Are cutouts really helping you. Look inside.
11-20-2003, 12:01 PM
#22
TECH Senior Member
I'll bet a 6-pack he looses nothing. 
Wasn't there someone in a recent thread that already vouched for having done this? Lemme go back and check...
Ok, here it is by Jabroni...
"
FWIW, I did dyno pre-cutout install right at 300 RWHP with a lid and filter swap. After the cutout went in, I redynoed sometime later and did 305 closed. I opened it up and did 322. Your theory sounds like it would be a little bit of a factor, but realistically, I don't think it's interrupting the exhaust flow all that bad. Especially at WOT when the exhaust gases are really screaming out of the tailpipe."
So he made 300 before the cuttout and 305 after the cuttout with it closed. Of course this is on two different days and dynos can vary a little but it is at least evidence that the cuttout doesn't hurt power.
Wasn't there someone in a recent thread that already vouched for having done this? Lemme go back and check...
Ok, here it is by Jabroni...
"
FWIW, I did dyno pre-cutout install right at 300 RWHP with a lid and filter swap. After the cutout went in, I redynoed sometime later and did 305 closed. I opened it up and did 322. Your theory sounds like it would be a little bit of a factor, but realistically, I don't think it's interrupting the exhaust flow all that bad. Especially at WOT when the exhaust gases are really screaming out of the tailpipe."
So he made 300 before the cuttout and 305 after the cuttout with it closed. Of course this is on two different days and dynos can vary a little but it is at least evidence that the cuttout doesn't hurt power.
11-20-2003, 04:58 PM
#23
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Bowtieman4life:
thanks for the question "When its open there is no problem but when its closed the exhaust gases are bouncing off the closed pipe and coming back to distrupt the flow." this I wanted to know also tonite I am installing pacesetters with 3" y pipe going to install a cutout at each first bend in y pipe( about 18-20" from collector , will be only a flat 1/4"flange -flow will be stright out from collector
PS: I haveing problem with left side collector beening only 1/4 " from bottom of car , going to split around the collector about 300 degs and cut a wedge about 3/16 wide from slit , pull collector down to close slit and weld back together to gain 3/4 clearnce,
just my .02's Johnny
thanks for the question "When its open there is no problem but when its closed the exhaust gases are bouncing off the closed pipe and coming back to distrupt the flow." this I wanted to know also tonite I am installing pacesetters with 3" y pipe going to install a cutout at each first bend in y pipe( about 18-20" from collector , will be only a flat 1/4"flange -flow will be stright out from collector
PS: I haveing problem with left side collector beening only 1/4 " from bottom of car , going to split around the collector about 300 degs and cut a wedge about 3/16 wide from slit , pull collector down to close slit and weld back together to gain 3/4 clearnce,
just my .02's Johnny
Last edited by SS SLP2; 11-21-2003 at 12:35 AM.
11-21-2003, 12:42 AM
#26
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Colonel, Was the 22 hp increase on a stock exhaust or on an after market set up w/ ORY. Just curious. Also, its only a hunch and I just wanted to hear other opinions and proof. THanks
Originally Posted by Colonel
I'll bet a 6-pack he looses nothing.
Wasn't there someone in a recent thread that already vouched for having done this? Lemme go back and check...
Ok, here it is by Jabroni...
"
FWIW, I did dyno pre-cutout install right at 300 RWHP with a lid and filter swap. After the cutout went in, I redynoed sometime later and did 305 closed. I opened it up and did 322. Your theory sounds like it would be a little bit of a factor, but realistically, I don't think it's interrupting the exhaust flow all that bad. Especially at WOT when the exhaust gases are really screaming out of the tailpipe."
So he made 300 before the cuttout and 305 after the cuttout with it closed. Of course this is on two different days and dynos can vary a little but it is at least evidence that the cuttout doesn't hurt power.
Wasn't there someone in a recent thread that already vouched for having done this? Lemme go back and check...
Ok, here it is by Jabroni...
"
FWIW, I did dyno pre-cutout install right at 300 RWHP with a lid and filter swap. After the cutout went in, I redynoed sometime later and did 305 closed. I opened it up and did 322. Your theory sounds like it would be a little bit of a factor, but realistically, I don't think it's interrupting the exhaust flow all that bad. Especially at WOT when the exhaust gases are really screaming out of the tailpipe."
So he made 300 before the cuttout and 305 after the cuttout with it closed. Of course this is on two different days and dynos can vary a little but it is at least evidence that the cuttout doesn't hurt power.
11-21-2003, 11:02 AM
#27
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I'm running an electric cutout. What I've been wondering is how long does it take for the computer to figure out that it is flowing better when I open and close it? My dyno runs were back to back, and I put down 272 closed, 289 open. (I don't know why my numbers are so low. That's with a lid too! Everything else is stock.)
11-21-2003, 11:10 AM
#28
TECH Senior Member
Purdone, the MAF sensor reacts instantly to your cuttout being open or any other change that increases airflow through it (elsewise a ramair kit would be useless, for example.) There is no learn time that has to take place. I've literally made one dyno pass while observing a wideband O2 sensor, opened my electric cuttout, made another pass right away, and the fuel/air mixture was identical but the power picked up 28 RWHP. The PCM commanded the required fuel based on input from the MAF just as it should. 