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2011 V6 6-Speed Mustang for Endurance Racing

Hello folks, wanting to consult the oracles on a build that my family and I are in progress (well, just started, technically). We are building an endurance-race 2011 Mustang. It has a 3.7 V6 and a 6-speed. And the 8.8 with 2.73 gears. Everything is stock right now. We have a few upgrades mapped out but need some suggestions on a few things. We're very limited on the modifications we can make to the car without having to take penalty laps and we're doing this series to stay budget-minded, so bear in mind we simply aren't able/willing to throw the best of the best of the best parts at this. We will do it where needed OR where the upgrade would net us enough gain to offset the penalties (that's very difficult, though).

We can upgrade the radiator for no points, so it's on the agenda (along with hood and fender louvers). We're looking at a Mishimoto unit for around $400. I have also seen the C&R (that are close to $1000) and the elusive Ford Racing Boss 302R radiator is still out there for around $750. We're leaning toward the Mishimoto, but before we pull the trigger, has anyone had any issues with that one? I can't imagine it wouldn't help us; it's still an upgrade over stock (plus entirely aluminum so removing the plastic end tanks as a failure point), and several people have told me they have no issues with their V6 on track with stock radiator. The size/number of cores is on par with other aftermarket offerings, and this is just a V6...but endurance racing is hard on everything, so we want to be sure it'll be up to the task.

We can replace any suspension bushings we want with aftermarket urethane or delrin at no points-cost. We can't use spherical/heim without taking penalties. We've seen the Ford Racing Competition Delrin front control arm bushings. We've also seen the $550 price tag for them. Are they going to be $450 better than some Energy Suspension or Prothane urethane bushings and will those hold up to hard track use? If not, we'll sink the coin, I'll just have a real tough time doing it.

I also saw the GlobalWest Delrin front control arm bushings. They list these as 1994-2014...which seems like it CAN'T possibly be right...the bushing diameter inside the arm not having changed for 20 years? Anyone ever looked at these or run them? They appear to be the cheapest option for Delrin IF they're legit.

What are the key points for the S197 rear suspension when maintaining factory 3-link? I know on the SN95s (what I'm familiar with) a PHB/Watts, torque arm, and complete removal of the upper arms are fantastic upgrades. All that's not an option here. Will switching to urethane bushings in any/all of the rear arms reduce compliance and induce bind like it does with the factory 4 link cars? Will the urethane destroy itself in the first 5 laps under hard cornering? Are stock replacement arms with rubber gonna be the way to go back there?

Brake hoses...my brother was told that the rubber brake hoses used on the Boss were not only stiffer than the standard V6/GT but even more than aftermarket stainless lines. That seems impossible to me, but, hey, technology changes, I dunno. I still like the idea of stainless. Less chance for a tire or sharp edge rubbing through. What say you fine folks?

There are a bunch of plans I didn't mention. Gear swap, 1-piece driveshaft, things like that.

I'm sure there will be some other questions coming...I've stayed somewhat knowledgeable on the SN95, but this is a new platform to me.
 

TMSBOSS

Spending my pension on car parts and track fees.
7,074
4,442
Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
One piece drive shaft is a must. The stock unit was limited to 115mph for a reason. They were know to “Self Extract” when turned too fast.
is the gear ratio 2:73 or 3:73?
The rear three link works well with some of the bushing replaced. The Panhard bar over Watts link discussion is almost a religious conversation. Some like one over the other. It’s hard to argue with multiple series championships with a PHB. Ford makes a good one.
Capaldi make a good radiator also. Venting the hood always helps cooling.
My daughter had a 2013 V-6 six speed manual. The shifter was just as bad on the V-6 as the GT. Lockouts were not a problem.
 
