'21 GT PP convertible (daily/track)

quirkynature · Apr 29, 2023

Hello hello! Longtime lurker here, first full post.

I wanted to post a build thread for myself to track, and for others to take inspiration from. After all, I wouldn't have come this far if not for @gone_n_60 posting MRTWSTR in all its glory.

Before we begin - the color is called 'Yellow Peel'.

Origin story (short version) -

Sometime in 2020 (when I was in a Mazda CX-5) I saw a Mercedes drop its top on a gorgeous 70 degree day, and the droptop bug bit me right away
When I visited Hawaii with the wife in 2021 we upgraded to an EcoBoost convertible, and I fell in love
First chance I got in 2021 - I swapped the CX-5 for a 2018 EcoBoost convertible in Orange Fury Metallic
I paid off the EB, and traded it in for a GT in 2022 to hear the raucous Coyote (the soundtrack is hits differently when the top is down vs being up).
The GT is fully loaded. Premium and performance packages, active exhaust, B&O sound system, MagneRide - the works. It's not a coupe, but the additional PP goodies means it's track-capable...
I installed a roll bar and then took it to the track in 2023!

Without further ado, mod list -

Aesthetic mods -

Performance mods -

Interior/misc mods -

Removed -

Pending -

Exhaust heat wrap
Mishimoto radiator
Mishimoto upper radiator hose kit
Mishimoto lower radiator hose kit
Oil cooler kit
Heat vents - curved fender louvers, upper fender louvers and lower fender louvers
Red Anodized Billet Aluminum Interior Hood Latch Release Lever
LED side marker lights
Mach 1 active exhaust upgrade kit
PP2 splitter kit
PP1 spoiler or spoiler lip
Black shifter handle
Interior LED lighting kit
Differential cooler kit
Transmission cooler kit
Wheels - still researching
Custom Car Grills precut mesh - still researching

Thanks for reading!

Edit - I try to go to a track once a month, less in the summer months. My goal at this point is to continue building a track daily leisurely, as it's in a very stable position at this time.

Aesthetic or performance recommendations welcome!

mikengail · Apr 29, 2023

Curious. Are you able to recline your driver's seat all the way back? I have to get a roll cage to race my convertible at the local drag strip...

quirkynature · Apr 29, 2023

mikengail said:
Curious. Are you able to recline your driver's seat all the way back? I have to get a roll cage to race my convertible at the local drag strip...

Willow Springs and Sonoma are satisfied with the 4-point roll bar I have installed - may I ask where you're located? I'm in NorCal.

I don't have a full roll-cage, and I won't put one in because that'd severely restrict the daily-ability of the car. The Watson Racing roll bar is very sturdy and has no give or play at all once installed.

I'll upload pictures later this weekend once I get a wash in.

mikengail · Apr 29, 2023

quirkynature said:
Willow Springs and Sonoma are satisfied with the 4-point roll bar I have installed - may I ask where you're located? I'm in NorCal.

I don't have a full roll-cage, and I won't put one in because that'd severely restrict the daily-ability of the car. The Watson Racing roll bar is very sturdy and has no give or play at all once installed.

I'll upload pictures later this weekend once I get a wash in.

Albuquerque, NM. I'm looking for nothing more than a 4pt bolt-in roll cage or bar. All convertibles at the Albuquerque Dragway that run under 13.5 must have a cage or bar. Yours would qualify. My car may be a high 10-second car even at this high altitude. I have the Steeda Subframe and Alignment Kit with the Steeda Vertical Links and the GT-350 Half Shafts. I also have a set of Nitto NTR05 Drag Radials in a 305 width, so I think that she will stick without any hop. I'm just hoping that I can recline my seat, because she is a daily driver and I like to lean back...

quirkynature · Apr 29, 2023

mikengail said:
Albuquerque, NM. I'm looking for nothing more than a 4pt bolt-in roll cage or bar. All convertibles at the Albuquerque Dragway that run under 13.5 must have a cage or bar. Yours would qualify. My car may be a high 10-second car even at this high altitude. I have the Steeda Subframe and Alignment Kit with the Steeda Vertical Links and the GT-350 Half Shafts. I also have a set of Nitto NTR05 Drag Radials in a 305 width, so I think that she will stick without any hop. I'm just hoping that I can recline my seat, because she is a daily driver and I like to lean back...

The red on red is GORGEOUS. Great pic - thanks for that!

How've you found the chassis holding up against the supercharger? In this video Throttlehouse did they found that Shelby Super Snake convertible widebody's chassis warps under full power - . That's the only concern holding me back from considering adding a supercharger down the line.

