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This fender cutting is an ugly, temporary measure - we will make some proper flares when we have more time, over the next few months
This fender is now cut "beyond safe", as the tire cannot physically get to that point without the struts exploding. We checked for clearance with the front wheels turned in both directions at full lock, while compressed at full bump and dropped at full droop, as well. This amount of fender clearance and testing might seem like overkill to some, especially the Stance/VIP crowd (who strangely LIKE it when their wheels rub their fenders?!) but I've seen too many racers cut brand new tires on under-trimmed fenders. I don't want to end a race weekend over something we can prevent with proper preparation and testing (I'd rather hit a curb on track and end a day early that way, ugh!). Ryan cut the offending portions off of both fenders with an air nibbler and a cut off wheel, then swapped in a stiffer front spring (we went from 60mm x 7" x 550#/in spring to an 800 #/in rate up front now) and firmly attached the now cut and very ghetto looking "new" fenders. Once on the ground I asked the guys to lower the front ride height by 1", which I've been wanting to do for a LONG time.
Left: Even with -3.4° front camber we have some "poke" on the new 18x12s. Right: Running to get a tank of 93 octane and ice before Hallett
Rear Spring and Ride Height Changes
Out back we lowered the rear ride height an inch, to match the front. Finally, the car is at the proper ride height. Yes, we've been running the car a bit higher than we wanted for a while now, simply to keep the 315s from rubbing on the front fenders in a big bump. I'm paranoid as
I've ruined front fenders before getting them too close to a new wide tire and wheel combo. The rear fenders already cleared the 12" wide rears at lower ride heights, and we had the rear LCA relocation brackets since last Fall (to fix any geometry issues on the very lowered rear heights), but the fronts were a worry.
No, fender rolling wouldn't have been enough - not even close. The 11's were already pushing the limits, and could have rubbed at a lower ride height. The 12" wheels were 1" out past the old 11's, so it would have been deep inside the sheet metal. Now that we have finally cut the front fenders, the overall ride height could drop. This will allow the front splitter to be more effective (the closer to the ground it is, the better it works) as well as lower the CG of the entire car by an inch - always a plus. We quickly found that loading the car onto our trailer just got a LOT harder, though. Doh! Oh well, nothing some longer ramps cannot handle (until we make the front end removable - later this summer, hopefully).
While the guys were working on the rear ride height, they swapped out the 250 #/in springs we had been running to a stiffer 350 #/in rate Hyperco spring, to match with the front spring rate bump. Why more spring rate? Well we had been noticing a lot more bodyroll than we liked in pictures of late. As grip and aero forces increase, spring rates need to rise as well. The Mustang is now truly "uncomfortably stiff" on the street (with the valving set for track use), but it isn't as bad as some cars I've driven over the years.
The custom valved Motons (using AST-USA's DDP digressive pistons) can be turned down a lot and it isn't as miserable as you'd think... but I'd still recommend lower rates for any dual-purpose car. If you are moving up to AST/Moton/MCS/Bilstein or another brand of monotube shocks we carry you can see them all compared on our revamped
shock intro page. If you have any valving or spring rate questions beyond that, please feel free to call or e-mail us. Suspension is still the meat of our business.
A-ha! Finally remembered this one. I meant to put these rear control arm weights somewhere in this thread many months ago. We added these Whiteline rear Lower Control arms (LCA) in the Fall of 2012, after we left the SCCA's classing behind for this car (STU and ESP doesn't doesn't allow aftermarket rear LCAs, relocation brackets, and all sorts of other common aftermarket parts available for these cars - "its the SCCA", what can I say?). These lower control arms are adjustable in length, tubular steel, stiffer yet slightly
lighter than stock, and filled with Whiteline's famous elastomer bushings. These things have worked very well on our Mustang (track, street and autocross), make no noise, and don't have the deflection of the SUPER SOFT rubber that are in the OEM arms (as well as the
Roush billet aluminum arms with OEM bushings - an odd item, that we recently installed for a customer). OEM stamped steel arms were 6.0 pounds vs the Whiteline arms at 5.3 pounds. I wouldn't have thought that the flexy, stock stamped steel arms would be heavier than the thick walled, tubular, alloy steel, adjustable length WL arms, but the scale doesn't lie. I hate it when I talk about a particular part and forget to weigh the dang things, and the OEM part it replaces. So this is just a catch-up to previous posts. Trying to stay consistent.
Mustang Braking Capabilities and Improvements
Now lets take a step back for a second and move to a higher level discussion of S197 Mustang brakes. This is another area we wanted to address on our TT3 Mustang, but a little background helps further the overall S197 discussion. We've been pushing the limits of the OEM 14" Brembo front/11.8" rear disc brake set-up that comes on the '11-up Mustangs (that have the Brembo option) as well as the Boss302 and most of the GT500 Mustangs (the GT500 upgraded to 13.8" rear discs in 2013 and 15" front discs and 6-piston calipers in 2014), and wanted to see what we could do next.
Long ago we found that these brakes could be overtaxed quickly on track if left 100% stock. The basics are there (size of rotor, proper caliper) but the factory installed "consumables" weren't quite up to the task of track events. Easy upgrades like flushing out the old stuff and installing real DOT4 brake fluid (like Motul RBF600), using proper track-compound brake pads (like Carbotech), installing upgraded brake flex lines, and especially front brake cooling ducts and hoses makes a
huge improvement in braking with the S197 Mustangs on track. Yes, even with the big 14" Brembos, you need to think about these upgrades if you want to push it on a road course. These are BIG, heavy cars with 420+ hp, and it doesn't take much effort to overtax even the larger Brembo brakes on track.
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