Modded vs stock performance. Figure this one out?
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Modded vs stock performance. Figure this one out?
Bear with me on this, this part leads up to the reason for this post. Last week I decided to put the stock muffler and tailpipe back on, I got tired of the drone from the DI/DO Magnaflow muffler. I got a Flowmaster Y pipe and Magnaflow tip for the installation and had them all installed. I figured I would lose peformance but my ears are happy so oh well. Yesterday I decided to remove the Airaid MIT I was using and reinstall the Hemi Hat making my intake stock except for the Ram-Air mod I've had to quite a while. I wanted to see what the truck would run basically stock except for the Superchips. When I got my Superchips, I tested both the 87 and 91 tunes. I posted a thread here showing my findings, the 91 tune was only slightly better than the 87 tune on my truck. When I did the Superchips testing, I had the MIT and Magnaflow exhaust on the truck. My best 87 tune time was 0-60 in 6.70 and the 1/4 in 15.18. My best 91 tune time was 0-60 in 6.67 and the 1/4 in 15.15. These runs were all done with a G-tech Pro.
Now the reason for this post! Tonight with the stock exhaust and basically the stock intake (except for Ram-Air which I had for the previous testing too) my G-tech time was 0-60 in 6.68 and the 1/4 in 15.13.. This is with the 87 tune. I was shocked! The truck "feels" good but it's obviously quieter with the stock exhaust on so it doesn't "sound" as fast. The 0-60 time is faster than my previous best by .02 seconds and 1/4 time is faster than my previous best by .05 seconds. Where's the performance loss from taking off the Magnaflow muffler and the Airaid MIT?? Any thoughts?
Jim
Now the reason for this post! Tonight with the stock exhaust and basically the stock intake (except for Ram-Air which I had for the previous testing too) my G-tech time was 0-60 in 6.68 and the 1/4 in 15.13.. This is with the 87 tune. I was shocked! The truck "feels" good but it's obviously quieter with the stock exhaust on so it doesn't "sound" as fast. The 0-60 time is faster than my previous best by .02 seconds and 1/4 time is faster than my previous best by .05 seconds. Where's the performance loss from taking off the Magnaflow muffler and the Airaid MIT?? Any thoughts?
Jim
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Hey Jim, Dhunckyn saw the same thing last year when testing the Volant CAI ( he got an early model ). The stock intake "hat" provides a large area of intake volume that aids in low end response and overall better breathing. Dhunckyn dynoed his stock and with the first rev of Volant ( deletes the hat ). He lost power almost across the entire range. After talking with Volant they sent him the current/new design that keeps the hat. All the power was back plus the "gains" promised by the CAI.
On the exhaust, a DI/DO type of system is notorious for gains on the top end with losses on the bottom due to the reduced restriction. My first guess is that your 60' and 0-60 times are improved, and the losses on the top end are nullified or not being seen.
My two cents....
On the exhaust, a DI/DO type of system is notorious for gains on the top end with losses on the bottom due to the reduced restriction. My first guess is that your 60' and 0-60 times are improved, and the losses on the top end are nullified or not being seen.
My two cents....
Last edited by ktmrider; 10-12-2005 at 03:39 PM.
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Originally Posted by ktmrider
Hey Jim, Dhunckyn saw the same thing last year when testing the Volant CAI ( he got an early model ). The stock intake "hat" provides a large area of intake volume that aids in low end response and overall better breathing. Dhunckyn dynoed his stock and with the first rev of Volant ( deletes the hat ). He lost power almost across the entire range. After talking with Volant they sent him the current/new design that keeps the hat. All the power was back plus the "gains" promised by the CAI.
On the exhaust, a DI/DO type of system is notorious for gains on the top end with losses on the bottom due to the reduced restriction. My first guess is that your 60' and 0-60 times are improved, and the losses on the top end are nullified or not being seen.
My two cents....
On the exhaust, a DI/DO type of system is notorious for gains on the top end with losses on the bottom due to the reduced restriction. My first guess is that your 60' and 0-60 times are improved, and the losses on the top end are nullified or not being seen.
My two cents....
Jim
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Originally Posted by bluecajun5.3
maybe weather conditons were different?
Jim
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If you go to wunderground.com you can track you weather conditions fairly closely and you can figure your Density Altitude. from that number you can tell if you make real gains or losses. those numbers are real close.... perhaps your mods were not helping you as much as you thought.....
Just another reason I have yet to do my exhaust.... I figure at least $1000 and I really want to make sure it is worth the cash. It would really suck to spend that much for nada....
TJ
Just another reason I have yet to do my exhaust.... I figure at least $1000 and I really want to make sure it is worth the cash. It would really suck to spend that much for nada....
TJ
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With going back to an almost stock exhaust your back pressure is closer to being correct for the cam timing and so on and so on!!!! Thus giving you a better torque curve across the board. Just my opinion.
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#8
Great info, guys. I have a stock 05 HEMI RCSB 4x4 with just a True Flow drop-in filter. Did I make a mistake purchasing an Airaid MIT???
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
#9
Originally Posted by hemidude
Great info, guys. I have a stock 05 HEMI RCSB 4x4 with just a True Flow drop-in filter. Did I make a mistake purchasing an Airaid MIT???
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
RJ
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Originally Posted by hemidude
Great info, guys. I have a stock 05 HEMI RCSB 4x4 with just a True Flow drop-in filter. Did I make a mistake purchasing an Airaid MIT???
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
Also, I've read that our exhaust is 3" Mandrel bent from the factory...a true 3"? Is it SS or Aluminized steel?
If I chose to "open" it up some, which Magnaflow would work best installed with the rest of the stock exhaust (resonator left intact)? I love the sound of the stock system but want some more "noise" out back.
Thanks!
Derek
Jim