To answer your question - if you recline the seat fully back it will rest against the roll bar -

The way I sit is a few degrees straighter so it doesn't touch the roll bar but I'm still 'lounging' instead of sitting upright -

quirkynature · Apr 29, 2023

Front -

Side -

Rear -

mikengail · Apr 29, 2023

It seems to be holding up fine. There's extra bracing underneath for the verts. That's why the jacking rails are shorter than those for a coupe. The S550 convertibles were the first Mustang ragtops that were purpose built from the ground up to be convertibles. All previous verts were converted coupes. Much stronger design. I have had S197 convertibles and they all had a little body wobble on uneven roads. Not the S550's. It should be even stronger when I install a 4-point cage or roll bar.

The yellow and black looks great. My previous Mustang was a 2015 yellow and black convertible. I was going to keep it, until the 2018 came out with the Gen3 Coyote engine. That poweplant was too much of a game changer to resist...

quirkynature · Apr 30, 2023

mikengail said:
It seems to be holding up fine. There's extra bracing underneath for the verts. That's why the jacking rails are shorter than those for a coupe. The S550 convertibles were the first Mustang ragtops that were purpose built from the ground up to be convertibles. All previous verts were converted coupes. Much stronger design. I have had S197 convertibles and they all had a little body wobble on uneven roads. Not the S550's. It should be even stronger when I install a 4-point cage or roll bar.

The yellow and black looks great. My previous Mustang was a 2015 yellow and black convertible. I was going to keep it, until the 2018 came out with the Gen3 Coyote engine. That poweplant was too much of a game changer to resist...

Just a heads-up on the roll bar - when Watson Racing ships it it's not primed or painted. It arrives in a dull grey color with flaking paint.

I'd recommend taking it to a paint shop and having them prime it and then paint it. It cost me ~$300, but the gloss black paint matches the PP wheels and blends into the interior well for mine. A red roll bar on yours would look menacing! Hope it doesn't catch too much undue attention.

Also note that it involves some cutting of the backseat to make space for the roll bar - it's not a 100% direct fit. Still worth it, though - as you said, tracks require it.

I wasn't aware that the S550 platform was built ground-up for convertibles - gives me some confidence in its capability, but the groans and squeaks aren't reassuring (probably the subframe moving around).

Before I got the '21 I wasn't aware of the huge difference between G1 vs G2 vs G3 of Coyote - that's been a pretty fun rabbit hole to dig deep into. Air-oil separator should probably be another priority before the next track day though...

gone_n_60 · May 2, 2023

Well I'll graciously accept being your motivation for getting your Yellow Peelin' out Mustang to the track. ;-) Looks like a lot of mods in that list. Unfortunately I can't track as often in the Midwest as we actually have a "season" called not-winter, LOL.

About that roll bar, best I can tell it looked to me like the Watson was powder coated. I installed mine stock gray as it arrived no peeling or flaking. Tip, while they claim removable it's a bitch to get in and out and reinstall the door panels, lower panels are the issue. I took mine out to get a custom rear seat delete done but don't think I'll take it out again.
About reclining, some but not too much. Being average height, 5'9" it's fine for me. In track mode you have your seat moved up anyway.

mikengail · May 2, 2023

Funny story about the "Wyle E Coyote" front vanity tag on my '15. I was driving back to Albuquerque from El Paso one day and had to stop at a large Customs and Border Patrol inspection station. I went through the search process as required easily enough and was heading out of the inspection lane when an armed Border Patrol officer noticed my tag as I was driving past him exiting the property. He snapped his head around and then went running to some of the other officers. Nobody came after me though. I guess one of the other officers was enough of a gearhead to let his comrades know that "Coyote" doesn't mean the same thing in the Mustang world as what those folks have to handle as part of their regular official duties. Lol...

quirkynature · May 3, 2023

gone_n_60 said:
Well I'll graciously accept being your motivation for getting your Yellow Peelin' out Mustang to the track. ;-) Looks like a lot of mods in that list. Unfortunately I can't track as often in the Midwest as we actually have a "season" called not-winter, LOL.

About that roll bar, best I can tell it looked to me like the Watson was powder coated. I installed mine stock gray as it arrived no peeling or flaking. Tip, while they claim removable it's a bitch to get in and out and reinstall the door panels, lower panels are the issue. I took mine out to get a custom rear seat delete done but don't think I'll take it out again.
About reclining, some but not too much. Being average height, 5'9" it's fine for me. In track mode you have your seat moved up anyway.

