g-50cab

Why bother - that will be refuted too - too small a sample size, the sun was in their eyes, that sort of thing.

There are many sides to this argument - some vaild - some not - I guess I always get a chuckle at Loren - It doesn't matter if it's one - or 100 happy Steve Wong customers - he stays fast in his position...

Lorenfb

The data have been presented by a reputable source:

Bruce Anderson in the Porsche Excellence Magazine

You guys can't read or what?

Have Fun
Loren
'88 3.2

JackOlsen

I don't remember what issues you had with my testing, Loren. I put my car on the dyno, got a baseline run, and then -- without changing anything or even moving the car -- got another run with the performance chip.

Engine: 1993 3.6
Mods: B&B Headers/Muffler
Chip: NBD 2-position chip (you use a toggle switch to go from stock to modified settings)

Run with stock chip settings:



Run with performance chip settings:



These numbers seem in line with reality. The headers get me some improvement over my stock 247 crank horsepower. I can't think of anything other than the chip to explain the second graph's results. It seems too much to qualify as normal dyno variations.

But let me know what you think would be a reasonable way to conduct the test, if what I did is significantly flawed. If it's practical to do, I'll do it.

porklover

Surely how the chip benefits you is all about what kind of fuel and breathing system you have. Standard Porsche chip - any fuel, Porsche would have wanted their cars to be as versatile as possible, good chip - good, high octane fuel, mechanically sympathetic driver and best chip for your car - specific fuel, specific intake/exhaust set up, specific car, dyno set up essential.

Thought I'd add my 2p to what's been a very enjoyable-to-read thread.

anh911

Hey Jack, that's useful. I noticed a marked difference in the A/F ratios on the second run too, interesting.

86NOH2O
asked a question a few pages ago about the differences between the early and late DME Carreras. Someone else please chime in withe the details but as I understand it '88> have the 28 pin chip. You can get a kit to adapt the earlier DME unit for the later chip, right?

r911

Jack, I don't think there is anything practical you can do -- you'd need to run a statistically valid sample of engines on an engine dyno to really resolve this controversy. Wheel dynos can easily vary by 10% tho -- just due to tire slippage. But the results don't surprise me -- I'd expect a bit more ho with a carefully engineered chip, and good gas. I'd worry about hitting some low octane gas in a lowland desert tho.

I solved the chip controversy by selling all the induction and electronics and reverting to carbs....

- Randy

JackOlsen

That's the cool thing about the NBD chip. They've put both the stock maps and the performance ones on a single (double-memory) chip. To change between the two, you turn the car off, reach behind the seat, and throw a toggle switch. When you re-start the car, the new set of maps are loaded. So most of the time you simply run the stock maps (better mileage, peace of mind) and on track or fun days you throw in a few gallons of high octane gas for security, and run the fast maps.

Of course, this is all in a 3.6, which has a knock sensor for an even greater margin of safety.

Mark in Hermosa

Jack:

Don't waste your time (but thanks for the chart!).

The guy is clueless.

Dave Thomas

Yeah, I meant to respond to that but forgot. Off the top of my head:

The 28-pin actually started mid-87. You can get a 28-pin socket soldered onto your 24-pin DME board. I believe Steve can also burn a 24-pin chip for you.

There are actually 3 different 28-pin chips. The first one ended with a 7, and the next one ended with an 8 and provides improved performance (BUT WAIT - DIDN'T MASTER LOREN SAY THAT PORSCHE KNEW EVERYTHING ABOUT THE MOTRONIC SYSTEM IN THE FIRST PLACE??? THEN HOW COULD THEY HAVE IMPROVED ON THEIR OWN CHIP??? THIS QUESTION KEEPS ME AWAKE AT NIGHT - PLEASE ENLIGHTEN ME, OH MIGHTY LOREN). I believe that something like 1/4 to 1/2 of the 28-pin chips out there are the "8" variety. The third variety is the Club Sport chip, which is identical to the "8" chip but has the rev limit raised on the order of 400 RPM.

