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

[KFC911]

Well, I have some good news & some bad news for all you 'chip lovers' out there (of which I am one). First, the good news... I dyno'd a Steve Wong chip yesterday (customized for a sport muffler, premuffler, & 93 octane), and she ran like a 'scalded dog', with excellent HP and torque curves imo. Now the bad news...I did NOT see a significant
difference between the SW chip and the stock (126735358) chip, which frankly, 'shocked the hell' out of me! Unfortunately, I don't have the dyno output in a format that I can post right now, but I will post that info within a few days.
For a brief summary... several of us NC guys spent yesterday morning dyno'ing our cars on a 'Mustang Dynamometer', and we all basically performed the same (HP & torque) runs - a 'wide open throttle' pull in 4th gear from 40 to 105 mph. I performed 6 runs, randomly selecting the SW chip for the first run, and alternating back and forth with the custom chip for the subsequent runs. All six runs produced very nice (and very similar) HP and torque curves, with 5 of the runs showing almost exactly the same HP (184 +/- 1 hp) at the rear wheels. The second SW chip run, was the only run of the six which had any significant deviation, and that run produced 191 HP (at the rear wheels). I cannot account for why that run varied from the other 5. Now, stubborn as I am, I still 'feel' like the SW chip improves the drivability of my car (perhaps it's an improvement in the 'part throttle maps' over stock...or is it a placebo effect?), but as far as comparing 'full throttle' perfomance, the dyno numbers sure indicate that there isn't much difference between the two chips. One other thing...the dyno operator was dividing our rear wheel HP numbers by .75 deriving (for example) 245 HP at the flywheel. He insisted that the (.75) divisor was a factor of the 'type of dyno', when I stated that typically a 15% loss (instead of 25%) was used to calculate this - opinions???
In closing (or is this just the beginning), I was very happy with my cars performance, and although there's no discounting the 'cool factor' of the earlier engine management systems (e.g. MFI or carbs), the 3.2 Motronic system (custom or SW chip) produced some VERY nice HP & torque curves, and more than held its own by comparison. As I stated earlier, I will post the actual graphs as soon as possible, but I just wanted to post this summary, and see what everyone has to say. Let the discussion commence, and I welcome all feedback! Loren, you can even post an "I told you so!", and I won't mind...I'm just learning as I go here and am definitely 'HAVING FUN' !

ps. I'm still keeping my SW chip, and would like to find a way to quantify a comparison between the 'part throttle maps'... I've read that a local 'Dynajet' can do a part throttle analysis... Is that 'legit', and worth pursuing?

[D Hanson]

Cool. Just curious about your torque curves. I know everyone talks about hp, but is it not torque that really makes the difference in accelleration 0 - 60 and 1/4 mile times. Did you notice much or any increased area under the torque curve. Just curious why main focus seems to be on hp instead of torque or increasing torque curves. Maybe I am missing the boat so to speak.

[Steve W]

No difference is extremely odd. Do you know if your throttle opens all the way and that the WOT switch engages?

[KFC911]

Other than the 2nd SW run (with both the torque & HP curves being a bit higher), all of the runs depict very similar hp AND torque curves... There just does not appear to be a significant difference (both HP and torque) at WOT between the stock and SW chip. Believe me, I'm still struggling with what the numbers 'say', and what I've been 'feeling' in my day-to-day driving. I'll post the graphs asap, so everyone can see what I'm referring too, but the unanimous consensus of everyone present at the dyno was...there's NO significant difference between the stock and SW graphs.

[D Hanson]

My question is, if torque peaked earlier and increased area under the curve even though it had only 2 or 3 ft lb spikes along the way at peak torque, but could have 5 to 10 ft lb increases outside the peak of the torque curve, would that still not make a noticeable difference in accelleration or 0 - 60 times.

[Wayne 962]

Without the graphs - it's difficult to tell what the full story is. However, it would make sense to me that there would be very little you could do to increase *total* peak HP out of an engine without making major mechanical changes.

Where I have always understood these chips to show their prime benefit is on the low-end of the RPM range - a range not typically well measured in traditional dyno tests.

-Wayne

[TimT]

Doing WOT pulls shows you just that WOT hp....what you should be looking at is how steep the curve is on the "up" side do you see the higher HP and torque sooner?

You need to use a dyno that can give some resistance for the car to drive against.. not sure if that model mustang dyno does that...inertial dynos read peak hp eddy current dynos can tell you hp at different rpms.. and let you play with the fuel and advance curves to maximize the engine output.

what you do is bring the car to say 2500 rpm.. then dial load into the dyno till the power starts to go away.. then go 3000rpm repeat same...

compare those power curves to the stock curve and Im sure you will see a difference....

[Otto]

I would like to see the charts. Otto

[KFC911]

I have just finished scanning the printed outputs, but they are still too large to post...I'll get them reduced and post them later today. Steve, I have not confirmed that the WOT switch is engaging (but I will). If that were the case, wouldn't the comparisons still be legit (i.e. not a WOT comparison, but essentially the same 'part throttle mapping') since my foot was planted to the floor on all runs? Thanks again everyone, and I do appreciate everyone's feedback on this!

[Paul Thomas]

I dyno'd my car Saturday with Keith and chip differences not-withstanding, his car ran and sounded fantastic. I think he has the GHL exhaust and i forget which muffler, but if you have a Carrera, get this set-up.

My main goal was to get some base line runs so i can experiment with the exhaust a little and smooth out the low end and find the optimal header size for what i want. I am going to weld in an O2 bung for the next time to use his wide band sensor.

