There is substantial information when it comes to modifying an Explorer ST, so I pulled together the ultimate modding guide.
Brakes
If you run the Sport-Technology (ST) Explorer hard, and are tired of brake fade, you might want to look into a brake upgrade. Brake upgrades range from just a rotor and pad change, all the way to 8-piston caliper, 405-MM rotor brake kits.
Stainless Steel Brake Lines
The best brake upgrade, whether you have a BBK (usually they should come with SS lines) or stock brakes are a set of Stainless- Steel Brake Lines. Stock rubber lines will swell and stretch when pushed hard, causing a mushy brake feel, diminishing brake feel, and poor braking. Stainless steel brake lines will not do that, and improve brake feel, and slow down brake fade.
Stock Brake Upgrade
PowerStop Z23
The best budget upgrade is the PowerStop Z23 upgrade. It includes slotted and drilled rotors (which look neat behind the wheels), and performance pads. It is a great upgrade if you don’t want to fork over the larger price of a BBK (Big Brake Kit). It should improve some brake fade, but don’t expect a large improvement.
OEM Brake Swaps
These two following OEM Brake swaps from the Shelby Mustangs’ are probably my favorite two options. Unfortunately, the rear brakes from either the GT500 or GT350 are not compatible with our electronic brake caliper on the ST.
Shelby GT350 Front Brakes + Adapter Brackets
This brake swap uses the stock GT350 (2016-20) 6-piston Brembo calipers, 15.5-IN. rotors, and adapter brackets from Tony Hernandez on Facebook. It is a great kit for a great price, and costs just less than $1,700 if you use the GT350R brakes (which are red) and less than $1,500 if you use the regular GT350 brakes (which are black). If you are still running stock wheels, then you need to use 1” spacers slip-on spacers (check spacers mentioned later), which isn’t all bad. 1” spacers will give the stock front wheels a perfect stance.
Shelby GT500 Front Brakes + Adapter Brackets
This brake swap uses the stock S550 GT500 (2020-23) front brake setup which includes 6-piston Brembo calipers, massive 16.5-In. (~416-mm) rotors, and adapter brackets from Tony Hernandez on Facebook. Used calipers go for around $800, and new rotors are another $900 from Ford. More information to come about caliper clearances.
Trackhawk Front Calipers + Racing Brake Rotors and Mounting Hardware
Another just-front BBK choice is using Trackhawk Front Calipers and Racing Brakes Rotors and Hardware. This is comparative to the GT350 swap, but is probably $1k more. The rotors and hardware from RB alone WITHOUT the calipers is the price of the any compelete Shelby brake swap. It would be a good option, but the Shelbys’ brakes are a better option because of the price.
SuperForged
SuperForged is the best choice if you want to go all out with a front and rear BBK. SuperForged’s brake kit includes 405-MM front rotors clamped by 6-piston calipers, 380-MM rear rotors clamped by 4-piston brakes, stainless steel brake lines, all the mounting hardware, and an 1-piston caliper for the parking brake (although there is a $100 option to integrate the parking brake into the caliper, which I assume saves unspring weight). This kit retails for a fair value of $3,800.
Rotora
This is the ultimate bragging rights kit. Rotora has many options for BBK, but they all come at a price. All feature 8-piston front calipers and 4-piston calipers in the rear. All the kits are just too expensive. The price for a front kit alone is the price of a front and rear Superforged kit. The performance benefit is not better either. In this case, bigger and more expensive is not better.
Drivetrain
Built Transmission
The 10r60 is a pretty stout transmission in stock form, but if you are launching with a tune often or have a trans-brake, then you will need a built transmission. Getting a built transmission will give you the peace of mind of knowing that the tranny can handle anything you throw at it. RSA Transmission is highly recommended, and their work can be vouched for by the fact they hold the crown for the fastest ST with which they have done dozens of extremely hard launches on the built transmission.
Differential Brace
1-bolt Rear Subframe
In late 2021, due to supply shortages, Ford decided to put the 1- bolt subframe from the 4-cylinder Explorers into the ST. Bad choice, horrible choice in fact. The 100+ extra HP that even the stock form produces is too much for the subframe to handle. Even on mild launches, the bolt is known to snap, which can lead to a domino effect taking out the rear diff, shoving the rear driveshaft up the transmission and boom, you could have a cracked engine block. Not fun even with a warranty. So, if you have the 1-bolt, get a differential brace.
