Lorenfb

"If Porsche could go back and optimize the mapping for 93 octane and various exhaust bypasses"

Really! Sounds like the typical sales hyperbole used to promote basically
valueless automotive mods. The engine's AFRs for those that actually
dyno their stock engines will find that the AFRs are within 5% of the
optimum which results in negligible improvement in performance.

Furthermore, the Lambda system via the O2 sensor controls the AFRs
for all driving conditions, where the majority of driving is done, except
full throttle and here basically no tweaking results in any improvement
for a stock engine.

"Plus they wrote the code 20+ years ago."

So! First, the "code" is NOT rewritten by the so-called tuners, most of
which likely have no idea of what the microcontroller code being
used is or how to rewrite it. Secondly, the "tuners" effort is very basic
and can easily be done by a high school autoshop student who only
needs to change values in a matrix using a PC laptop, hardly a great
intellectual endeavor requiring any engine engineering competence.

Thus anyone these days can become a "tuner" by just using a laptop
and buying a tuning app found on the internet. Then just start hyping
the performance claims and get a number of lemmings to evangelize
for you and you're become a "tuner". Few if any will ever claim that
they wasted money buying the "performance" product, as who likes
to admit their ignorance.

Ritter v4.0

"Few if any will ever claim that
they wasted money buying the "performance" product, as who likes
to admit their ignorance."

I bot a MAF for my car; waste of time and effort IMO. I'm a dumbass. How's that?

911Jetta

Thanks Loren,

Specifically addressing my previous comments helps me understand what you are talking about. I know you have a lot of experience with these cars, so I can understand it might be really frustrating reading (over and over again) such unscientific statements from a newbie like me.

I have no idea if my car is making additional power or what mechanical impending doom I'll one day face through installing this chip?

I'll be the first to admit I'm ignorant in sooooo many ways and areas. That's probably why I'm so happy. I come at everything as an opportunity to learn and have fun. I hate to think that I just departed with $375 with no possible improvement, but at the end of the day the car just feels better, feels sharper. I'm happy.

At least there is a 100% policy, so anyone not happy with the results can return it and in the process they probably learned a little more about their car. As a service to the forum, they should also post their reasons/results.

Again Loren, thank you for taking the time to post your comments.
Best,
Udo

P.S. Can I get a RLer to come over one night and secretly re-install my old chip?
I'd love to do a "blind taste test" to put my own subjective comments to the test?! Could my butt-dyno tell the difference? Hurry over though, I've only got a couple weeks before Wong's Rtn. Policy runs out...

springer3

You will be able to tell a difference if you have good fuel and test on a cool day on relatively flat ground. If you try to climb a long hill, particularly on a hot day, the knock sensors will kick in to protect the engine. If you get the engine up to track temperature, the knock sensors will make the car a slug.

Out of curiosity, I deliberately triggered the knock sensors while driving with the Hammer set to count knocks. I floored the throttle in an upper gear while climbing a steep hill on a hot day. The knock sensors stopped the pinging the instant I could barely hear it. For the next several seconds until the system reset, the car was a dog. I do not remember the timing retard value, but 15° comes to mind - enough to kill any feel of performance. I was burning 93 octane Chevron, and the engine was original including factory chip, factory intake, cat, and both mufflers What I learned is that the factory has it set pretty close to the knock limit already - and that is why knock sensors are needed.

Enjoy the chip. Just remember to use octane booster on hot days, track days, and any drive where you might pull a long grade.

Lorenfb

"Out of curiosity, I deliberately triggered the knock sensors while driving with the Hammer set to count knocks. I floored the throttle in an upper gear while climbing a steep hill on a hot day. The knock sensors stopped the pinging the instant I could barely hear it. For the next several seconds until the system reset, the car was a dog. I do not remember the timing retard value, but 15° comes to mind - enough to kill any feel of performance. I was burning 93 octane Chevron, and the engine was original including factory chip, factory intake, cat, and both mufflers What I learned is that the factory has it set pretty close to the knock limit already - and that is why knock sensors are needed."

Great post with non-subjective data, i.e. the more scientific approach
to evaluate a system and external effects to it. Too bad more don't
use it when possible to do evaluations and then to make decisions.

