i am doing an na build and really wanted to keep my stock muffler because i just dont want the car to be loud and i want to keep the stock tone. i was thinking i would put an exhaust cutout at the beginning of the midpipe. so then my exhaust would go, megan headers, kinetix hfc, HR ypipe, ecutout, stock midpipe, stock muffler. will this kill my mid to lower power? i know if would if the cutout was right after the headers, but not sure what it will do, if anything, if i put it at the beginning of the midpipe. at first i was set on getting one, but im having second thoughts. any suggestions?

 

Cut outs are a popular drag racing subject going back 8 years. Question is how do you tune? With cut outs open or closed? Or do your run multiple maps?

 

I have a utec so multiple maps. I just don't want to do it if it will barely make a difference. Plus I'm pretty low and not sure theres enough room down there

 

anyone else?

 

Most of my best NA times have been done with an open Y-pipe which is basically a ghetto exhaust cutout. Works well at the track.

 

Good to know, thanks. You talking road course track or drag strip track?

 

NA build and stock anything shouldnt be in the same sentence

 

In your opinion

 

I've always been interested in the cut-outs and juggled around the idea of getting them for years but never liked the idea of having a pipe that's not in the direct stream of the exhaust gasses.

Also, I would think that the stock HR y-pipe would be the bottleneck in your system due to its smaller inner diameters. This y-pipe probably gives you more low-end but not as much top-end when compared to the aftermarket y-pipes. When you're racing, low-end doesn't matter anyway so I'd look into a different y-pipe before anything.

If you do get the cut out, please please post pics and dyno comparisons. If everything turns out well, that might just be what finally convinces me to get the cut-out (mine will at the x-pipe, assuming I have enough room).

 

if i do it, i will pm you the results. i originally was going to start a build thread, but people are just too critical and close minded on here so id rather not post then hear everything thats wrong with what im doing. post 5 has renewed my enthusiasm for a cutout though, so it will prob happen. ill let you know.

kinetix hfc are 2.25" ID so im guessing that would be my next restriction, not the ypipe.

 

Well, any cats in general should be the bottleneck. I forgot you had the HFCs. What's the inner diameter of the HR y-pipe at the inlet and at the outlet? What about the headers' outlet?

 

IIRC the HR ypipe is just over 2" inlet and 2.5" outlet. the megan headers are just over 2.25", so ill prob work the hfc a little bit to match that. i might try to work the HR ypipe too to try and match the cats, but i dont know if ill be able to get it to completely match

 

Don't all aftermarket Y-pipes have inlet IDs of at least 2.25" and at least 3" for outlet? Also, if you don't need cats, why not get test pipes?

Everything I'm suggesting/asking is with the most power in mind. If you don't really care for that last few whp, then just go ahead with your original plan instead of spending more money.

When are you planning on getting the cut-outs?

 

emissions testing here so i dont know if id pass with test pipes. i could get simulators, but if im that worried about another few hp, ill change out my jets and pull another degree of timing. but i know what youre saying, ive been through the same thought process

 

I don't know where you are, but they do emissions testing in TX, also. I've always passed, but being a 03 with the narrowband sensors, it's easier for me to pass with less effort. Still, since you have a DE, non-foulers should work.

So when are you getting the cut-outs?

 

prob sometime in the next couple months. i want to have the engine put together first though

 

anyone else?