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Stock rear gear for an '11 V6 is 2.73, but you also have to keep in mind the V6-specific MT82 has different gear ratios (except for the 1:1 5th) as well.
There may be room for a slightly more aggressive ratio (maybe even a standard GT 3.31) and a different type of diff over the stock Trak-lok (such as a helical) if rules allow and you'd feel like it would be useful for your track.
If it is allowed I bet some brake air ducting/cooling flaps would go a long way to increasing your endurance.
I didn't see any notes regarding shocks/dampers/springs, but if you go lower the only thing that may be worth adjusting on the rear end geometrically is the lower tailing arm angle with relocation brackets if you drop it significantly. Don't put urethane or delrin in the diff-side 3rd link bushing since it may restrict axle pivot, especially if using a helical diff where you'd be concerned about lifting a wheel (same reason to keep the rear swaybar a low spring rate in that use-case).
In 2011 models, when you fit much stiffer than OEM front control arm bushings that replace the original hydrobushings you have a chance to make the steering wheel shudder constantly due to an issue with the road crown programming making the EPAS go into a feedback loop. It looks like according to the part numbers all models of Mustang used the same EPAS rack, so it may be worth keeping that on your radar and sourcing a 2013-2014 EPAS rack used from a dismantler on eBay/local yard or getting the Boss 302R rack. They rectified the issue midway through the 2012 production year, so unless you have a build date for your donor vehicle it's often easier just to get one from a 2013 or 2014 so you know for sure.
 
I'm hoping it's 3:73........;)
One WOULD hope that...alas, it IS the stock 2.73 🤮

Stock rear gear for an '11 V6 is 2.73, but you also have to keep in mind the V6-specific MT82 has different gear ratios (except for the 1:1 5th) as well.
There may be room for a slightly more aggressive ratio (maybe even a standard GT 3.31) and a different type of diff over the stock Trak-lok (such as a helical) if rules allow and you'd feel like it would be useful for your track.
If it is allowed I bet some brake air ducting/cooling flaps would go a long way to increasing your endurance.
I didn't see any notes regarding shocks/dampers/springs, but if you go lower the only thing that may be worth adjusting on the rear end geometrically is the lower tailing arm angle with relocation brackets if you drop it significantly. Don't put urethane or delrin in the diff-side 3rd link bushing since it may restrict axle pivot, especially if using a helical diff where you'd be concerned about lifting a wheel (same reason to keep the rear swaybar a low spring rate in that use-case).
In 2011 models, when you fit much stiffer than OEM front control arm bushings that replace the original hydrobushings you have a chance to make the steering wheel shudder constantly due to an issue with the road crown programming making the EPAS go into a feedback loop. It looks like according to the part numbers all models of Mustang used the same EPAS rack, so it may be worth keeping that on your radar and sourcing a 2013-2014 EPAS rack used from a dismantler on eBay/local yard or getting the Boss 302R rack. They rectified the issue midway through the 2012 production year, so unless you have a build date for your donor vehicle it's often easier just to get one from a 2013 or 2014 so you know for sure.
Funny you should mention the 3.31. That's the ratio we're looking at in the calculators.

I think that helical diff WOULD be beneficial over the clutch type, BUT it would cost us. Even the stock Torsen from the Boss likely would get us points. And with where we're starting, we need to take as few as possible.

We may go lower. We have to be careful. Changing them up adds up points fast. We can run non-adjustable shocks/struts with no penalty. So we may go Bilstein NA. We aren't sure yet.
 
Forgot to mention it in my original post, but if you're allowed to change shifter you may want to look into getting an MGW one. Critical piece of componentry? Probably not. However, you will likely enjoy the shifting experience a lot more and if you're doing it a ton in an endurance race it may be a nice quality-of-life upgrade.
 
One piece drive shaft is a must. The stock unit was limited to 115mph for a reason. They were know to “Self Extract” when turned too fast.
is the gear ratio 2:73 or 3:73?
The rear three link works well with some of the bushing replaced. The Panhard bar over Watts link discussion is almost a religious conversation. Some like one over the other. It’s hard to argue with multiple series championships with a PHB. Ford makes a good one.
Capaldi make a good radiator also. Venting the hood always helps cooling.
My daughter had a 2013 V-6 six speed manual. The shifter was just as bad on the V-6 as the GT. Lockouts were not a problem.