911Jetta

sringer3,
Great info., you guys with brains and cool tools.
I'm so out of my league around here...
Now I'm not feeling happy about being so ignorant...
Udo

TheOtherEric

Anyone interested in counting knocks without a Hammer can buy a $14 Curtis digital pulse counter (see here) and plug it straight into your OBDI port for power, ground, and knock signal. This is kind of a work-in-progress because it's not exactly clear that it's indeed counting knocks the way the Hammer does.

mongrelcat

Wow, cool.

OP, just FYI but there are a ton of posts regarding Steve Wong chips over on Pelican.

evoderby

Hi Loren,

You've just triggered me into writing my first post on here:-)

Firstly, Porsche engineers were already successful in extracting more power from the 964 engine way back in '92 in something called the (Euro) Carrera RS ;-)

It features a more aggressive (advanced) ignition maps to get the most out of 98RON knock resistance (and revised idle maps to handle single mass flywheel). Official power claims were 260 Bhp...which are claimed to be very conservative.

The RS engine is exactly the same as standard 964 -bar a camshaft without aircon drive- but was hand picked & assembled to the tightest tolerances. So to which part would this be responsible for the RS' higher power?

To isolate the above we need to use RS mapping on a standard production line C2 engine. Adrian Streather has put a bog standard C2 on the rollers which gave 258 Bhp with the standard ECU and 282 Bhp with the RS ECU. A good 9% increase in performance.

I have an interview in which one of the Weissach 964 CUP staff claims the K&N cup filter is the cheapest way to gain 7 Bhp on the 964. Can we agree Weissach Competition department knows what they're talking about?

This leaves us with all sorts of laws and regulations that Porsche has to abide with, whereas the individual owner can play around with a bit i.e. cup pipes, cat replacement pipes etc.

We've just seen that through mapping and low restriction airfilter an increase of around 30 Bhp is possible. I have never seen 964 dyno data on cup pipes and cat deletes, however the fabspeed header/muffler kit without cat showed 25 Bhp on the dyno....so let's conservatively say a cup pipe in combination with cat replacement only brings a third of this...8 BHp.

30 Bhp is possible (proven fact) .... 38 Bhp might be possible (reasonable assumption). This brings us exactly in the realms of what most 'tuners' claim performance wise 280-290Bhp.

Many of them are indeed complete idiots when it comes to engine design, volumetric efficiency, anti knock strategies etc. However the likes of Ruf, RS Tuning, and of course the OE RS mapping have all been established through proper dyno tuning. These chips have been copied and pasted 1000's of times, Steve Wong for one openly claims to use the best parts of these with some additional refinement...whatever the latter means.

Cheers,

Harald

964 RS (FVD MAF - cup pipe - brown trousers)

Lorenfb

"OP, just FYI but there are a ton of posts regarding Steve Wong chips over on Pelican."

Hardly a forum in the same league as Rennlist, with most posters just basically
able to intelligently comment on which are the best paint polishes! Call it
what it really is, just a free-for-all blog with little regard for any real level
of technical competence in discourse.

That situation, i.e. over on the 'dark side" for the 3.2 911, is even worst than
the 964, as 911 3.2 lacks knock sensors and as such is more prone to engine
damage the result of chip tweaking.

"However the likes of Ruf, RS Tuning, and of course the OE RS mapping have all been established through proper dyno tuning."

We really have yet to see any real corroborative data here on Rennlist to support that
as it applies to the stock 964 engine.

ThomasC2

FWIW...but I have a copy of a Euro RS chip in my car, modified to work in my C2 DME box (you can't put a RS chip straight in a C2/C4 box). The result on my car is +14 Hp (meaning 264 Hp in this case) and 19 Nm. The difference is top end power is really hard do notice if you can't compare them back to back, but on track I can see that I can keep up with other cars better. Mid range is a bit smother but the big difference is a much more stable idle with the LWF and the throttle response on low revs. The power is just a bonus compared to this. I 've a cup pipe and K&N filter (before and after) and I always use 98 RON petrol.

mongrelcat

You figured all that out, after 6+ years and 1,874 posts over there? Hmmm.

