HPDE/TT without adding camber

[Open Loop]

Greetings. I just picked up a 2016 GT with PP. I have been doing TT events with the SCCA for the last two years in re-invigorated time trials program in a Scion FR-S I have about 10 TT events under my belt, along with a few HPDE events including and PDE instruction (as a student of course).

The Sport classes in SCCA TT do not permit camber adjustment beyond what is available from the factory, per my understanding. In the class I have been running, this has caused an issue of extreme edge tire wear, where a set of RE71R'S can be corded on the outer edge after two weekends of racing. I am interested in whether anyone has been racing this car in its Sport class and has had a similar experience with tire wear.

Ultimately, my question will be "what SCCA classes for autocross and TT is this car best suited for so that I can make a call as to whether and how to build it for competition." My preference is to do less modding than more, but I don't want to end up heading in the wrong direction.

Thank you

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[SteveW]

One question: what made you move from an FRS to a 2016 Mustang?

In my mind the 15-17 Mustang's competitive days are over in FS (Street/Stock) autocross so plan on building the car for a higher prep level. Street Touring, with its limited allowances, does not have a competitive place for Mustangs to play. ESP is an option but you will need to be on Hoosiers, which takes you into the Unlimited Category for TT (not good, IMO) unless you have a set 200TW tires for TT and run in P1, I think.

Which brings up CAMC - where I think you should focus. The comparable TT class is M2 I believe.

For autocross, the 2015-2017 GT is hampered by too short a 2nd gear so, plan on a gear swap and 7500 rpm tune to get your 2nd gear up near 70 mph.

Easy button on wheels and tires is 19x11" 305/30-19 RE71R or Rival S 1.5. There are other options for that wheel with perhaps the GY Supercar3. In 18x11 there are a few more tire options but your 2nd gear might be too short on big autox courses unless you look at the 295/35-18 Yoko A052. I don't think anyone around here has tried that tire yet though.

Suspension is a can or worms. Much of the easy bolt-ons in the Mustang aftermarket contain different bushing material and therefore not legal for ST/SP autox or Prep level TT.

1. I feel strongly you need a set of front coilovers with a spring rate above 500 lb-in before the car really starts working and there are some custom valved shock options for great prices that can handle springs like that. Be careful here on offset ones for tire clearance and the impact on interference with the front swaybar endlink connection depending on what bar you decide on.
2. Easy button rear springs are Steeda Dual-Rates. These are working great for a few of us.
3. Plan on replacing the god-awful rear camber and toe links with one of the aftermarket replacements that have spherical bearings and proper adjusters.
4. There are bolt-on diff inserts and rear subframe lockout kits that make it easy to shore up those bushings without going through a lot of drama to install poly bushings in place of the factor rubber ones.
5. A front bumpsteer & roll center correction kit is highly recommended.
6. Weight reduction - how much money you got? haha

 

[Open Loop]

Thank you, this is great. I still have the FR-S and I plan to keep it and keep racing it. I may continue to focus my money and energy there (which is cheap to run). I like the idea of having more power (who doesn't) in a sports car which for the price made the Mustang GT a standout. It may be that this car does not get developed beyond track day use.

 

[BmacIL]

Fwiw I use mine in T2 in addition to CAMC.

 

[Open Loop]

Fwiw I use mine in T2 in addition to CAMC.

I see that it competes against the GT350 in T2, and I didn't read the entire list of cars it competes against. So it looks like it's an underdog in S2 and T2, which is ok but good to know going in. It also looks like building to the limits or even close to it in cam-c would require alot of modification.

 

[BmacIL]

I see that it competes against the GT350 in T2, and I didn't read the entire list of cars it competes against. So it looks like it's an underdog in S2 and T2, which is ok but good to know going in. It also looks like building to the limits or even close to it in cam-c would require alot of modification.

Diminishing returns. You can be pretty competitive in CAMC without spending bookoo money. Definitely more than FS, for sure, but less than people think.

 

[NightmareMoon]

Camber (and properly wide wheels) is whats needed to stop the bulk of the tire edge wear. If you can’t go get camber, then definitely flip the tires left/right before you cord the outside edge. That can almost double your tire life so its worth the labor cost.

 

[Open Loop]

That is a nice thing about the RE's - the flipping.

 

[Grintch]

See the FS legal camber mod in that thread.

Basicly, you slot the upper strut mounts to gain camber. It is in the Ford Service manual, so legal. IIRC this gets you to around 2 degress, which is still not enough, but much better than stock.