1-Piece DS is ABSOLUTELY going to happen. That was my first suggestion for the build.

They are 2.73 currently. Looking at 3.31. I think that's penalty-free since it was a factory option. It also comes out ideal in our calculators.

We need to stick with the PHB. I think there's no chance a Watts makes up a couple seconds on average in lap times. I've heard of people breaking the factory ones, especially the 05-09. My brother even had it happen on his 2006 Saleen. Did they fix that issue on the 2011+? If not, $200 for a Whiteline, etc with urethane bushings is cheap insurance.

Forgot to mention it in my original post, but if you're allowed to change shifter you may want to look into getting an MGW one. Critical piece of componentry? Probably not. However, you will likely enjoy the shifting experience a lot more and if you're doing it a ton in an endurance race it may be a nice quality-of-life upgrade.

Yes, I agree. There's just the $$$ involved there. But that piece is in the discussion.

If this car belonged to me, I'd be throwing money at that sort of thing. I'm not good at budgets. But my dad and brother own the actual car. A group of 5 of us will be racing it and chipping in. But I have trouble throwing money at a car without a clear idea of what the future for our racing team holds. I know they won't screw me over. But nobody makes money on building a racecar and selling it lol. So I'd hate to throw money at it and then they decide to retire after a year or something.
 
There's just the $$$ involved there.
If you want to get thrifty, try joining some of the S197 FB Marketplace groups. They'll definitely lower your sanity level if you look at them for too long, but I've seen used MGW shifters for those moving to 6R80, 10R80 (since most people in them are drag racers), or T56 setups for around $100-150 at the lowest (average for new or lightly used ones being like $250-300). Just make sure whatever transaction you do, you're meeting in person or using PayPal Goods and Services (you get your money back if the delivered goods never arrive or if they're not as described). If you're savvy and know what you're looking for (and know the warning signs of an online scam), they can be a great way to find parts for a budget build. If you wanted to find a 3.31 rear gear, for instance, I bet there are tons of people who swapped it out of their car and have it lying around. If you didn't want to join a group you can just use the regular FB Marketplace and search for car parts in your area by radius. It seems like it has effectively become the new Craigslist, for better or worse. So far I've saved more than $1,500 on brand-new-in-box or lightly used parts from abandoned projects from Facebook, but I think I'm fairly good at navigating their swampland to find the good bits so I understand it's not for everyone.
 
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If you want to get thrifty, try joining some of the S197 FB Marketplace groups. They'll definitely lower your sanity level if you look at them for too long, but I've seen used MGW shifters for those moving to 6R80, 10R80 (since most people in them are drag racers), or T56 setups for around $100-150 at the lowest (average for new or lightly used ones being like $250-300). Just make sure whatever transaction you do, you're meeting in person or using PayPal Goods and Services (you get your money back if the delivered goods never arrive or if they're not as described). If you're savvy and know what you're looking for (and know the warning signs of an online scam), they can be a great way to find parts for a budget build. If you wanted to find a 3.31 rear gear, for instance, I bet there are tons of people who swapped it out of their car and have it lying around. If you didn't want to join a group you can just use the regular FB Marketplace and search for car parts in your area by radius. It seems like it has effectively become the new Craigslist, for better or worse. So far I've saved more than $1,500 on brand-new-in-box or lightly used parts from abandoned projects from Facebook, but I think I'm fairly good at navigating their swampland to find the good bits so I understand it's not for everyone.