Steve W

Thanks everyone for your feedback and kind words. I would like add to the discussion and make some clarifications before incorrect information becomes disseminated as fact:

The AFRs of stock programming are actually ideal for emissions and not power. Unless you can back up your statements with test data, my research and those of other prove otherwise. AFRs below 4000 rpm are targeted in stock programming to about lambda=1.0 for low emissions, however that leaves very little margin against predetonation because at this mixture combustion temps are very high during high loads as measured by EGTs. That is why the factory programming can only have a conservative amount of ignition advance, and if pushed hard under high heat conditions, the knock sensors can be triggered. The AFRs go even leaner by about 0.75 when cat or muffler bypasses or headers are added. Examining the Bosch AFR vs power chart below illustrates the power dropoff that occurs with Lambda=1.0 and the accelerating decline as it continues to go leaner.



When AFRs are richened to approximately Lambda 0.88-0.89, or 12.6-13.1 as in the above chart, not only is max power achieved but the combustion temperature is significantly reduced cooling the motor enough to prevent predetonation and allow increased ignition advance without reducing the the margin from stock. A good example is a knock controlled turbocharged motor with 9.0:1 compression. If the fuel mixture is kept at a Lambda of 1.0, the engine will ping as low as 6 psi boost and the knock sensors would limit and regulate the boost to no more than that. However, richen the fuel mixture to 12.0-12.5:1 and the same knock controlled system will allow boost up to about 20 psi because of the absence of knock. Done properly, the power optimized mixture, along with additional advance makes a significant improvement not only to torque but throttle response without any more risk to the motor.

This statement is actually incorrect and shows clear assumption. The O2 sensor is not only ignored at full throttle, but also at part throttle above 4000 rpm. Below 4000 rpm, the stock chip is mapped to closely follow Lambda=1 at part throttle for emissions, but it can easily be overridden via remapping to a Lambda of 0.87 under high part throttle loads and throttle transients achieving the principles described previous.


Now Loren, I understand you have been trying to develop your own chips and break into the Porsche tuning market. If I might make a suggestion to be less abrasive and self serving WRT your posts, you'll achieve better receptiveness and credibility with other owners with respect to your products and services, FWIW.

Jeff Curtis

A.M.E.N.!! ...and I second that comment.

Lorenfb, I don't know you from a can of paint, but I have to say I wouldn't buy one from you! There's much to be said about discussion board tact/attitude, etc. I'm not exactly the "poster child" for discussion board politics but wow...

ANYWAY, subjective data, scientific data...whatever...believe it or not, most of it works!!

I've had a Wong chip for about a year now, the HP gains were noticeable via the "butt dyno" and two other Dynojet rigs. I race the hell out of my 964 and no knocks, no overheating...no piston ring meltdowns due to the chip.

I did have an intake runner slide off during a race and I kept banging on the car...so that's the one engine issue I've ever had with this car.

I paid the extra $100 to leave an "open" with Steve to reprog. another chip for optimum performance - ONCE I send him dyno figures, but I am too damned lazy to get a good readout and send the data.

So Steve, as long as my "open" is still active, I'll say good things about you.

FWIW, I don't care what anyone says, if you put a good quality chip in your 964, HP WILL be improved over stock, no doubt. Myself, I saw a good 28+ HP but that was coupled with an upgrade to B&B headers and a race muffler. There is about a 12hp difference when I plug in another chip I had from a tuner in Pennsylvania, I think it's Cyntex, his name is Paul?? ...I might be wrong on that.

ANYWAY, with the headers, I can plug in the Cyntex chip and get 12hp less than the Wong chip...but then the Cyntex chip is NOT optimized for headers...

SO, do the math, whether it be idiot logic, butt dyno runs (that sounds sick) or subjective/non-subjective data...I'd put my next paycheck on a bet that says Steve Wong can SAFELY add HP to your 964.

Just the facts: I am not affiliated with Steve Wong whatsoever, I paid retail price for his chip and have nothing but good things to say about him, his customer service skills and of course, his product.

AND for the record: I think my car is doing JUST FINE with the chip in it.

Duck

Group buy on Steve Wong chip?