The good news is that with a differential brace, you will not have that problem. There are quite a few different options. Stay away from the FenFab DiffyStiffy. The AWR brace is ok, it does the job, but the best one, though the most expensive one, is the ID-Speed brace, but it is worth every penny. Steeda’s brace is comparible with the ID-Speed brace, but the bushings are slightly inferior to the ID-Speed’s.
2-Bolt Rear Subframe
The 2-bolt alone pretty much handles anything you throw at it, but after a lot of launches, can go out. I would personally purchase it no matter that, it is better safe than sorry. It just never hurts to be too careful. Again, splurging for the ID-Speed brace is very worth-while.
Oil Catch Can
A catch can removes oil droplets from air circulating from crankcase to intake. It is very important, and every 5k miles usually nets two shot glasses worth of oil that would have coated the valves, had the catch can not stopped it. The best catch can that does the job perfectly is the UPR Catch Can, but it is 4 times the price of the runner up, the JLT 3.0. The JLT will do 90% of the job that the UPR will do, but at a quarter of the price.
Ford Performance Skid Plate
Kind of an odd part for a street-oriented performance vehicle, is an engine skid plate. This protects the engine from being damaged by any objects from below. Ford Performance panned this part from the Timberline, and it features an easy access hole for the oil plug. If you drive trails/dirt roads or just want the extra protection, the Ford Performance skid plate might be a good peace-of-mind part.
Upgraded Fuel System
Nostrum is the sole provider for upgraded fuel system (high-flow fuel pump, upgraded injectors) if you need more fuel to be dispensed than the stock injectors can provide. Reasons you need larger injectors are you are running high ethanol mixes or have an upgraded turbo.
Upgraded Turbos
If you want to go all out, usually upgraded turbos are the first thing that comes to mind. There are a few options though, and all options are a ported stock turbo with an upgraded rotor. The stock turbos are very efficient already, so this would one of my last mods. If you are running ethanol mix, that is where you will see large gains. Upgraded turbos will squeeze every last HP from the car. The thing is though, with that extra power and harder launches, you will need a built transmission, all the suspension mods described in the suspension section, upgraded fuel system, and intercooler. All this adds up: upgraded fuel system costing around $3k, built transmission varying on labor ($3k for the rebuild kit alone), and $4k for the upgraded turbos themselves. This path is not for the light of heart, but if you are running ethanol, you could be running high 10’s in the quarter-mile.
Upgraded Rear Half-Shafts
DriveShaft Shop offers upgraded rear half-shafts that can handle up to 1,000-HP. With a fully built transmission, this finishes of a bullet-proof drivetrain.
ECM Tuning
This is the most important effective modification. Just an ECM tuning can bring the quarter mile times down to Low 12’s. There are quite a few options when it comes to tuning so I will just recommend the best for each purpose:
Ford Performance tune: Entry-level tune
The Ford Performance tune is great for people who just want to dip their toes into the world of tuning. It retains the 3 year/36k mile warranty but will not retain the powertrain warranty for any extended warranty. It’s advertised HP is 430 HP and 467 LB.FT.TQ.. It is a bit expensive at $825. Throttle response and shifts points become noticeably better. Like I said above, it is an entry level tune for people who just want improved throttle response and shift points. Reported quarter-mile times are 12.6 sec. with the tune.
ZFG tune: Best all-around tune
The ZFG tune is the best tune as recommended by many of those that have purchased it and the numbers that the tune achieves. Adam at ZFG knows how to tune these 10r60s and 3.0L perfectly. His work speaks for itself, and a quick youtube search brings up a lot of amazing results from his tune. Reported quarter-mile times have been up to 11.8 Sec. with just an intercooler.
Exhaust
This part is highly subjective, as the “perfect” exhaust note depends on one’s taste. I will summarize this section.
The stock catback, though extremely quiet, is actually not that restrictive. Upgrading to an aftermarket exhaust will not net a worthwhile gain if you are just looking at it for power, but sound and replacing the rattle-prone flex-pipes (which will rattle in the future no matter what) are the pluses.
Stock Cat back with Aftermarket Tips
If you like the quiet exhaust but want something better looking than the tiny 2” quad-tips that come stock, it is quite simple to make it look better. 3” quad-tips with a 2” inlet slips right on with no fabrication. It is as simple was cutting off the stock tips, and welding-in the new exhaust tips. I do not recommend screw-in type tips, as they have a good probability of falling off.
4” exhaust tips will fit with some fabrication, but you will need a 2.5” inlet so that you can properly space the tips. They will fit in the diffuser perfectly but are not as easy as just slipping them on.
