cut out open or closed
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TECH Apprentice
Joined: Mar 2004
Posts: 323
Likes: 0
From: North richland hills texas
cut out open or closed i am going to go get my car dynoed tomorrow at speedtek and was wondering if i were to leave the cut out open would i pull more hp than with through the muffler. i have k&n fipk kit,mac mids and carsound cats through a single chamber flowmaster dumped to the ground. my car is 2000 ls1 a4 pretty much just exhaust work. what should my car pull.
Do a pull w/ it closed and open and u'll see maybe a few hp( jus my 2 cents) Im guessing 320rwhp+ or - with the verter locked. I did 330rwhp on my 99z28 w/ similar mods plus a few more but all dyno's are different. Hope you get the numbers ur hoping for!!
Originally Posted by M6HuggerSS
keep it open! i gained about 5rwhp before H/C
and about 15rwhp after H/C......
KEEP IT OPEN!
and about 15rwhp after H/C......
KEEP IT OPEN!
Lazy, Are you just makin some pulls or actually getting a tune?
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i have 1 on each side of the y-pipe and then one on the i-pipe.
i had the one on the i-pipe first and then just added the other 2 to the y-pipe.
its actually pretty cool to have 3 because i can close the front 2 and only have the back one open so that way its not to loud.
with the front 2 open its LOUD.
one of the guys at qtp has 3 on his also.
i gained 20rwhp by having only the rear one open and then another 15 or so with all 3 open (35)
i had the one on the i-pipe first and then just added the other 2 to the y-pipe.
its actually pretty cool to have 3 because i can close the front 2 and only have the back one open so that way its not to loud.
with the front 2 open its LOUD.
one of the guys at qtp has 3 on his also.
i gained 20rwhp by having only the rear one open and then another 15 or so with all 3 open (35)
Originally Posted by WicketMike
i have 1 on each side of the y-pipe and then one on the i-pipe.
i had the one on the i-pipe first and then just added the other 2 to the y-pipe.
its actually pretty cool to have 3 because i can close the front 2 and only have the back one open so that way its not to loud.
with the front 2 open its LOUD.
one of the guys at qtp has 3 on his also.
i gained 20rwhp by having only the rear one open and then another 15 or so with all 3 open (35)
i had the one on the i-pipe first and then just added the other 2 to the y-pipe.
its actually pretty cool to have 3 because i can close the front 2 and only have the back one open so that way its not to loud.
with the front 2 open its LOUD.
one of the guys at qtp has 3 on his also.
i gained 20rwhp by having only the rear one open and then another 15 or so with all 3 open (35)
You gained another 15 rwhp opening the 2 in the y-pipe OVER just one in the I-pipe? That is pretty tough to believe especially considering your car only has 400 hp. Do you have a graph you can post? How was torque affected?
Sorry but until you prove me wrong, the flag is going up.
Originally Posted by matts22
You gained another 15 rwhp opening the 2 in the y-pipe OVER just one in the I-pipe? That is pretty tough to believe especially considering your car only has 400 hp. Do you have a graph you can post? How was torque affected?
Sorry but until you prove me wrong, the flag is going up.
Sorry but until you prove me wrong, the flag is going up.
my 400rwhp is unlocked also.
go buy some more cutouts and you will see. i do have a graph but noway to post it right now.
11 Second Club
Joined: Feb 2002
Posts: 955
Likes: 4
From: Silver Spring, Md.
Keep it open. On my 99SS, I gained 8 rwhp/tq when I opened it. On my 94Z28, I gained 15 rwhp. Amazing how the cutout was worth more on the 94 considering I do have a flowmaster cat-back. On the 99 the cat-back is stock.
Launching!
Joined: Jul 2003
Posts: 237
Likes: 0
From: Ft. Worth, TX
I just got done dynoing my car yesterday and this past weekend after getting it back. Leave the cut-outs open, I've still got the stock cat-back on the car with dual cut-outs at the collectors I gained 28 rwhp & 32 rwtq at the wheels when I opened them they work. But leave it closed for the first pull then un-cap and see what you put down.
I gained 18 rwhp and 10 lbs of tq with cutout over edelbrock catback. Now I just added the fm13 cam and when I get it tuned I will make a pull with the muffler to see if it changes
Originally Posted by WicketMike
i actually gained 40 but that was the first time. thet next dyno day it was 35.
my 400rwhp is unlocked also.
go buy some more cutouts and you will see. i do have a graph but noway to post it right now.
my 400rwhp is unlocked also.
go buy some more cutouts and you will see. i do have a graph but noway to post it right now.
Originally Posted by matts22
I never said that gaining 35 from cutouts wasn't possible. Not probable but possible. I just have a hard time believing that you gained 15 rwhp with 2 cutouts in the y-pipe OVER 1 cutout in the I-pipe. Maybe if you replaced restricting cats in the y-pipe, MAYBE I would believe it. But if you just put the cutouts in open pipe, that's pretty far fetched. Explain or find a way to post up the graphs.
i dont have cats.
the cutouts on the y-pipe are right after the headers. its almost like having open headers. i still have stock muffler but the cutout on the i-pipe is before it of course. ive had the car dynoed about 20 pulls and same results everytime.