SW chip issue put to rest...or not :)

[KFC911]

Originally posted by P-THOMAS
Keith,
I was passing 105mph pretty quick when i let off. The graph says about 5900rpm but i wasnt looking at my tach. If we use Taylor's 25% loss rule, that puts me at 246hp, which is about what i would expect. BA has a dyno graph of a twin-plug 3.5 in his book and it topped out at around 250, but it didnt post toque numbers.

My peak torque was at around 3900 and the 395 lb-ft it said i was making is way off. That is more than a 959 at 5500rpm (369).

I think we can agree that these runs will be good only for tuning purposes and future runs on the SAME dyno. I will go back in a month or so with different headers and an O2 bung for wide band analysis. If you want to have a go at Turbo Tune let me know.

Paul

Paul, I could believe Taylor's 25% loss rule if it only applied to your 'hot rod' motor, but his calculations also put my 3.2 in that same 245 range, and although I WISH I had that much hp, I obviously don't. I'd definitely like to check out Turbo Tune, but I'm in no hurry, so maybe we can get a 'group day' there whenever you're ready. One other thing...do your hp curves continue to increase all the way to 105 mph, or do they ever drop off?

[KFC911]

Originally posted by Lorenfb

Many still fail to accept the facts even with this latest data. All the other B.S. that
gets posted won't change the reality about performance chips!

For the sake of arguing, do you conceed that there 'might' be performance increases that are not measurable on a dyno? How would you account for the guys that post better track times with a chip, and why aren't they allowed in PCA racing? I'll be the first to admit (as I did in the beginning of this thread) that the dyno shows no difference (although I question the numbers), but I'm still convinced my car's drivability is improved with the SW chip. Just because the performance isn't measurable on a WOT dyno run, doesn't PROVE there aren't improvements to be had by the chips. (Where's my gas can...there's a fire here !) Thanks everyone!

[Mike Feinstein]

I have to side with Loren on this one. Having tried 3 different chips in my 3.2, I never found a "noticeable" difference with any combination...including an Autothority MAF setup and chip, Steve Wong chip, and stock. Now that the dyno results (side by side under same conditions) confirm no difference, it seems the argument has become one of "driveability". A nebulous / unmeasureable term to say the least. The actuation of the WOT microswitch is meaningless considering both chips were tested under identical circumstances. If the switch was not actuating, and WOT was not achieved, this confirms that even in part throttle situations, there's still no difference.

Look through a high-end audio rag one of these days. You'll see carbon fiber cones (and a variety of other magical types) that promise greater "transparency" and "musicality" when placed beneath a component (doesn't matter which one). They even have little "lifts" to keep your cables from touching the floor...providing improved "clarity" and "spatial integrity". How about $600 wooden discs that, when placed on top of your speakers, deliver greater "dynamics" and a "blacker background". I suspect that chip swaps (without other changes) fall into this same category.

Bottom line is one that we all face up to eventually....there's no such thing as "real" cheap horsepower with a 911.

[KFC911]

Thanks Mike for your input, and I tend to agree with you regarding the WOT vs it not being engaged...it would still be an 'apples to apples' part throttle comparison IMO. By the way, I DO know what you mean about audio bs... By the way, I've got some great interconnect cables that retail at 5000 $ per foot that I can LET you have for only 4995 if you're interested

[KFC911]

I have come to the conclusion that the 6 graphs I posted earlier in this thread are grossly incorrect (i.e. the rpms, torque curves, and hp curves are obviously not realistic), therefore, I have deleted them. If anyone would like to see the graphs, I will be glad to send them to you via a pm or email, but I do not want to leave them posted here to be mis-interpreted in the future. I just do not have any credibility in the data displayed on those graphs, but I will reiterate that the graphs showed no significant differences between the 6 runs. I will perform another chip comparison on a different dyno withing a few weeks and will post my results at that point in time. I do not necessarily believe that another comparison will yield any differences between the stock and SW chip, but I do desire accurate dyno runs for my car, so I'll give it another shot. As I've stated many times before, I'm just learning as I go, so I apologize for these inaccurate graphs, and thanks to everyone who has responded to this thread!

[geof33]

Well, not that this data is "scientific" or otherwise... I strongly suspect, my chip improves the performance of my car. Having run the stock chip, VS the SW chip there IS a noticable difference in how the car drives, accelerates etc. As Steve stated there is a VERY good poss that you WOT switch isn't coming on. I was shocked after checking mine to find I was BARELY getting 2/3rd throttle. Wow, THAT made a difference. Now, with that, testing both again (for kicks and giggles) I noticed the same basic changes, but REALLY noticed a difference in the overall top end. 80 to 135 was faster by over a second. So is it all in my mind?

[Steve W]

Keith, thanks for all your hard work. Just as a side note, even if the WOT switch is not engaging, the graphs could not accurately depict part throttle power. Note there are 12 load axis in the part throttle maps, and not all of them can be depicted in a dyno run. Near WOT after 4500 rpm, if the WOT switch is not engaged, the air flow meter flap bottoms out, and the Motronic computer defaults to an extreme rich condition of 10.5-11:1 afr, stock or modified chip, so no matter what the ignition timing, the fuel will flood the motor and the power will come out the same in both instances. Below are the stock part throttle maps.