Thank you! I'll play around in the groups and see what comes up. We're on both time-crunch and budget, not a great combo. But I admit I haven't even tried. My personal SN95 just gets new stuff nowadays. Got too sick of getting used parts, having pieces missing, something didn't fit right, it was listed for the wrong year, etc. Plus dealing with real people buying things just takes more effort than clicking "Add to Cart" 🤣
 
47
41
Exp. Type
Drag Strip
Exp. Level
Under 3 Years
Florida
Can you use a tranny cooler or an external fluid pump to keep the gears in the transmission happy for extended periods, without receiving a penalty? If so, consider adding one or the other. I added an external pump to my MT82. Here‘s are some pics of how I did it. I’ve also added a video of me testing out the spray pattern using brake and parts cleaner. As you can see, when the system is active, oil will spray directly onto the gears and bearings.

6346E40D-95C1-49DE-83DE-5D80717A19AC.jpeg

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B2DCF93E-0708-46B5-BEB1-02AD2183D902.jpeg

891E2639-11FD-4BCA-B3B9-D679834656E4.jpeg

FA5F9ED5-9BFD-45E0-8A33-A768A10A83CF.jpeg

A5577593-EE6E-4D56-8C12-C8D67123E9EF.jpeg

9159D797-66BF-4196-980C-0D8FE4CE8C77.jpeg

8C47F295-DC7B-4F74-8151-7FCB9E9D1C9C.jpeg
 
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47
41
Exp. Type
Drag Strip
Exp. Level
Under 3 Years
Florida
Here is what my input shaft bearing looked like at 6400 miles. I can only imagine how much extra heat and stress will be generated when road racing.

B272A737-5B92-4F56-B0CB-7E49509220A8.jpeg
 

Dave_W

Cones - not just for ice cream
649
784
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
Vorshlag has a nice kit using Bilsteins. https://vorshlag-store.com/collecti...treetpro-monotube-suspension-kit-s197-mustang
Don't lower the nose too much, or you'll end up needing more parts to correct geometry; you can drop the rear more than the front.

If you have to stick to the clutch-type LSD because of modification points, at least try to rebuild it using the Ford Performance carbon-fibre clutch pack.

Yes, very much considering those Bilstein nonadjustable and finding good springs (not just "lowering" springs). We can't run camber plates (well, we could, but it would cost us another penalty lap). I'm not sure how much camber we can "redneck" into this car, but it's no penalty to modify what's there with slotted mounting holes. That's probably where we'll start.

We were debating whether it would be good or bad to have a tight LSD setup. That rebuild kit has gotten much more expensive and hard to find the last few years. With the tire setup and only 305hp, I don't see having too much of an issue getting the power down. Will having a real tightly packed LSD not introduce other issues like making the car more pushy? It seems counterintuitive to me to lock the rear wheels together tighter and tighter, especially on a partly banked track. When my dad was running the NASCAR tracks in the 80s (ARCA), he says they were either running lockers or open diffs...total opposites. So Idk.

We're swapping the driveshaft for a good one-piece aluminum. Ditto for the flywheel. Converting away from the V6 dual mass (33 pounds!) to the GT-fit parts. My understanding is that the only special piece is a throwout bearing spacer and then we can run 5.0 stuff. We shall find out soon.
 
Will having a real tightly packed LSD not introduce other issues like making the car more pushy
The Ford Trac-Lok or any differential that combats slip by locking the two axles together at the same speed will introduce push in corners since the outer wheel cannot run at a different speed for the wider arc. That's where helical-style differentials come into play.

If you want to try the carbon clutch pack, it's part # M-4700-C and is available on Ford's own site. Warehouses from Summit and LMR suggest a restock around Feb 11-16th.

Also, if you're doing a low-cost build, remember that Summit has a price match guarantee. You can use links from website vendors you're unsure of and as long as it is 1. the same exact item, 2. in stock, and 3. they can add it to the cart (the one test they do) you can take advantage of Summit's reputation and shipping while still getting the lower price. I've done it with Ford OEM parts for big bucks off the listing price and with aftermarket parts. As an example: For my daily driver, I used Amazon links for brake components that were significantly under Summits listing price by $120 for the whole kit (but I didn't really want to order from the Amazon vendor). They price matched and I got the parts 2 days later. Best method I have found is to go to their FB page, click on their chat (Messenger) icon, request a price match check, and use the chat in order to send over the links. They'll generate an invoice number with the marked-down items and then you just call into their support line and pay for the order.
 
