Ok....so I'm second guessing a purchase. My 91 CRX currently has a 2.25" catback with a jdm b16a. I am going with a disco potato turbo (the actual Garrett) and am keeping the engine stock. I am looking to keep it under 300 hp, (between 250 and 275 whp) and am second guessing going all the way to 3". Am I going to lose mass torque or will the boost negate torque loss? My reasoning for going 3 was that going from 2.25 to 2.5 wasn't going to do anything. I will be running a 3" Vibrant resonator, (maybe a high flow cat also..but don't need to because we don't have emissions) and then a nice big magnaflow or something because I want it quiet. I am also piping the wastegate into the exhaust for noise pollution control. I've read a lot, but haven't seen if 3" is overkill yet...if it is...well...lol oops...I'll sell it and take the hit and add 2.5". What about thoughts of running a high flow cat? I HATE rice sounding Hondas, I hate raspy, ricey sounding exhaust.

 

Best exhaust for a turbo is no exhaust, performance wise. But you'll have no problems hitting your goal with 2.5". The difference is minimal at that level. You would definitely feel the loss in some scavenging torque between the 2.

 

Lightning is on point here. The 2.5" option is workable for your 300whp goal, however, I highly recommend relieving as much exhaust backpressure energy as possible. There's nothing wrong with a full 3" system, while still remaining with a quietly professional sound. It's really a matter of the parts that you choose in order to make that happen.

Now, I'm also in a situation in which we have no emissions, and like yourself, I like exhaust systems to sound professional, (Stock-like "quiet" will never happen, and nor should it ) and reasonable without the drone. But I'm also rather picky about how my exhausts sound, so I use an older approach that users of recent years don't, and the formula hasn't failed yet, honestly. Even V8 gear heads like the sound of my exhaust system because of the fact that I did a few subtle tricks to make it sound great, but not raspy, ricey, or high pitched.

Now, I would love to know exactly what Lightningteg used as his 3" exhaust system, as his sounds very nice and professional, even at higher rpms. (please feel free, my friend to post that information either here or on your LS-VTEC page, if you don't mind).

I tend to like much more quality mufflers to start off in the first place. Now, I know I'll probably get flogged for this, but that means NO VIBRANT anything on my systems. I find that the more expensive companies, both American and Japanese, tend to have a MUCH better performance record overall because of their better baffling systems.

*soap box*. I find it funny that people go through 2 resonators, a high-flow cat, and a partridge in a pear tree, to think that they can make a better exhaust system for less money, when in actuality, by the time they get a more quality muffler to start off with, they spend about the same money. *end soap box*.

Or they don't want to use an entire 3" exhaust system that is made already because of the overall cost... This really points to the Thermal R&D 3" turbo exhaust that is available, and honestly, fits the bill more than anything you have suggested, and uses a fantastic muffler that is properly baffled, 3" mandrel bend piping, warranties, and easily fits the CRX. Better than all that gobblty-**** you're trying to make and the cool part is, they actually MAKE IT FOR YOU (I think even the muffler is Magnaflow). For under $600, best choice.

My 1st suggestion is as follows

Thermal R&D CRX 3" turbo exhaust choices

B137-C134
Standard 3" exhaust CRX

B137-C134T
ST Style CRX 3" turbo exhaust

A couple of mediocre videos. The sound quality is never great with amateur videos so bare with it. Even mine aren't that great


Closest example for you. I recommend a 3" high flow cat to keep it a little quieter if necessary.

2nd Suggestion

This is a bit more complicated.

You have to look at the type of muffler you want (shape, baffles, styles, etc) and work around that first. I Still like my "canister" style exhaust muffler, but unfortunately, eBay, vibrant, and other lower-quality companies made the canister styled mufflers get a bad rap because they were using such crap materials.

The problem is you're a CRX, so it keeps your choices limited, unless you're completely willing to start fabricating.. (which looks like something you're willing to do).

For the straight-through, "standard" muffler system, stick with Magnaflow or Apex'i World Sport, (Apex'i makes a great 3" world sport muffler for turbo cars. Forget Vibrant "stealth" and all that nonsense.
There's the standard 156-A010, and there is theNOIR 156-A017. Prices are actually lower than the MSRP you might see on their official website, so don't let that scare you off.

