exhaust cut-outs ..... thoughts

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  1. Canadian1968

    Canadian1968 Well-Known Member

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    What is everyone's opinion on exhaust cut outs. Doesn't matter if they are electric or bolt on. Are they mainly just a head Turner or do they offer any real performance gains. ?

    Thought about them but also looking at the design and how it would change the flow of exhaust when open and closed. They seem like more of an attention getteer' than anything .
     
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    • toolmanmike

      toolmanmike Moderator Staff Member FBBO Gold Member

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      They never sound as good as open headers.
       
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      • vintage chromoly

        vintage chromoly Well-Known Member

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        Don’t be that guy
         
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        • 67charger383

          67charger383 Well-Known Member

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          • LemonWedge

            LemonWedge Well-Known Member

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            I’ve run 3” cutouts for years. Open at the track, corked on the street. It’s worked great for me, honestly. But I’m not driving my car on the street much anymore, so I dropped the 75-lb system in favor of a short, light race-specific system that will still be street legal.
            If it’s truly a street / strip effort that’s trying to be suited equally to both, I think they’re a great option. As far as opening them on he street..... no thanks.
             
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            • 70chall440

              70chall440 FBBO Gold Member FBBO Gold Member

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              They seem like a "neat" idea but I suspect that at some point the electric ones will fail due to carbon build up; either won't open or close and given the price of them I wouldn't do it. Back in the day I worked at an exhaust shop and we made a lot of cut outs wherein we had a 3" freeze plug that we would cap off the exhaust using a stud we would weld into a short collector extension. I would uncap them from time to time to street race and such but you had to crawl under the car and remove the wing nut (which was hot) and repeat to cap them. Way more trouble that I would do today, just not worth it.
               
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              • Canadian1968

                Canadian1968 Well-Known Member

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                I am not looking to use these on the street. So everyone can relax.

                The thought is would they offer any benifit at the track ?
                 
              • mr. b

                mr. b Well-Known Member

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                i had them on my 63 fury it pulled harder with them open at the track also my buddy has them on his Cordoba it went 2 tens faster with them open
                 
              • 69sunfireGTX

                69sunfireGTX Well-Known Member

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                Set them up just like you would for track use. Open at the track and get some extra power. I have mine setup at 18"s after the header collector. Works well! Dynoed and tuned with them open. Plus you can hear your car at the track when the guy next to you is running open header type system.

                If you are running a stock engine it might not be worth it. It doesn't sound as cool as something with high compression and HP
                 
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                • malex

                  malex FBBO Gold Member FBBO Gold Member

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                  —-
                  LW what is your new exhaust system.
                   
                • slepr1

                  slepr1 Well-Known Member

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                • LemonWedge

                  LemonWedge Well-Known Member

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                  Keeping the Hooker Comp 1-7/8” headers; using 3” mandrel to get Aligned to the torsion bar crossmember reliefs (approx. 12”) then a set of Flowmaster FlowFX bullets (16” long) then short turndowns at 45*.

                  whole system should weigh about 12 lbs. so I just lost 63 lbs and gained some HP via a better flowing System in the process.

                  23207788-25F0-4E96-8D5A-A48762BEF4FC.png
                   
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                  • 493 Mike

                    493 Mike FBBO Gold Member FBBO Gold Member

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                    I run Doug's cut outs and picked up 20 HP on the dyno with them open. This is in a 3" system with X-pipe, Flowmaster Delta 44s, dumping ahead of the axle. Doug's uses a guillotine style, self cleaning mechanism. Not the cheapest but mine are bullet proof. I just love to listen to the sound of no/very little throttle cruise-reminds me of drag strip return road music.
                    Mike

                    044.JPG
                     
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                    • Dennis H

                      Dennis H FBBO Gold Member FBBO Gold Member

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                      QTP’s on the street for 15 years. Reliable. Close tight every time.
                       
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                      • Dominic

                        Dominic Well-Known Member

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                        I use 3 inch dual electric cutouts w/ 1 7/8ths TTI headers... work well and sound bitchin'... Usually closed on the street, but sometimes I gotta give a ricer some of that Mopar sauce and uncork it. Eh, sue me! Or at a car meet I roll with it opened up, because who doesn't want to hear a stroker Hemi uncorked?? :icon_fU:
                         
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                        • kiwigtx

                          kiwigtx Trendsetter Staff Member FBBO Gold Member

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                          Same here...except only 3 years running. Makes it easier to hear your own vehicle at the track, and they are a bit of fun on the street. Definitely made a difference at the track.

                          I got sick of crawling under my vehicle at the track to disconnect exhaust pipes. etc. Flick a switch and I am good to go.
                           
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                          • biomedtechguy

                            biomedtechguy Accelerati Rapidus Maximus FBBO Gold Member

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                            Mike, if I could have given 10 green checkmarks in one post I would have!
                            You hit every point I have experienced with my Doug's cutouts. I roll into monthly car meets w/them open, and run up and down Beach Road for Cruisin the Coast w/them open almost all the week long event.
                            I have 3" exhaust, 40 series Flowmasters
                            a prefab 3" X pipe and :lowdown:Doug's cutouts that are "self cleaning" and get out of the exhaust stream 100% when opened. They had a recall on the serial numbers my 2 electric motors fell w/in, and one had failed. They sent me TWO replacement electric motors, and I still have one as a spare.
                            1 7/8ths TTi ceramic coated headers.
                            Performance difference?? Probably NONE, but that's because my exhaust system is EXCEPTIONALLY WELL done.
                            How do open cutouts sound?
                            I'm SO GLAD you asked!!


                             
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                            • alfaitalia

                              alfaitalia FBBO Gold Member FBBO Gold Member

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                              20horses is a lot more than I would expect....the rest of your pipework must be pretty restrictive/missmatched to give such a big gain.

                              ....have any members got their cutouts set up to only open at WOT? I'm thinking about fitting them and if I do I'm thinking that having them open at only WOT would mean less attention from the Police and would give any gain when you needed it most....at WOT! Perhaps a manual override should I ever go to the track....which I almost certainly wont as drag racing is not really a thing over here.
                               
                              Last edited: Oct 25, 2020
                            • BSB67

                              BSB67 Well-Known Member

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                              I've lost track - do you have headers?

                              Not directly on point with cut-outs, but years ago, through a lot of track time and observation, I concluded that uncorking the headers on a 12 second car was generally worth 0.2 sec, and 2 mph. I would suspect that this is still generally true and would be similar to cut-outs. But what you have behind the headers will make a difference too. Back then, people were not running 3" mandrel bent exhaust with straight through mufflers.
                               
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                              • biomedtechguy

                                biomedtechguy Accelerati Rapidus Maximus FBBO Gold Member

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                                That's what I was alluding to in my case.
                                Now because of the rarity (in the past) of the number of times I took my car to the track, I don't have back to back timeslips to prove that my 3" exhaust allows for the same ET and MPH as when my cutouts are open, and I usually run with them open at the track because I like the sound and it makes it easier to hear my engine working, and eventually I'll get to a local chassis dyno for some data and tuning, but I am confident that there's no significant difference in performance between open and closed exhaust on my car because the full exhaust flows so well.
                                The other reason why I haven't been able to do a direct comparison is my traction problems were so bad that consistency was nearly impossible to achieve, but many of my recent mods should resolve that with some adjustments once I get the time at the track.
                                 
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