dyno testing results
03-17-2004, 01:59 PM
#32
AutoX
Join Date: Dec 2003
Location: North Carolina
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Boris' dyno data
Agreed. Here's my take on Boris' data...
The "control" for his experiments was stock intake + stock chip + RS pulleys and mufflers, which gave a max hp of 251.
We don't know whether the RS pulleys and mufflers produced more or less hp than 100% stock (no results for 100% stock setup - this is a bummer, but his reason for not going all the way back to stock is certainly understandable).
In combination with the RS pulleys and mufflers, all of the intake mods he tried actually reduced max hp vs the stock intake, no matter which chip he used.
In combination with the RS pulleys and mufflers and a stock intake, the GIAC chip he has (which one?) only increased max hp by 2, to 253 hp, vs the stock chip. We don't know what the other chip did (e.g. more or less than the 251 max hp of the stock chip).
We don't know what gas or chip he was using.
This is interesting data, however, because I am/was? planning to do one of Steve's (GIAC) chips with Robin's mufflers and probably drill out my airbox cover like the Motorsound airbox, on my '95 C2 (same as Boris' except could be a different DME-->chip).
Boris' data makes me wonder about doing the airbox mod, unless I do it exactly the way porsche did it (assuming porsche wouldn't make a airbox giving away hp for sound)??? Not a big deal for me, though, since I could take or leave the airbox sound.
Am most interested in getting the sound from the RS mufflers. Original thought was to get a little hp & torque, say 12-15, from the GIAC chip and sound from the RS mufflers. But Boris' data suggests there is little advantage of a chip IF you already have the RS mufflers (regardless of whether the RS mufflers increased or decreased max hp relative to stock mufflers). I'm assuming any effect of the RS pulley would pretty much be a "constant", independent of chip or muffler.
If anybody out there has any dyno work for "100% stock" vs "stock + RS mufflers" vs "stock + RS mufflers + chip(s)" on the same dyno, I would love to see it. Haven't been able to find this data so far.
Lacking such data...
At least in theory, the chip should be optimized for the muffler (among other mods, e.g. intake) that will be used. But I'm wondering if the mods that Robin does to the muffler are small enough that a chip optimized for the stock muffler would provide the same benefits it provides with a stock muffler (assuming there is something else in Boris' experiment that causes the chips to provide little/no benefit - his data is only "one data point" in the big scheme of things), i.e. the RS muffler behaves basically the same as a stock muffler???
Am almost thinking I should just do the RS mufflers and be done with it (assuming the RS mufflers don't actually decrease performance when everything else is stock).
Comments? Suggestions? Mountains out of molehills? Actually, I'm not so much interested in max hp as I am in a little more acceleration in the say 2800-5500 rpm range - and obviously, a nice sound.
Thanks.
Mark
The "control" for his experiments was stock intake + stock chip + RS pulleys and mufflers, which gave a max hp of 251.
We don't know whether the RS pulleys and mufflers produced more or less hp than 100% stock (no results for 100% stock setup - this is a bummer, but his reason for not going all the way back to stock is certainly understandable).
In combination with the RS pulleys and mufflers, all of the intake mods he tried actually reduced max hp vs the stock intake, no matter which chip he used.
In combination with the RS pulleys and mufflers and a stock intake, the GIAC chip he has (which one?) only increased max hp by 2, to 253 hp, vs the stock chip. We don't know what the other chip did (e.g. more or less than the 251 max hp of the stock chip).
We don't know what gas or chip he was using.
This is interesting data, however, because I am/was? planning to do one of Steve's (GIAC) chips with Robin's mufflers and probably drill out my airbox cover like the Motorsound airbox, on my '95 C2 (same as Boris' except could be a different DME-->chip).
Boris' data makes me wonder about doing the airbox mod, unless I do it exactly the way porsche did it (assuming porsche wouldn't make a airbox giving away hp for sound)??? Not a big deal for me, though, since I could take or leave the airbox sound.