Muffler Delete Axle-Back
A very cheap option is to do a muffler delete, and it sounds decent….but it will drone like crazy on the highway.
Resonator Delete
A resonator delete usually does wonders, as shown in the Mustang GT for example. But the res delete on these Explorer’s will give it a very slight sound improvement, but nothing you can hear inside.
Thermal R&D 2.5” Exhaust
This is the best exhaust for people who want some more sound when they step on it, but quite on everything else, the Thermal 2.5” Exhaust is the best choice for them.
Thermal R&D 3” Exhaust
The best all-around exhaust is the Thermal 3” exhaust. Zero drone, mild sound when normal driving, and awesome sounding on acceleration. This is the best exhaust for people who want to hear EcoBoost sing the best song it can sing.
Downpipes
Downpipes are a great upgrade and help reduce restriction from the turbos. They also replace the crack-prone downpipes from the factory. Downpipes have been tested to show gains of up to 15 HP on pump gas. FenFabrication, CVF, and SPD are all great with no difference between them, just price.
Exterior
Who knew that the Explorer could transform from a blocky SUV to a Mustang beating sleeper? Why not show that power in the exterior?
Hitch Cover
The hitch-cover will give the rear of the ST a cleaner look in the rear. There are a few options to choose from, from the likes of Waido, Zeus3d, and a couple of others.
Front License Plate Delete
If you want to clean up the front end of the car, a front license plate delete is probably one of the best ways to do so. Bumperplugs.com is the best way to go. Their color matching the paint is amazing and is worth the extra price. To plug the whole in the bumper, you can go to your local auto parts store and buy some fender fasteners, and they will work fine.
ECU Cover
FenFab’s ECU cover is a great way to dress way to dress up the engine bay.
Emblems
One of the things that is frustrating, is that the ST did not receive the black emblems from the Timberline, among other things (like a Torsen rear diff.). I love how a pair of custom emblems look. Emblem City makes a great pair of emblems if you are looking to go custom, and Ford Accessories have the Black emblems from the Timberline. The difficult part is you have to remove the front bumper to remove the emblem, unless you use @Unbroken ’s, which you drill the tabs out through the stock emblems. Once you remove the bumper, you will need to drill some new holes for the emblem, even with Ford’s ones. It is quite easy though, when you use the included templates.
As far as the front “ST” emblem, a cool idea that @Unbroken came up with, is he removed the stock “ST” emblem on the grille and used an ST overlay to make it like a “ghost” emblem. It gets rid of the chrome too.
Rear Exhaust Exit
Waido recently released a new rear diffuser that slots beneath the rear bumper. I think it finishes off the look of the rear.
Rear Tailgate Wing
SS-Tuning offers a rear tailgate wing, which gives the car a hot-hatch look to it. It retails for 450 euros (yes, part comes from Europe), and shipping costs another 250 euros.
Hoods
There are two aftermarket hood offerings to choose from if you are looking to bring out a more aggressive look from the hood.
Stock Hood
There is an interesting thing you can do with the stock hood. @Unbroken used Jeep Wrangler hood vents and cut into the stock hood. It looks pretty good but is not for the light of heart.
https://www.explorerst.org/threads/unbrokens-iconic-silver-st- build.503/page-51#post-74923 (Post 1,004)
i5 AutoHouse
i5-AutoHouse’s offering is a Raptor-style hood which is functional. Price is around $1,100.
Austin Pucket
There is a custom carbon-fiber hood offering from Austin Pucket. It is also functional and is very aggressive looking. Thanks to the carbon fiber, it also reduces weight.
Front Splitter
A front splitter is something that will give the SUV a sports-car- like front end look. There are two options to choose from: Waido and SS-Tuning.
Waido
Waido’s front splitter is very classic looking, bringing the front end lower, giving the car a low, aggressive look.
SS-Tuning
A very aggressive option is the SS-Tuning Front Splitter.
Side Splitter
Side-splitters help give the car a low look when viewed from the side. I think it complements the lines of the car very well.
Waido
Waido is the only true side-splitter offering. They look great and would work perfectly with their front splitter.
Aftermarket Step-Boards
Step-bars on a low car like these cars don’t make sense, but they would be more for cosmetic purposes than functionality. They actually look really good, and maybe even better than Waido’s actual side-splitters.
Waido Mid-Spoiler
The looks of Waido’s mid-spoiler are in the eye of the beholder, and there are a couple of different variants of the spoiler.
