I have been debating on what to do for an exhaust set up. I live in CA, so I have to be careful what I do for smog purposes.

How much would a cut out help at the Y-pipe merging help me in terms of performance. The same/better than running true duals with Magnaflow mufflers?

What cut outs are good and wont leak?

 

I have the DMH cutout and it has worked great for over a year. Although when my truck was nearly stock it was a total dog with it open. Now it is just barely slower/almost the same open/closed. I lost a tenth et and mph. Maybe with more boost and/or cam/heads it would be beneficial. It is fun to open up and suprize people though

 

Where do you have it located? I was going to make 2 interchangable pipes where I could remove my cats and place my cut outs on the pipes and install it in place of the cats. This would be before the the merging of the 2 pipes after the header.

What type of exhaust set up of you have after the y-pipe? Any signs of restriction?

Thanks man.

 

I have the supermaxx system which includes a Y pipe with "high flow" cats, then after the Y I have a section of 3" pipe, then the cutout, then directly after that is the Magnaflow single in/out muffler with a turn down before the axle. Its possible that my setup isn't the best for exhaust flow, but I've checked with oxidizr (magnaflow) and he said it sounded fine, thats how he has his. I plan on deleting my cats soon, so we'll see how that affects things. Having cutouts instead of cats would be a real nice setup, I'm just not sure at what hp/boost range having a completely open exhaust would yeild any extra hp.

 

I got dual exhaust with the DMH cutouts and with them open I can definitely feel a slight loss in low end but it does pick up at the top end....and VERY LOUD I still run the cats too; no problems with them yet.

 

I run my dual cut-outs after the cats and after the x-pipe and it is loud but sounds awesome. You will lose some bottom end but I have 3000 stall so I dont even notice it anymore I just notice the gain up top. I have flowtechs. They work good I dont even use the supplied gasket and they seal good.

 

I have single 3.5" cutout on my new exhaust system that I have only opened once since it has been on to test at the track. I only got four runs in that day, so my results are all but conclusive. Ran once on motor thru exhaust, once on nitrous thru exhaust, one motor with cutout open and one n2o with cutout open. The cutout open/closed times were about the same for each. It was actually a little faster on motor (less than a tenth) and slower on the spray (also less than a tenth). I did have to hotlap the last two runs cause it was time to go. It felt slower with the cutout open when I first opened it at the track but I left it off to cruise to our local spot afterwards. It started felling alot better as I rode around so I am curious as to how it would do at the track if I open it sooner and let it adjust.
I have to agree with 03 though... it is fun to open it and see the looks on peoples faces on the street.

 

I wonder what boost level it would be effective. We are definately flowing a lot of cfm and the cats have to be restrictive as well. Some people have claimed over 20rwhp with just removal of the cats on NA applications.

I also dont think that my exhaust is free flowing and trying to figure out my best option to maximize the flow of my exhaust.

 

Duals with cut-outs would be my choice. Dont forget an x-pipe. Stock cats flow pretty well with lower miles on them.

 

What would be the benefit of the x pipe? I run duals but don't have a x. Also, I did dyno with the cutouts open and picked up 16rwh with them open. They were all in shock including me