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S550 GT 350 SCCA Autocross Build Build Thread Profile - S550 Mustangs

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Bill Pemberton

0ld Ford Automotive Racing Terror
8,489
8,481
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Welcome and don't wait till 2023 to come to Nationals, do it this year. The huge benefit is you will have seat time at Nationals to gauge, but much more importantly you will see what everyone is using , the tricks the fast guys employ, the recent advancement in tires ( there are late changes that one often finds out about ) and more. That way you won't pop up in 2023 and find out you were a year behind with some common changes in the Class. It may also help you validate what changes you want to make before you spend money only to find you should have done something else.

Trust me, going while still learning or modding your car is 100% positive and so much better than going the first time after everything is done and finding you should have gone a different direction.

I have learned this from being 1 mile, or 112 miles, or 60 miles from the various Solo Nationals sites over the past 41 years.
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
All,

This is my first OP on this forum, and the first time 've ever posted anything like this, so go easy on me. I wanted to document the performance modifications and progress improvements in times as I upgrade my GT350. So first, what's my big plan with this thread? Well, I enjoy the hell out of autocross. I started with a Focus ST, moved up to a Hellcat, and then finally to my GT350. It finally felt right in my GT350, so I decided I am going to build this car more than I had my other cars. The purpose of this thread is to document my road from effectively a bone stock GT350, to SCCA Nationals run in the SST class. I plan to post all upgrades I do, what does and doesn't work, my skills as a driver, as well as what I learn while driving it.

This first post will be me trying to catch up on progress since I purchased in April 2021 until January 2022. Sorry as it is sort of long.

First, the car. I picked up a 2017 GT350 in June of 2021, after owning a 2020 Hellcat Charger Widebody. The reason I ditched the Hellcat and moved to the GT350 was simple, I loved the HC, and it carried my family well, but I realized quickly that it would never be the track car I wanted it to be without serious modifications. Pic of the Hellcat because let's face it, its a super cool car (The photos don't do that blue justice):

20200523_170337.jpg20200523_184407.jpg

So I sold it (For more than the car cost me, plus insurance, plus fuel, plus registration!), and picked up my GT350 (For much less than my HC sold for!). I dreamed of a GT350 white with blue stripes, (which I personally believe is the only acceptable paint scheme :crackup: ) and found two reasonably close to Houston. Went to check this one out in Dallas, and was immediately sold on it.
PXL_20210501_144929571.jpg

I bought it used, with ~3,000 miles on it, and had it delivered. It is white with the blue stripes, and the previous owner added the red pinstripe on the outside of the blue stripes, and colored the Shelby badges red. I fixed the badges almost immediately. The previous owner also installed one hell of a stereo, and it sounded awesome. Beyond that, he also replaced a handful of interior panels with the carbon fiber version, and had to put a different frame around the center stack. Otherwise the car was completely stock. No scraping underneath, signs of a well maintained car everywhere, panels all spotless. The car was babied.
PXL_20210507_215548590.jpg

Bits of Stereo:
PXL_20210511_012921009.jpgPXL_20210511_223943752.jpg
PXL_20210511_224033860.jpgPXL_20220119_020240272.jpg
PXL_20220119_020300639.jpg

That's right, you can see 4 different channels in that second photo. There is a 5th channel installed up on the dash, in front of the A pillar, blocked in this view. The speakers are supposedly something really special, and was told the lower door speaker is something like $2k. I don't know, never confirmed it, but when I took the car to the audio shop and told them I wanted all of it removed, they looked at me like I just ordered them to shoot their dog. Long story short, they talked me into leaving it for the time being, and as we had #2 on the way in June 2021, I figured I could at least cruise around in the car with a thumpin' stereo until I got the go ahead to start going hard after our daughter turned 6 months old. And if those speakers really are that valuable, well I just got that much more money for modifications.

