Cut out comparision
07-30-2012, 10:22 AM
#44
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i still vote for the dynomax ultraflows if you can fit them. Maybe you can even run a dual in dual out in the back of the car. my high comp motor made about 5 more RWHP with that muffler then a magnaflow.
07-30-2012, 11:26 AM
#45
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see this is why i am going to use cut outs...
if i want sound... closed
if i want performance... open
ill tune it for open becuase it will only be a few off and not enought to hurt the engine (people run new exhaust without tunes all the time)
if i want sound... closed
if i want performance... open
ill tune it for open becuase it will only be a few off and not enought to hurt the engine (people run new exhaust without tunes all the time)
07-30-2012, 07:01 PM
#46
IMO, they are worthless, if you have a good flowing cat back.
I had a 412ci LS2, it made 519rwhp in 2005 with open Kooks 1 7/8" headers. We put the Magnaflo cat back on with the kooks 3" into 4" Y pipe and it made 512rwhp. Then put dual 3" QTPs and dual Randomtech metallic cats. Put it back on the dyno with the cutouts closed and it made 478rwhp. Open the cutouts behind the cats and it made 511rwhp.
So it still made 511rwhp through the cats for a loss of only 8 hp.
You can only have your tune correct in either open or closed, your pick. I prefer full hp when ever you want it.
BTW, had 5 cutouts fail in one season, 2 different brands. Driving home 40 miles with one failed open. That has to be bad for the motor.
I had a 412ci LS2, it made 519rwhp in 2005 with open Kooks 1 7/8" headers. We put the Magnaflo cat back on with the kooks 3" into 4" Y pipe and it made 512rwhp. Then put dual 3" QTPs and dual Randomtech metallic cats. Put it back on the dyno with the cutouts closed and it made 478rwhp. Open the cutouts behind the cats and it made 511rwhp.
So it still made 511rwhp through the cats for a loss of only 8 hp.
You can only have your tune correct in either open or closed, your pick. I prefer full hp when ever you want it.
BTW, had 5 cutouts fail in one season, 2 different brands. Driving home 40 miles with one failed open. That has to be bad for the motor.
You made:
-519 open headers
-512 trough a Magnaflow exhaust (loss of 7hp)
-478 after adding cats and cut-outs(loss 34hp)****
-511 with cut outs open (gain of 33hp)
****I believe the majority of this loss was due to adding cats as opposed to the claimed "turbulence." If you had added cats only (no cut-out) the loss would have been similar.
You can't say the loss was ONLY attributed to the cut-out since you made two modifications(added cats and cut-out) on that dyno pull.
Am I right or missing something?
07-30-2012, 09:03 PM
#47
You are making misleading statements/observations.
You made:
-519 open headers
-512 trough a Magnaflow exhaust (loss of 7hp)
-478 after adding cats and cut-outs(loss 34hp)****
-511 with cut outs open (gain of 33hp)
****I believe the majority of this loss was due to adding cats as opposed to the claimed "turbulence." If you had added cats only (no cut-out) the loss would have been similar.
You can't say the loss was ONLY attributed to the cut-out since you made two modifications(added cats and cut-out) on that dyno pull.
Am I right or missing something?
You made:
-519 open headers
-512 trough a Magnaflow exhaust (loss of 7hp)
-478 after adding cats and cut-outs(loss 34hp)****
-511 with cut outs open (gain of 33hp)
****I believe the majority of this loss was due to adding cats as opposed to the claimed "turbulence." If you had added cats only (no cut-out) the loss would have been similar.
You can't say the loss was ONLY attributed to the cut-out since you made two modifications(added cats and cut-out) on that dyno pull.
Am I right or missing something?
You can believe what you want, but your current assumption, is 100% wrong, I was there and have the dyno sheets to prove it somewhere here. It was quite interesting doing all the back to back stuff, and it cost me for all the extra tuning and dyno time, but that is how I do things. I want to truly learn from the experience and gain first hand knowledge. Not internet hearsay.
Same as all the flow bench time to experiment with things on my Harrop intake, and gained 45cfm through it, and know what each individual change resulted in to get that total. Not all my experiments resulted in gains though.
Sorry to the OP, this is a little off base,
I personally am more interested in a refined sound, smooth idle, pass emissions, and make lots of NA torque and power with no road side hassles or interest from the local constables.
Last edited by RAMPANT; 07-30-2012 at 09:08 PM.
08-03-2012, 08:35 AM
#52
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they wont be before axle
here is where my mufflers will be
crushed bends over axle
summit x pipe
with extra piping crush bent to get it where it needs to be
still debating between 2.5 and 3 inch
here is where my mufflers will be
crushed bends over axle
summit x pipe
with extra piping crush bent to get it where it needs to be
still debating between 2.5 and 3 inch
