DrJupeman

What did the factory do wrong in their design of the headers or what compromise were they forced to consciously make that results in aftermarket headers being better?

Adrian

They did nothing wrong. Noise and emissions compliance whilst maintaining the best possible performance.
You have to remember that whilst in some countries like the US there are no rules to auto modifications in other countries there are. All Porsches are designed to meet the strictest noise (Switzerland) and emissions (CA, Switzerland, Germany) first so they can be certified and sold. It is a compromise. However by meeting such requirements it does allow for aftermarket performance improvements because there is no question, noise and emissions systems coupled with the CIS and hybrid electronic support systems of the Turbo and Turbo 3.6 cause a loss of performance. If you drive a Motronic controlled 964 Turbo like a RUF RCT Evo you will see what can be done whilst keeping within noise and emissions laws.
Ciao,
Adrian
964C4

cobalt

Actually there are laws in the US against removing cats, along with noise restrictions, they vary from state to state by the level of which they are enforced. Some aftermarket add ons are allowed so long as they do not alter these requirements. Depending on the state and the chances you are willing to take determines how far some people will go. Most people will go through the extra aggravation to replace the stock setup to pass inspection then replace the mods after the car passes inspection.

Adrian

Dear Anthony,
Maybe you do have some laws in some dusty cupboard somewhere. A visit to any American car related web site or ebay shows that, if you have any auto modifications laws (which encompasses more than just removing cats) they are clearly ignored and not enforced.
Example: In how many states is it illegal to install 18 inch wheels on a normally aspirated 964?
How many states require emissions tests?
How many states have noise Police?
To the outsider like myself it appears that you have no laws. Laws which are not enforced are not laws they just occupy space in some archive.
Ciao,
Adrian
964C4

69COU

Adrian

Has that Ruf in the picture somehow joined you collection???

cobalt

Adrian,

Although this varies, some states like CA & NJ amongst others require emissions tests & check for cats. I hear CA highway police spot check quite often. We may not limit wheel size on specific models but do check for proper wheel clearance. I myself have sat through several road side check points and was inspected for cat, emission and db levels. I was able to convince the officer that the heater boxes were cats.

A flaw in the system is the use of passing inspection stickers. Some states use private organizations to monitor this requirement. When small independent shops get involved there is room for the few that play the system for an extra $. Also if a car passes CO etc many times they pass the car without visual inspection just to speed up the process due to the volume.

Many areas in the US that are heavily populated with no way to police everyone. Once in Austria a Police Officer followed me for ten miles to give me a ticket for not wearing a seat belt. I saw five other cars the entire time. In ten miles around here you may see 100,000 cars. How can you Police that many people unless there is cause to check?

Laws in the US are not the same as they are there. The laws do exist and depending on were you live and to what extent you modify will determine what you get away with. Large scale enforcement is not easy. Spot checks are done but there is no way to check everyone.

Since the Federal Government cannot control laws in a state the laws vary making it harder to regulate. Police enforcement agencies work differently here. Small towns don't have the funds to enforce these laws and the State agencies have larger concerns. If I remember correctly in CH the Police you are talking about are funded by the government. I believe you also have less cars registered in the entire country then those registered in the state of New Jersey.

Although it may appear to an outsider that the laws do not exist, they are real and if caught can cost more than you realize.

bogey1

I think the total weight savings is in the 40-50 pound range. I had B&B, and went to GHL/Fabspeed for quality issues referenced above. The fit on the GHL is much better, and I have no leaking or cracking problems any longer. The old heater boxes are very heavy, I picked mine up last night for you, and still have the old B&B's which I picked up after. There is a meaningful weight savings. I think the real performance gains from the header/exhaust upgrades becomes stronger as other mod's are performed. A hi-flow turbo is your best bet in my opinion, with cams and headwork following close behind. I installed RS door panels, a carbonfiber hood, lightweight clutch set-up, removed a ton of intake material, headers/exhaust, FIKSE wheels, coil-overs, and went to the GT3 seats. All-in-all, the car dropped just over 250 lbs if the scale can be trusted. My car weighed just under 3100 with a full tank of fuel.

DrJupeman

What cams do you recommend?

Also, what is the GHL/Fabspeed combination you reference? GHL headers and Fabspeed cat bypass? Stock muffler?

maverick

Ok visited my car at the shop today. The difference in weight between the stock flywheel, clutch, pressure plate etc and the leightweight Sachs RS kit is 14lbs. The headers aren't off yet but will weigh when they are. My mechanic is taking pictures as he goes so i will post at the end of the operation. One of the motor mounts was completly shot something you can't see when the engine is in. She only has 40K miles so age is eating the rubber. The air pump was frozen also and the belt had been wearing the grooves off the pulley! The power steering pump has a small leak and the output shaft seal from the gear box was leaking. It is amazing what you find when you pull it all apart! I am also going to replace the shocks and springs probably with heavy duty Billstiens and H&R springs.
Maverick