Anyways, when I got the car in April, I installed a catch can (that I will be swapping for something more substantial) and before our daughter was born in June, I got it on the autocross track twice, and even took it to the strip once. Mind you, this car was still on the factory PSS from 2017, and they were absolute garbage. I finished mid field in autox, and didn't launch hard on the strip to put down a good 1/4 mile time, but I left both places with a much better feel for what the car could do with some quality rubber and suspension upgrades.
GT350.JPG

I should have upgraded tires first. But I went about upgrades ass backwards. First upgrade was a DSC tuner, which some other folks on another forum, said was really good out of the box. Well I didn't do my due diligence (I'd like to say it was my kids fault, but I really just dropped the ball). I should have known better, but live and learn. I spent more than a month trying to tune it myself, to no avail. I actually had the controller sent back to DSC, where they supplied me with a new controller. They are a great group to work with, and more than understanding. With the tuner as it sat, the car was wallow-y, like the shocks were basically doing nothing. It was tough to get loose, and tough to get to turn in.

I wasn't making headway with getting the suspension dialed in, and was getting close to throwing the factory controller back on when I discovered M6G and another Mustang forum. After discovering M6G and sleuthing threads for two weeks, I was pointed to @TeeLew to help with the suspension tuning. On top of that, in January 2022 I added some hella sticky Falken 660's (Compared to the rock hard PSS) in 305/30 and 315/30 and got back to the track, with a better car # (trying to channel Ken Miles and his flying GT350R!). The benefit, I moved to upper 1/3 of the autocross event in January 2022. The car could still do way more than I was capable of. The car became very balanced. Sorry I don't have a good photo of the new tires, but they are massive, and an impressive upgrade.
PXL_20220129_193226701.jpgPXL_20211217_225549927.jpg

One thing to note. While I mention in my opening I am planning to run SST, I have CAMC on my car. At the time I ordered the letters, I didn't understand the SST rules. I believe my car will fit better in SST. I am talking with some track friends that have done nationals before to get their opinion. The foregoing upgrades are progress through January '22. As you can see, "relatively" minor modifications so far have brought me from mid field to upper third by January '22.

Before I wrap this up, I did want to say thank God for my wife. She is an angel. She is the most understanding and easy-going wife in I could have ever asked for. Whether I spend the whole night in the garage, buy something stupid for the car, scouting for elk, or take my bow for a walk on the side of a mountain in Colorado, she has always supported whatever hair-brain idea I have running through my head. I am so thankful for that. Without her, none of this is possible.

Anyways, there is more to come later today or tomorrow, but likely this weekend. Going forward, I have video's of my runs that will be included, and more of a discussion of upgrades done at how the car handles, as well as changes in driving style. Thank you all for following along. If there is more info you want, just reply and I will get it to you.

And a shout out to @DSC Controllers.
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
Welcome and don't wait till 2023 to come to Nationals, do it this year. The huge benefit is you will have seat time at Nationals to gauge, but much more importantly you will see what everyone is using , the tricks the fast guys employ, the recent advancement in tires ( there are late changes that one often finds out about ) and more. That way you won't pop up in 2023 and find out you were a year behind with some common changes in the Class. It may also help you validate what changes you want to make before you spend money only to find you should have done something else.

Trust me, going while still learning or modding your car is 100% positive and so much better than going the first time after everything is done and finding you should have gone a different direction.

I have learned this from being 1 mile, or 112 miles, or 60 miles from the various Solo Nationals sites over the past 41 years.
I certainly appreciate your comment on going this year. Unfortunately chasing elk in the mountains takes precedent this year over autocross. Several of my track friends go every year, and have been a wealth of information, including S550 guys. Also, I leave my wife with a one year old and what will be a three year old in Texas. I figure this year I have 6 months to tell her what I plan to do and get her mentally prepared haha!

Thanks again for following, and I appreciate the feedback!
 
225
177
Exp. Type
Autocross
Exp. Level
Under 3 Years
Colorado Springs
I certainly appreciate your comment on going this year. Unfortunately chasing elk in the mountains takes precedent this year over autocross. Several of my track friends go every year, and have been a wealth of information, including S550 guys. Also, I leave my wife with a one year old and what will be a three year old in Texas. I figure this year I have 6 months to tell her what I plan to do and get her mentally prepared haha!

