Porsche Enthusiasts Club Forum

just a chip as far as i'm aware

Hi Kenny,

There are many different types of performance chip on the market for the 944S2. Different cars and different chips will each show a different result on the Dyno (gains are minimal if you are measuring peak power and torque), but some will result in improved performance on the road; either as better throttle response or better acceleration in the mid range - such as from 70mph in top gear (for example).

It takes a lot of time to develop a good chip (ECU EPROM). The chip is an electronic lookup table of data used by the ECU. Compared to modern cars (with dynamic advance and very granular data maps for Ignition and Fuel delivery), the S2 uses a relatively unsophisticated data map.

There are 3 maps each for Ignition Advance and Fuel Delivery (Idle map, partial throttle to 80% and wide open throttle). The ECU looks for data every 500 rpm, which for a 2 dimensional map (Idle and WOT) means 12 values. The partial throttle map uses the AFM for input also, resulting in 144 values.

The time required in developing a chip map is setting these values to achieve the best possible performance. This has to be done via considerable (and subtle) experimentation (and simulation) whilst measuring (and logging) the AFR (Air Fuel Ratio) using a wideband O2 sensor and measuring device. A chip is often developed on a Dyno to determine comparative performance improvements, but extensive development is then required on the road to ensure that the car performs well when driven in real world circumstances (this is where the partial load map can make a lot of difference).

Most cars that have an electronic ECU (such as the S2) will be programmed to run with 95 Octane fuel; deliver a reasonable compromise between economy & performance and help the engine achieve maximum lifespan and durability in a variety of different operating conditions. Changing to a performance chip (that has been developed for a UK car) will probably require the use of 97/98 or 100 octane fuel - but the durability of the engine is likely to be unaffected by any measurable amount. The difference between an off the shelf chip and a bespoke mapped one for standard S2 models is unlikely to yield a great deal of difference.

What matters is whether you can feel the difference when you drive the car with the chip fitted. With the S2, gains are very minimal, but the driving experience is often noticeably enhanced.

Regards,
Andrew

Just as a comaprison here is a Dyno of my wifes totally standard S2 compared with Mike Holmes old S2 that had a Promax chip. These tests were done on the same day on the same Dyno so are a pretty good comparison with all else being equal. The headline peak figure is a useful increase, and if you look back at all the intersection points through the rev range (3500, 4000, 4500 etc) you can see that the difference is even more - eg 20bhp at 4000rpm

http://www.cannell.co.uk/images/Dyno_Gr ... TTO_TQ.jpg

http://www.cannell.co.uk/images/Dyno_Gr ... AUD_TQ.jpg

Hi,
Try link link below on ebay. I brought and installed this ECU chip myself on my 944s2. It's
easy to fit and comes with good clear instructions. The chip adds around 18 extra hp. There
is quite a noticeable difference in the cars performance after installation. I was pleased with
the chip, the price and the service provided by the seller.

http://cgi.ebay.co.uk/Porsche-944-S2-3- ... 240%3A1318

Also take a look at this website in the states. They sell a new "revolutionary" type of spark
plug. They are a little expensive but they last for around four years so they pay for themselves over the time.

I replaced the old plugs with these and have noticed a difference in torque, power and
also a saving on petrol.

http://www.pulstar.com

Best Regards Warren
944 s2 1990
chipped
pustar plugs and green cotton sports filter

One of my members runs the E Bay supplied one & rates it. Also the supplier came along to one of our meetings a few months ago, a very interesting chat ensued!