Shock/spring suggestions - CrownVic police an option?

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kdv

New member
I know I'm not going to make friends by saying this, but I don't really care about the Lincoln ride, would prefer a stiffer more responsive ride for my '09 TownCar Signature; which still has functioning air suspension in the rear.

The shocks are pretty soft, with almost 200k miles on probably original shocks.

Would really like to put struts from a Crown Vic police interceptor in, have KYB 551602 struts picked out for the front, and KYB 555603 for the rear.

But will they physically bolt in? I'm assuming so, but want to confirm.

Or if there are better alternatives?
 

Brian J. Patterson

Well-known member
446
328
63
Northern Illinois
I know I'm not going to make friends by saying this, but I don't really care about the Lincoln ride, would prefer a stiffer more responsive ride for my '09 TownCar Signature; which still has functioning air suspension in the rear.

The shocks are pretty soft, with almost 200k miles on probably original shocks.

Would really like to put struts from a Crown Vic police interceptor in, have KYB 551602 struts picked out for the front, and KYB 555603 for the rear.

But will they physically bolt in? I'm assuming so, but want to confirm.

Or if there are better alternatives?

Hi, kdv.

The panther chassis does not use struts in the rear. The springs and shocks are still separate units.

The KYB 551602 front strut is only the "strut core," and does not include any spring.

In both cases, you will need the Crown Vic P71 springs, and also (at least to start) the P71 front and rear anti-sway bars.

According to Summit Racing's fitting advice, these shocks/strut cores are not recommended on non-police/taxi panthers due to the difference in ride height between the P71 and non-P71 panther chassis. Since you basically intend to convert your front and rear suspension almost completely to the Crown Vic P71, this may not be a problem for you.

If you go with these KYB units, the rears will need a separate "installation kit" with the nuts and bolts to actually install them, and the front units might, too.

Good luck.
 

kdv

New member
Thanks for the reply Brian, and the tips about the installation kit. Figured the stuff 'should' just bolt in, being *almost* the same car, but have had issues with Lincoln's in the past that aren't quite the same as the Ford they're based on. And yes, knew the fronts were struts - but still a shock. Not sure how best to describe them lol.

Question about the front springs, could one reuse the factory TownCar spring on the CVPI strut? Also why the need for the CVPI sway bars when doing a strut/shock/spring upgrade? Is it a ride height issue? Even though I'd love to have them for the lateral stiffness in turns/curves. I've been looking at RockAuto for info on what's available, but will also check out SummitRacing.

Am starting to wonder though, if it's 'worth' doing the CVPI stuff - when all I really want is something stiffer, am operating under the assumption that the CVPI stuff is the best bang for the buck.
 

Brian J. Patterson

Well-known member
446
328
63
Northern Illinois
Thanks for the reply Brian, and the tips about the installation kit. Figured the stuff 'should' just bolt in, being *almost* the same car, but have had issues with Lincoln's in the past that aren't quite the same as the Ford they're based on. And yes, knew the fronts were struts - but still a shock. Not sure how best to describe them lol.

Question about the front springs, could one reuse the factory TownCar spring on the CVPI strut? Also why the need for the CVPI sway bars when doing a strut/shock/spring upgrade? Is it a ride height issue? Even though I'd love to have them for the lateral stiffness in turns/curves. I've been looking at RockAuto for info on what's available, but will also check out SummitRacing.

Am starting to wonder though, if it's 'worth' doing the CVPI stuff - when all I really want is something stiffer, am operating under the assumption that the CVPI stuff is the best bang for the buck.

Hi, kdv.

I'm guessing that you're trying for improved handling with a minimum loss of "smooth" ride on the straightaways or when driving over rough roads.

Using the "soft" Lincoln springs with the CVPI cartridges might give you a harsh ride with little to no improvement in handling. While stiffer shocks alone can improve handling, there are limits which I think the CVPI cartridges might easily exceed. If you exceed those limits by a big enough margin, your car will actually handle worse as well as having a crappy ride. While it usually isn't unsafe to drive a car with "too much" shock absorber, it's more or less a waste of money.

The CVPI anti-sway bars are mostly to keep the car from leaning excessively when going through curves at speed. The more the car leans in a curve, the closer the car is to losing traction, not to mention the unsettling effect of all of that leaning on the driver.

