Brake upgrade for non-S

[Paul]

BTW my major at Penn State was Aerospace engineering, want to talk about Reynolds number, stagnation pressure, force equations for deformable bodies???

0.29 - Porsche Boxster, 2005
0.29 - Chevrolet Corvette, 2005
0.29 - Mazda RX-7 FC3S Aero Package, 1986-91
0.29 - Lancia Dedra, 1990-1998
0.29 - Honda Accord Hybrid, 2005
0.29 - Lotus Elite, 1958
0.29 - Mercedes-Benz W203 C-Class Coupe, 2001 - 2007
0.28 - Toyota Camry and sister model Lexus ES, 2005
0.28 - Porsche 997, 2004


.29 for a boxster, .28 for a 997?????

[MNBoxster]

Originally Posted by Paul

BTW my major at Penn State was Aerospace engineering, want to talk about Reynolds number, stagnation pressure, force equations for deformable bodies???

0.29 - Porsche Boxster, 2005
0.29 - Chevrolet Corvette, 2005
0.29 - Mazda RX-7 FC3S Aero Package, 1986-91
0.29 - Lancia Dedra, 1990-1998
0.29 - Honda Accord Hybrid, 2005
0.29 - Lotus Elite, 1958
0.29 - Mercedes-Benz W203 C-Class Coupe, 2001 - 2007
0.28 - Toyota Camry and sister model Lexus ES, 2005
0.28 - Porsche 997, 2004


.29 for a boxster, .28 for a 997?????

Hi,

Well, if we're comparing resume's, I have a BS in Aeronautical Engineering and a BS in Materials Science from the University of Minnesota and an MS in Aeronautical Engineering from M.I.T (courtesy of the US Navy), Certified Test Pilot - (USNTPS) US Navy Flight Test Center - Naval Air Station, Patuxent River.

Now that that's out of the way, you make my point for me - the Boxster is clean, the 996 is cleaner...

Happy Motoring!... Jim'99

[Paul]

Congrats!

I was going to make the Air Force a career (ROTC) but in 1969 my draft number was 324 and a lot of my classmates were just back from Vietnam (GI Bill) and told me I was crazy.

I did go on to get a private license and an instrument rating and bought a Piper, but I envy your flight experience, since I've always wanted to push the throttles on a fighter!!! I have shot approaches several times at Patuxent.... My brother is stationed at Mountain Home (a lifer).

But I still doubt that the Boxster would need to have 100 more hp than a 996 to have the same drag limited top speed.

[MNBoxster]

Originally Posted by Paul

Congrats!

I was going to make the Air Force a career (ROTC) but in 1969 my draft number was 324 and a lot of my classmates were just back from Vietnam (GI Bill) and told me I was crazy.

I did go on to get a private license and an instrument rating and bought a Piper, but I envy your flight experience, since I've always wanted to push the throttles on a fighter!!! I have shot approaches several times at Patuxent.... My brother is stationed at Mountain Home (a lifer).

But I still doubt that the Boxster would need to have 100 more hp than a 996 to have the same drag limited top speed.

Hi,

I hear ya, my Draft Number came up #12! So I ran to the NROTC Office, raised my right hand, and signed up (I had been in JrROTC in HS) as a Naval Flight Officer. This allowed me to complete school before reporting, but my intention had always been NAVY AIR.

Then, I passed the Flight Exams (got my Private License at 17) and was off to NAS Pensacola for Basic Flight Training (T-34C Turbomentor). Then to NAS Beeville,TX for Advanced Jet Training (AF-9F). Luckily, I graduated high enough to get a coveted 'fleet seat' and was off to NAS Miramar.

RAG (Replacement Air Group) VF-121 for training and certification in the F-4 PhantomII, this included Air-to-Air (NAS Miramar), Gunnery (NAWS China Lake), then back to Miramar for Seaquals.

Finally, I was assigned to VF-142, the "Ghostriders", on the USS Midway and did 8 WestPacs, mostly MigCap, ResCap, but also some IronHand. Two tours on Yankee Station (Gulf of Tonkin) and one on Dixie Station (Mekong River Delta - South China Sea). Got my 3,000 Flight Hours and shot at a few times.

Then Graduate School and off to Pax River for Test Pilot School and 3 years in the Navy Flight Test Center flying nearly everything in the inventory - F-8, A-4, F-4, F-14, F/A-18, F-16 (yes, this was originally spec'd for the Navy and still carries it's Tailhook today). It was fun - I got to fly REALLY fast airplanes and spend copius amounts of the Taxpayer's Money - for Pay!...