Mate - your car was 100% inspiration for me purchasing and then tracking my GT. This is a bit of meeting your heroes moment.

Ooooh could we get a picture of your rear seat delete please?? I mulled over the idea when I was getting the roll bar installed but the visuals weren't too pleasing without the seat.

gone_n_60 · May 3, 2023

quirkynature said:
Mate - your car was 100% inspiration for me purchasing and then tracking my GT. This is a bit of meeting your heroes moment.

Ooooh could we get a picture of your rear seat delete please?? I mulled over the idea when I was getting the roll bar installed but the visuals weren't too pleasing without the seat.

Many gracious thanks for the laurels. I consider myself an Ambassador for going out a driving that Mustang as it was intended (but safely)!

About that rear seat delete, the story:
first nobody makes rear seat deletes for convertibles, don't know why, but I found a group that said they could do it (or said "he" could do it) $250 and months later I got it. Tried to see how to fit it and couldn't figure it out, even my buddy mechanic from this forum no go. I now have my local hot rod shops reference for their guy who they say can make it fit. So if/when it's done I'll send pics but not sure how it can be replicated.

Pronichkin · May 8, 2023

This looks like a great thread, thanks for inspiration. I too own a 2021 GT PP1 convertible, and I'm currently in the market for a roll bar. May I ask why you have chosen Watson Racing, and what other options you considered? Thanks!

quirkynature · May 8, 2023

Pronichkin said:
This looks like a great thread, thanks for inspiration. I too own a 2021 GT PP1 convertible, and I'm currently in the market for a roll bar. May I ask why you have chosen Watson Racing, and what other options you considered? Thanks!

Hey Pronichkin!

Beyond the Watson Racing roll-bar, I had 3 other roll bars on my radar to choose from -

1. https://www.steeda.com/autopower-70265-e-s550-4-point-race-roll-bar (with cross-bar)
2. https://www.steeda.com/autopower-71265-e-s550-4-point-roll-bar (sans cross-bar)
3. https://www.tpsmotorsports.com/rpm-...e-gopro-style-action-camera-harness-belt.html

I didn't opt for options 1 and 2 because it's made to order with at least a 4-6 week lead time, and my timeline was tighter than that. This thread (although related to older Mustangs) also made me wary of buying an Autopower roll bar - https://www.moddedmustangs.com/threads/which-roll-bar.450697/

The third option was enticing but with options it quickly became stupid expensive so I disregarded it (and a rush charge of $2000? that money's better allocated for a coach/instructor smh).

The Watson Racing roll bar was available to ship immediately, and their website states it's a full bolt-on (some trimming and cutting of the backseat was required - but very minimal). It arrived very nicely packaged, too - no movement in the box, and with adequate padding. The bar comes with built-in loops for a harness add-on also, which is a nice thought.

The Watson Racing bar's reviews also bolstered my confidence in it - https://shop.watsonracing.com/ReviewsList.asp?ProductCode=WR-15-BOLTINCAGE&Reviews=Y

It seems the Watson Racing roll bar's gone up in price by about $100 since I bought it (https://shop.watsonracing.com/S550-...OLLCAGE-2015-CURRENT-p/wr-15-boltincage-c.htm), so YMMV.

Beyond that it seems there aren't too many roll bars for convertible S550 Mustangs. With S650 on the horizon I don't believe there'll be more development for S550s either.

Your profile states your 2019 'vert was 'totaled by a puma'? There a story to be told here? And kudos to you for springing for a '21 'vert!!

Pronichkin · May 8, 2023

quirkynature said:
Hey Pronichkin!

Beyond the Watson Racing roll-bar, I had 3 other roll bars on my radar to choose from
<...>
Beyond that it seems there aren't too many roll bars for convertible S550 Mustangs. With S650 on the horizon I don't believe there'll be more development for S550s either.

Thank you very much for the very detailed and elaborative response! Definitely something to consider here, and I'm inclining to the same conclusion as you are now.

quirkynature said:
Your profile states your 2019 'vert was 'totaled by a puma'? There a story to be told here?

haha, here's the story: https://www.mustang6g.com/forums/threads/introduce-yourself.6728/page-396#post-3086571

and here's what we've ended up with, about half a year after that
https://www.mustang6g.com/forums/threads/carbonized-gray-s550-mustang-thread.139630/#post-3217884

...and here were some of my first impressions
https://www.mustang6g.com/forums/threads/2021-vs-2019-first-impressions-subtle-changes.157549/

'21 GT PP convertible (daily/track)

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mikengail

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