Thanks again for following, and I appreciate the feedback!


Lets make this an elk hunting thread! ;) Where do you go and which season? I have to balance the 6 days away just before Thanksgiving (Rifle 3 near Rifle, CO) vs long race weekends. And am waiting to get a couple archery trips onto the calendar.
 
Last edited:
225
177
Exp. Type
Autocross
Exp. Level
Under 3 Years
Colorado Springs
Back to the Track Prep, I wonder how much the sound system weights. Looks like a quality install but if Im trying to cut weight etc... :)

What is the difference between SST and CAMC? I don't know their set up, but was chasing a number of newer GT350s in CAM-C out here.
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
Back to the Track Prep, I wonder how much the sound system weights. Looks like a quality install but if Im trying to cut weight etc... :)

What is the difference between SST and CAMC? I don't know their set up, but was chasing a number of newer GT350s in CAM-C out here.
I am game for an elk hunting thread!

We hunt where we can draw. We are building points in all the western states so that one day we can chase a monster. First year going guided was New Mexico Rifle. Guided was a bad idea. Then first two years DIY was Gunnison area, the first year rifle, second was bow. Then we failed to draw so went to Idaho for archery, and last year was Montana. My buddy and I both drew back, he got to release and made a bad shot. Last year in Idaho I made a bad shot as well. It sucks. Worst feeling ever.

It sounds like you got it figured out. I have a 2 yo and 9 mo, so it's REALLY hard to leave my wife right now. But in the next few years, this trips will pick up. I can't wait to take my son out west to chase elk. Or in my case, take my bow on a nice nature walk.;)

Back to the car. The sound system so far has weighted in at 160 lbs. I will be posting a write up shortly. Weight was cut, that's for sure!

My understanding is big picture, SST is the car for the guys who don't have an unlimited budget to modify like CAMC. For example, SST, you can't cut/bore out the top of the strut tower. So for an S550, you are basically limited to -3 degrees camber. CAMC you can go to coil overs, SST you can't. There is a lot of other stuff, but those stuck out to me.

I appreciate the comments and follow up!
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
So to follow up from my first post. After my January 2022 event, based on tire temps and tire wear, it was obvious the front needed more camber on the front, and most likely the rear. I knew the factory set up wouldn’t get my camber to -3 degrees on the front. I had heard guys could get to -2 on the rear, but I had two shops tell me my car had no adjustment left in the rear. If you are in Houston, PM me and I will let you know the shops so you can steer clear.

I had Vorshlag camber plates installed. Unfortunately, I did not take a photo of them before the install. And the install photo doesn’t show much other than they are already maxxed out, at roughly -3 degrees.
1647898386656.png1647898391948.png
But the results of the camber plates are below. Without widening the top of the strut tower, I was able to get to just about -3 degrees on both sides.
1647898406627.png
I also had the shop put as much camber in the rear with the factory set up as they could, and unfortunately was told they could only get to basically -.09. I don’t think they even tried. The Vorshlag plates are very well made, and definitely a high-quality product. There is no clicking, grinding, or other odd noises coming from the front that I have experienced with cheaper products. I would highly recommend them to anyone looking to install camber plates.

Also, I did not install the Vorshlag plates myself, but took them to a shop here in Houston. This was because I do not have a spring press at home, and the janky ones from the auto parts stores just scare the hell out of me, even though I’ve used them before.

So back to the car. February 2022, I ran with SCCA. With the new camber plates, the grip from the front is astonishing. The GT350 is not a light car, but I am able to come into corners with much more of a point and shoot approach, as opposed to having to get the car set up just right to get it around the corner. In addition to the camber plates, I dropped weight. I pulled the subs in the rear seat, pulled the deep cycle battery, and pulled one of the amps. With the DSC tuner, I saw my rear ride height go up 5 mm in the rear. The subs, amp, and rear seat weigh in right at 70 lbs. The battery another 27 lbs. Nothing like 100 lb weight reduction with minimal effort.

