Cutout on CME
Cutout on CME I have tried several different searches on what gains would be yielded from a cutout on the SLP CME catback system. Most of the results were just irrelevant information on CME while I did find one thread on how restrictive the CME is, it did not answer my question.
I have a 2002 camaro SLP SS with 1 3/4" headers 2.5" y pipe into 3" merge connected with the stock 3" I pipe and into the CME exhaust of course. Also have a tune, and a SSRA.
Anybody have personal experience or another's experience that can be referenced to a cutout showing gains on a stock internal ls1 that used the SLP 3" CME system?
Thanks,
Parker
I have a 2002 camaro SLP SS with 1 3/4" headers 2.5" y pipe into 3" merge connected with the stock 3" I pipe and into the CME exhaust of course. Also have a tune, and a SSRA.
Anybody have personal experience or another's experience that can be referenced to a cutout showing gains on a stock internal ls1 that used the SLP 3" CME system?
Thanks,
Parker
At one point I logged the airflow readings w/ cutout
open and closed (air mass flow equating to HP more
or less) and saw it pull away only above 5K RPM with
the cutout open vs closed. But this was when I still
had cats. Minus these the muffler is probably the
worst remaining restrictor.
I know there is substantial backpressure with the CME
because I blew an O2 sensor out of my Mufflex tubes
(worn threads, used pieces) at WOT and it had taken
maybe 20 lb-ft of torque (more and it would yield) at
install. What I don't know, is how much better any other
muffler setup might be.
open and closed (air mass flow equating to HP more
or less) and saw it pull away only above 5K RPM with
the cutout open vs closed. But this was when I still
had cats. Minus these the muffler is probably the
worst remaining restrictor.
I know there is substantial backpressure with the CME
because I blew an O2 sensor out of my Mufflex tubes
(worn threads, used pieces) at WOT and it had taken
maybe 20 lb-ft of torque (more and it would yield) at
install. What I don't know, is how much better any other
muffler setup might be.
At one point I logged the airflow readings w/ cutout
open and closed (air mass flow equating to HP more
or less) and saw it pull away only above 5K RPM with
the cutout open vs closed. But this was when I still
had cats. Minus these the muffler is probably the
worst remaining restrictor.
I know there is substantial backpressure with the CME
because I blew an O2 sensor out of my Mufflex tubes
(worn threads, used pieces) at WOT and it had taken
maybe 20 lb-ft of torque (more and it would yield) at
install. What I don't know, is how much better any other
muffler setup might be.
open and closed (air mass flow equating to HP more
or less) and saw it pull away only above 5K RPM with
the cutout open vs closed. But this was when I still
had cats. Minus these the muffler is probably the
worst remaining restrictor.
I know there is substantial backpressure with the CME
because I blew an O2 sensor out of my Mufflex tubes
(worn threads, used pieces) at WOT and it had taken
maybe 20 lb-ft of torque (more and it would yield) at
install. What I don't know, is how much better any other
muffler setup might be.
I reckon I should just band clamp the cutout on my I pipe and and do some testing for myself. If I do not gain anything I can just put the piece of I pipe back in place. Although I think there might be a noticeable gain in ET.
I gained some hp/tq taking my cme tip off but I have it going from my kooks 3" dual exhaust to the tip.. I v banded after the mufflers so I could remove them ...
https://ls1tech.com/forums/dynamomet...i-afr225s.html
https://ls1tech.com/forums/dynamomet...i-afr225s.html
10 Second Club
Joined: Aug 2009
Posts: 249
Likes: 8
From: Oshawa, Ontario, Canada
I was wondering the same...I like the sound of my stock CME with ARH 1-3/4" LTs and catted Y, but was thinking maybe the factory catback might be holding some back on top end...here's a quote from a thread I found through a search:
Might install a 3" cutout in the I-pipe before the axle bend, then throw it on the dyno and see what she does, sounds like it might be cheap HP for when you need it, especially for a H/C setup down the road
Might install a 3" cutout in the I-pipe before the axle bend, then throw it on the dyno and see what she does, sounds like it might be cheap HP for when you need it, especially for a H/C setup down the road
I had the borla adjustable catback on mine but wanted the CME look and wanted to quiet it down. Could not find any factory CME setups for sale for 2 months that weren't beat to hell and I didn't want to hack up the I-pipe, so I went with the Walker factory replacement I-pipe and over axle pipe from summit. (see link in sig) Welded in a 14419 into the I-pipe to quiet it down (didn't help much) along with a Dynomax muffler but it's still loud with cutouts closed. I hope to have dyno numbers of the cutouts open and closed on my setup soon, but it's not exactly a factory SLP CME setup.
Pace Setter Coated long tubes
Pace Setter Y PS82-1163 with dual 3 inch cutouts
Magnaflow 14419 welded in the I-Pipe
Walker I-pipe 54064 / 53061
6LE Designs CME Exhaust tips and elbows
Dynomax muffler #17227
Dual DMH electric cutouts
With the labor and install of the valence and exhaust and excluding the cost of the long tubes and Y pipe, I spent $1400 on the above and would do it again. CME with duel electric cutouts off the Y is the best looking setup on these cars IMHO. Open cutout to get full performance when needed and keep closed when pulling in the driveway.
Pace Setter Coated long tubes
Pace Setter Y PS82-1163 with dual 3 inch cutouts
Magnaflow 14419 welded in the I-Pipe
Walker I-pipe 54064 / 53061
6LE Designs CME Exhaust tips and elbows
Dynomax muffler #17227
Dual DMH electric cutouts
With the labor and install of the valence and exhaust and excluding the cost of the long tubes and Y pipe, I spent $1400 on the above and would do it again. CME with duel electric cutouts off the Y is the best looking setup on these cars IMHO. Open cutout to get full performance when needed and keep closed when pulling in the driveway.
