Jerry

Since I do several track events a year I have been thinking of going to the big reds (C2 turbo brakes) to replace my S4 (turb S brakes)on my 944TS but are the worth the extra cost? I'm thinking they wont get as hot, they will stop better, and they will last longer although the pads cost more money. From what I understand the big red pads are the same length as the S4 pads but the big red pads are about a half inch wider. How much bigger is it in area? So is the $950. up-grade worth it?

ian

Ahh the good old S4 vs Big Red debate... You are going to find that there are people on both sides of this one.

The S4 brakes are great, and in fact they are a touch stiffer than the big reds and will flex less on heavy use. But with the Big reds you get a greater swept area and better heat dispation.

edit:
I was going sugest using the brake cooling kit, and propotioning valve, but you have those already.

Anyway, the Big Reds are stronger, and will fade less. But do you want to pay the price. I know I am going to put them on my car when I get the chance.

Good luck, if you do the swap let us know how it goes.

Danno

Are you overwhelming your current brakes now? Some good options lay in pad selection. And the 968/996 A-arm brake-scoops appear to be a good cooling upgrade as well.

Alan C.

You will extend the pad life with Big Reds. And that extension has been cost effective in my case. However, my car weighs in at 2500 lb. I could get away with the S4 units on this car. The Big Reds are touchy on a car without ABS. You can get some nice octagon shaped tires in a hurry.

If you go the Big Red route you might want to check and see what rotors the kit uses. On my car the front rotors, floating, go for $265 each. That hurts if you cook a set in a couple of weeks. Some kits use the 94 3.6 turbo front rotor. Those rotors go for $125 - $135. I used them on my RSA and could get a whole season out of them.

Alan

Robby

Yeah, KVR says the BR's are NOT an upgrade, but most people beg to differ- I think the biggest benefit from going to BR's is getting the larger rotor, but it ALL adds up- the extra pad area is about 15% I believe- ONE thing though- you HAVE to have 17's or larger to run them- unless you have some unique aftermarket wheel. I think it's a cool thing- the larger rotor looks cool- especially if going to 18's- then you almost HAVE to have the larger rotors IMO- anyway, I'm playing it by ear w/my turbo S- it's really a street car, so I doubt I'd really get enough benefit to be worth it- like Danno said- pad selection would be a better (cheaper) investment- but, if you're running lot's of track events, then it might well be worth it. I would personally like to get some hollow spokes w/slightly larger RD- like 275/35/18 instead of the more traditional 30 series- it would add a lot more weight though, so my DREAM is to get the new GT2 calipers w/some 14" ceramic's (to offset some of it- maybe even REMOVE a pound or two)- like brakes off the new Carrera GT- of course, since I'm dreaming- a 2.8L (stroked) or larger (stroke & bore) monster, that puts down 450+RWHP & 500+RWTQ, @ 15psi that will run for 1,000,000 miles w/full interior at <2800lbs w/full tank (slightly larger than stock fuel cell) and is as quiet as a new BMW 540i- not to mention it being a convertible that SOMEHOW is stiffer than a normal coupe, AND, having several extras to drive around, etc, etc, etc... but I don't ask for much


As for your situation- shop wisely- you should be able to get BR calipers for ~$550/pr, so don't go paying some $2500 for a set w/rotors, etc- you can piece it together for much cheaper in most cases....

Brian Morris

I just did this switch on my 89. I had the S4's with Pagid Orange pads which I found to be marginal on my 300HP car (K27-8, chips, test pipe, cam, 16 psi). I don't have any cooling beyond what's stock (I'm working on it), but I wasn't really getting any fade. I just found the power of the S4's to be marginal under really hard braking - turn 1 at Lime Rock. I also overheated the Pagid Oranges and got tons of pad transfer.

I upgraded to the Big Reds with Kokeln hats and 993TT rotors, PFC 97 pads, stainless lines, and the 5/33 valve. I did more than just the Big Reds so it's not a pure apples to apples comparison but the pedal was rock hard and there was *a lot* more braking power.

My first event at NHIS my instructor's reaction was "Wow, this car has great brakes - you got your money's worth." I just did two days at the Glen with hard braking from 130+ on the back straight. I can absolutely feel a huge difference since my change.

I didn't look at this as just an upgrade, it was somewhat preventative maintenance. Even though my car only has 40K on it the calipers are still 13 years old and time takes its toll with corrosion and degradation of the seals. Calipers don't last forever and they would need to be replaced or rebuilt eventually. In my opinion brakes aren't an area where you want to say "I think they'll be OK."