The results are immediate. 29th out of 159. Top 20%.
1647898443219.png
Here is a video of that run. As you can see, I left a lot of time out there. Even at that, I was impressed with the newfound responsiveness of the car.


Most of the February event was learning the car with the grip in the front, and weight loss in the rear. While the front gripped extremely well, the rear, at ~-1 degree camber, left a lot on the table. After the February event, I had a better feel for the car, and began researching what to do with the rear of the car. This meant sleuthing M6G again, as well as other forums, for the best options. In the mean time, I left the car alone, and focused on improving my driving. If anyone knows about Texas u turns, they are a good test of grip!

I get to the March event, feeling good about how the car reacts both on the throttle and let off, having found some open parking lots to “practice”. Well that is perfect because this course has a lot of shrinking radius corners that really exacerbated the let off oversteer. I also showed up with water to cool the tires this event, as last time they got pretty warm and I could feel the grip fading. The following video is my “two” best runs. I in the first run, I caught up to the car ahead of me (transmission issues, in a 2022 Caddy CT-5 V). I am certain the 1st run was faster, but I also thought I clipped a cone, so I stopped, for “safety”, and got a rerun.


Well that got me 17th place (of 187), top 9%!
1647898481015.png

Better yet, it got me closer to the competition in CAMC, where I was 2.76 seconds back in February, I was now 1.43 seconds back, and I ended up in third place in CAMC.
1647898494077.png

Eric and Chris who beat me, also share notes with me, so would be lying if I said their advice, tips, and tricks haven’t helped me immensely. Eric also drives a 911 that is an absolute monster, and has been co-driver in an NSX, GT350, GT500, and plenty others I can’t remember. Chris has pulled about 400 lbs out of his car and done a lot of work to the suspension. It’s something to watch it at the track, absolutely planted around corners.

Back to my car. I still had issues with rear grip. So I reached out to my suspension guru, who said my car SHOULD be able to get to -2 degrees rear camber in bone stock format. He also suggested AAD camber arms for the rear, and all my reading and research was leading me towards AAD anyways. So I ordered a set, and waited for their arrival.

In the meantime, I continued weight reduction. I pulled the remaining two amps, the welded brackets and everything that held the amps in place, the crossovers mounted in the rear dash and the controller, and most of the power cable. What I thought would take me two days to do ended up taking an entire week, from pulling panels, labeling wires, organizing wires for future use, and keeping everything from damage so I could sell later. All said and done, I pulled another 60 lbs out of the car. The car had 160+ lbs of audio equipment! The following photo is the result, looking from the drivers side door into the trunk.
1647898523686.png

That has got me caught up to about two weeks ago. Since then, I received my camber arms, and got them installed. I ended up with the AAD camber arms, as well as the vertical link and toe link. First to go on was the camber arms, since I’ve heard and read they are pretty rough to get on without dropping the rear cradle. The AAD system is pretty simple, and I wish I would have took more photos of the various bits. As I said in my first post, I am learning. Basically there is two lockout washers that are offset, so if you are drag racing you can get your camber more vertical, or if you are roadcourse/autox, you can flip them 180 degrees for more camber. These lockout washers go where the camber arm mounts to the subframe, and then you slide the camber arm right in the middle. Then there is a simple dish shaped washer (Sorry, don’t know the technical name) that bolts to the spindle. The camber is then adjusted by loosening the middle bolts, and installing a new shim plate (The silver piece in the following photo) which has the hole drilled in a slightly different spot, left or right depending on if you want to add or remove camber.
1647898539518.png

The set up is pretty slick. While it lacks the infinite adjustability of a threaded type camber adjustment, the arm also doesn’t have threads at point where the arm feels the most bending force. This is just my opinion, but it looks incredibly strong compared to the others I researched. And camber adjustments take maybe 20 minutes from when I start jacking the car until I am climbing in the drivers seat to go for a ride. Here is the arm compared to the factory arm. It is about 2.4 lbs, where as the factory arm was around 5 lbs.
1647898555357.png