Widebody Kit
A wide-body kit sounds awesome for the car, and SS-Tuning and Waido offer them. But in reality, to actually put that extra body width to use, you need a wider wheel and tire setup. At the offset needed to make the wheels flush, the front wheels will rub the metal on the rear of the fender and rub like crazy on the liner. So sadly, a wide-body doesn’t actually work.
Painted Exterior Trim
Some people are not fans of the plastic trim that the 6g Explorer’s feature. Unfortunately, it is not cheap nor easy to paint the plastic. You cannot just wrap the plastic, as the vinyl will not adhere properly. To paint the plastic, there is a lot of prep work. Quotes have reported to be around $1,600. Once done though, many will say it is worth it.
Rear Windshield Wiper Delete
Pioneered by @Unbroken, Houston Speed Freaks brought the ultimate windshield wiper delete to the market. This windshield wiper delete is so flush and transparent, it looks like it isn’t even there. Some people are worried about the rear visibility loss due to no wiper in the rear, but if you clean the rear window thoroughly with a good waxing cleaning spray, the water will just run down.
Roof Rail Delete
This is dependent on one’s taste, but if you desire to remove the roof rails here is a quick run-through. There are barely any parts involved, just two roof rail delete trim pieces. The hard part is you have to remove the headliner to get to the rail bolts. It isn’t hard, just time-consuming.
Headlight’s Chrome Black-out
Ford took the time to black out the taillights and the headlight marker lights but didn’t black out the chrome inside the headlight. The Interceptor’s receive the blacked-out headlights (though without a DRL) but we don’t. There are a couple ways to hide the chrome. One way is to use headlight tint to cover the chrome, or you could open the headlights up (by baking them) and paint the chrome.
LED Light Strip
A cool modification is the addition of an LED light strip. It connects the bright DRL’s with a bright strip, which is neat.
https://2023-exst.blogspot.com/2023/03/really-slick-led-light-strip-for.html
Rear LED Sequential Marker Lights
I love the way that sequential lights look, it gives cars a more premium look. These are good ol’ eBay specials. It retails for $65. Full writeup below:
https://www.explorerst.org/threads/rear-bumper-led-swap.6784/#post-86311
Mud-Flaps
In my experience, the dirt that the front wheels kick up damages the plastic cladding. It is not a pleasant look. The easy way to prevent that are step bars, or in this case mud-flaps. Both Ford and WeatherTech make sets, both don’t require drilling. WeatherTech’s set looks quite a bit better than Ford’s, and their reputation precedes them.
Functionality
Hood Strut Kit
If you are opening the hood often, it might be a worthwhile purchase for a hood strut kit. The best one, since it does not require drilling, is the no-drill MRT Hood Strut kit.
Reverse Light
The reverse lights that come stock are horrific. You are better off riding the brake so you can at least see. I highly recommend Houston Speeds Freaks reverse lights. They are brighter than most headlights and are of great quality.
Turn Signal Lights
This is a pure cosmetic mod, but one that I like. The stock halogen lights look cheap, and the LED turn signals look crisp and premium looking. Again, I highly recommend HSF’s LED turn signal lights.
Intake
BOV
A blow-off valve or BOV releases excess pressure from the turbos when the valve body closes to the atmosphere. 2020-21 MY ST’s feature a BOV, while 2022+ deleted it. In case you are wondering, it is hyphosized that the ECU leaves the valve body slightly open, which removes the point of having a BOV.
How to get that Pshhhhhh
The blow-off sound of the valve is addicting. If you want to make it apparent, a BOV adapter is a cheap mod that makes it perfectly audible.
Of course, you could just go to the aftermarket, and Boomba and Turbosmart are legendary in the BOV market.
Intercooler
The intercooler is very undersized from the factory for the ST (top is stock intercooler, bottom is Mishimoto). There are quite a few different intercoolers (also known as heat exchangers) but there isn’t noticeable differences between them, I would just pick the cheapest ones at time of purchase. They all have the same numbers, and some of them are the exact same just different branding. The front bumper is required to come off so any other accompanying mods like emblems, charge pipes, etc. would be a good idea to get down while it is off.
Intake
The stock intake is not too restrictive, but there are some decent gains when an aftermarket intake is paired with charge pipes. Adam at ZFG can confirm that the S&B Intake is the best choice, and plus the clear cover displays the dual air filters, which is pretty cool.
Charge Pipes
The factory charge pipes are restrictive in the fact that they change diameter and shape throughout the part. Just doing the cold-side charge pipe is not worthwhile but if you pair it with hot-side charge pipes, the gains will be noticeable. If you want to do charge pipes it should be done with an intercooler since bumper removal is required for it, and having the bumper off will give you more working space to install the pipes.