TimT, the dyno we were on (my first) put ALOT of resistance on the rear wheels. Under normal driving if i stomp it in 4th, it takes off. On this thing, it was a much slower increase in RPM and speed.

I still had some grunt left at 105mph but am unwilling to run it that hard for high RPM numbers that i am not that interested in. My engine (3.5) has alot of low end torque, but the numbers that the dyno came up with were impossibly high. I guess they will be good for future comparison if i stay on the same dyno, but were unrealistic, which raises some questions.

Paul

[Steve W]

Keith, about half of the 3.2s that I have worked with have throttles that do not open all the way, some only about 2/3s and therefore do not contact the WOT switch. Part throttle and WOT are completely different. Part thottle will still be controlled by the O2 sensor to keep the mixture at a stoichiometric 14.7:1 at steady state, and so the ignition advance can only be programmed out to a certain limit. WOT ignores the O2 sensor and allows a WOT fuel mixture at a optimum fuel mixture of 12.6-13.0, allowing a more ignition advance. Some difference has to be accountable, as the WOT maps are just too radically different from stock. Either the performance chip produces less hp, or more, but not identical to the stock. Although each 3.2 engine seems to flow differently from each other, especially with all the mod each owner does, this is what the AFR curve of your car should look like at WOT from idle to 6800 rpm:



Owners tell me how they reduced their best a few seconds just with a chip change. Bill Miller emailed me last week with respect to a chip for his 87 3.2. I think it takes a lot to drop 2 seconds off a lap time with an extra 200 lbs in your car:

Hope my referrals worked out. They are the PCA region President and the Chief Driving Instructor so if they like your chip it's good for some word of mouth among the regional racer crowd.

I was happy with the way the car performed in Time Trials yesterday. I had a big guy for a student (200+ lbs) and didn't get to run without him in my car yet I took 2 sec off my best time from last fall. I may do a lap times comparison at our next DE later this month.

Bill Miller

Remember Mike Wong who's G-tech registered a 14 hp average increase? He redid some of his G-tech runs after we took some AFR loggings and redialed in his last chip. He has a freshly tuned 88 with only a Fabspeed premuffler. After cutting out an additional 8% fuel at 6000 rpm (and actually quite a bit less than the stock chip). This was his email:

Finally had the chance to make a few runs today. Got 4 good runs in using
the new chip with the pre-muffler. The average was 195.8 hp, again, using
the G-tech measuring just second gear at wot from around 3k rpm till
redline. Anyways, great work and thanks again for all your work and
help! Ttyl, regards, mike

btw, the 4 runs today were: 185, 207, 188, 203, avg-195.8

previous runs:
stock car and stock chip: 171, 175, 174, 179, 164, 184-last two tossed out,
avg-174.8

stock car and your chip: 175, 190, 190, 198, 174, 199-last two tossed out,
avg-188.3

I'm not sure what to say about your runs, as I'm not an expert on all the different types of dynos, although I have seen that on a dyno, engine hp decreases at the runs progress, probably due to heat soak which will reduce the fuel, and on my recent chips, I've actually programmed additional dynamic ignition timing retard based on temperature so that additional knock protection is provided in hot weather. This could be a possible factor for less hp output. It is not an issue when the car is moving, as the air flow keeps the engine compartment and manifolds cool. Here is a screenshot of the correction factors computed in hp decrease on the dyno as the dyno runs progressed every 15 minutes on this 88 3.2. The stock chip was used as a baseline for the first and second run, and used again on the 7th run for a baseline that computes the decline factor. You can see by the 7th run, peak hp has decreased by 8 hp on the stock chip, and around here is where the decline has stopped.



So differences I would expect, but same?

Steve

[KFC911]

Thanks Steve (I will read your post carefully a bit later), in the meantime, here are the graphs that my 6 runs produced (in the order that the runs were performed). One other thing, my car's temperature didn't budge throughout any of the runs (w/ the guage sitting slightly below the first 'tic' mark). I've only been able to get her to climb to the half-way mark on the very hottest days of the summer, so I'm in great shape there!

edited: Ha, let me work on resizing these a bit more before I post any of the other graphs... I'll be back this evening.

edited: to remove graph

[D Hanson]

That is some whacked out looking lines. Were you with the individual who had the 996 3.6 that dynoed at 230 something??? He said something about being with 4 other individuals and in North Carolina. No way a 3.6 C2 that is healthy does only 230 something at rear wheels.

[KFC911]

Let's try these graphs again: Here's the first run:
SW #1:

edited: to remove graph

[KFC911]

Here's the first run with the stock chip:
Stock #1[

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[KFC911]

Here's the second run with the SW chip
SW #2

edited: to remove graph

[KFC911]

Here's the second stock run:
Stock #2

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[KFC911]

Here's the third SW run:
SW #3

edited: to remove graph

[KFC911]

And the last stock run:
Stock #3

edited: to remove graph

[KFC911]

Originally posted by D Hanson
That is some whacked out looking lines. Were you with the individual who had the 996 3.6 that dynoed at 230 something??? He said something about being with 4 other individuals and in North Carolina. No way a 3.6 C2 that is healthy does only 230 something at rear wheels.

Yes, you must be referring to Ken Charnock. Take a look at these graphs now, and let me know how everyone interprets them. To me, the actual numbers don't matter nearly as much as the delta changes between the runs since I'm primarily concerned with comparing the two chips.