to the trouble of removing it. I'd probably still not use it as a retarder though unless there was a way to modulate it based on exhaust backpressure readings.

 

I Miss mine. I use my truck everyday, and the days I don't let it warm up enough I'm shivering down the road in a frozen truck for a few miles. I'll be glad when I get to fix it.

 

As for me I deleted the EBPV in both our F-250 and Excursion. The F-250 (mostly used for towing) has the van turbo so no EBPV. I removed it and the AIH for the same reasons as Pikachu - remove the restriction & lower EGT's. But I did this when we lived in SE Oklahoma (Fort Sill) and wasn't too concerned about cold weather.

When I bought the Excursion I planned to either install the Van turbo or the H2E - so the EBPV went by-by as well.

To add some info to the use of the EBPV as a exhaust brake:

Some tuners won't offer a decel tune because of the same reasons as Pikachu posted. Here is what PHP has on their website (FAQ section)........

Do you offer a "decel" or "exhaust brake" calibration?
"Simply put, no, we don't because it goes against our business philosophy which, in part, is to provide safe, reliable products to our customers.

For those who don't know, this is a calibration that uses the EBV (Exhaust Backpressure Valve) as a makeshift exhaust brake. While this setup may work reasonably well for lightly loaded vehicles, we generally do not recommend this type of calibration... at least not for automatic transmission vehicles. There are a few reasons we don't recommend this.

First, in order to transfer the energy of the moving vehicle to the engine during deceleration, two things must occur: the torque converter must remain locked, and the coast clutch must be engaged. The problem with this is that the coast clutch on a stock transmission only has 3 friction plates, and these are smaller than the standard forward clutches. On 2001 and later transmissions, you also run the possibility of damaging the intermediate sprag or "diode," which will result in an immediate transmission teardown. Again, lightly loaded vehicles would have less of a problem with this, but the general idea of an exhaust brake is to be able to slow larger loads without overheating the standard brake system. It is these types of loads that can cause transmission damage. Obviously, a manual transmission would be free from these types of situations.

Second, whenever you increase exhaust backpressure, you need to make sure that the exhaust valve springs are capable of preventing the pressure in the exhaust system from lifting the exhaust valve from the valve seat, as this would result in a collision with the piston. Normal valve spring seat pressure is 70-75 PSI for NEW valve springs and deteriorates from there. Given that the surface area of the back of the exhaust valve is approximately 1.9 square inches, it would take only 40 PSI of exhaust pressure to lift the valve off the seat, even with new valve springs.

To put it simply, if you plan to use an exhaust brake, either through the use of the EBV or by purchasing an aftermarket stand alone unit, you will need to consider the condition of your transmission and exhaust valve springs in order to ensure safe, reliable operation."

So instead I have a tow tune that automatically keeps the TC locked down to 30-35 mph and automatically downshifts from OD to 3rd at 45 mph. Much better than using the brakes alone.

 

Here's some more info from Jacobs themselves:

 

Interesting...I wonder why my never overheated transmission failed on me at less than 150,000 miles...

As for thr EBPV I love having it. It warms the truck quicker. I like that on these cold mornings.

Rich, DP highly discourages the use of high idle immediately at start up. They say too much wear and tear when the oil is cold like that. Jody says wait a minute or two before engaging it. FWIW...

 

Mine was deleted before I bought the truck. I'm looking to put it back on. I'm also considering putting the AIH back in during the winter months. I run in stock tune during the winter because it is much safer on icey roads.
Temps here have been -20 for the last couple of days. I have seen -40.

 

Is this what we are talking about?

(Images stolen from ToMango07 without permission.)

The reason I ask is because I also have a van turbo and I have one.

 

I won't consider removing it given the fact I'm in cold climates and temps are below freezing from End of October thorugh March.......anything that helps warm the beast warm up quicker for me is a good thing.

Tugly, I assume your warm up tune is similar to the stock high idle mode right? What is different?

The comment a few posts back by Pikachu about the EBPV taking up 21% of the exhaust diameter........doesn't that change with a wider exhaust? I'm not sure exactly where along the line the EBPV is located so I don't know if a 4" vs. 5" exhaust would make a difference.

 

The factory programming has the engine idle for some amount of time before the high idle kicks in...whereas any of the high idle tunes jump immediately to the high idle without regard for any of the factory parameters.

 

 

I'm no expert but from the looks of the exhaust valve in the picture above, I don't think there is any way that it takes up 21% when the engine has warmed up. It may take up 21% when partially closed during the warming process of the engine, but that's what it's supposed to do.

This may be way off, comparing gasoline engines to diesel engines but a friend of mine is a professional engine builder and his specialty is boat racing engines. He builds engines to run in the 6,000 to 8,000 RPM range. When he was rebuilding my 1994 bronco engine he told me not to waste the money on headers unless I was planning on running the engine over 3,000 RPM constantly. He said there was not enough benefit under 3000 RPM to make it worth it. Well, this is gasoline engines but our diesel are low RPM, high torque engine. I wonder how much difference it makes unless you are making a racing engine out of your 7.3?

 

Back in Houston I wanted to dump it. Now that we live in northern Colorado, no way in heck would I live without it. I also agree the restriction in most cases just isn't enough to worry about. 1500-3 thousand rpm is easily 90% (if not more) of the range my truck sees.

 

With the new to me 96 I had forgotten about the EBP system as I had removed it off my other trucks long ago. IMO the incremental difference between having and not for cool weather operation is not worth the long term cost to maintain this gimmick feature. And considering year round operation I can hardly wait to yank it out of the 96. I will say with my first Powestroke I wired it up as a brake hooked to the fuel peddle with an override and as that truck had a ZF it worked ok and did in fact save brakes in the long term.
In terms of chilly/ hot weather here I can see -40 C to +40 C or (-40 F + 105 F).

Soon as I get the 97 up and running the '96 EBP system is gettin it. Looking forward to seeing the up tick in spool and cooler EGTs as I think there is some iirc.

jrc

 

Yes that is the valve, and van turbo's in vans do have them, its when you use them in a truck you have to use an outlet adapter, that they are eliminated since the exhaust size is larger on the trucks.