3.2 Performance Chip Dyno Results
02-17-2004, 09:05 PM
#1
Race Car
Thread Starter
3.2 Performance Chip Dyno Results
From the Pelican Parts Forum 2/14/04:
Thread - "SW chip issue put to rest...or not
"
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?
__________________
Keith Craver
'88 911 CE coupe
Thread - "SW chip issue put to rest...or not
"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?
__________________
Keith Craver
'88 911 CE coupe
02-18-2004, 11:43 AM
#2
Burning Brakes
Hi Loren, I just now saw this post...If you haven't yet, take another look at that thread's latest graphs and posts, and let me know what you think. At this point, I've lost any credibility in the dyno numbers, or maybe I'm just interpreting them incorrectly. That being said, the runs did not show any 'significant differences' between the chips, but the graphs just don't depict 'believable numbers', so I'm beginning to have even more questions than before . Thanks...
Keith
edited: Here's the link for anyone that's interested:
http://forums.pelicanparts.com/showt...hreadid=148823
. Thanks...Keith
edited: Here's the link for anyone that's interested:
http://forums.pelicanparts.com/showt...hreadid=148823
02-18-2004, 06:52 PM
#4
Race Car
Thread Starter
Another post from the Pelican thread:
"One thing to keep in mind is the relatively correct order the cars fell. By that, I mean that the new 996 had the expected highest number, and Tom's '73 E was the lowest with you slotted properly between them. Paul's 3.5 and my 2.7 were clearly the exceptions and both of them were way down over expectation.
As someone totally disinterested in the "chip wars" I would say that the only possible variable for stock vs SW is a malfunctioning WOT switch. If you find that to be in good working order, then IMHO a chip is probably doesn't buy much new top end performance. Maybe a better butt-o-meter feel or mid-range feel, but not top end.
__________________
Hal Michael
1970 911 E Targa w/ 2.7 RS spec"
Although the torque numbers numbers are in error, i.e. torque = HP @ 5252 RPM,
K = 5252 in HP = (torque x RPM)/K, the meaningful result is the difference determined
between the chips - insignificant. The results are consistent with other dyno tests
that have been done over the years, e.g. Bruce Anderson's test of six different
perfomance chips indicated no significant differences.
Most DMEs with non-358 chips will probably see a very small improvement with the
performance chips, because Porsche improved the torque output slightly (10 ft-lbs)
with the 082 DME (32K in '87 & 358 64K EPROM in '88/89). For most 3.2 Porsches,
though, as the data further indicate, performance chips are a waste of money.
Have Fun
Loren
'88 3.2
"One thing to keep in mind is the relatively correct order the cars fell. By that, I mean that the new 996 had the expected highest number, and Tom's '73 E was the lowest with you slotted properly between them. Paul's 3.5 and my 2.7 were clearly the exceptions and both of them were way down over expectation.
As someone totally disinterested in the "chip wars" I would say that the only possible variable for stock vs SW is a malfunctioning WOT switch. If you find that to be in good working order, then IMHO a chip is probably doesn't buy much new top end performance. Maybe a better butt-o-meter feel or mid-range feel, but not top end.
__________________
Hal Michael
1970 911 E Targa w/ 2.7 RS spec"
Although the torque numbers numbers are in error, i.e. torque = HP @ 5252 RPM,
K = 5252 in HP = (torque x RPM)/K, the meaningful result is the difference determined
between the chips - insignificant. The results are consistent with other dyno tests
that have been done over the years, e.g. Bruce Anderson's test of six different
perfomance chips indicated no significant differences.
Most DMEs with non-358 chips will probably see a very small improvement with the
performance chips, because Porsche improved the torque output slightly (10 ft-lbs)
with the 082 DME (32K in '87 & 358 64K EPROM in '88/89). For most 3.2 Porsches,
though, as the data further indicate, performance chips are a waste of money.
Have Fun
Loren
'88 3.2
Last edited by Lorenfb; 02-18-2004 at 09:32 PM.
02-18-2004, 07:38 PM
#5
Burning Brakes
Originally posted by Lorenfb
Another post from the Pelican thread:
Although the torque numbers numbers are in error, i.e. torque = HP @ 5280 RPM,
the K = 5280 in HP = K X torque, the meaningful result is the difference determined
between the chips - insignificant. The results are consistent with other dyno tests
that have been done over the years...
Another post from the Pelican thread:
Although the torque numbers numbers are in error, i.e. torque = HP @ 5280 RPM,
the K = 5280 in HP = K X torque, the meaningful result is the difference determined
between the chips - insignificant. The results are consistent with other dyno tests
that have been done over the years...
Last edited by KC911; 02-18-2004 at 08:19 PM.
02-18-2004, 09:32 PM
#6
Race Car
Thread Starter
With regard to the dyno data:
1. It is now obvious that you should have made a calibrate/setup run to check
and correlate your data.
2. Do you have a tabular output or just the graphs?
3. You can determine actual torque by finding the HP at 5252 and then
calculating the scale factor for the dyno readings, e.g. HP @ 5252 = 180
then the torque = 180, dyno shows 300 then scale factor is .60.
4. The torque on a Porsche engine, as with most engines, should be fairly
constant over the RPM range above 3000 RPMs. As an example, the Porsche
Cayenne has a perfectly flat torque curve over the full usable RPM range.
5. Was the dyno connected to your ignition system to determine RPM?
If it was, then you must determine why the discrepancy in RPMs. If not,
then what RPM was being read?
Bottomline: I'm sure all the data are there, but some corrections must be
made.
Have Fun
Loren
'88 3.2
1. It is now obvious that you should have made a calibrate/setup run to check
and correlate your data.
2. Do you have a tabular output or just the graphs?
3. You can determine actual torque by finding the HP at 5252 and then
calculating the scale factor for the dyno readings, e.g. HP @ 5252 = 180
then the torque = 180, dyno shows 300 then scale factor is .60.
4. The torque on a Porsche engine, as with most engines, should be fairly
constant over the RPM range above 3000 RPMs. As an example, the Porsche
Cayenne has a perfectly flat torque curve over the full usable RPM range.
5. Was the dyno connected to your ignition system to determine RPM?
If it was, then you must determine why the discrepancy in RPMs. If not,
then what RPM was being read?
Bottomline: I'm sure all the data are there, but some corrections must be
made.
Have Fun
Loren
'88 3.2
Last edited by Lorenfb; 02-19-2004 at 01:20 AM.