The next step up is STU which allows camber plates and most bolt on suspension mods (but NOT a lot of the diff locator mods). For TT (Tuner 2), the equivalent class allows a much wider tire, so improving the classing verses autocross (Mustang too heavy to be very competitive in STU autocross). Last time I looked, all the Mustang friendly stuff from the now dead STP was allowed in T2.

CAM-C I am not sure even has a direct TT equivalent (Max category maybe) . But even if it does, do you want to trade the ability to run common stop the hop mods for having to run against very heavily modified cars (like supercharged, turbocharged, big aero, etc.)? While a lot of these extra mods don't have a big impact at autocross speeds, especially when limited to street tires. At higher speeds on a road course, they will make a big difference.

 

[Open Loop]

Basicly, you slot the upper strut mounts to gain camber. It is in the Ford Service manual, so legal. IIRC this gets you to around 2 degress, which is still not enough, but much better than stock.

This is great. Do you know where I can find these instructions?

 

[strengthrehab]

See the FS legal camber mod in that thread.

Basicly, you slot the upper strut mounts to gain camber. It is in the Ford Service manual, so legal. IIRC this gets you to around 2 degress, which is still not enough, but much better than stock.

The next step up is STU which allows camber plates and most bolt on suspension mods (but NOT a lot of the diff locator mods). For TT (Tuner 2), the equivalent class allows a much wider tire, so improving the classing verses autocross (Mustang too heavy to be very competitive in STU autocross). Last time I looked, all the Mustang friendly stuff from the now dead STP was allowed in T2.

CAM-C I am not sure even has a direct TT equivalent (Max category maybe) . But even if it does, do you want to trade the ability to run common stop the hop mods for having to run against very heavily modified cars (like supercharged, turbocharged, big aero, etc.)? While a lot of these extra mods don't have a big impact at autocross speeds, especially when limited to street tires. At higher speeds on a road course, they will make a big difference.

Why would a CAM car not fit into T2 again?

 

[BmacIL]

See the FS legal camber mod in that thread.

Basicly, you slot the upper strut mounts to gain camber. It is in the Ford Service manual, so legal. IIRC this gets you to around 2 degress, which is still not enough, but much better than stock.

The next step up is STU which allows camber plates and most bolt on suspension mods (but NOT a lot of the diff locator mods). For TT (Tuner 2), the equivalent class allows a much wider tire, so improving the classing verses autocross (Mustang too heavy to be very competitive in STU autocross). Last time I looked, all the Mustang friendly stuff from the now dead STP was allowed in T2.

CAM-C I am not sure even has a direct TT equivalent (Max category maybe) . But even if it does, do you want to trade the ability to run common stop the hop mods for having to run against very heavily modified cars (like supercharged, turbocharged, big aero, etc.)? While a lot of these extra mods don't have a big impact at autocross speeds, especially when limited to street tires. At higher speeds on a road course, they will make a big difference.

Where your CAM-C car fits into SCCA TT rules depends very much on how much you do for CAM-C. The key staples to going fast in CAM: coilovers, camber, suspension bearings, fat wheels & tires, would not put you out of Tuner category.

 

[Grintch]

Where your CAM-C car fits into SCCA TT rules depends very much on how much you do for CAM-C. The key staples to going fast in CAM: coilovers, camber, suspension bearings, fat wheels & tires, would not put you out of Tuner category.

While I agree on tires, which were also legal under STP (as was all the rest of the above too). I thought what bumped everyone to CAM was the ST illegal diff bushings/inserts/etc.

Basicly T2 reads like STP to me. So a long list of CAM-C mods would not be legal. And we know most people seemed to choose CAM-C over STP, so I assume their cars fit better there (not legal in the lower class).

PS - the specifics of the FS camber mod are buried deep in the "What's everyone doing for FS" thread.

 

[BmacIL]

I thought what bumped everyone to CAM was the ST illegal diff bushings/inserts/etc

That and cradle lockouts and such, yes.

For SCCA TT rules, there is a unique exception which applies to our cars:
"If the standard bushing accommodated multi-axis motion via compliance of the component material(s), the replacement bushing may not be changed to accommodate such motion via a change in bushing type, for example to a spherical bearing or similar component involving internal moving parts."

That ^^^ is true for the rear LCA bushing and the front tension link bushing...which are both very worthwhile pieces to replace. The diff bushing inserts aren't valuable for anyone other than drag racers, TBH.

 

[Grintch]

An exemption? How is "MAY NOT" an exemption? Looks like it is explicitly illegal to me.

Anyone else have a problem with the TT rules not being properly published like all other SCCA rules. Just that stupid, poorly organized web page. What next, we have to watch a YouTube video that vaguely describes the rules?

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