The are a couple of other variables, like how much HP your car has, what tracks you drive on, how much you like to use your brakes, and your personal philosophy to doing upgrades. There are plenty of people who drive they're S's hard, but stay off the brakes a little more, use cheap pads and just replace them and count every dollar they spend on the car.

A lot of it is just personal preference, but I felt it was a worthwhile upgrade.

--Brian Morris
89 951

Tom Pultz

[quote]Originally posted by Brian Morris:
<strong>I upgraded to the Big Reds with Kokeln hats and 993TT rotors</strong><hr></blockquote>I have the same setup with the hard anodized hats. Pictures are on my website for those that are interested.

Also, if anyone is interested in a brand new set of Pagid Orange pads for the big reds drop me a line. I'd like to get around $200. I bought them but decided to stick with a combination street/track pad instead.

kellyk

You can save a little money by using the 928 GTS rotors (322mm) with the big red calipers. All you need is proper spacers for the calipers which Kokeln builds. The GTS rotors are the same size but are not "floating". My brakes are incredible with SS lines and Pagid orange pads.

BTW if you go with the big reds you can transfer your front "S" rotors to the rear. They bolt on for most years and will give you an additional 20% sweep.

Tom Pultz

[quote]Originally posted by kellyk:
You can save a little money by using the 928 GTS rotors (322mm)<hr></blockquote>The 3.6 turbo rotors have come down a lot in price and are now only about $105 each from a good mailorder Porsche dealer. I don't know the prices on the GTS rotors but they may not be too much less. [quote]All you need is proper spacers for the calipers<hr></blockquote>You don't need any spacers for the calipers if you use the GTS or 3.6 turbo rotors on an '88 S. Just bolt everything on and go. [quote]BTW if you go with the big reds you can transfer your front "S" rotors to the rear.<hr></blockquote>Yes, in theory this sounds good, but certainly not for a car that may be driven on the street. You may also have problems with a mushy brake pedal because of the huge difference in piston sizes compared to the normal rear calipers (44 and 36 versus 30 and 28), and since the front calipers were designed to work with 32 mm thick rotors they aren't going to fit too well with 24 mm thick standard rear rotors. You could actually experience a situation where the pistons would come out of the bores if the pads were well worn. Take a look at the 993TT rear calipers. They only use 28 mm pistons in all locations. I know this swap has been done, but I don't think I'd recommend it for anything other than an all-out track car.

Robby

Actually, many people say it's even too much to run the front calipers from a Turbo (NON-S)- car on the rear, much less the Turbo s fronts in the rear- hell, that would be almost the same as running front BR's out back too- the piston bores are the same for the Turbo S (S4) & the BR's- I really wanted to do something like this a long time ago- I even considered getting some normal; 951 fronts to mount in the rear, and keeping my Turbo S calipers up front- maybe going to BR's eventually, but, I decided against it- I think the best thing to do is just to get a better bias valve and leave it alone- 5/33- or, maybe get BR's and regular rear turbo caliperws, and got to a 5/44- I've heard some say that this works well- not sure about trying it w/out ABS though- I woudln't- at least not on the street... I DO have a 5/33 on my Turbo S (stock calipers & rotors all around), and I like it- Windward said I couldn't change the bias valve on a Turbo S OR '89's- they were WRONG!

eugene

Robby.

You did the right thing going to the 5/33 bar bias regulator with the TS(S4) brakes.

I have a 87 Turbo that I initially upgraded to the TS fronts(got them for free) with a 5/33 bar regulator. ( Too much front bias with the stock 5/18 bar regulator.) Last year, I upgraded to the BR's in the front and found that the 5/33 unit did not give sufficient braking to the rear
relative to the BR in the front. (BTW, this is all on the race track)

I put the 5/45 bar bias regulator and all is well. Part # for the 5/45 is 964.355.305.00

Pat Kennedy

I don't think Windward has ever been right about anything. They get my vote for worst vendor of all time.

Duke

Would be alright to run a 5/33 bias valve on a street driven (track occasionally) Turbo S?

I always think the ABS lock up to early and it always seems to be the front that lock up. It seems that the rear brakes could do some more work!

Robby

Eugene- you're one of the one's I remember doing the 5/44 w/the BR's- cool- maybe I'll move up to that set-up eventually...

Duke- that's the way I have my Turbo S- mine's MOSTLY (99.9%) street...

ninefiveone

I'm running the 5/33 on a non-abs '86 with the stock baby brembo's and it was a worthwhile improvement in performance, so on a Turbo S it's a no brainer in my opinion. Good on the street, and really good on the track.