The PO had the original put back into the car. I have two additional chips that I would guess give the car more HP. Can you guys think of a reason why he would have the original chip put back in?

Is installation a plug and play process or is it more involved? The car is an 87S4. If its chipped, is gas mileage lowered. My car is at tint shop so I don't have the chip set to look for identification.

 

Chipped would be hard to pass smog..I could not.

All it is is fuel & timing..junk.

 

Many prior dyno test runs have shown that chips do little for the S-4 except for raising the RPM cutoff up 200-300 RPM. Now that sharktuners are available to reprogram, those chips are so 1990s Right up there with adjustable fuel pressure regulator and higher flow injectors trying to TRICK the system into putting out more horsepower. They did little then and little now. Not worth playing with.

 

My car had Autothority chips, adj FP, and rheostat on temp sensor that passed Cali smog. All stock now plus Sharktuned and runs much better, MPG went from 14 to 21.

 

Huh...the chip I had..was unidentifiable.

Couldnt get in a mile with it, passed no probs without it.

 

What's Shark Tuned and how/where can I get it done?

 

http://www.jdsporsche.com/sharktuner.html

You only need one once you get a good decent set of intake/exhaust mods on the car.

And then..better to borrow one for the little you'll get.

With good intake, headers, exhaust..ya..theres some ponies there..

a GOOD tuner is required, its not weekend work for the novice.

Ive tinkered with it, but..its a large analytical fun problem to solve..working with ECU maps.

 

I put a set of Autothority chips in my 89. They were inexpensive so I thought I would give it a try. Took about 1 hr to do. The car did feel quite a bit more lively between 4000 and 6000 rpm. And it sounded more aggressive. I did not dyno it with the chips in. However, it was running too rich for me and the idle was too high. I took the fuel chip out and replaced it with the stock chip. Is there any issue with leaving EZK chip in place? It seems to run fine and again was still more responsive at mid to high rpms. Now with the x-pipe installed it will break the tires loose when you stand on it at 3500 rpm and sounds even angrier.

Murray

 

In order to avoid the "Use the Search Button dummy" jab, I'll add to this thread:
Last week, through a stroke of serendipity I traded my stock DME chip for an Autothority chip.
Much improved throttle response ( even with my throttle cam ); lack of hesitation from 2800 rpm on up ( replaced my original ignition coil last month); perfect idle ( I've set a rather high 1100 rpm on purpose).

I often submit my posts for those new 944 owners ( like me ) who are less experienced than the 2000+ posters.that I so appreciate... For those considering it, a chip MAY improve your experience.
It did for me.. Cheers!

 

Sounds like you're talking about 944's? The Autothority chips for 928 S4 onwards are junk, and in some cases downright dangerous to the engine.

The 944 may be different, best place to discuss them would be the 944 forums

Yes. At least one version of the 928 S4 autothority chipsets advances timing a bunch - far enough that when the EZ-K detects knock and retards up to 9 degrees, timing is still more advanced than the stock chip's non-knock setting. This is especially an issue for places with poor gas (e.g. California), or for 928 engines which are prone to knock (e.g. GTS). The autothority "fix" for the knock is massively rich running, so by using the stock LH chip, you're removing that (nylon) safety blanket.

Your '89 is true 10:1 compression - compared to the lower compression 87-88 S4's.

In your shoes, I'd run stock chips and an X-pipe and maybe EIS. Then consider sharktuning if you really want new chips.. get a tune that matches your mods/gas.

 

I agree with Speedtoys. 87+ cars do not respond well to pre-programmed upgraded chips from yesteryear.

Gas mileage would probably be worse since largest chipper from 15-20 years ago, Autothority, was found to have pushed fuel upwards in their 928 chips.

 

The Autothority chips were crap in the early models too! If it were an 85, 86 or the bell-ringer 86.5 you could use Porken performance chips for 1/4 the price and they do wonders for throttle response and overall performance across the board - you'd like 'em. The 87 & later models are more advanced in the computer compartment & arent good platforms for "old" technology.