I know some have wondered about the placebo effect of the part throttle maps, but if one were to monitor the part throttle air fuel ratios between the stock and performance chip, it would verify what you feel. The stock chip keeps the air fuel ratio at 14.7:1 +/- 0.5 afr no matter how you gun the throttle, the older chips are worse, as in the 84-86 programs because there is ablsolutely no fuel enrichment at all, and the O2 sensor really locks the afr hard at 14.7. They also have extremely retarded pt ignition maps, which kills throttle response and pt torque. Max power is around a afr of 12.7-13.0:1 and with the 87-89 chips and some reprogramming, it allows us to keep the 12.7-13 afr for at least a couple of seconds out after jabbing the throttle before the O2 sensor brings it back. This is enough time for the majority of driving that we do, and if we need more power longer, just hit full throttle. The caveat of course is that if we are pretty aggressive with our driving style and a have a lot of throttle movement, the extra acceleration fuel enrichement will consume more fuel. The only other way to maintain a rich pt mixture without it leaning out, is to run with the O2 sensor disconnected, and optimially remap the chip like the European chip.

[tobluforu]

I dissagree with all chips used on 911's do not do a thing. Put a chip on a turbo, dial it in and you will see noticable gains in HP and torque. Like I said in my org. post, get a chip that can be burned while YOUR CAR is on a dyno and I bet you can get any 911 n\a to see an increase in both as well. Not much, but some.
Once again that's my 2 cents.

[Steve W]

James Achard just emailed me his Dynojet 248 runs. It a stock 87 3.2 motor with his custom headers.
Dyno Results!! 3.2 Race Exhaust system!!! Stock Motor
The red line is the stock 302 chip and the blue line is the performance chip programmed for 91 octane. There's no rpms, but from the hp chart, it represents a run from 3K on up. 113 mph is probably around 5900 rpm, where a stock chip typically peaks, and 118 mph is around 6200 where the performance chip typically peaks. I think there may be more hp left on the table 5000 rpm up, because it probably is running a bit rich here.

[Lorenfb]

From the Rennlist 911 Forum Thread:

KC911
Addict
Rennlist Member

Registered: Mar 2002
Location: Greensboro, NC
Posts: 122

Loren, let's move beyond the chip comparison issue for a minute...I have conceeded from my very first post after the dyno runs that the graphs show no significant difference between the chips ...that's not what I'm confused about. What I'm asking is: if you look at a single graph, do the curves 'make sense'?

Last edited by KC911 on 02-18-2004 at 07:19 PM

[KFC911]

Originally posted by Lorenfb
From the Rennlist 911 Forum Thread:

KC911
Addict
Rennlist Member

Registered: Mar 2002
Location: Greensboro, NC
Posts: 122

Loren, let's move beyond the chip comparison issue for a minute...I have conceeded from my very first post after the dyno runs that the graphs show no significant difference between the chips ...that's not what I'm confused about. What I'm asking is: if you look at a single graph, do the curves 'make sense'?

Last edited by KC911 on 02-18-2004 at 07:19 PM

And the purpose of copying one of my posts from Rennlist (restating what I've already posted on THIS thread at least three times) is ??? I don't know about you Loren, but when I'm given some obviously 'bogus' information (and those graphs just don't make a damn bit of sense), I will NOT draw any meaningful conclusions from that information. I would appreciate it if you would cease to selectively copy SOME of my posts from one board to the other, that's just not cool (although pointing to the complete thread is perfectly OK imo)! I am now going to do something that I've never done on a bbs before: Loren, welcome to my ignore list! Life's just too short (and I am having fun), to continue to respond to your arrogant bs...bye, bye!

[Embs]

It absolutely amazes me that this debate continues. Are people really that desparate for cheap HP? Save your $280.00 for REAL modifications that translate into REAL HP. I fully understand that a custom chip designed for a particular engine with specific modifications will be necessary in many applications. But to pull a "one size fits all chip" out of the cabinet and stick it in a stock/virtually stock motor expecting to add real HP is a complete JOKE.


Despite which camp your in, let's look at the most basic facts (again):

Your motor is an air pump, no more - no less.


The only way to increase power in your engine is to PUMP more air matching it with the right amount of fuel and a carefully timed spark. That can only be accomplished by two methods known to man at this time, forced induction (super-turbo charging) or increased displacement. Take your pick, THOSE are your choices.


Taking a "chip" from the cabinet and installing it into a stock motor that it was not specifically designed for will not win more races. If any HP increase could be realized with a chip only, it would be no more than the normal variation for stock motors of the same type from the factory.


Save your money, I would think Pelican would rather sell you exhaust systems and larger P&C's than chips.

[KFC911]

I appreciate what you're saying, but I do not have a stock system...I have already made the exhaust modifications, and I already run 93 octane exclusively. I do not believe that that installing a chip that has been designed for those mods, and expecting a 'slight' increase in performance is that far-fetched...do you? It's not a matter of $ with me, hell I pi$$ away $230 (in my case) without even blinking. I've spent close to 10K on my car in suspension and brake mods, etc. since I've had her, so the $ just AREN'T an issue...the question is: does the chip make 'any' improvement at all? According to some VERY reliable sources that I've read, a performance chip (along with the mods I've already made), should give me just 'bit' more, and that's all I've ever suggested...that I DO indeed 'feel' a difference in my day-to-day driving with the SW chip vs. the stock chip. Just about every mod I've made thus far has been beneficial (but not necessarily measurable) from 930 brakes, turbo tie rods, stiffer suspension, poly-bronze bearings, etc. The SW chip is no different imo...