Am most interested in getting the sound from the RS mufflers. Original thought was to get a little hp & torque, say 12-15, from the GIAC chip and sound from the RS mufflers. But Boris' data suggests there is little advantage of a chip IF you already have the RS mufflers (regardless of whether the RS mufflers increased or decreased max hp relative to stock mufflers). I'm assuming any effect of the RS pulley would pretty much be a "constant", independent of chip or muffler.
If anybody out there has any dyno work for "100% stock" vs "stock + RS mufflers" vs "stock + RS mufflers + chip(s)" on the same dyno, I would love to see it. Haven't been able to find this data so far.
Lacking such data...
At least in theory, the chip should be optimized for the muffler (among other mods, e.g. intake) that will be used. But I'm wondering if the mods that Robin does to the muffler are small enough that a chip optimized for the stock muffler would provide the same benefits it provides with a stock muffler (assuming there is something else in Boris' experiment that causes the chips to provide little/no benefit - his data is only "one data point" in the big scheme of things), i.e. the RS muffler behaves basically the same as a stock muffler???
Am almost thinking I should just do the RS mufflers and be done with it (assuming the RS mufflers don't actually decrease performance when everything else is stock).
Comments? Suggestions? Mountains out of molehills? Actually, I'm not so much interested in max hp as I am in a little more acceleration in the say 2800-5500 rpm range - and obviously, a nice sound.
Thanks.
Mark
03-17-2004, 02:13 PM
#33
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: SF Bay Area
Posts: 1,955
Likes: 0
Received 0 Likes
on
0 Posts
Mark,
couple of comments. i tried some mods which i'm not disclosing. the reason is simple: i don't want to slam vendors with products that claim HP increase that in reality decrease HP.
also the rs mufflers are not Robin's mufflers. RS mufflers are different (and in a way worse than stock mufflers). Robin typically refers to his mufflers as RSR mufflers.
Cheers,
Boris
couple of comments. i tried some mods which i'm not disclosing. the reason is simple: i don't want to slam vendors with products that claim HP increase that in reality decrease HP.
also the rs mufflers are not Robin's mufflers. RS mufflers are different (and in a way worse than stock mufflers). Robin typically refers to his mufflers as RSR mufflers.
Cheers,
Boris
03-17-2004, 02:41 PM
#34
Banned
Chips need to be optimized for the car's individual configuration and fuel quality. That makes this type of mix and matching harder to judge. Ideally you would need to give the provider of each chip an opportunity to provide a different chip for each car/fuel combination to see how well they do on a level playing field. Gets complicated...
03-17-2004, 02:58 PM
#35
AutoX
Join Date: Dec 2003
Location: North Carolina
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Oops. Thanks Boris. I was actually talking about Robin's RSR mufflers in my post (mistakenly called them RS mufflers).
Just to make sure... you were using Robin's RSR mufflers in your dyno work - is that right Boris?
Thanks.
Mark
Just to make sure... you were using Robin's RSR mufflers in your dyno work - is that right Boris?
Thanks.
Mark
03-17-2004, 09:25 PM
#36
Addict
Rennlist Member
Rennlist Member
Regarding chips, some time ago Bruce Anderson did a detailed comparison of a variety of chips and the net result was very small difference. This was in the late 80's early 90's. So I am not surprised that the technology that Porsche developed 10 years post testing would leave much on the table.
If I find the article I will post a copy of it or a reference to where it can be located.
Levino
If I find the article I will post a copy of it or a reference to where it can be located.
Levino
03-18-2004, 12:04 AM
#37
RL Technical Advisor
Hi:
A few comments are in order.
1) Nobody's chip makes a car grow "fangs",...
A properly made chip enhances mid range power and throttle response; the latter one which cannot be measured by any inertial or load-type dyno.
Acceleration is what chip tuning is really about, not necessary big horsepower figures and a good chip will deliver.
2) Please bear in mind that we do not drive dynos and such results & comparisons should be kept in context.
