Jadz928

If you running on original shocks, new Bilsteins will really wake up the handling.
Couple them with the Eibach's and you may land under $1K with top-of-line handling.

redpathtribe

LOL!!! I just responded to your question re: the wing in your other thread. I decided not to go through the brain damage painting my original wing and found a factory GTS wing and had it painted locally. Others have painted their S4 wings and are happy with their results. As I said in the other thread, do a search on painting a factory S4 wing, lots of info. I would NOT recommend getting an aftermarket fiberglass replica wing.

Exotic Motorwerks is off of 40th St. and Greenway, so may be close to you in North Phoenix. 602-840-3420, you'll be talking to Yolanda, she'll get you set up with Dan.

Love my 19" wheels and my GT is a daily driver. You can find some really good deals on take offs from some of the dealers. I got mine from Boardwalk Porsche in the Dallas, TX area. Roads here in Phoenix are pretty good (i.e. few if any potholes) for the most part, so no issues like some others have.

James Bailey

No supercharger is smog legal in California and the car needs to have cats to pass the visual test as well as have good numbers on the emissions rolling tests....... As you have been told be sure it is running right ,gets full throttle, has a happy flappy etc. etc. Simple test is floor it for 14 seconds shift well and see if you are doing 100 mph

auzivision

Oh, don't forget about:

http://www.sharkwerks.com/main.php

Oh that's right, they don't sell anything 928 related... hense the name.


Dollar for dollar would have to be x-pipe at about 7.5% rate of return (HP/$)

AO

WHat do you mean by "performance?"

It can mean many many things to different people.

If you want more power, getting the engine running the right way - knock sensors, hall sensor, caps, rotors, spark plugs, cam timing, etc, will probabaly get the most power. Then exhaust. After that, you need to look for power adders like Nitrous (cheapest way to add power), then Supercharger or turbo.

If you want to go faster through the twisties, swaybars, droplinks, suspension, and tires will help considerably, but probably the best thing would be driving school. We all think we're good drivers, but in reality we all suck.

Glenn Evans

Greg Gray started his performance upgrades on his MY84 by making his own equal-length headers, X-crossover like the local V8 touring cars use, twin 3-inch system and high flow mufflers (no cats on cars that old in Australia). Even as a 4.7-litre, it made about 299 bhp and 313 lbft at the wheels. He's done more to it since but, even if those figures aren't quite right, it felt like a manual GTS.

Nicole

In the old days, Susan from DEVEK used to recommend upgrading in a certain sequence. IIRC, it was:

1. Handling
2. Braking
3. Performance

... or something like this.

Supercharger in CA: You'll have to undo it every time before you get the car smog tested. Some people don't mind, but it's quite a bit of work.

orangecrush

I am originally from Idaho. My whole extended family lives there. I can get it registered there without bringing the car to the state. That way I could keep the supercharger on all the time.

RKD in OKC

Yep I have to agree... After a proper tune up and making sure everything is working properly. If you want to go faster at around a race course...

1. Handling, ie, springs, swaybars, dampers, wheels and tires.
2. Braking, ie, big blacks, and bias valve.
3. Performance, ie. x-pipe, cams, headers, sharktuning, supercharger, bottle.

And follow the creed "If you do what everyone else does, you will merely be competitive. If you are willing to do something different, you might win."

dprantl

Best bang for the buck for power? Wait for a used S/C kit to pop up on this list...

Dan
'91 928GT S/C 475hp/460lb.ft

928 obsession

Changing my stock Boge's to Bilstein/Eibachs was probably the best improvement I've done to my '82. Also poly swaybar bushings are a nice cheap upgrade that will tighten up the suspension.

Franks928s

What's a "bias valve?"

Frank

AO

We already have a bias valve or sometimes called a prop valve or proportioning valve. IIRC the stock valve is an 18% bias vlave that directs 82% of the master cylinder pressure to the front brakes and 18% to the rears. There are 33% valves and 55% vlaves available on the 928. Racers, often have variable vlaves they adjust differently for different corners. The advantage to a increasing the rear bias is you get those giant rear tires to help slow you down faster - allowing one to drive further into a corner before braking. Disadvantage is it can be harder to control the car under extreme braking.

RKD in OKC

Well, that's not quite how the bias valve works, but the effect description is close enough.

The Porsche brake bias valve regulates at what pressure in Barr the rear brakes receive less pressure than the front brakes. When you first start applying the brakes both the front and rear receive the same pressure. As braking increases the bias valve tapers off the pressure going to the rear brakes. They come in 5/18, 5/33, 5/45, 5/55, and 5/65, 5/18 is stock on a 928. The higher the second number the higher the braking pressure before the pressure to the rear brakes does not increase as quickly as the pressure going to the front brakes.

Mongo

You have to be really careful with this now. A law was passed back in '09 that makes ONLY OE cats legal according to CARB. However, if your OE cats are dead, you can obtain CARB-certified aftermarket cats that are universal. These are EXTREMELY expensive. They are essentially the same aftermarket 3-way cats as every other one out in the other 49 states, but for more $$$$ just because it has a stupid CARB stamp on it.

If you can get 49-state aftermarket high flow cats, you should be able to pass smog if your car is well-maintained and running good. I am currently dealing with this issue right now as my cats are toast.