So the car went up on jacks, beginning on the driver’s side, started unbolting, easy-peasy. In my head I thought what were all these guys complaining about? This came right out.
1647898568071.png1647898573828.png

Well I spoke WAY too soon. Getting out was no big deal. 2 hours into trying to get that freaking bolt on with the new camber arm, covered in blood sweat, dirt and grease, with my hand jammed between the bolt and a gas line, the shock, spring, sway bar, ride height sensor, and various brackets removed, I finally got that stupid bolt in! Lesson learned, the drivers side is brutal. Here is the finished install.
1647898587083.png

The passenger side only took an hour, and that was mostly trying to get the top bolt in again. I didn’t have to remove the shock or anything else, and it really was significantly easier without that gas line in the way.

With that, I got the string lines out, and figured out how much I had jacked up the toe, and where I was at with camber.
1647898603640.png

The toe is massively off, at 7mm in both sides (I am looking for 2 mm toe in), the camber was at -2.9. A little more than I wanted. So new shim in, and I got it back to -1.8 degrees. Toe still not right. Close enough for now. Here is the final install, without fixing the toe. That will be done once I put the toe arms on. (Yes I could have done them at the same time, but due to time constraints, and my wife wanting her half of the garage back, they are on hold until next week).
1647898624706.png

It's difficult to tell in the photo, but the front is at -3 degrees, and the rear at -1.8. My next autox is April 24, so I have some time where I will install the rear seat delete, vertical links, and toe links.

Finally, I want to give credit to @AADPerformance for awesome camber arms. They are very tough, and the paint held up perfect even after the beating the drivers side took last night trying to get it in. Not to mention the red looks awesome. And Parker over there has been incredibly helpful with purchasing, and quick deliver. In fact, all their S550 parts are in stock (Except for blue camber arms, which was my first choice), which is rare these days.

I appreciate everyone reading. I will follow up at some point next week with the next bit of install. Many have reached out, and I promise I will respond. Just trying to keep my head above water at work right now. Appreciate the feedback!
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
I wanted to give a brief update since my last post. I was one of the lucky ones to catch when OP had spindles with the GT4 studs in stock. I picked up a set, as well as some spacers. With the added camber, I am going to try and get the front track a little wider. I picked up a set of 10mm for the factory rims, and 28mm for when I go square. I am in the midst of researching rims, and have leaned heavily towards the Apex Forged Sprint VS05RS or EC-7RS wheels, so I would love to hear anyone’s real world feedback. A 10 lb weight reduction would be massive on this car!

Since last post, I received a pile of new AAD stuff, which will all get put on this week. First, I got a catch can, which I need to get put on and then get hose on order.
1648070446180.png1648070451722.png

Built very well, and looks like something I would like. My Hellcat had an orange catch can, so blood red works wells for me. I also received hubs and GT4 studs from OP. As I said earlier, I am planning on going square, so I have been paying attention to OP since I will need the hubs at some point, and I like the idea of an extra set of hubs anyways. Ignore the diapers, it was a big day for deliveries at my household!
1648070475839.png

I also received AAD toe links. With my camber arms, as others pointed out, the toe got all out of wack. I plan to get these installed once the vertical links show up. Hopefully tomorrow or Wednesday.
1648070494628.png1648070501125.png

Everything sent has been well built. I am a little nervous about the AAD toe links getting me to exactly 0mm - 2mm toe in just because it is predefined positions or keys for the toe adjustment, but we will see once I get them on. They are a solid unit just like their camber arms. Built like Reggie White.

I will provide an update once I get everything on. Going to be a busy week and work, and I hope to get in the garage as soon as I get the vertical links.

To those who have sent PM’s, I really appreciate the feedback and comments. This whole “writing about what you have done” has been far more difficult than I ever expected, much less remembering to take photos of bits you want to write about later. So as always, any feedback you have feel free to each out!
 