86NOH2O

I knew about the 24/28 pin difference. What I was asking is: Is there any difference in motors between 86 & 87 other than the new 28 pin re-mapped chip which provides the 10 extra hp?

And.... Is this the same chip that I have heard is a good idea to carry a spare?

ricwon

I think that is dme relay that you should carry as a spare. ric

Lorenfb

Jack:

It would have been better to have had a tabular data output to make comparisons.
But that aside, the max torque is only 4.5 ft lbs over stock. The 4000 RPM torque
did come up about 10 ft lbs, though. This about 6+ HP.

Now, in evaluating the peak HP increase of 14.5 (RWHP & NOT cranK) you'll see
that it occurs above 6000 RPMs. This results from a little pickup in torque. The
question is, what's the true basis for this torque increase?

First, I think your 3.6 is not totally stock, i.e. you have a non-stock exhaust. Also,
there maybe other not stock things. So making a chip comparison on a non-stock
car and extrapolating that to a stock one is questionable. This is because once you
change an exhaust or intake system, the engine will need to be tweaked which
will potentially show more HP improvement than just a chip change on a stock
engine. You can see that much more fuel is being dumped at or near the peak
torque (AFR = 10 versus about 12 for stock) and max HP.

Bottomline:

The results seen could have also been achieved with an AFM tweaking. You still
have the stock AFM and not a MAF unit? What you're getting in HP gains is what
usually occurs and is not much different than the Bruce Anderson runs. If you review
that data, you'll find that the most HP gain was at around 6000 RPMs.

I was involved over 8 years ago with a number of shops, (You probably know which
ones.), installing and evaluating chips. Most of the shops have stopped installing
chips, especially on the 3.6 because of problems, e.g. idling and pinging.

So, for most stock engines and the way most Porsche owners drive, performance
chips in my view are of questionable value. This outlook is based on a purely objective
evaluation over the years. For many, though, installing a perfomance chip may be
worthwhile from a subjective point or track racing at or near 6000 RPMs.

Another point: Can some of you guys make intelligent comments like the few
who do and not always "trash talk". Come on now!

Have Fun
Loren
'88 3.2

m42racer

Have chip, need shoulder to put it on.

Lorenfb, I can tell first hand that Porsche is not the authority on engine performance. There is probably lots of room to change the setting safely. As one said here, you seem not to like new people in your sandbox. You have shown that with the discussion you and I had over the new CDI units now available for Porsche's. I'd be trying to upgrade an analog system to work better in a digital world. Lets face it, the new CDI's have it all over the old stuff. Your comment about BA and his opinions. Another self appointed "know it all". Hey, just my opinion though.

Lorenfb

One of the best posts (TimT - Pelican Forum) describes how a perfoamance chip
and mods should be developed/tweaked":

"When we set up cars on a dyno, we first tune for AFR, we get the AFR somewhere between 12.5-13.5 for maximum potential power.

Then we go back and adjust timing at each load site. Timng is adjusted to provide max torque at each load site.

For example we run the car to 3000rpm, then dial load into the dyno. then while holding at 3000 rpm the timing is adjusted to the point where max torque is seen, then begins to fall off. The timing is then backed off to the point we found max power.

If you have a system with a knock sensor installed you can leave the timing at the point of maximum power. If not to give a margin of safety we back the timing off a touch from the instantaneous max we observe."

The proper way it's done. Great isn't it! Simple & very logical. No guessing here.
Jack Olsen could probably squeeze a little more out of the 3.6 using this approach.

Have Fun
Loren
'88

Lorenfb

Hey m42racer (or whatever your name is), I doubt that you know the difference
between analog and digital circuits. So, try to avoid speaking in hyperbole and
and provide an intelligent comment.

Good luck in clearing your thoughts.
Loren
'88 3.2