Hello

I noticed a few S4 performance chips offered on eBay (below) that claim decent gains. I’m skeptical but curious to see if anyone has given them a shot. Anyone?


http://www.ebay.com/itm/87-91-Porsch...302d8a&vxp=mtr

 

The PO of my car (an 88 S4 auto) put in an Auto Authority chip years ago. All it did was pump too much fuel, which is just as bad as too little. I'm having it removed and reprogrammed back to factory spec this week.

 

Is this an Auto Authority chip? No markings on the photos.

 

The problem with generic chips:

1. They are.....generic.
a. No two engines are the same, when they are brand new.
b. Used engines have varying amount of wear, carbon build up, oil consumption. These variables
require different tuning.
b. Fuel varies in parts of the country/world.

2. The people that make and sell them do every little trick with the dyno that they can to "optimize" the results.
a. If "joe average" can't pull up to his local dyno and repeat the advertised results without having to do an
entire litany of things to trick the vehicle/dyno into giving better results, the results are bull****.
b. Ask for a guarantee that your results will be as good as the claimed results. or you get your money back.
Listen carefully for the excuses why your results will not be the same.

 

And people who buy them plug them into cars which often are NOT running like they did when everything was new ...?? wires , flappy not working, MAF degraded, knock sensors failed, throttle cable stretched, trans linkage misadjusted.....

 

I recall reading on here a few months ago that a vendor is finalizing an S4 chip. What ever happened to it? I believe there is a chip out there for the 85-86's.

 

That would be Porken and they are available now.

Check out liftbars.com

 

Read post #4.

Apply that post to all chip purchases.

 

I am pretty sure the eBay chips in the original post are Autothority clones. Nice label, though.

Let me second what Greg said in post #4.

Engine parts all have tolerances, sometimes they stack up in your favor, and sometimes against you. The manufacturer creates a set of ECU maps which work well over that whole range, including the "worst case" combination of tolerances. This worst-case design means that it will work always, not just for the average motor or the best ones, but all of them. This is important, because none of us really knows where our motor lies in that spectrum of best to worst.

The good news is that Porsche builds really nice engines, and the tolerances are pretty tight. So the variation when the engine leaves the factory is not huge. When it leaves the factory.

Now add in the things that Greg mentioned: Oil consumption and resulting carbon build-up raises the compression ratio, sometimes substantially. Do any of us know what our CR really is? Fuel octane varies, altitude changes combustion pressure, air temperature makes a big difference. These things all effect tuning, both fuel and ignition, and particularly how much ignition advance is safe. The factory tune accounts for all of that also, as part of the worst-case scenario.

Custom one-size-fits-all chips are generally developed on a singe car with a limited range of conditions. The Autothority chips are an especially poor choice: More fuel, more timing (more than the EZK's knock-retard can accommodate), and a higher redline-- for why?? Good tuners will try to test under as wide a range of conditions as possible, but it is a big job. And the result is a tune that is perfectly suited for that engine. See above.

The wild-card for S4's: Porsche changed compression ratio halfway through the '88 model year. For early cars there is some headroom for adding advance, later cars not so much.

Before John Speake and Niklas Kämpe developed the Sharktuner, a modified chipset was all there was. Sharktuner allows you to develop your own tune, for your engine, and also provides great diagnostic capabilities.

Engine tuning is not simple, it requires a good basic understanding of how engines work and some time to learn the tools. If you are willing to make the investment then you can get some nice results. Our (early) '88S4 picked up +15 rwhp and +23 tq with Sharktuning alone, with a few hours of driving and tuning. The real treat, however, is the much better mid-range "punch" and throttle response. Your engine is different, your mileage will vary-- maybe better, maybe worse, but it will be optimized for your engine.

Disclaimer: I handle Sharktuner sales and support for John Speake/JDSPorsche. I am probably biased.

Cheers, Jim

 

Hmmm...well, while individual engines of course do vary, that doesn't mean that there aren't gains to be had by improving on the smog-throttled cars of the mid-80s. I've seen more than a few dynos and bits of anecdotal evidence about somewhat significant improvements to be had by using a chip and an x-pipe. I thought that was pretty well acknowledged. Are we disputing that now? Am I opening an ugly can of worms lol? Just trying to see what is realistically possible....

 

There's only two ways to "add power" when changing chips.

Add additional timing and change the fuel mixture.

The stock chips are generally very "safe" and will have a fuel mixture fairly rich at WOT. Sometimes less than 12.0, but not often.

Since there's not much change, in power output, on a naturally aspirated engine all the way from 12.0 to 13.0.....it just doesn't make much difference.

That pretty much leaves "adding timing" as the only way to improve performance.

I've spent endless hours in threads talking about excessive ignition timing pounding out the rod bearings on the 928 engine and keeping the knock count under 75 on a 10,000 knock test.

How long do you want those rod bearings to last?

Add more timing, with that thought, in your head!

I personally find the Sharktuner system to work great....not so much to improve horsepower at WOT, but to improve power in the ranges that we spend 95% of our time driving in...less than 1/2 throttle.

It's great to be able to tune your car with the fuel you use, in the part of the country you live (altitude and temperature), and for the condition of your engine currently. It's great to have the ability to go back and retune, if you change injectors, or add in a "y" pipe, or simply change brands of gasoline.

But the best part is being able to add a couple of MPG when you are cruising and still improve the output!

Sharktune and Sharkplot.

Forget the generic chips.

 

What year? Which chip?

Certainly, adding an x-pipe (with the associated hi-flow cats, or none at all) will increase power. I've seen lots of different numbers, to do that test properly would require changing only one variable- the "X". But the combination of X-Pipe plus hi-flow cats does work better.

My +15hp / +23 tq was Sharktuning alone-- change bin-files and nothing else in back-to-back runs on the same dyno within 10 min's, same x-pipe and hi-flow cats. I have not dyno'ed it with stock cats. Those maps work well with this motor. And they would be a good starting point for a different 87/early-88 motor, for further tuning.

There is more opportunity with the 85/86 32v cars than S4's. Porsche was more conservative with ignition timing with the 85/86 tuning, because there were no knock sensors. Without knock sensors you have no idea how close to the "edge" you are, detonation-wise. So Porsche backed out enough timing so that, worst-case, it wouldn't get into detonation with age/wear/carbon/fuel/temperature/etc.

 

Thanks for the replies.

 

I was specifically referring to the Porken chip with the 85-86 "S3" models, since that's what I am likely to be getting soon. I hope :-)

The post about knock count increasing with timing a few posts up is a concern of course. I don't suppose there's been any real evidence collected as to exactly how much extra knock is induced with these chips..

 

Well the whole point is that it will vary significantly car to car, depending on condition.

Since I'm sure lot of folks just add chips to cars that already have other issues that limit their performance in stock mode (just hoping for the magic cure), results can be all over the map.

Before you do anything its always wise to ensure the car is working quite as intended in the stock config. Only then start changing other things.

Alan