If you went "all CVPI," your "end product" would handle similar to, but not identical to the CVPI or Mercury Marauder because of your minimum 5" longer wheelbase. But while the CVPI handles better at speed than the Lincoln Town Car, it still isn't necessarily the end-all-be-all in handling for a 5-6 passenger sedan. So, you need to figure out what changes you want in your handling, and then figure out and decide how to get those changes.

You can do a "plus one" or "plus two" tire and wheel change, along with getting more performance oriented tires in the new size. That means to switch from the standard rim diameter to a diameter either one inch or two inches larger, while reducing the aspect ratio of the tires you fit so the tire and wheel set is the same circumference (or very nearly so) to the factory-fitted tire and wheel sets. The lower aspect ratio tires will have less "give" in them, improving cornering and stability at the expense of some increased ride harshness. Since the circumfrence of the tire and wheel sets will basically be unchanged, your speedometer and odometer will still display your actual speed and miles traveled, etc.

You can also increase the width of the "new" rims slightly over factory-fitment. This will give you a larger contact-patch to the ground, and further reduce the aspect ratio of the tires, providing you stay within the factory-fitted tire circumference.

Unless you want to modify your fenders or fender tubs, you have to be careful, and will likely only be able to increase the rim width by an inch or so. If you can, you will also want to spread the width increase evenly between the outside and the inside of the rim due to steering geometry issues. But if you can get that inch without a torch, you'd be surprised what a difference it can make.

You can move the battery to the trunk to improve weight distribution, since having even weight distribution tends to reduce understeer.

Weight reduction on the Town Car isn't really practical, since Lincoln already reduced weight wherever they could for fuel economy. If you don't mind increasing weight, you can have cast and bolt lead weights to the center chassis rails to lower the center of gravity, and improve your cornering ability. Why should Teslas have all the fun.

75-100 lbs, properly distributed along the length of each chassis rail would make a major difference. Mind you, you would "lose" 150-200 pounds of passenger or baggage capacity. However, by having that weight on the frame rails under the passenger compartment, three inches below the center-line of the axles, you would flatten your cornering out a fair amount.

Likewise, running the Town Car front anti-sway bar with a CVPI rear anti-sway bar would greatly reduce understeer, perhaps bringing you close to oversteer.
To "over-simplify," understeer means if you lose control of the car, the front end leaves the road first, where with oversteer has the rear end leaving first. So, the "ideal" goal for a performance-handling car is to have the car handle neutrally as much as possible.

American market non-sports cars are designed to heavily bias towards understeer, since such a car will tend to keep inexperienced or inattentive drivers from "getting into trouble." Witness multiple models of Porsche or the Chevrolet Corvair, both of which had much more neutral steering that could "snap" into oversteer with little to no warning if not driven properly. Since both cars also had a "swing-axle" type independant rear suspension, they had additional issues. While the Porsche's reputation wasn't "hurt" in the long run, the Corvair never really recovered from the reputation their first two model years earned, even after suspension modifications in 1964 and a completely redesigned rear suspension in 1965.

Back to your Town Car. Keep doing your research, and if possible, try to actually drive examples of cars with more neutral steering and handling. A Tesla Model S would be a great example. Driving an actual CVPI or Mercury Marauder would also be a great idea. Decide how close you want to get to that kind of handling or better, and how much ride comfort over rough roads you're willing to give up to get it.

Chassis tuning is every bit as much an art as it is a science, and it is a science. While I can't think of a book title to recommend to you right now, there are several great ones out there. You can also subscribe to the CVPI performance enthusiast forums for other ideas. In the end though, you are going to be doing a fair amount of "trial and error" even doing your research first. After all, most "ordinary" people don't buy a Lincoln Town Car to pull 1.5 g's on a skidpad.

Good luck.
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wolf_walker

Junior Member
684
446
63
I'd be willing to bet that sticky tires, the kind nobody wants to pay for, and big sway bars would be a better combo for a daily driver. Less roll, more grip and retain most of the ride quality. An astonishing number of people upgrade to stiff springs and dampers and large sway bars and then put cheap all season tires on. Tires are usually the weak link unless you're driving hard enough that body roll is jacking up the contact patch badly.
My 04 seems to have quite a bit of grip for what it is and the shoes it wears, you just can't sling it around violently. And if you could you'd slide out
of the seat anyway, so hey.
 

Brian J. Patterson

Well-known member
446
328
63
Northern Illinois
Hah! Ain't that the truth! I love the way mine corners but I have to anchor myself with a death grip on the steering wheel!