The Ford Trac-Lok or any differential that combats slip by locking the two axles together at the same speed will introduce push in corners since the outer wheel cannot run at a different speed for the wider arc. That's where helical-style differentials come into play.

If you want to try the carbon clutch pack, it's part # M-4700-C and is available on Ford's own site. Warehouses from Summit and LMR suggest a restock around Feb 11-16th.

Also, if you're doing a low-cost build, remember that Summit has a price match guarantee. You can use links from website vendors you're unsure of and as long as it is 1. the same exact item, 2. in stock, and 3. they can add it to the cart (the one test they do) you can take advantage of Summit's reputation and shipping while still getting the lower price. I've done it with Ford OEM parts for big bucks off the listing price and with aftermarket parts. As an example: For my daily driver, I used Amazon links for brake components that were significantly under Summits listing price by $120 for the whole kit (but I didn't really want to order from the Amazon vendor). They price matched and I got the parts 2 days later. Best method I have found is to go to their FB page, click on their chat (Messenger) icon, request a price match check, and use the chat in order to send over the links. They'll generate an invoice number with the marked-down items and then you just call into their support line and pay for the order.

Yes, I am a big fan of Summit (and their price-match). I have only ever used it once, but it saved me about $120 (they matched to a competitor running a sale on an intake). I thought I bought my M-4700-C kit I put in my 01 GT back in 2015 for like $80. I'm probably misremembering tho. I was looking for it for a friend a year or two ago and it was out of stock everywhere. Appears to be better now.

"The Ford Trac-Lok or any differential that combats slip by locking the two axles together at the same speed will introduce push in corners since the outer wheel cannot run at a different speed for the wider arc. That's where helical-style differentials come into play."

Based on this statement, wouldn't it be preferred to run a less tight diff (where helical isn't an option)? Allow lockup under higher torque input situations (power applied coming out of a corner, where the driveshaft torque is forcing the clutches together and preventing wheelspin is desirable) without locking up on corner entry? Seems to make sense in my mind at least?

I've left the S spring out for that reason (to theoretically reduce preload on the clutches...and only like 23% because it's such a PITA to get back in). I've also heard tell of open diffs being better on handling BUT not as effective on most cars because of the limits of traction on the unloaded tire. That may still be an issue for us though, so open probably isn't best, but why not a "loose" diff that takes more torque input before locking up?

Sorry for the noob questions. Diffs and their impact on handling have always been an area of weakness for me. The typical answer is to just go helical.
 
If you're trying to be cost effective, I'd just run it stock. After some seat time you can decide if it's worth putting further money into it. If you can find a boneyard local to you with a track pack 2013-2014 you may find a torsen with some spider webs on it looking for a new home.
If you want to ever get the S-spring back in, the bench vise and locking pliers trick works great:
 
If you're trying to be cost effective, I'd just run it stock. After some seat time you can decide if it's worth putting further money into it. If you can find a boneyard local to you with a track pack 2013-2014 you may find a torsen with some spider webs on it looking for a new home.
If you want to ever get the S-spring back in, the bench vise and locking pliers trick works great:
I can get them back in, I just don't see any performance advantage of keeping it. Or really any advantage except when the tires have so little traction that the spring preload actually comes into play. Maybe it happens on ice. That's the only case I could see.

We have a factory Boss Torsen and 3.73s. We just can't run them because they would cost too much in penalty laps to make them worth it.
 
Do you have the rulebook for the race series you want to participate in? Would be an interesting read. I wonder if since it's a Ford part that came in OEM vehicles if there's a loophole on what 'stock' is :)
 

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