2007GT/CS almost certainly has wheels that are wider relative to the tire size than what FS limits competitors to, and ought to be able to work with slightly less without sacrificing lateral tire stiffness.

But ditto regarding current tires and "rolling over" with the 18" GT BFG tire/wheel package as well. At cornering levels where slip angles can clearly be felt and maybe 34 psi in the fronts the scuffing barely goes halfway around the shoulder. I miss not having the little triangles though . . .


Norm

 

I'd agree, but only to a point. Yes he has wider wheels (good), but the tires are also not as stiff being street tires--though they are relativelystiff. At the same time the stock 235/55-17 Pirelli's on 8's aren't rolling off at only 32 psi. I'd expect as least as much from his tires, but you never can tell, all tires are not the same.

I don't know he needs 40 psi, and would lying if I say that was anything but an educated guess, but better safe than sorry starting off.

 

You are correct - except that I'm also replacing the GT500 ball joiints with the Steeda X-5 ball jointsto compensate the the front end drop. On May 19 we'll find out how it all works.

 

Hi Sleeper_08,

I think you are going to like the chassis but go easy on the throttleandbe sure to bed the pads and rotorsmaking sure you havegone through two or three full heatcycles on the rotors before going to the track.StopTech and Baerhad somepretty good bedding and rotoraging directions on their websites. I have notlookedat them lately but Stoptech used to have some very good technical white pages on brake systems that I think were some of the best on the internet. And don't forget your tire pressure gauge.

HTH!

 

F1Fan

Thanks for the reminders.

The front pads are Ferodo DS2500 and the rears are Hawk HPS. The plan is to bed them in on my way to alignment shop after we finish the work. I'll check out the web sites you suggested for bedding instructions.

Since picking up the car last monthI have learned to give it a lot of respectas even with the new 285/40/18 KDW2s it will easily break the back tires loose in first gear.

 

I believe that Caster on the S197 is non adjustable. Mine is set to 6.8 to 6.9 deg.

 

Hey Sleeper_08,

How did you pickHawk HPS fora rear pad compound? I think you will be giving up a lot of friction and some stopping power on your rear axle once the DS2500's in front are bedded and up to temp. They bite a lot harder when fully warm and will still work well past the HPS compound'smelting point.

HTH!

 

I am trying to find a combination that can be driven daily but will still work well on the track days. From what I had read this seemed like the best combination.

What would you suggest?

 

Hi Sleeper_08,

I would have used DS2500 all around or EBC Yellow "R" all around. Personally I think I'd want a rear pad material witha coeffiecent of frictionequal tothefront pads based on what I've seen with large grippy tires all around these cars.By addinga largerfront brake system capable of higher than stock torqueI'd want to increase the rear friction as much as the front to let the rear brakes have a chance at lasting longer and not over heating.

The DS2500 pads are sort of dusty butare very high friction and have a very high MOT for a street compatablepad. EBCYellow"R"compoundis almost as high friction as DS2500 but dust aless and top out heat wise sooner thanDS2500 does.The HPS pad compound is really just an improved street pad with an extended upper heat range and lower dust.HPSpad materialis not a competitonlevel by any means andcan be overheated if you use them hardand they seem to wear fasterwhen overheated and then pushed.

The rear brakes on the S197 are surprisinglyheavily used as evidenced by all of the worn out rear pads with only maybe 25%-35% front pad wearI've seen on people's cars around here. I was trying to seeif there is someway to getcool air to the rear rotors in the form of a little duct and scoop clamped on the axle tubeala vintage Shelby 350Rbut there seems to beno room on the stock backing plateto get cool air to the rotor cores. I may have another hard look at it but I don't think there is an effective way to cool the rear rotors. If I can't figure out an effective way tocool the rearrotorsI'd be tempted to go to Baer's larger 14"2-piece rear rotors and bracket to move the stock 1-piston clampsfarther out but I'm really against it if I can get some cooling to the stock rears to keep the rear axle's unspring and rotating weights as low as possible.

Cheers!

 

F1Fan

I hope the OP doesn't mind me hijacking this post.Thanks for the suggestions.

Because of theGT500 front brake kit I was able to get Ferodo pads for it but after checking the web and doing some searches it does not look like there are any Ferodo pads for the stock rear calipers. The EBC site lists rearYellowstuff pads but no GT500 fronts.

In addition, in my naivety my thinking was that with thestock front end weight bias compounded by the additional weight of the SC andweight transfer during braking that the rear brakes would not have much load on them. Your experience obviously shows my theoretical thinking was incorrect.

As we do the install next weekend I'll go with what I have for now unless you think the combination is not safe.