Drop-In Air Filter
The K&N drop-in filter is a waste of money plainly put. It is two- times the price of the Motorcraft unit and does not give ANY gains.
Velosa Tech Intake Snorkel
This is still a highly controversial part. Adam’s (at ZFG) chart above shows that it makes a difference, but others have shown different. In my personal opinion, the extra cold air will help, and for $150, it doesn’t hurt. Plus, it looks cool behind the grille.
Suspension
Rear Sway Bar
The rear sway bar will completely transform the way that this 4,000LB. SUV. Steeda and aFe are the two manufacturers of aftermarket rear sway bars for the Explorer ST’s, and I would recommend aFe. As far as performance goes, Steeda is slightly better but Steeda’s sway bar rusts out really bad in just a year or two.
Front Sway Bar
The front sway bar is extremely hard to install and there is no worthwhile difference.
Lowering Springs
Lowering springs are probably my favorite cosmetic mod, but it also helps handling and paired with a rear sway bar it about wraps up the suspension department. Steeda, H&R, Lethal Performance, and now Eibach are offerings for lowering springs.
Steeda Lowering Springs
Steed’s lowering springs retain the factory “rake” of the suspension (rear is higher than front). If you tow any type of medium-large trailer or if you just plain like the look of the “rake” this is your best option. Steeda’s setup will give youmore control over a trailer then other offering.
H&R
H&R is the best springs for looks. H&R was the first company to provide lowering springs for the ExST community and they are the most popular offering. They are a great springs and nothing but positive reviews for them. The advertised drop is 1.6In. front/1.75In. rear.
Lethal Performance
Lethal Performance’s springs are plagued with problems. You could be lucky, and not have any problems, but most likely you will have problems. They have squeaking problems, have been known to bottom out often, and some have even lifted the vehicle, the opposite of the purpose. The advertised drop is 1.8In. front/2.0In. rear.
Eibach
Eibach is the newest to the game, but their reputation precedes them. Advertised drop is 1.6-In. front/1.8-In. rear. They are my favorite choice, as once they settle they have the lowest drop.
Coilovers
Coilovers look amazing, as they drop the car a lot. I do not recommend them though. The reason is, is when you drop the car more than lowering springs do, it is pretty much impossible to get the wheels aligned right.
Rear Toe Links
Rear toe links prevent instability and wheel hop during hard launches. It is one of the top noticeable mods and paired with a subframe lockout, eliminates any wheel hop. Wheel hop on these cars can lead to the destruction of the axles and half-shafts. Steeda produces inserts, and for $100 you can’t go wrong, but Fen Fabrication produces full replacements, which are the better way. For $299, the extra price is fully worth it.
Rear Vertical Links
Rear vertical links also help prevent instability and wheel hop during hard lauunches. FenFab is the sole aftermarket offering, and their part is so much stronger than the stock link.
Subframe Lockout Kit (also known as Subframe Bushings)
A subframe lockout kit helps prevent the subframe from moving during hard cornering or launches, giving the car a solid feel, no wheel hop, and a connected feel when cornering.
Suspension Strut Brace
I am not sure of any improvements over the stock strut brace from any aftermarket strut brace. The looks alone win me over though. This is probably just for cosmetics, but could make a difference when combined with other suspension mods.
Wheels
Who would have thought a 4,000LB. SUV could spin all 4-tires and run 11’s in the quarter mile all day long!? To put all that AWD grip to use, a good wheel setup is needed. Thanks to @Unbroken we have the perfect wheel formula.
The best setup is 22×10.5 et.30 wrapped in a variety of sizes like 295/40R22, 305/40R22, 305/35R22, and steamroller 315/35R22, all fitting without rubbing (even with lowering springs. If you are going custom from the like of Vossen, Velgen, or others, this is the only way to go.
Forged rims are what you always want to aim for, as they are lighter than their cast counterparts. The best-looking wheel is in the eye of the beholder so here are a couple threads that can help you choose:
https://www.explorerst.org/threads/aftermarket-wheel- thread.1052/
https://www.explorerst.org/threads/22-wheels.1467/
Spacers
If you still want to keep the stock 21″ rims, but want a more aggressive stance, spacers are the best way to do that. Not any spacers though, quality spacers like Bora. The best stance is 1” front spacers and 1.25” spacers in the rear.
And that is mostly every modification available for the Explorer ST! Thanks for reading!
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