dougn

well... we will see. when i'm done here i'll believe what ever my results are....

for now i'm going to try some union 76 100 octane to see if it makes a difference

i find it unlikely that porsche set these cars up for max advance and let them retard as needed

Lorenfb

"i find it unlikely that porsche set these cars up for max advance and let them retard as needed"

1. Read the Porsche 964 manuals.

2.Andial (ex-Porsche USA racing & Le Mans engine builders) explains it very well.
Re-read their web site info.

dougn

their web site says subtle differences....5 percent. i would be thrilled with 5 percent or 10 hp

Lorenfb

"their web site says subtle differences....5 percent. i would be thrilled with 5 percent or 10 hp"

Don't count on it! Remember, the HP gains most claim occur at the max RPM
which translates (assuming fairly flat torque curve) to 1/2 of the claimed HP
at 1/2 max RPM (~3000).

HP = K X Torque X RPM

Red rooster

I am find it hard to believe that Porsche had maximised the 3.6 964 as they were able to increase the power by +10 bhp for the RS by a simple ECU re-map.

I believe that the need for a 272bhp 993 motor meant that a little was kept in reserve !
This is not the only time that marketing has played a part in technical decisions!

All the best

Geoff

Lorenfb

As posted by dougn on another forum:

"my 91 C2 60000 miles put out 235 RWHP/220 ft lbs on a dynojet with a cone intake and GHL headers. the addition of a SW chip made almost no difference at all (there was an increase from 4000 to 4500 rpm)."

"after fixing an ignition problem, my 91 C2 now measures 245RWHP, 231ft-lbs on the same dynojet 248...in line with the original post. as a reference point,"

Basically what has been stated before on this forum many times!

Again:

That's why Porsche and others use knock sensors so that the ignition
timing can be maximized for performance irrespective of octanes,
temperatures, and driving conditions.

dfinnegan

While I have no background to support or refute any of these claims I am curious about the references I've seen to the 10hp gain with the RS given a simple remap.

Perhaps a couple of you who are more knowledgeable could speak to that claim.

For those of us who have no background in engine tuning it seems like a simple and cheap way to get an extra 10 hp out of our cars. Yet, the results posted here, time and again, suggest that it is simply not that easy.

I'm always looking to learn.

Cheers,
Dave

Christer

Regardless of whether 10HP is possible or not, I would say that 99% of owners would not notice this increase even if it was across the majority of the rev range. If you are going to tune your car I would just do it properly, rather than for example putting in a chip which raises your rpm limiter to say 7200 and indeed does record a 10hp increase (surprise, surprise)

C H

Any high quality chip will increase power gains in the high RPM range when used with a high octane fuel(93+). 10 HP peak is pretty standard, but that is not 10 HP throughout the band. Saying that, you also will increase your chance of knock, and your engine will retard the engine and you will lose power until the ECU decides it is safe you advance the timming.

If you use poor gas, you probably will get squwat! I noticed my car didn't like ethanol blend, even thought the octane rating was higher that regular premium gas.

KirkF

MY OPINION:
---------------
1. Your 1990 car has the older style DME (911 part number) It doesn't work as well as the slightly newer 964 part numbered DMEs.

2. There is no chip that will solve your stalling problem.

Kirk
(Owner of an 89 964, with RS flywheel setup, a chip and a car that stalls)

Lorenfb

"1. Your 1990 car has the older style DME (911 part number) It doesn't work as well as the slightly newer 964 part numbered DMEs." - KirkF -

All the 964 DME ECMs are basically the same with the exception of the EPROM.
Since many of these ECMs have non-original EPROMs whether Porsche/Bosch
or aftermarket ones, results in little meaning to the ECM part number.

Chris M.

In Adrian's book he talks about using different ECUs in a standard C2 and the power gains are there. The RS and Cup Car ones produced around 280hp as opposed to 258 for the 911 part # versions.
On ther other side of the coin, as I stated in my post on the "why a 964 over a 993" thread, the power difference between my car and the Varioram 993 I recently drove was just barely noticeable, if at all. It certainly convinced me not to spend a single penny on a chip that's supposed to give me 10hp when I could barely feel a difference of 35hp. As everyone always says, the money could be put to much better use on suspension.

c

Lorenfb

"In Adrian's book he talks about using different ECUs in a standard C2 and the power gains are there. The RS and Cup Car ones produced around 280hp as opposed to 258 for the 911 part # versions."

It's NOT that simple!

kgorman

Chris M,

Good point re: 35hp. I wonder how much weight one must remove to roughly equate to 10hp? The benefit is not just better accelleration, but also better handling, and braking.

fstockcarrera

The early 90 ECU's have and adjustable pot. on the left side to adjust fuel +/-. Position 2(to the right) add's 6% more fuel and 10 rwhp. greater than later 964 ECU"s
The Euro RS ecu and dmechip yields 11 Rwhp over the stock C2 @ Fuel position 2.
The most gain is achieved with a cat by pass or Euro premuffler and primary and secondary by passes About 20 RWHP. The cup air box mod is 4 more rwhp. Do all the above with a Euro RS chip and expect up to 30 RWHP.
All runs done on a dynopac Dyno. Adding back the secondary muffler to control noise looses 9 rwhp.
All dyno results on a fresh m64/01 motor