My tuner is recommending bigger brakes for my 4S for the track; he says it will stop faster. I'm not sure about that because my antiskid is engaging on hard braking, which indicates to me that my brakes are maximizing the stopping power of the tires (Michelin Sport Cups). The physics seems pretty simple; the brakes are overpowering the tires and adding additional braking power will not help anything, except perhaps brake fade when they get hot.

Any thoughts?

 

Not always true. In fact some Brembo big brake kits can degrade stopping distances.

The benefit is braking over and over - like tracking the car. The upgraded brake kits reduce fade and perform well over longer time frames of being run hard.

Sometimes this can also be improved with a simple brake pad swap depending on your goals. There is definately no need for a big brake kit, the Porsche brakes are world class. I would look at pad options before going in head first and always get recommendation from someone other than the guy selling you parts

 

Gmoney is correct...your "tuner " is just trying to get you to drop a bunch of money for no reason.
What you are experiencing under heavy braking now (antiskid is engaging), are the laws of gravity and physics and the subsequent adhesion (or lack thereof) of your tires. Bigger brakes will not help you stop any quicker. Keep your brakes, they are more than adequate unless you are developing fade and the pedal is getting mushy.
Try getting a set of R compound competition tires for the track or go full bore and get a set of super lightweight track wheels (18") and a set of slicks to go with them.
Let me know if your eyeballs are still attached to your skull after some heavy trail braking from about 140mph

 

Porsche big reds are made by Brembo

 

Thanks for the feedback, guys. Always nice to get an objective, informed opinion. Better than a blank stare followed by "Well.... ours goes to 11".

 

You got it...I guarantee you, if you put a set of slicks on your car you will be able to dive MUCh deeper into turns. Once you get the hang of it, you will never want to run street tires on the track again.

 

I originally wanted to get slicks but don't have a way to get them to the track to swap out with street tires. So I got Fikse 18" wheels and the Sport Cups, which I can put on at home and drive to the track. Was also told that slicks would require a different camber/alignment set up from street tires.

 

i have swapped wheels and put on slicks w/no problems on previous 911's. I see no reason why the 997 wouuld be any different.

 

gmoney is spot on. you have s c4S right? you already have turbo brakes right?

bigger brakes do not necessarily mean shorter stopping distances. if the bigger brakes exceed the loads that the ABS is programmed for then the ABS will kick in and stopping distances might actually be longer. read the tech notes from STOPTECH

slicks?! what's your track experience? i suggest before you go on the deep end to get a few days of tracking with street tires then progress to r-comps like MPSC or toyo ra1s the progress to r comp hoosiers. they are easier to deal with than slicks. you really have to work slicks to get heat into them to get them to stick. if you don't have the skills to do this then you are wasting your time. if you haven't even tried race compound pads then you are wasting your time with slicks.

 

Karlooz, no turbo brakes on the 997 C4S. Just the regular 997 S brakes which are, IMHO, good enough for the track.

 

Take it from a racer, putting bigger brakes on the car without the use of wider tires or slicks is not going to be worth the money. It's simple physics, your brakes will only work as well as your friction to the surface.

 

i guess that's a difference with the the 996 c4s and the 997c4s. the 996 had the turbo brakes.

 

go G-Money, go G-money. what he said is true.

 

I tracked the car once with the PS2s and it really seemed to chew them up, so I got the Sport Cups and they're much better. Regarding skills, I guess everyone has to start somewhere, so why not with good equipment? When I went throught pilot training in the Air Force we went straight into jets without flying props, and that worked fine.

 

safety equipment, yes go for the best. going with super sticky tires and full blown race suspension for a newbie, no. street tires will allow you to learn how to handle the car better. they give progressively and talk to you, i.e. squeal. yes stickies will give you great lap times but when you keep pushing and pushing and speeds are very high and you finally go off, and everyone goes off, you go off big time. your level of skill won't allow you to catch and correct the spin.

all i am saying is progression but if you think you are good enough to take advantage of slick then have fun.