3) Porsche can be faulted for making the 993 too quiet for many people's tastes, but they cannot be fairly criticized for equipping these cars with restrictive exhaust. The very best aftermarket mufflers do not improve power more that 5-6 HP and you really cannot feel that. In this respect, the dyno doesn't lie,...
4) Airbox mods make more noise than power on stock engines but when equiped with big-bore kits, RS cams and some other things, opening the airbox cover with some holes does help.
5) Lastly, its unfair and inaccurate to make generalizations about chips and Porsche did leave much on the table regarding chip tuning up until the latest N/A 996's. Now THOSE are really good,... Can't really help the drive-by-wire 3.6 litre 996's.
A few comments are in order.
1) Nobody's chip makes a car grow "fangs",...
A properly made chip enhances mid range power and throttle response; the latter one which cannot be measured by any inertial or load-type dyno. Acceleration is what chip tuning is really about, not necessary big horsepower figures and a good chip will deliver.
2) Please bear in mind that we do not drive dynos and such results & comparisons should be kept in context.
3) Porsche can be faulted for making the 993 too quiet for many people's tastes, but they cannot be fairly criticized for equipping these cars with restrictive exhaust. The very best aftermarket mufflers do not improve power more that 5-6 HP and you really cannot feel that. In this respect, the dyno doesn't lie,...
4) Airbox mods make more noise than power on stock engines but when equiped with big-bore kits, RS cams and some other things, opening the airbox cover with some holes does help.
5) Lastly, its unfair and inaccurate to make generalizations about chips and Porsche did leave much on the table regarding chip tuning up until the latest N/A 996's. Now THOSE are really good,...
Can't really help the drive-by-wire 3.6 litre 996's.
03-18-2004, 01:46 AM
#38
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: SF Bay Area
Posts: 1,955
Likes: 0
Received 0 Likes
on
0 Posts
yes i am using the RSR (Robin's muffler).
also i wholeheartdly agree with Steve on the topic of chips. The GIAC chip is the best of the breed. The one thing i slightly disagree with - is that steve mentioned that you can't see the difference on a dyno. I would break this up into two points:
1. Dynos only measure full acceleration. In the full acceleration model I do see a difference. The difference is that it smoothened out the torque and power curve in the midrange RPM area. This is where most people drive typically and so i do think it shows it. The graph doesn't show a significant horsepower increase.
2. What it does not show is partial throttle. I would venture to say (based on my butt dyno) that the GIAC chip is more driveable and hot in this range.
Just my 2 cents...
also i wholeheartdly agree with Steve on the topic of chips. The GIAC chip is the best of the breed. The one thing i slightly disagree with - is that steve mentioned that you can't see the difference on a dyno. I would break this up into two points:
1. Dynos only measure full acceleration. In the full acceleration model I do see a difference. The difference is that it smoothened out the torque and power curve in the midrange RPM area. This is where most people drive typically and so i do think it shows it. The graph doesn't show a significant horsepower increase.
2. What it does not show is partial throttle. I would venture to say (based on my butt dyno) that the GIAC chip is more driveable and hot in this range.
Just my 2 cents...
03-18-2004, 03:13 AM
#39
RL Technical Advisor
Boris:
A clarification, Sir....
What I meant say is that dyno results do not always tell the whole tale about any chip,...
Certainly the wide-open throttle settings used in inertial dyno testing (Dynojet) should show increases in torque and Boris is right, but that is not the complete picture. HP isn't everything.
Torque increases at throttle positions ranging from 10% to 90% are accomplished by timing and fueling changes and make a very noticable difference in acceleration and smoothness. The dyno doesn't accurately display this.
A clarification, Sir....
What I meant say is that dyno results do not always tell the whole tale about any chip,...
Certainly the wide-open throttle settings used in inertial dyno testing (Dynojet) should show increases in torque and Boris is right, but that is not the complete picture. HP isn't everything.
Torque increases at throttle positions ranging from 10% to 90% are accomplished by timing and fueling changes and make a very noticable difference in acceleration and smoothness. The dyno doesn't accurately display this.