Hi, dave42.

If you were actually going all-out in building a "Q-Ship" on a Lincoln Town Car, the seat isn't that big of a problem. Simply add more, and stiffer foam to the side bolster areas, leaving the middle "as-is." A good upholstery shop can do this and have it look at first glance just like a stock seat.

@wolf_walker, I couldn't agree more with you on good performance tires. If @kdv were to try the "plus two" plus one to one and a half inch wider rims, I don't think that he would go with the "economy" tires and lose the advantage his rather expensive new rims would gain. Switching to a 245/45R19 from the stock 225/60R17 without having the tread design and tread compound to back it up wouldn't be a good move. If he doesn't want to drive every day on $175ish or more each tires that are only good for 40,000 miles or so, he can still run the old tires and wheels "during the week" and save the "good" tires for the weekend.

Setting up a car so you don't have to slow down at all for all but the tightest of curves is increasing a car's performance just as much as adding 50-100 horsepower. And, it can become just as expensive. Handling comes in for "road race" or rally type performance where "top-end" speed can not be the end-all-be-all, as opposed to "light to light" or the quarter mile where horsepower and torque are everything.

"Speed is expensive." How fast can you afford to drive?

Thanks.
 

kdv

New member
Thanks for the replies guys, and the EXCELLENT advice! My apologies for not replying sooner, was on a work trip with just my phone, too hard to reply on that.

CVPI sway bars are definitely on my list of items to find; had a set of Addco sway bars years ago on a Marquis, loved how they kept it flat in the corners.

Currently running stock Marauder wheels, 18", (not sure of width - 8"?) with 255's. Plenty of grip there, in comparison to the 225 wide winter tires on 17" wheels - horrible for handling, but great for not crashing! Am considering getting a set of Mustang 20" wheels next time my tires need replacing (next year?).

The weight distribution is just fine, I prefer a tail happy rear wheel drive any day over the understeer of a front wheel drive. Have 25 years experience now driving various Panther bodies, quite comfortable with that tail wag.

Not committing just yet to those KYB shocks as I'm not 100% sure they'll be a simple install, it's just that my stock shocks are so damn soft, and am in the 'research' phase I guess. What I don't want, is to install a new set of soft shocks and be disappointed.
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Brian J. Patterson

Well-known member
446
328
63
Northern Illinois
Thanks for the replies guys, and the EXCELLENT advice! My apologies for not replying sooner, was on a work trip with just my phone, too hard to reply on that.

CVPI sway bars are definitely on my list of items to find; had a set of Addco sway bars years ago on a Marquis, loved how they kept it flat in the corners.

Currently running stock Marauder wheels, 18", (not sure of width - 8"?) with 255's. Plenty of grip there, in comparison to the 225 wide winter tires on 17" wheels - horrible for handling, but great for not crashing! Am considering getting a set of Mustang 20" wheels next time my tires need replacing (next year?).

The weight distribution is just fine, I prefer a tail happy rear wheel drive any day over the understeer of a front wheel drive. Have 25 years experience now driving various Panther bodies, quite comfortable with that tail wag.

Not committing just yet to those KYB shocks as I'm not 100% sure they'll be a simple install, it's just that my stock shocks are so damn soft, and am in the 'research' phase I guess. What I don't want, is to install a new set of soft shocks and be disappointed.

Hi, kdv.

The Marauder rims, providing your rim and tire set clear your wheel wells, should prove to be a good choice for a "plus one plus" rim conversion. I would recommend going to a 245/50R18 over the 255/45R18s you're currently running to maintain speedometer accuracy, though at least you're running so the speedometer is reading high instead of reading low.

The KYB shock and cartridge set will not be a "simple" install unless you also fit the CVPI/Marauder springs at the same time to increase your ride height. They might not be that simple even with the CVPI springs. If you decide to stay with the stock ride height, even with stiffer springs, you will want something other than the CVPI shocks, no matter the brand.

The Addco sway bars may be more to your liking than the "stock" CVPI bars. Or, they might not. How much does each choice cost? What are the specs for each bar? You would probably want to set up a maneuverability course in an empty parking lot to test where you're at.