328
332
Exp. Type
Autocross
Exp. Level
20+ Years
So Cal
Do you know what these toe-links have for an adjustment sensitivity? It's tough to feel anything less than a 0.5mm change at the rim. It's _really_ tough to feel less than 0.25mm. I am a picky bastard on that type of thing, though. I have the J&M toe links, which use a threaded adjuster, just so I can annoy myself by taking too long on the alignment.

I love the AAD Camber arms. Like you say, complete job done in 20 minutes, and small changes in camber affects toe negligibly. It's a cool design.
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
Do you know what these toe-links have for an adjustment sensitivity? It's tough to feel anything less than a 0.5mm change at the rim. It's _really_ tough to feel less than 0.25mm. I am a picky bastard on that type of thing, though. I have the J&M toe links, which use a threaded adjuster, just so I can annoy myself by taking too long on the alignment.

I love the AAD Camber arms. Like you say, complete job done in 20 minutes, and small changes in camber affects toe negligibly. It's a cool design.
I will let you know this weekend when I align it. I had to catch up with the AAD guys and get some stuff clarified. They have been great to work with. I got the camber arms, toe links, and verticals installed last night, and will have a better write up hopefully this weekend once it's all aligned. Between replacing those three, I am down about 5 lbs on each side too.
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
So a question for folks watching this thread. As you lengthen your toe links, your toe should open up, or go from a toe in to a toe out situation, correct?


When I look at the geometry, it sure seems like that should be the case. Can anyone shed some light on this? But I sure am getting some odd measurements as I lengthen the toe link. Any help is greatly appreciated!
 
25
23
Exp. Type
Autocross
Exp. Level
3-5 Years
Houston
It has been a while since I posted. Since then I have gotten the AAD arms installed, AAD camber links installed, and vertical links installed. The alignment process turned out to be an absolute monster, mostly due to my inability to understand geometry, which often led me to installing the wrong tab into either the toe link or camber arm. Which then led to wonky alignment specs. Here are the three new components installed.
1648844563320.png1648844569493.png
The install was relatively easy. However, these AAD arms should be aligned in a specific order. First get camber dialed in, then mess with toe. It took me nearly two weeks to learn this one, despite speaking with the AAD guys several times, and them specifically telling me to do this.

AAD were fantastic. They sent basically another complete set of toe tabs to get the car dialed in when mine was outside of the typical tabs they send. The final result was slightly over -2 degrees camber both sides, and – 2mm driver side, -1mm toe in passenger side. I can go down one to link and I think I will be matching, but after two weeks of all my tiny amount of free time going towards the alignment, I am done. I will probably take it in or buy an alignment rack before I do it from home again!

I also had some free time to swap out the old catch can. The can I had in there was from a company who made quality cans for Hellcats. I assumed that same level would apply to the GT350, but it actually rested on the studs coming out of the valve cover and intake and felt cheap. This new one, also from AAD, replaces the radiator mount, and then sets between the radiator and the windshield wash filler.
1648844599714.png1648844603616.png
The finish is nice, and feels much sturdier than the old can. The only downfall, it isn’t exactly easy to get to.

I also got the rear seat cleaned up. I kept all the wires in place as I am going to wire an amp back in at some point so I can listen to music again. Until then, its just the sound of the FPC.
1648844625174.png
I am not particularly happy with the fit and finish, but it’s better than looking at wires and the trunk. I will eventually swap it out with the Ford Performance delete once I can get my hands on one.

With the suspension swapped out, and all the other weight reduction I have done, I am down 173 lbs. I am ready for the next autocross to see how the camber does in the rear, or if I need to find more rear grip somewhere else. I took it around a curvy stretch of road outside our neighborhood, and there was definitely more grip. Time will tell what it gets me for lap times!

I am caught up for now. I have hubs on the list to do, but they are not pressing as I am going to hold off on rims until later this year. Apex has something in the 20 lb range, but I would guess they, or someone else, has something a little lighter later this year.
 

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