exhaust?

[Lumpyguy]

Got a question about exhaust, would a chambered muffler hurt the performance of our turboed cars? I had a stage 2 with COBB and it had bellmouth catless down pipe and 3 " all the way back on my donor car, I was told by a few people anything other than a straight pipe/resenator it will hurt the power? anyone experianced this?

I was thinking of a 3" inlet/outlet round race muffler from Flowmaster with 3" pipe from the bellmouth to the tip?

[Kurk818]

I was informed by my tuner that it wasnt an issue. I used a flowmaster 40 muffler in conjunction with a high flow cat. Sounds nice and throaty with no droan. I like it. Put down 380hp/tq to the wheels

[Hindsight]

I was informed by my tuner that it wasnt an issue. I used a flowmaster 40 muffler in conjunction with a high flow cat. Sounds nice and throaty with no droan. I like it. Put down 380hp/tq to the wheels

What turbo?

[RM1SepEx]

Mine will be on the dyno soon... 3 inch bellmouth, hi flow cat, 90 angle 3 inch SS muffler

40400

3 inch offset a bit, a baseball could roll through the perforated core, plenty of volume to reduce sound

http://www.ebay.com/itm/OFFSET-OFFSET-3-INCH-EXHAUST-OVAL-MUFFLER-SILENCER-M-/360389108740?fits=Year%3A2003%7CSubmodel%3ASS&hash=item53e8dd6404&vxp=mtr

[Hindsight]

That looks pretty slick Dan. My current plan is very similar minus the cat. Same exit spot. Though lately I've been toying with getting a flowmaster muffler that has single inlet with dual outlets, and then routing the duals out the back lower mesh screen like in V-Man's mockups of the blue car. It obviously would be better from a performance standpoint to just go out the side or single pipe straight out the back but I doubt I'd lose more than a couple HP doing a dual setup like I just described and it would sure look cool.

The muffler would be like this. The only problem is that it's listed as a dual INLET, single outlet. They don't have one with a single inlet dual outlet but I'm wondering if the orientation really even matters?
http://i.imgur.com/45RwPIqh.png (http://imgur.com/45RwPIq)

[Scargo]

Any muffler hurts. Even restrictive exhaust piping hurts. You see many making big torque and power with 3+ inches of straight through exhaust, so there is little restriction.
The answer is only turbo size, muffler size, piping size, gasoline and money. The turbo is just one element. Can it overcome the back-pressure to allow you to make your desired horsepower or torque?
If you are worried about sound levels then likely you are building a street-legal 818. If you stick with X stock turbo then likely you can get additional boost to overcome most exhaust restrictions for street use. If you want 300 WHP and quiet exhaust then it may not be within the capabilities of a stock turbo. Plug in a bigger turbo, muffle the hell out of it and throw a lot of gas at it and it may perform as you want and be quiet as well. It's not a simple either-or or "does it hurt" situation.

[Harley818]

My plan - magnaflow single in, dual out.... like the Vman concept.
Street use only, so I want good but not too loud sound.

Here is it mocked up. I have some pipe bends coming from frozenboost, so should have this tacked up in a week.
40401
one side goes straight out, other goes up and over the tranny. Probably will have to move the shifter line a little up or down.

I thought I saw single in/dual out on flowmaster website.
http://www.flowmastermufflers.com/?page_id=11118
there are a couple others there as well, but they are pretty long.
I went MF because they are a bit shorter.

You can also look at the camaro muffler where you have one inlet on one side and an outlet on both sides. One of the threads just did this.... muffler located above the tranny, and outlets one to each side.
I didn't want to sacrifice my trunk space.

[Harley818]

check this thread post #59.

http://thefactoryfiveforum.com/showthread.php?14108-818s-Build-Tri-cities-WA&p=193951#post193951

[Kurk818]

What turbo?

Bloush 2.5xtr

[Scargo]

Kurk, You said, "Put down 378hp and 381tq at 21.4psi on 91 octane." With that Blouch Dominator 2.5XTR, "Polka Pickle" (http://www.flatironstuning.com/p-1993-blouch-dominator-25xt-r-polka-pickle-full-ball-bearing-turbocharger.aspx), you might could get 5 or 10 more before needing more than pump gas. That would make up for the muffler restriction. :cool: Then there's always water and meth and Torco.

[Kurk818]

Kurk, You said, "Put down 378hp and 381tq at 21.4psi on 91 octane." With that Blouch Dominator 2.5XTR, "Polka Pickle" (http://www.flatironstuning.com/p-1993-blouch-dominator-25xt-r-polka-pickle-full-ball-bearing-turbocharger.aspx), you might could get 5 or 10 more before needing more than pump gas. That would make up for the muffler restriction. :cool: Then there's always water and meth and Torco.

I think my current power level is plenty. Im actually going to put it down to 15psi, which is around 330hp/tq to put less wear and tear on everything. Who knows, after a month or so and getting used to the power level, some race fuel may be in the future. :)

[Hindsight]

With a 2.5, it sounds like you already have it turned down a bit no? A Dom 1.5xtr will put out 23+lbs of boost and around 375-400whp on pump gas so your 2.5 should be capable of much more. If you are going to de-tune down to 330, you might consider going with a smaller turbo like an 18g for faster spool and better efficiency. Just my two cents!

[RM1SepEx]

I'm thinking that my 3 inch diameter with perforations will add the least back pressure possible in a "real" muffler. Muffling sound requires an enclosed volume of space for the gasses to expand. Without taking up valuable trunk space I think that my muffler is about all that you can fit. I need the CAT and muffler to get inspected here in Maine.

Since I'm running the stock turbo and a simple Cobb tune, I'm pretty sure that I'll be just fine. I'm not capable of driving a 2400 lb vehicle (my design, max weight) with 240 RWHP (my ultimate design goal) Between the quaife and street tires I expect that steering with the rear wheels will be common.