Happy Motoring!... Jim'99

[insite]

Originally Posted by Paul

But I still doubt that the Boxster would need to have 100 more hp than a 996 to have the same drag limited top speed.

jim - i think you're off by a decimal point. i get 10HP more to go the same top speed.

[demonz]

From the pic in my Bentley manual, the brake calipers of the base vs. the S look identical except the red paint.


The bigger rotor is apparent enough.


Anyone know for sure?

[SD987]

986/987 S brakes also use a power boosted brake system not used on the base models that requires less actuating force, thereby making the response more direct.

The Boxster S employs a mechanical vacuum pump instead of a conventional sucking jet pump to provide the vacuum for the brake booster. The pump is driven in tandem configuration together with the oil extraction pump of the right cylinder head (bank 2, cylinder 4) by the exhaust camshaft of the right cylinder bank (bank 2, cylinder 4–6). This design enables a high and constant level of vacuum supply and subsequent effective brake boost even when the most unfavourable underlying conditions apply, e.g. low external air pressure at high altitudes, and in highly dynamic driving involving a high proportion of full-load operation, e.g. on race tracks.

I got my degree via mail-order from RETS Electronic Institute. Dual-major in TV/VCR Repair and HVAC. Now top that !

[Adam]

Lets get to the bottom line here, instead of a comparison degrees? If you track the car the boxster S big reds are better than the base brakes. If you are just driving it on the street the base brake are more than adequate. Nuff said.

[arenared]

Originally Posted by demonz

From the pic in my Bentley manual, the brake calipers of the base vs. the S look identical except the red paint.

The bigger rotor is apparent enough.

Anyone know for sure?

They are NOT the same.

Boy, this thread sure degenerated pretty quickly. The need for bigger/larger brakes depends on the usage. A 3.4L has 50% more power than a 2.5L and will generate speed a lot faster. If you are over-heating the stock brakes, then you are perfectly justified in putting in bigger brakes. I presume the poster that put in a 3.4L did so because he drives "enthusiastically". The difference in weight between base and S is minor. Going to 350mm GT3 brakes is another story however which is why Porsche offers PCCB in that size.

Contrary to what most people think, IMHO, upgrading the fronts without the rears is a mistake. The problem is that by enlarging the fronts, you increase front brake bias. The cars already have heavy front brake bias. There are significant gains to be had with shifting brake bias to the rear.

[MNBoxster]

Originally Posted by arenared

They are NOT the same.

Boy, this thread sure degenerated pretty quickly. The need for bigger/larger brakes depends on the usage. A 3.4L has 50% more power than a 2.5L and will generate speed a lot faster. If you are over-heating the stock brakes, then you are perfectly justified in putting in bigger brakes. I presume the poster that put in a 3.4L did so because he drives "enthusiastically". The difference in weight between base and S is minor. Going to 350mm GT3 brakes is another story however which is why Porsche offers PCCB in that size.

Contrary to what most people think, IMHO, upgrading the fronts without the rears is a mistake. The problem is that by enlarging the fronts, you increase front brake bias. The cars already have heavy front brake bias. There are significant gains to be had with shifting brake bias to the rear.

Hi,

This is a fallacy. Power has nothing to do with it at all. Power will get you to 60 or 90 MPH faster, but the brakes are still hauling the car down from 60 or 90 MPH just like before, no change whatever. If they were adequate before, they still are. They are more fade resistant, but this is a non-sequitor on a Street Car which has adequate cooling time between normal brake applications.

If you Track the car there is an improvement worth the expense, if not, there simply isn't. You can brag that you have the 911 upgrade, and if you are ever in an accident situation where you could only stop within 7 ft. of the other guys bumper, than the 'S' brakes will be an asset, otherwise, not at all...

Happy Motoring!... Jim'99

Hey Doc,

I'm no scientist but this is what i was told. The Boxster brakes on the base are amazing. No need to buy S brakes.

If you ask me, they only put those brakes on the S to make it different from the base model. Meaning that they needed to justify an S model, so they gave you red S brakes, a new bumper, 6speed and so on. So pretty much it's a waste of money to put the S brakes on a base.

If you plan to drive the car at 150mph and come to a complete stop everytime that you drive, then yes get the S brakes.

I'm under the impression that the big brakes just make the car stop faster / better / closer ?

n for that matter, the base brakes are pretty big. I painted mine yellow, and they are pretty big.