yes, those are the specs on the performance brakes. What is the dimension on the high-performance rears?

 

High performance rears are the same 326 as the base.

Standard brakes are:
Base 355 front 326 rear (performance)
V6S 380 front 326 rear (high performance)
R 380 front 376 rear (super performance)
The base can be optioned with either of the higher spec set ups and the S can be optioned with the super performance set up.
My S came with the standard S brakes, so high performance 380 front 326 rear, but last week I upgraded the rears to 376 so I now effectively have the super performance brakes.

 

My doc says 325mm rears, not 326mm. This is from 2014, presumably hasn't changed.
https://www.dropbox.com/s/x0x62a2t0z...rakes.pdf?dl=0

To summarize:
Performance (silver caliper): 355mm front
Performance/High Performance: 325mm rear
High Performance/Super Performance: 380mm front
Super Performance: 376mm rear

And as of 2014, the Super Performance calipers were black with red as an option. I thought they were red, but maybe everyone chooses that option.

 

I know Philly Single has sold his car and moved on, but I see these look great with a 20x9 and 20x11. Im curious as to what the proper offset would be, without spacers, on H&R lowering springs. unhingd? And what size tires are pictured.

 

 

Excellent. Trying to find the best width and offset to go with. I have a nice set of 295/30/20 MSC2 in the basement. I take it push it out 15mm, to make up for the 15mm spacer people use when putting stock wheels with 295s.

 

Front 9.0, Rear 11.0
For 255, 295 you want 37mm and 29 offsets.
For 265, 305 you’ll want 42mm and 34mm offsets

 

thats flush with fenders, no spacers?

 

Correct. No spacers needed or wanted. This puts the tires just inside the fender lip with just enough clearance to avoid tire rub at full spring compression.

 

You are the best my friend

 

Many would disagree, but thanks.

 

There is a lot of misinformation of the benefits of reducing unsprung weight and I wanted to explain the benefit in simple terms.
Unsprung weight is everything attached to the pivot points of the suspension and the chassis. From control arms, to rotors, calipers, hub, sensors, wheel tire etc. On flat roads, it will not make any difference but anytime suspension travel is involved it will come into play. When the wheel hits a bump, the bump or road irregularity will prompts the wheel to travel, the spring is the only opposing force and the shock absorber is tasked with dampening the travel. The energy that the suspension will be counteracting is a factor of the mass of all unsprung weights and the acceleration imparted of that. You want to minimize that kinetic energy in order for the suspension to work as efficiently as possible and maintain the contact patch of the wheel as large and effective as possible. You have no control over the acceleration imparted on it but you can reduce the mass of unsprung weight and therefore minimize the energy that the suspension needs to counteract. So basically, anyone claiming that lighter wheels make a huge difference on a racetrack in improving their cornering abilities is full of it. In real life, on the road, where the pavement is less than ideal, you will certainly see a difference, like in turns at high speed on a bridge or road with expansion joints. The only real benefit on a track is the overall weight reduction but "unsprung weight" isn't the factor. Additionally, with a great reduction of unsprung weight, springs and dampeners should be adjusted as well for best performance (adjustable coilovers with preload adj. and two way dampening adjustments). That is the way to maximize an investment in unsprung weight reduction. Hopefully I made this explanation as easy to understand as possible.

 

Name one! (Other than me, DJS and Mbourne).

 

Track surfaces must have improved immensely in the last few years. Nelson Ledges, Summit Point, Second Creek, Aspen, Pueblo, Waterford Hills all had surfaces that would be put to shame by most mountain twisties. Unsprung weight was always a consideration when we were building racecars.

 

Then they did. For racetrack I can tell you that Limerock, Pocono, Monticello have amazingly smooth surface... Most real track cars have very limited suspension travel for that reason.

 

That's a huge change from 30 years ago. It must be due to improvements in asphalt formulation. Back then, even a freshly surfaced track could be turned into rough surface and pea gravel half way through the season by the ground thumpers (the heavy V8 production cars).

 

On newer tracks, I assume that the paving system used must be more consistent. Also, the fact that most newer race cars rely very heavily on downforce to stay on the road forces the need for a very even surface to avoid "catching air" and having cars truly take-off. The bottom line however remains that reducing unsprung mass is certainly good for normal road. It would be nice if the stock Bilstein Damptronic could be finely tuned instead of just comfort or sport. By reducing unsprung weight there should be a corresponding reduction in dampening for ideal performance, maintaining the same level pretty much negates a good part of the mass reduction as the spring will still compress at the same rate of speed and transfer the surface disturbance to the chassis just as harshly and overtaxing the tire.

 

I was wondering about that myself, as I am contemplating a further 70 or 80 pound weight reduction with carbon fiber wheels. Is the setting on those shocks selecting an alternate hydraulic circuit or is it modulating a flow valve. If the latter, a rheostat might be used to control the shock. If not, filling the shock with a different viscosity oil might accomplish what is needed. On my racing Bugeyes, I would fill the cantilever shocks with STP oil treatment to stiffen the suspension.

 

Never in a million years would I have thought Waterford Hills would be mentioned on this forum.

 

that’s where I learned raise. At the time (1975) it was nothing more than 1.1 mile long circuitous driveway .