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2012 Boss 302 Build Profile - S197 Mustangs

KonaBoss

TMO Advanced
115
69
Metro Detroit
Hey all,

Have been lurking around this forum for a couple of years now, all I can say is thank you to all the members that post on this forum! I have learned a ton from here, and have (hopefully) applied what I have learned to my build up that I'm about to begin.

As of right now, my boss is mostly stock. Has ARH longtubes with the 3" x pipe with provisions for retaining the side pipes. It also has '10-'12 GT500 axle backs, and the QTP electronic cutouts for the side pipes. I have a tune from Shaun at AED (93 octane), a stainless steel clutch line, and an MGW shifter.

Goals for my build/vehicle usage: I drive this car in the summer on nice days on the street. Here in Michigan (Detroit area), the roads are pretty abysmal, so ride quality is a key factor for me, as well as ride height. I put between 2500 and 5000 miles a summer on it. I also autocross it 1 to 2 times a summer. I do it more for fun and to compete against friends than for FTD or anything along those lines.

So, with those goals in mind, I started accumulating parts to enhance the suspension on my car. I'm content with the ride quality of the factory suspension, but I would like to fix a couple of weak points that I have identified.
A. I'd like to reduce the amount of axle hop the car has on hard acceleration
B. Leveling the ride height front to rear has been on my to-do list for a while. More of an aesthetic thing than anything else
C. I have found that with the stock tires and suspension setup, the car understeers at the limit when autocrossing. I'd like to dial that out and get the car closer to neutral handling characteristics.

Parts acquired to meet my goals:
1. Ford Performance M-5300-T boss 302 specific lowering springs - These seemed to be the best balance of ride and lowering height from what I have seen to fit my goals. I will be re-using the factory boss 302 struts.
2. Ford performance M-5570-A bump stop kit - I got this kit since the used T springs I bought didnt come with them. As far as I can tell, this is what should have come with that spring kit from the factory.
3. Whiteline KTA195 adjustable rear lower control arms with MAX-C bushings - I bought these in hopes that they strike a good balance between NVH and helping to reduce the axle hop under acceleration. Since they are an elastomer bushing, I don't think they will clunk and squeak like spherical bearings do. Also, they are adjustable so they should allow me to dial pinion and driveshaft angle back in once I re-assemble everything.
4. Maximum Motorsports Mm5RLCA-57 lower control arm relocation brackets - should help me ensure that the lower control arm angle is correct once I lower the car. I chose these over the whiteline ones due to the better design/increase adjusability. Hopefully they play nice with the whiteline LCA's...
5. Maximum Motorsports Mm5PBAR-3 adjustable panhard bar - this has spherical bearings on it, I'm hoping I dont run into too much clunk/squeak behavior since it will only be (theoretically) traveling in one plane of motion.
6. Maximum Motorsports Mm5CC-6 caster camber plates - to help dial in the front caster and camber alignment
7. Vorshlag S197 Stainless steel brake lines and motul RBF-600 fluid - I'd like to get a bit better brake feel as well while I'm at it.

So, with those items in mind I'm hoping to achieve my goals outlined above. I'll be digging in over the next couple of weeks, so I'll keep everyone updated. If anyone has comments/concerns/hints/tips to share, please feel free! I'm going to start with the following steps:
Step 1: Measure pinion and driveshaft angle before tearing everything apart
Step 2: Measure axle location side-to-side before beginning
Step 3: Measure stock ride height for a comparison to once I am done

Last note: The plan is to move to a 19x10 square wheel setup with 285/35/19 PS4S (or equivalent) tires once I am finished with the suspension work. This should further help dial out the oversteer from the factory setup.
 

Coz

TMO Addict
869
652
Philly Metro Area
HPDE
3-5 Years

KonaBoss

TMO Advanced
115
69
Metro Detroit
I'm not sure the adjustable LCAs will be enough to adjust your pinion angles. You may need an adjustable UCA. Whiteline used to sell one with their Max-C bushing but they don't seem to offer it anymore. However, American Muscle sells an RTR UCA that uses the Max-C bushing.

https://www.racingjunk.com/news/2016/03/02/bmr-suspension-adjusting-s197-mustang-driveline-angles/
Thanks for the link! That is the most thorough article on driveline angles that I have seen yet. I'll definitely keep that in mind. I'm going to start with keeping the stock rubber one and I'll see if I have enough adjustability in the LCA's to cover for it. If not, I suppose I'll have to go down the aftermarket UCA rabbit hole...

