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Old 04-22-2008, 01:17 PM   #1
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Default Turbo Exhaust Question

my question was can i buy a full exhaust that will work for me when i get my turbo kit. i was looking into the begi kits. would i need an axle back or what is the most i can remove from the car as far as exhaust? From what I understand, Turbo exhausts are xtremely loud without a turbo because they have no backpressure. I dont want to lose torque on my stock car. so what is the best exhaust option for me that i can re-use down the road? (no pun intended)
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Old 04-22-2008, 01:26 PM   #2
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Turbo exhausts are extremely quiet due to the turbo being a muffler itself. If I wire my wastegate open it's the most annoyingly loud exhaust. The best option is a fully done turbo back exhaust, at least 2.5" inches in diameter.

Here's my 3" turbo back exhaust with only a single 5x8x14 muffler:



notice you can still here the intake?

outside:




if you keep anything stock on the exhaust, you hurt performance. Back pressure is evil. N/A or F/I. Most turbos will make it's boost threshold so early (1000-1500rpm) that you'll never have low-end loss of power. The best thing you can do for a turbo setup is open the exhaust with good flowing pipes, high-flow cat, and a straight through muffler.

Having a smaller exhaust adds more backpressure on top of what the turbo adds. when you start making high boost and tons of HP it's harder for the exhaust to flow out. this causes extra backpressure and the turbine and engine have to literally push against the exhaust to force it out. This causes a ton of torque loss, since energy is wasted pushing the exhaust out of the chamber and not the piston downward.
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Old 04-22-2008, 01:26 PM   #3
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An exhaust thats made for a turbo is gonna be **** loud and annoying on an N/A car. Why don't you just save your stock exhaust in case you want to go back to n/a?
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Old 04-22-2008, 01:45 PM   #4
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i dont think i made the question clear. my car is non turboed. all stock. i want to do my exhaust before i do a turbo kit. what exhaust should i get that can be used when i get a turbo. i want an exhaust before i get a turbo kit, but i want to make sure that when i get my new manifold/downpipe that it will match up.
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Old 04-22-2008, 01:49 PM   #5
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I wouldn't bother then. You'll want the best flowing exhaust you can get, which will be the equivalent of not running a muffler at all without the turbo.
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Old 04-22-2008, 02:32 PM   #6
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Quote:
Originally Posted by Braineack View Post
I wouldn't bother then. You'll want the best flowing exhaust you can get, which will be the equivalent of not running a muffler at all without the turbo.
+1 Any free flowing turbo exhaust will most likely be too loud running NA for most people. I remember paul ran one NA awhile back and I could hear him coming from like a couple miles away.
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Old 04-22-2008, 04:12 PM   #7
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so i should just leave my stock exhaust until i turbo the car?
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Old 04-22-2008, 04:15 PM   #8
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Sure, why not? The BEGI downpipe will bolt right up to the stock exhaust. I ran mine like this for a couple of months before I installed the turbo exhaust.
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Old 04-22-2008, 04:22 PM   #9
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so i should just leave my stock exhaust until i turbo the car?
I regret getting my Borla Dual. I purchased it a year before I turboed, however, it only saw less than 5k of use. It was a big restriction and removing it for something better netted me 50rwhp.

If I were you, id highly consider getting in on the Enthuza groupbuy for a 2.5" budget racer. Try it out, if you don't like it, swap it back and hold on to it until you turbo.
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Old 04-22-2008, 06:23 PM   #10
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Or, if you are near houston I'll sell you my 2.25" cat and cat-back for $100. You'll just have to modify the angle of the front flange to work on a 1.6 car. My enthuza 3" should be here thurs.
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Old 04-22-2008, 08:19 PM   #11
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I'm running a 2.5" exhaust NA....no cat...it is raspy and a bit loud...should be quick as **** when I'm finished.


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Old 10-08-2008, 04:15 PM   #12
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Quote:
Originally Posted by Braineack View Post
I regret getting my Borla Dual. I purchased it a year before I turboed, however, it only saw less than 5k of use. It was a big restriction and removing it for something better netted me 50rwhp.

If I were you, id highly consider getting in on the Enthuza groupbuy for a 2.5" budget racer. Try it out, if you don't like it, swap it back and hold on to it until you turbo.
Wow, really that much?! I need to get rid of my OEM cat and maybe also my aftermarket (reflection) muffler.
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Old 10-08-2008, 04:36 PM   #13
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FWIW I'm running 3" DIY exhaust header back on a N/A 99'. I even have 3 glasspacks and a magnaflow muffler. Should make for a quiet turbo exhaust with very little backpressure, but damn it's loud for N/A. Sucks. It's seriously louder in the car than it is outside for some reason. If I wasn't so close to turboing it I'd be switching mufflers. Unless you like loud **** keep the stock exhaust on till you get ready to turbo.
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Old 10-08-2008, 08:01 PM   #14
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you should check out motec exhausts. Make sure and check out the manifold welds, bro.
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Old 10-09-2008, 04:36 AM   #15
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My manifold is log-style so does not have many welds. I will check and recheck all connections though.
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