Page updated: February 2, 2002
Modifications
This is generally the fun page. So what have I done to this car? Not too much, actually. I’ve tried to describe some of my modifications, and some of things I’ve tried to do on the car below by major body parts (the car’s, not mine). Click an item below to jump down to that section, or just scroll at your leisure.
[
Engine
]
[Suspension]
[Brakes]
[Wheels & Tires]
[Other]
Engine
Performance Chips - Autothority Stage II
I’ve tried two different chips on this car, the Welmeister and the Autothority Stage II chips. First the Weltmeister. I bought this from Automotion in CA. It requires changing two chips in the Bosch controllers, replacing the fuel pressure regulator, and putting a shim on the waste gate. I ended up paying someone to put these in for me. The performance was exciting, especially once you crossed 3000 rpm. It seemed as if I couldn’t shift fast enough. The effect was best in 3rd gear, where you could shock passengers easily. I didn’t like this on/off personality on the track, however, no matter how fun. I’m not good enough to handle it. (The friend whom I gave the Weltmeister seems to think it generates more power than the Autothority chip.)
I eventually took
this out and went with the Autothority chip set. Other
than replacing the chips themselves, you add a threaded screw
into a bolt that’s attached to a tube that goes into the intercooler
(see picture). Believe me, it’s easier to do than to explain.
That hard part is drilling a hole inside of this screw. You have
to play with it a little. For performance, I don’t think it’s
as fun as the Weltmeister, but it feels strong throughout
the rpm range. If “feels” better even down low compared
to stock, but you still won’t mistake this for an LT1 V8, for
example. Still, it dyno’d at 262 hp (rear wheels) with this chip.
I think that’s high, but I’ll go with it for now.
-->My
preference is the more linear response of the Autothority
chip.
Air Filter - K&N
I’ve always found this to be a strange topic, but here goes anyways. I’m running a regular K&N filter in the normal filter housing right now. However, I’ve tried the cone K&N filter, too. That’s done by removing the standard filter housing and replacing it with only a filter. It’s a pretty simple job to do. As for performance, it seemed to have a little more at the low end when you first get started, but it didn’t seem to have anything at highway speeds (this was pre-chip). And if the engine got warm, it felt down on power. For me, this was the biggest issue. It looks as if it’s sucking warm air coming from the radiator (and intercooler). Heated air doesn't add to performance in my book, so I decided not to use it. Of course, I can’t prove any of this.
-->I know others with the cone setup, and they seem to like it. I’m sticking with the original.
Addendum:
Here’s a setup I’ve seen in a couple of cars: use the standard filter
box housing, but cut a hole in the panel with the script “turbo”
writing on it. If you look at the picture above, they cut the
entire panel set lower than the rest.
I don’t know of all the benefits of this setup. It’s possible that you would still suck warm air as with the cone filter (it’s still getting air from behind the radiator and intercooler), but at least there’s some material around it which may minimize this effect. Also, they left the original intake tubing which goes to the side behind the headlight. This may add cooler air, but I’m not sure of the “ram” effect of this tubing. Try it and let me know, will ya?
Spark Plugs - AC Delco Rapid Fire
Yeah, I experimented here, too. I tried “Torque Masters,” which has a normal central electrode, but arcs to a ring all the way around the edge of the plug. I’ve also tried the Splitfires, and the AC Delco Rapid Fire plugs. What did I find out? In general, any new plugs will give you a performance gain. The Torque Masters seem to last a long time. As for the Splitfires, the central electrode kept rounding off (this happened on my Beretta, too), which means there's no “edge” to easily initiate a spark. The Rapid Fires have ridges (cut-outs) for its central electrode.
Bosch is now selling a plug which has four electrodes around the central one. I may try this next.
-->I’ve been using the Rapid Fires because they’re pretty easy for me to get. They’re about the same price as the Splitfires, and cheaper than the Torque Masters.
Suspension
Strut Brace - Weltmeister
Right now I’m using a Weltmeister strut brace. It was pretty easy to install, but I have to say the Racing Dynamics one is prettier looking. Does this strut brace help in performance? To be honest, I can’t tell, but I certainly feel better about it. In my book, stiffer is better. I bought this from Automotion. This is their newer version, which fits anything from a 924 to a 968, I think. Note that with the new, upgraded engine mounts, the strut brace interfered with the engine on my car. I grinded a little bit off the brace to make it fit. I suppose I could have put a couple of washers under the strut brace, but I didn’t think of that at the time.
I’m
running two different sets of wheels right now-- the forged
factory set and Antera 101s. The factory wheels are 16-inch forged
aluminum. They are pretty light and pretty expensive. I use them
mainly for the track. The front wheels are 7"×16"
with 225/50ZR16 tires, while the rears are 9"×16"
with 245/45ZR16 tires. Tire pressure is 36 psi all around.
I’m using a Deist 5-pt harness
up front, with padded shoulder harnesses (padding is nice). Installing
a harness is straightforward, but you have to remove the seats
(four bolts), and drill some holes. (Umm... if power tools aren’t
your thing, ask someone to help you with the drilling, to keep
from perforating the floor of your 944.)