But, as @Mad Hatter said, changing up the UCA can induce alot of NVH, depending on the type of bushing.
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Your "B" goal is likely going to counteract your "A" and "C" goals.

The camber plates will help with your understeer issue. Going to a wider front tire (square setup, as you have planned) will help significantly with understeer.
@ArizonaBOSS as I understand it, having a bit of forward rake is good. I think the FP "T" springs may leave a small amount of it in place.

Can't wait to go square! Will also be good to get off the stock 9 year old pirellis...
 
Last edited:

KonaBoss

TMO Advanced
115
69
Metro Detroit
9 year old Pirellis!!! Its a drift car!! To be fair about the UCA, I went spherical on both ends (I regret and will remedy..).

If I remember right, even the Phoenix 33 car has the stock OEM UCA?
Yea... The last couple of autocrosses have been an exercise in correcting understeer with copious amounts of throttle, so pretty well a drift car. While entertaining, it certainly is not the fastest or most efficient way of doing things. However, it does burn the Pirellis off faster :)
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Got the car up in the air tonight and took some measurements.

Stock ride heights (referenced from ground to top of wheel arch, 1/2 tank of fuel):
Passenger front: 28"
Passenger rear: 29"
Driver front: 27 3/4"
Driver rear: 29"

Driveline angles (factory 2 piece driveshaft, measured at ride height, all measurements taken from driver's side of vehicle):
Trans output flange: 5.8 degrees downward toward rear of car
Rear piece of driveshaft: 5.4 degrees downward toward rear of car
Rear diff pinion flange angle: 1.9 degrees downward towards rear of car.
 

APEXRaceParts

Race Proven, Street Approved
Supporting Vendor
515
656
Bay Area, CA
Looks like a fun build with a solid parts list so far, plus I'm a sucker for a Kona Blue and white Boss! Let us know if we can help out on the wheel department, we've got a few of those 19x10s laying around :cool:

For what it's worth, we've had some people run 18x10 square with a 275/40-18 Bridgestone S007A and been very happy with the performance for the kind of driving you do.

- Cory
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Looks like a fun build with a solid parts list so far, plus I'm a sucker for a Kona Blue and white Boss! Let us know if we can help out on the wheel department, we've got a few of those 19x10s laying around :cool:

For what it's worth, we've had some people run 18x10 square with a 275/40-18 Bridgestone S007A and been very happy with the performance for the kind of driving you do.

- Cory
Hey Cory, thanks for the kind words. I'll definitely keep you all in mind when it comes time for wheels. Unfortunately I'm not really a huge fan of how 18" wheels look on the S197 chassis (at least 2010+ anyways), and since this is mostly a street car I like the looks of the 19's better. Otherwise, I'd take the 18's in a heartbeat and save myself a bunch of $$... Quick question for you, do you all offer custom colors on your wheels at all?

On another subject, I went to put on my front Vorshlag stainless brake lines last night, and the fitment seemed way off. I think the previous owner of the lines may have bent them slightly differently to clear brake ducts or something along those lines. I was able to gently bend them to get the brackets in the middle of the lines to bolt up to the retention bolts on the struts, but I'm not so sure I trust them anymore after having bent them...

Does anyone know the size of the copper crush washers for the front 4 piston brembos? Need to replace mine after changing lines.
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Made more progress this weekend. Up front, I got all the suspension bolts on the struts tightened back up, and and initially set the caster/camber plates based on the instructions from Maximum Motorsports. Also finished installing the brake lines, for the record they use 10mm crush washers. I found the thinner ones worked better and formed a better seal.

In regards to the rear suspension, I pretty well tied it up. Put in the new springs, lower control arms, relocation brackets, panhard bar, and brake lines. I adjusted the lower control arms to factory length to start with, as well as the panhard bar. I know I'll need to adjust the panhard bar at a minimum, but I'll probably wait to do that until I can get the car to a facility with a lift in the springtime (unless anyone here has some good hints/tips to adjusting it on jackstands).

Working on bleeding the brakes now. Putting in some Motul RBF600 and ordered up a motive power bleeder to streamline the process.

