3" cut-out w/ stock exhaust vs. full 3" exhaust

[alika86]

So I'm thinking about doing something with my exhaust. I'm debating between a 3" cutout and a full 3"exhaust. I got quoted $550 for a full 3" exhaust from a local exhaust shop.

As an alternative, I was thinking of buying a bolt- on 3" test pipe to replace the cat and welding in a 3" electronic exhaust cutout.

That way I can just bolt on and bolt off if necessary. The flow should be pretty good with the cut-out right?

The stock system is 2.25" so mounting the 3" cutout where the cat is should give me about the same flow as a full 3"?

The cutout setup would cost me about $300 compared to the $550 for the full 3". If they flow about the same, I'd rather get the cheaper setup.

What you guys think?

 

[redtsi252]

Try a 3'' ebay n1....i got mine with a 3'' down pipe for about $325 shipped

 

[alika86]

Thanks for all the info guys!

Black Bullet... Damn that ride sounds mean! I was pretty impressed with the numbers you put out when you dyno'd with the cut-out open and then closed... that's about 50hp.. damn that'll be felt. A video of those dyno pulls would be great!

I was concerned about the downpipe bottlenecking to the stock exhaust, but I've been seeing that most people are still gaining a little power and not really feeling that bad of a loss of power at all. I think I'll go get an apex'i. It should bolt up to the stock cat- back right?

Thanks for clearing up the issue about the flames. I knew it had something to do with running too rich, but I thought it had to do with power too. Thanks for clearing that up. It doesn't sound so bad if you haven't felt any bad effects so far, so I'll just fab up a heat shield if I see anything I don't like.

Yah I heard about the motors burning out if the button is held for too long. That's another reason I got the controller.

Another issue: I've got no tuning or datalogging tools...I plan on getting dsmlink for all of that. I was looking for a datalogger for now, but they seem to have disappeared from ebay (that's where i got my last one).

You think I could still be running alright with just the downpipe and cut-out for now? If not, you know where i can get a logger until i can get the dsmlink? Thanks again for all your information guys!

 

[Black_Bullet]

Sorry for taking so long to get back to this thread.

I had my DP off last night, heres a pic of how it looks with the cutout motor and Y pipe.
Sorry the pic isnt so great, but I just snapped it real quick.
(That little black fuzz in the bottom of the pic is my dog Aja. )

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Heres another pic. ( Dont mind the beat up cutout, that thing is like 3 years old and I tinkered with it a little bit.)

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This is my 2nd time going to the dyno, I havent yet dug up the older vids of me on the dyno I had originally told you about which are a little better than these but this will have to do.

This is with cutout closed, it made I think 237awhp.... \

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Now on this nxt vid, this is how my car sounded on the dyno w/ the cutout open that day.
I was on 17psi and only made 276awhp that day.
I normally run 24psi daily but I was having boost controller issues and another boost leak popped up which killed my day because I was going to dial in the tune better on the dyno, when the guy drove my car off the dyno I heard some ppl in the back ground saying what the hell , since I did a run with cutout open, and another w/ it closed.

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[DSMunknown]

• Thumbnails
• Exhaust Cutout

 

[Black_Bullet]

I Added a pic up above. ^

 

[chavez408]

Hm I think I am going to get one for my megan dp. And just sell the megan catback and testpipe.

 

[alika86]

Thanks for the vids n pics guys!

I FINALLY got everything on last weekend!

I ran into a bump in the road, so that's why it took me so long. I ordered a 3" Megan Racing Downpipe from Tuningpros on ebay and they sent me the GS-T pipe when I ordered the GSX one . So I had to return the pipe n they shipped the right one back out to me and I got it about a week later.

When the weekend came, I decided to put everything on. I was pretty surprised at how quick things went. The downpipe took only a half hour to replace (gotta LOVE PB BLAST!)

Unfortunately, the downpipe does NOT bolt on to the cat, so I just took the cat off and left the downpipe open and went to a local exhaust shop to have them weld the Y-pipe in place and weld in a staight pipe to the stock cat-back exhaust. That only took about a half hour as well.

Then, when I got home, I just installed the cut-out valve, hooked it up to the electronic controller (I just spliced into my cigarette lighter for power) and everything was pretty much done! That was about 45 minutes.

So if I include driving times and a taco bell lunch break, it was a 3 hour project, costs about $400, and put a big ass smile on my face when I did a short WOT run with the cut-out open for the first time. Sure, it sounds kind of like a mix between a bus and a tractor, but it pulls like a beast! I say it was all worth it!

Here's a video of just how the controller works. I'll post up some revving and in-car videos when I get a chance to record them:

YouTube - QTP controller in car

 

[Black_Bullet]

Cool.

 

[fwdmaster]

sick cutout

 

[alika86]

Hm I think I am going to get one for my megan dp. And just sell the megan catback and testpipe.

Yup, I would definitely suggest doing that. I had a full 3" turbo back on my old 1g talon and this cut-out set-up kicks its ass in terms of power and versatility. Also, this definitely helps preserve the sleeper status

 

[Novice]

Grats man. I think I'll be going this route. After my last car I don't know if I can deal with "Highway Drone" again.

 

[xxShaneOmac]

I just wanted to give you props man.

Everything looks really clean and Im glad that someone is happy with their job on their car.

Congrats I really like the setup. Looks clean, out of the way, dosn't look like there will be many problems.

Smooth sailing.

 

[alika86]

Thanks guys! I really do enjoy the setup and have no complaints thus far. I would definitely recommend this mod!!!

 

[ed_GST]

I know this thread is old
Just wanting to add this
Recently installed my 3" cut out and comparing it to stock exhaust vs the cut out
is well worth it

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[matthewdesigns]

Zombie thread...but I'll chime in, too. Looks like a nice install you have there, Edwin.

I've got a 3" cutout, a catless 3" dp, and a stock catback. The cutout is just above the curve in the dp, about a foot below the turbo, so when it's open it's essentially like an open dump. I have had it installed for a while, and have logged 3rd gear pulls with it both open and closed. Oddly enough, I see the same peak airflow with it open vs. through the 3"dp/stock catback. What the cutout does for my setup is allow me to hit those peak numbers over 1Krpms earlier, so spoolup is greatly affected. I'm flowing 5+lbs/min less through the stock catback when I'm peaking through the cutout...in round numbers that's roughly 40-50hp more 1Krpms earlier when using the cutout. And I can only imagine the tq increase is even more dramatic. I'll be dynoing the car next month, so perhaps I'll do a comparison at that point given enough time.

And aside from all that, the stock catback keeps everything quiet when I'm just driving around. I would definitely recommend one for keeping a sleeper look, or to avoid an annoying drone from a larger full exhaust.