One other place where you can "tighten up" your suspension is by fitting stiffer bushings on all the bushed pivot points of your suspension. The "factory-fitted" bushings for the '09 Town Car are quite soft, and also almost twelve years old. You don't necessarily have to go to hard nylon bushings, but you can go firmer than what you have. Even replacing the eleven year old bushings with fresh original type bushings may see some improvement.

Something that seems to have escaped notice to now is that you still have a functional air suspension system in the rear. This is not a bad thing. Though I haven't personally dealt with them yet, I'm told Arnott has great technical support. If you call Arnott and explain what you're trying to do handling-wise, they should be able to recommend a pair of Arnott air springs that will give you the desired firmness and capacity, whether that would be the "heavy-duty/limo" springs, or a different Arnott product that would still work seamlessly with the Lincoln air suspension system.

Good luck.
 

kdv

New member
Thanks again Brian,

I should clarify that I'm not really looking to make an auto-cross style handling TownCar, just wanting a stiffer ride than stock when replacing worn stock parts. Although it'd be awesome, it's really just my daily driver first, and a toy 2nd. Not in a life stage where I can throw money around un-necessarily. Once the kids grow up and go, then we'll see...

Ride height isn't too much of a concern for me, if it's a bit taller with PI springs than stock TC, it's fine. More clearance over snow drifts!

Sounds like the right tire size, they were the right height for my 2003 Marquis LSE, but yes my speedo is out by about 5% in the TownCar, but the tires have a season left in them yet. Hence looking for a set of 20" Mustang GT wheels, then sell off the Marauder wheels? I've always had as wide as possible tires on summer wheels.

Addco still make swaybars for the later year Panthers? The ones I had were for a 92 Marquis, swapped them onto my 94 TownCar, and sold that car with them on it. Not sure I want to spend that kind of cash again though, a used set from a junkyard PI should do just fine. EDIT - just looked up ADTR.net , sure enough - Addco still makes them! A little much for my budget though, kinda wish I had hung onto the rear one at least...

Poly bushings - did them in my 92 Marquis, and my 92 Cougar XR7, and generally loved the responsive handling - but hated the noise and harshness! Will stick with stock, but will only replace them if/when the ball joints wear out. Had Eibachs+Bilsteins on the Marquis, and Eibachs+Koni's on the Cougar. Good times... But ultra low cars are hard as I get older anyways, almost like having a 'normal' height car lol.

Air springs - yes, mine are still functioning fine, and I love them. But depending on if/when they fail, I will definitely be using a CVPI spring in the back. Had to do that with my Marquis, it was a $40 fix. Would buy the helper bags that go inside (that you manually air up) if I have to do that job again though, it's always nice to have a level car when towing.
 
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G-84427

Thanks for the reply Brian, and the tips about the installation kit. Figured the stuff 'should' just bolt in, being *almost* the same car, but have had issues with Lincoln's in the past that aren't quite the same as the Ford they're based on. And yes, knew the fronts were struts - but still a shock. Not sure how best to describe them lol.

Question about the front springs, could one reuse the factory TownCar spring on the CVPI strut? Also why the need for the CVPI sway bars when doing a strut/shock/spring upgrade? Is it a ride height issue? Even though I'd love to have them for the lateral stiffness in turns/curves. I've been looking at RockAuto for info on what's available, but will also check out SummitRacing.

Am starting to wonder though, if it's 'worth' doing the CVPI stuff - when all I really want is something stiffer, am operating under the assumption that the CVPI stuff is the best bang for the buck.
I have a super clean non p71 and added the front springs and shocks for a p71 and then threw in an addco front sway bar. Added stiff shocks in the rear as well. It made a world of difference made it tight and it doesn’t float at all. Whole new car. It didn’t even need an alignment. Downside is it did raise the front up a noticeable amount. It doesn’t hit in the same driveways she used to. But well worth it.
 

Hound Dog

Active member
129
79
28
I have on 04 ultimate. My wife doesn't like the float too much as it makes her car sick. Since I made a bunch of performance mods to make it get up and go I followed through with handling.

I changed out the shocks for Motorcraft P71 shocks and struts. Don't forget new rubber isolator pads even if the old ones appear good. It's only a few bucks more while you are in there.

The big difference? Addco sway bars front and rear. 1.25 solid up front and 1 inch solid in the back. Unreal difference. Sure Addco does not stock them for way outdated cars but they came in a month.

Oh yea, ordered Vic parts. They don't list them for Town Cars. Same part though.

Next is new rims and slightly wider tires.
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