Remaining items:
Torque rear shock lower mounting bolts and mark them
Mark the rear sway bar bracket bolts
Alignment
Check pinon angle
Adjust panhard bar
 

Coz

TMO Addict
869
652
Philly Metro Area
HPDE
3-5 Years
I know I'll need to adjust the panhard bar at a minimum, but I'll probably wait to do that until I can get the car to a facility with a lift in the springtime (unless anyone here has some good hints/tips to adjusting it on jackstands).
If it is a double adjustable bar and you have (or can borrow) a reasonably high set of ramps you can get the rear on the ramps and adjust the turnbuckle fitting until your rear is centered.

 

KonaBoss

TMO Advanced
115
69
Metro Detroit
If it is a double adjustable bar and you have (or can borrow) a reasonably high set of ramps you can get the rear on the ramps and adjust the turnbuckle fitting until your rear is centered.

Chris,

Very good point, didnt think of that. I have the Maximum Motorsports double adjustable bar, so I could definitely do it on ramps. I'll have to ask around the friend group and see if anyone has a sizable set of ramps.
 

LS291

TMO Intermediate
64
33
Pennsylvania
Welcome back KonaBoss!

Glad to hear you are wrenching on your Boss. Sounds like we still have similar directions for our cars. I too use mine mostly for street with the hopes of squeezing in a single track day or autocross once a year. I did my first track day at the Boss Reunion at PittRace back in early September and can see how one can get addicted pretty quick.

I have followed a similar mod path with my 2012 LS. I am trying to keep it as Ford centric as possible:

Ford Performance filter and removed side baffles
Ford Performance lower control arms
Ford Performance panhard bar
Ford Performance T springs
Ford Performance AL drive shaft
MGW X-spec shifter
MM caster/camber plates
Track Key

The T springs with the factory struts feel like a good combo for someone at my skill level and street oriented desires.

I ran the Motul RBF600 at my track day and never had an issue. Seems like good stuff based on what little experience I have with it. I picked that up from this forum (thanks everybody!!).

I can second Cory's comments about the Bridgestone S007A's. I put a set on for the Boss Reunion on the factory LS wheels (275 front, 285 rear). They ran great for my skill level. The got good and sticky (for lack of a better term) on the track and autocross and were totally fine on the street. I can see myself getting dedicated track wheels in the future if for anything else but to not have to clean those pretty red LS wheels again.

Anyway, keep us posted. I am also more of a lurker than a poster but I can be brought out now and again for good stuff I can relate to.


PS, I would also be very interested in a PM/Conversation update on your 95. Hope all went well there.
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Finished up bleeding the brakes last night, and torqued the lower shock mount bolts. Everything is buttoned up, will be dropping it back on the ground either tonight or tomorrow night. Will post some pics of the finished product once I can figure out a good directory for them that the forum likes.
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Meant to update this a couple days ago, but have been busy at work. Car is finished up minus an alignment and adjustment of the panhard bar. My final measurements for ride height after the lowering springs are:

Driver Front: 27 1/4 in
Driver Rear: 27 3/4 in
Passenger Front: 27 1/4 in
Passenger Rear: 27 3/4 in

So, if I compare that to the numbers before the lowering springs, I got an ~1/2-3/4in drop in the front and 1 1/4in drop in the rear. Car looks fantastic, exactly the ride height that I wanted. Gets rid of the large rake from the factory. Cant wait to get it out in the spring and drive it!
IMG_20200111_193437.jpg
IMG_20200113_220647.jpg
IMG_20200125_143755.jpg
IMG_20200125_143807.jpg
 

KonaBoss

TMO Advanced
115
69
Metro Detroit
Update for everyone:

Got the car in for an alignment before this whole corona-crap started, alignment went great! While the car was up on the rack we took the time to adjust the panhard bar to make sure the rear axle was square (I eyeballed it pretty well). This was the first time I have had this car aligned, and looks like I got a good one! The rear axle is totally square side to side, and acutally has a little bit of camber built into it on both side. For the front I went with about 2.5 degrees of camber.

Has been a cold spring here in Michigan, but the last couple of days have been really nice so I took it out for a drive yesterday, and let me say the car has made a pretty big transformation! Goes exactly where I point it, no more rear end shifting around under relatively hard cornering, etc. And this is still on the old, crappy, hard as a rock pirellis that came on the car.

Next up is a new wheel/tire setup. I'm going to go with Forgestar F14's in 19x10 square fitment, thinking +35mm offset. Does anyone have any experience running a setup like that? Is +35mm too aggressive on the offset? For tires I'll be running 285/35/19 Michelin Pilot Sport 4S's.
 

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