PIU struts/shocks

Go take it apart and measure then. Or…just measure axle center to fender on both. And no…I’m not scrolling through years of a FB group to hunt something down.
There’s also no proof the PIU shocks and struts are more dampened than the ST versions. There’s talk…and rumors…but there’s no actual proof.
There’s also multiple ground clearances advertised for the PIU depending on engine choice…as high as 7.6”…there’s most of your difference in tire height.

When I picked up the PIU rear bar and shocks, I cross-referenced my ST springs and their codes came up as the same for a PIU. As mentioned, the ride height difference is most likely weight and tires. I still say the dampers are stiffer per SOTP feel, but again, no hard data. Either way, the shocks go great with the thicker rear bar, and there’s most likely a reason for it.

Why would the GVWR be different between the PIU and ST then?

What's the weight difference between the 3.0L EB PIU and ST?

I assume something to do with its structural reinforcement vs the ST.

Unlikely. In fact, given the same/unchanged spring rate, additional structural reinforcement would increase the curb weight of the vehicle and, therefore, decrease payload. It will probably make the vehicle handle better as the chassis would deflect less under dynamic load.

Structural changes shouldn't yield minor changes in GVWR. And I say this because the chassis shouldn't be a mode of failure. Structural changes should yield significant changes in GVWR if it was chassis limited. Most cases, minor differences in the same model but different trim/package are a result of spring rate differences. For example, the F150 was sold in different configuration options such as Max Tow versus HDPP. The difference in GVWR is largely due to the difference in the rear leaf pack. Same thing with the SRW F250 vs SRW F350. The difference in GVWR is due to the additional leaf in the rear leaf pack but structurally, the trucks are basically the same.

So some additional considerations. Look at all the different GVWRs for each PIU powertrain variant:



I'm willing to wager there are no significant structural changes between each PIU variant and that these minor differences are a result of different springs / spring rates. They will use higher spring rate coils in heavier variants to preserve the payload capacity of 1,670lbs which is advertised for all PIU variants.

https://www.autoblog.com/buy/2024-Ford-Explorer-ST__4dr_4x4/specs/
The ST appears to have a payload capacity of ~1,459 lbs (6,160 lbs GVWR - 4,701 lbs curb weight). I would expect a PIU to be rated with a slightly higher payload capacity compared to a ST.

There sure are a heck of a bunch of spring combinations:

https://www.oemfordpart.com/v-2022-...3-0l-v6-gas/suspension--shocks-and-components

This makes me wonder... hypothetically... is it possible the PIU spring for the lightest PIU variant with the lowest GVWR and the highest ground clearance - the 3.3L DI V6 - is also used on the ST? If this was the case, then it would appear to someone, "Oh, the part number of my coil spring on my ST is the same as one of the PIU variants."

Now that I think about it, I think the PIUs that the State Police use seem to be lower than the ones the Police Departments that cover more urban areas. I wouldn't be surprised if urban Police Departments purchase the 3.3L DI V6 variant because they may not have the same performance requirements as the State Police that primarily works the highways.

So moral of the story. For right now better to just swap the rear shocks and front struts along with rear sway bar. And leave everything else as is….given the lack of preponderance of evidence for new springs?

I want to revisit this while referencing some of the things I suggested in Post #90.

What you are saying may be true, but I'm curious if the ST uses the same/similar springs as the 3.3L DI V6 PIU variant which, coincidentally, has the lowest GVWR and highest ground clearance of all the PIU variants.

I think the issue is that we don't know, for sure, which spring part number goes with which PIU variant at this point.

Some people may correctly claim that the ST spring part numbers match ONE of the PIU variants, but I don't think anyone can say with certainty which PIU variant.

And there are a heck of a lot of part numbers for coil springs that are labeled "PIU":
https://www.oemfordpart.com/v-2022-...3-0l-v6-gas/suspension--shocks-and-components

The “structural reinforcement” is the cross brace that takes place of the 3rd row seat and all of its accompanying trim. The seat weighs more than the brace.

Interesting. I wonder how much these weigh.

"Ballistic door panels – Level III+ Power passenger seat (8-way) with no-charge option(heavy-duty)
aftermarket consoles and Level IV+"

The primary purpose of this is more protection for a rear impact I would presume.

Level III+ rated body armor should be soft panels so they won’t weigh a lot. Maybe 10-15 lbs per door at most?

I can’t see most police departments outfitting most of their PIUs with Level IV armor.

The 3rd row seat frame acts as a structural member. The PIU loses that seat so they replace it with the cross brace that bolts into the same spots as the 3rd row and a couple of other spots further forward. It does increase the rear impact protection.

You’d have to find one and get the spring codes off the VIN label to know.

PD gear would do it.

The 3.0L Ecoboost PIU is the highest performing PIU variant. If you want to duplicate the suspension, try to get a VIN# from one and ask a dealer to search for the parts. Supposedly, even the drivetrain mounts are heavy duty.

Probably true. Maybe different crumple zones add more weight.

I would imagine this would be accessories installed after the fact. Of course the PIU having a higher GVWR (and payload capacity) is Ford engineering anticipating that the PIU would need to carry additional gear than a retail Explorer.

But not all PIUs are outfitted with a lot of gear. A lot of ours were purchased due to cost and are used for investigative purposes rather than for reactive responses or working the road.

Armor from factory is approx 40 lbs per door, aftermarket external mounted soft armor about 20 lbs

what is the part number for PIU sway bar and what’s needed to change?

If you’re gonna do a RSB…and you definitely should…just do the Steeda or AFe or whatever. These cars like a lot of rear bar and any of the aftermarket options will net you better results than the still smallish PIU bar.