For Canister type.. (If you care)
The APex'i N1 Muffler Turbo 3". (I have one of these in black chrome myself).
The last choice is really a GReddy Revolution RS universal. But it is a canister type. Just the right canister type. Full cambered baffles, nice sound, lasts for years.
But then you have to fabricate everything else.

My Apex'i N1 muffler at start up.. BEFORE GSC Camshafts. No resonator, no cat, but slightly angled to the upper right for better clearance and to eliminate any residual "rasp".

I have this exact unit:
Apex'i N1 Black 80mm turbo muffler.

Finished exhaust product of TA Integra

Starting up and backing out

Driving down the road at about 370whp

 

Honestly, you're gonna laugh, but its a $160 eBay special N1 style exhaust (http://m.ebay.com/itm/3-N1-GUNMETAL-STYLE-CATBACK-4-5-EXHAUST-TIP-FOR-94-01-ACURA-INTEGRA-GSR-DC-2-/231289527304?nav=SEARCH) lol. Its been on the car since 2010, hasn't rusted and the noise level is not bad at all cruising in the car.

 

You , my friend , are one lucky SOB!!. Everyone I've worked with, rusted horribly, but that's after sitting each winter.

The Bends of the exhaust make a difference in Noise DB as well.

 

Yeah it hasnt seen winter so non issue. My Last one blew out the packing in the muffler after about a couple weeks it was all over my bumper. But this one has held up. Got lucky lol.

 

Care to tell us which brands specifically? I have a Skunk2 Megapower 3" catback /w GSR motor and ITR cams I just feel like there are better mufflers out there

 

Read my above post. I have videos, links and examples

 

Lol I've been using one of these on my Accord except it was only $120 shipped. Chopped off the canister style muffler and added a vibrant streetpower. No ragrets. Sounds great. Been on there for a few years without issue.

 

I dont think it sounds bad

 

In my experience 3" is almost always worth it. Ive seen gains going from 2.5 to 3 inch even on sub-250hp setups. In particular you will see spool improved, but there is power too.

Like mentioned above, run as big of a straight through 3" muffler as you can and it will sound pretty good. Miata guys have tested this theory with huge straight through mufflers and seen zero loss in power and get a setup that is very stealth.

 

Yeah its definitely a little better. But there is also a noticeable small torque increase at low rpm with the smaller exhaust in part throttle

 

thanks! guess jus a little loud for my taste I tried using the silencer but I think i rather have the added power

 

THANKS SO MUCH TO EVERYONE who replied. It is a relief not to get the typical trolls preaching about searching first. I did a lot of reading prior to this and requested The Shodan's input. And boy did he come through with a response with everything and more I could have asked for; a gentleman and a scholar. Also, everyone else who replied, thanks so much. Well, it's too late to choose components, but from what I have read here, I should be pretty happy with the results when it's all together. The car currently has a Greddy 2.5" catback WHICH SOUNDS GREAT...on both the stock engine and now the stock JDM B16a. My new exhaust will be a 3" stainless piping kit (Kteller), vibrant ultra quiet 3" resonator (sorry Shodan...already had it before your reply) and a Magnaflow Oval that fits like my Greddy in the stock location. Links below and a very big thanks, once again to all those who helped me realize I'm on the right track.....oh....an no catalytic converter....
KTeller Exhaust Piping Kits - KTeller - Exhaust | Engine | Suspension

 

It would behoove you to post videos of the finish product

 

I will definitely post up vids....car is currently in pieces getting the Disco Potato transplant onto the B16a.....waahooooo.

 

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Running 3" on my setup. Its fine. Had to raise the car a bit for clearence

 

thats the same one i have, maybe not the exact. no issues and its been about 3 years. but keep in mind i live in south texas where it doesnt snow

 

3" dp,exhaust piping. No cat,testpipe,resonator....just 3" SS piping to an oval Magnaflow muffler

If I had to do it over, I would put a resonator for a quieter crusing db

 

Yeah, see I'm a little different. 10 years on the 1st N1, now at 4 years on the second one.

I tend to keep things a long time

 

I had another ebay n1 years ago but I kind of learned how to weld on it so it was pretty gross lol.

 

I ran a HKS hi-power that was 2.25in on my turbo piston and rod b16, it had a 3in down pipe I reduced to the 2.25 for the exhaust and made 321whp and 265 lbft.