25 replies to this topic

[L8 APEKS]

It's just about go time on my "phase 1" of modding the DD! I'm keeping it mild, but I want it to be fun too!

At this point, I have the intake (K&N filter) and ECU (TLAO Stage 1 tune) already accounted for. I will have about another $500 to spend, and I guess my biggest concern is opening up the exhaust.

My last turbo was 3" turbo-back, straight-thru, with no cat, and it wasn't too loud (vids on YouTube: seanwilliams78). But, I wanted to do something different with this car. I thought an electric cutout would be fun; quiet when I want silence, but a nice roar when I want to play around. The trouble I'm having is: how to get the most flow for 500 bones; or, do I try to compromise and save a little dough?

Option 1: 3" DP (on the conical 15G) and 3" electric cutout (pre-cat). But, there's only 1 conical DP for sale on the board.

Option 2: Keep the stock DP, and install a 2.25" (is that about the stock diameter of the exhaust?) cutout...not as much flow, but saves me some cash.

Option 3: Wuss out and do a 3" cat-back...though, I really think more power would be had from the cutout.

What would you guys do for $500? I'm doing it this week, so your input is needed ASAP! Thanks!

[Jaxx]

I would start off with a 3" cat back, as you get the money look into getting an angled or straight flanged exhaust housing. That or get an angled exhaust housing and then buy that OBX setup. lol

[L8 APEKS]

I just don't know if I'll get the power I want from the cat-back, you know? I'll have to poke around for dyno sheets. But the cutout would be cool because I can dyno with and without the exhaust at the push of a button, to really see what gains are had from opening it up. And of course, it's quiet when I want it to be.

I was planning to use an extra transmission "Econ/Sport" switch to operate the cutout. Sport mode = open cutout. Fast and Furious!

Grrr...sell me that DP!~

[Spanky]

I have a angled flange and a new dynomax 3" turbo muffler that I want gone. Willing to go cheap to get them out of here.

[L8 APEKS]

Unless you had the DP to go with that flange, I couldn't really use it. I know it flows better, but it would get me maybe 10% of the flow an exhaust would. Besides, I think if I go through the trouble of removing the turbo to swap out the flange side...I'm spending the 300 bucks to turn it into a 19T. Don't plan to do that for a while! If you have a DP for sale though, let me know...I might consider doing it then.

[gilber33]

swap flanges and throw on an OBX. Awesome bang for the buck. And removing the turbo to swap housings is easy and fairly quick, you'd be back there anyways removing the DP. I did my OBX with a housing swap in a day, and that's with several breaks since I'm easily distracted.

[L8 APEKS]

Any links to the OBX DP? Who sells 'em?

[gilber33]

Exhaust is here

[L8 APEKS]

Wow...that's cheap! I can pick up locally too, no shipping! Hmmm. OK, looks like I'll go with the OBX stuff and an angled turbo housing. Crap...do I just go ahead and do the 19T now?! Bah. Decisions, decisions!

Also not sure if I'll use the rest of the exhaust...I may only use a DP. If that's the case, I'd have a straight flange DP and a cat-back SS exhaust available. Would anyone be interested in buying that stuff?

Thanks for the advice!

[gilber33]

If you only use the angled dp and sell the rest, I may be interested, I am going to be picking another obx for my wagon and was going to sell the angled dp anyways.

[BoostedBrick]

I did almost exactly what you are planning, upgraded to an angled 16t and obx DP with an electric cutout and left the rest of the exhaust alone. If you just get an angled exhaust housing for your 15G and sell off the rest of the OBX kit you will be able to do it for much less than 500 bucks. On the other hand, while you're in there it's a perfect time to swap out the turbo

[L8 APEKS]

Fugg it. I'm going 19T next week. I may as well if I'm taking the turbo off to replace the housing. Only wanna do it once! If anyone wants the extra OBX exhaust parts, let me know. Thanks!

[ryan850-t5]

make sure you get the supporting mods too for the 19t such as injectors at least a good mbc, preferably an ebc.

also i would think about getting an wideband to monitor air/fuel.

[L8 APEKS]

Already working on the rest of the stuff. On recommendation from a tuner, I'm going to run either the 18 or 19T (after looking at the compressor maps, I'm leaning toward the 18T) on a Stage 1 15psi tune and see where the AFR's sit. I won't be running any more than 15psi. I'll adjust accordingly. The car isn't hammered on that bad; it's my DD. So cruising around easily until I make the necessary adjustments shouldn't hurt anything at all (especially since I'm on the stock exhaust, unless the cutout is open). I don't plan on running an MBC...but we'll see what happens once it's all together and I see what the numbers look like.

[HeavyIron]

Here is how I did my electric cutout. 3" Quicktime cutout. lighted switch mounted in spare switch slot on dash.

[gilber33]

Sorry for the silly question, but what exactly does the cutout do? I mean, I know it opens and closes obviously, but what's its purpose?

[sacrifice]

To dump exhaust right out of the downpipe. Lots of skepticism on whether it adds power or not.

[L8 APEKS]

sacrifice, on 09 November 2009 - 02:22 AM, said:

To dump exhaust right out of the downpipe. Lots of skepticism on whether it adds power or not.

Talked to a guy in this thread who dyno'd his...3" DP with 3" cutout. It made close to 30 *wheel* HP over the stock exhaust with the cutout open...

Quote

I haven't dynoed my car with the cutout yet, but I was there when a friend did. He only gained about 3 peak HP (under 4k rpm), but the biggest difference was from ~4K rpm on. The less restrictive exhaust improved top end power BIG time, and at redline the gain was almost 30 wheel HP over the closed run...

Not sure what there is to be skeptic about...wide open is wide open.

[gilber33]

So you still have a full exhaust and what not, but when under full load you can open that up and provides a faster and shorter exit point for the exhaust? I mean, it sounds like it would work, I think it would be noisy as fruck.

[Bah]

L8 APEKS, on 09 November 2009 - 03:01 AM, said:

Talked to a guy in this thread who dyno'd his...3" DP with 3" cutout. It made close to 30 *wheel* HP over the stock exhaust with the cutout open...



Not sure what there is to be skeptic about...wide open is wide open.

Yea but the stock exhaust blows out loud.

Thats like comparing apples and oranges. Stock VS 3inch turboback??? id expect significant gains =p

Now, if you can show something where they had the 3inch turboback, then they did the same system with a cutout, and they gained 30whp...and i'll be a believer =p

I'd expect some form of a gain, but, no more then running with no rear O2 sensor and just a DP =p On a turbo car of course..not talking NA