Red rooster

The major changes done in the RS ECU were to WOT topend timing.I think it is pretty well known that the 964 ECU was calibrated to give 250 bhp ( Europe ) .
A simple recal gave the RS 260 ( +10 ) .
I believe this was done so that the 993s 272 would look like a valuable improvement and lots of BS could be written about exhausts.
Its a common belief that car manufacturers squeze the absolute best from their motors with no thought to model positioning ! Work for a manufacturer and you find out different .

Geoff

Lorenfb

"Customization, imho, is necessary because of the little things that will be different on every engine - e.g. the airflow meter resistance. If all the 964s of a particular model have the same fuel maps for WOT, but slightly different AFM sensor feedback, they will all be burning different mixtures because the DMEs all have a different reading on the air going in (assuming it's really the same) and therefore inject different amounts of fuel based on what they "think" is the airflow."

- chancecasy -

Reading too many performance chip hypeboles!

AFM resistance - B.S., as the AFM is ignored at WOT.

Check the torque graph as a function of AFR here ( www.systemsc.com/graphs.htm )
to see how flat the torque curve is over the AFR range from 11 to 14. This indicates
that further AFR tweaking yields little. (Lambda = .75 - .95)

The performance chip guys "push" the timing maps, as the fuel maps yield little
in performance "feelings", i.e. the closed-loop Lambda system tweak to AFR=14.7.

Note: The above relates to a stock 964 engine.

Cupcar

If you don't use the 93 octane R+M/2 the RS brain was designed for, you are wasting your time with an RS brain.

I have an RS brain in my car, it pinged on 92 octane that used to be available here in California and I havn't even tried the 91 octane we have now.

I have to run a mix of 100 octane unleaded and 91 octane unleaded for the car to run without pinging under load.

Pesty

we get 95 or 98 out of the pumps over here in the UK.

Cupcar

in California

Pesty

don't cry dude
1 its always warm in california.
2 petrol altough it may not be as high octane reading cost a quarter of what we pay.

£100 in petrol last week

Pesty

edited to add I think you guys measure ocatne different anyway so its probably the same

Christer

Yes I think that the 95 we get is the equivalent of 91, and the 98 is roughly a 93....

JackOlsen

I have a chip that allows me to use a switch on the outside of the DME box to go between stock settings and 'the kind that scare Loren.' On the same day, the same dyno, with nothing changing other than the chip, there was a 17 hp increase with the modified maps.

The nice thing about the two-position chip (it's made by 'No Bad Days Racing' in Santa Barbara) is that you only run the more-aggressive settings when you need them. With other chips, you could find yourself climbing a long hill on a hot day and not be able to avoid worrying about knock. I usually only use it at the track, and then mix some race gas in as a safety net.

Millemiglia

Aren't we getting a little here?

more like 32hp...

Well can someone on this board comment on this?
In "the book" it clearly states that replacing the stock DME with a RS or CUP DME gives a significantly higher bhp in an otherwise stock 964.

True or false?

Red rooster

RS DME is calibrated to give 260bhp on a 964 motor . +10 over a std European 964.

Geoff

Cupcar

In Europe the octane rating on the pump is the "Research Octane Rating", there is another octane rating called the "Motor Octane". The Motor Octane is usually around 10 points lower than the research number.

In the USA we have on the pump the Research + Motor Octane/2 or average of the 2 octane numbers.

The European 98 is roughly the equivalent of the 93 R+M/2 here in the USA.

Where I live in SoCal the fuel prices are the HIGHEST IN THE USA (over $3 per gallon) and the best I can get is 91 R+M/2 octane, other states get 93 for less money so I am

On 92 octane, my car pings and I can hear the knock sensors and DME work to eliminate the knock and the throttle response gets less sharp. With 100 octane the throttle response is always sharp and the engine never pings.

With it's RS DME brain, RS engine (single mass flywheel, single fan belt, no power steering), Cup bypass pipe, Cat bypass and open airbox my car running on 100 octane showed roughly 16 more SAE rear wheel horsepower during a test day than several standard C2 cars tested on the same dyno the same day back to back (257 vs 241 average for the other C2 cars).

The factory says 10 more DIN HP at the flywheel with stock muffler and airbox, I think the above results show this is probably true.

Adrian

I strongly recommend that those calling me a liar and those misrepresenting what is actually written in the book in the first place, go back and reread it and quote the story in full.
I find it very sad to see my work misquoted and misunderstood like this and even worse others trying to use this in public, in order to make me out to be a liar albeit using crafted statements.
Read the story and report back, but let me give you some clues.
964 RS (NGT) DME. NOT a Basic 964 RS version DME.
964 Carrera Cup DME.
Land of the "Long white cloud", for those that do not know, this means New Zealand.
I went to great lengths to explain that different countries had different versions. Many countries still used leaded fuels in the early 1990s. Guess what, New Zealand was one of them. What did this mean? Option M150 engines. Same for the first 993s also in NZ.
However none of this was regarded as necessary to explain in the little story in Chapter 11 because it had been covered in the book, the reader was not considered stupid AND the DME used was a 964 RS NGT version which is not commercially available outside of the racing world.
Oh and the 260HP figure for the standard Basic 964 RS (NOT the RS NGT DME used in the story) has been proven to be at least 20HP low. This also has been stated and data provided on this very forum before. 13 years later the Basic version of the 964 RS is still putting out up to 285HP at the flywheel without modifications. I have never seen one putting out less than 275HP.
So to answer the question as originally posed. If you install a Basic version of the 964 RS DME into a USA version of the 964 Carrera 2 or 4 you will not see 32HP and the story in the book never said it would.
Ciao,
Adrian.

Pesty

Thanks for replying Adrian,

When I first saw the item on e-bay I checked the part number listed against the one listed in your book and I thought it matched didnt realise there were diferent versions in different parts of the world.
I personaly have never heard of NZ being reffered to as teh land of the long white cloud you learn something every day.

will re read again when I back. confusion on my part probly comes from going streight to that page without reading whatever was writen before.

PS my car is a uk model

Adrian

Some UK models of the 964 are also M150 versions.
Ciao,
Adrian.