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Power Gains From Exhaust Only - Dyno Results

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Old 04-24-2013, 01:11 AM
  #1  
JCON
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Default Power Gains From Exhaust Only - Dyno Results

There was a mobile dyno in town last Saturday (4/20/13) at the Pepboys Car Show so I put my car on. The car's only performance changes are: Mac longtubes, Mac ProChamber, Bassani Race mufflers, and 4.10 gears.

The car was dynoed with just 4.10 gears and 87 octane last year (4/21/12) to get a baseline. Stock numbers were 270 RWHP and 292 RWTQ. Dyno below:



It was then dyno'ed with the above mentioned parts installed and 87 octane again. With exhaust, numbers were 283 RWHP and 296 RWTQ. Dyno below:



Below is a table of the changes in performance. I made a mistake in the most recent dyno in not having them start at the same RPM so the data is not as accurate as it could be below 3000rpms but, the basic story is yes, I lost some low end torque but were the runs to start at the same time, I would expect it to be single or low double digit losses (not 30% as pictured).



I picked up peak gains of 13rwhp and 4rwtq. Non-peak max gains were 14.51rwhp and 14.41rwtq. The average was 3.4% gain in power across the rpm band from 2,700 to 6,100 rpms.

Here are both runs plotted together:



I knew that most of us knew that a full exhaust isn't going to post major gains by itself but it is a building block for a stronger car. Before now, I never could find a dyno on just these parts (mostly because it just isn't very cost efficient to do a dyno after each round of mods) but here is the proof I was waiting for. So for all of you in the future, you should be able to better determine where to spend money and what to expect from it. Using a 91-93 octane tune would have likely netted me another 5rwhp and 5rwtq but I just remembered that I didn't even think to switch it (although not sure how great a canned 93 tune would have been).

The next round will be Steeda Charge Motion Delete Plates, Steeda Under Drive Pulleys, WMS High Velocity Intake, and an 87 and 93 octane tune.

Here is the exhaust only dyno video:

Last edited by JCON; 06-30-2013 at 12:27 PM. Reason: More accurate data
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Old 04-24-2013, 06:06 PM
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Ricardo
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Excellent post. You just sold a pair of longtubes!
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Old 04-24-2013, 06:09 PM
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CMcNam
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Great comparison, thank you!
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Old 04-24-2013, 09:12 PM
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JCON
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Ricardo, the Mac longtubes I have are more mid-length but no one calls them that. There was an article done years ago on a blown 05 GT and the Macs came out with the best gains. They provide a solid platform for any future mods. I also had mine ceramic coated.
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Old 06-30-2013, 12:29 PM
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Updated the first post. Finally got the dyno runs from the shop for the baseline. Picked up an average of 3.4% based on the new more accurate dyno run (vs my old plotting of 3% gains from 2600-6100 rpms). Also significant is there wa no mid range loss which was previously plotted and resulted in a 1rwhp/tq loss for about 300 rpms in the mid range.

Last edited by JCON; 06-30-2013 at 12:39 PM.
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Old 06-30-2013, 12:35 PM
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Rudolph Hucker
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interesting thread that man..
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Old 06-30-2013, 12:38 PM
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Nice! This post was the reason my car now has headers. Can't wait to get it dynoed as we have the same type mods. What octane tune were you running for the second run?
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Old 06-30-2013, 02:17 PM
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All runs were on 87 octane. The next round of mods will be done on 93 octane. Because I don't want to drop $150+ on more dyno runs, I am going to do the intake/pulleys/CMDP's all at one time then actually get it tuned.
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Old 06-30-2013, 02:17 PM
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Originally Posted by Ricardo
Nice! This post was the reason my car now has headers.
Glad I could help and this is the reason I'm doing it!
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Old 06-30-2013, 03:17 PM
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Originally Posted by JCON
Glad I could help and this is the reason I'm doing it!


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