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Old 10-23-2013, 01:20 PM   #21
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If 3">2.5", then why not 3.5"? 4"? Maybe with a 6" exhaust it'll spool up at 500 RPM!!! Where's the diminishing returns?

Anyone have data showing an improvement on a 1.6 going from a 2.5 to a 3"? I cheked on my VVT motor and the difference was slight (<100 rpm).

I'll be the dissenting voice and say at his power level a good 2.5" exhaust will not spool noticeably worse than a 3".

After eliminating leaks in the intake piping and the 2.25" exhaust as the cause of slow spoolup the biggest improvement will come from a smaller turbo. The GT2554 is big enough to max out the torque capacity of the stock rods in a 1.6.
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Old 10-23-2013, 01:36 PM   #22
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If the question was 'should I upgrade from my good 2.5" exhaust to a 3"' I would agree with you. But if OP is getting a new exhaust anyway, why not go for 3"?

And if a 3.5" downpipe would fit without major modification I would bet that everyone would would have 3.5" turbo back. Why not?
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Old 10-23-2013, 02:07 PM   #23
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The muffler will likely be a big restriction if it isn't a straight through design that you can pass a golfball through.
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Old 10-23-2013, 02:11 PM   #24
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Is the enthuza 2,5" or 3" very loud? I know it's louder than stock, but I mean too loud for road use? I like a sportive street sound, but not a very loud exhaust

2,5" vs 3" found this for what it's worth
"nahh you dont need 3 inch exhaust for power..." - MX-5 Miata Forum

I'm getting smarter, please feed me more guys
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Old 10-23-2013, 02:12 PM   #25
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y8s ran a 3" exhaust and a 5x11x22 muffler and it was barely louder than stock.
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Old 10-23-2013, 02:20 PM   #26
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Quote:
Originally Posted by miatadaxdriver View Post
Is the enthuza 2,5" or 3" very loud? I know it's louder than stock, but I mean too loud for road use? I like a sportive street sound, but not a very loud exhaust
I've never heard the enthuza exhausts, but the 3" FM exhaust is definitely a streetable noise level. You're not going to mistake it for stock, but it's quite reasonable.

--Ian
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Old 10-23-2013, 02:31 PM   #27
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Enthuza is loud to me. YMMV.
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Old 10-23-2013, 02:40 PM   #28
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So a 2,5" or 3" exhaust is a must, thats for sure now. Lets say that the spool will improve about aprox 300rpm compared with my 2" now? Right???

If I would mount forged rods an go to a safe 1,3bar=18,8psi would this improve my spooling?
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Old 10-23-2013, 03:00 PM   #29
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More boost just takes longer to reach. You could turn it up to 18 psi today if you wanted, it would still reach 10 psi at the same rate it did yesterday.
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Old 10-23-2013, 03:10 PM   #30
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ok thanks Braineack & thenuge26


more good exhaust system brands?

Other advise?
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Old 10-24-2013, 05:29 PM   #31
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Old 10-24-2013, 05:31 PM   #32
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almost everyone gets them custom made or tailored. there isn't a lot of aftermarket companies we are aware of, especially outside the US, that make miata turbo specific exhausts
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Old 10-25-2013, 03:11 AM   #33
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Quote:
Originally Posted by Reverant View Post
Use EBC, as it will aid spool by quite a bit.
Agreed.
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Old 10-25-2013, 11:25 AM   #34
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Originally Posted by Braineack View Post
Enthuza is loud to me. YMMV.
If you give Enthuza a call, you can customize the number and type of resonators and/or mufflers. I talked to the owner about my Miata build, sound/noise level requirements, etc and he built a header back exhaust to the agreed to specs. He was very helpful.

Doesn't help someone in Europe and lot, but thought a more local reader might find this a good option.
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Old 10-25-2013, 11:29 AM   #35
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I asked jason to fit a 5x11x22 muffler for me; he refused so i did it myself.
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Old 10-25-2013, 11:33 AM   #36
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I've sent Abe an e-mail. Those Artech pipes are absolutely beautiful...

I will order one from the USA if no other option...


the only 2,5" made in Europe I found was this: Simons:
Mazda MX5

It's a shame that magnaflow doesn't provide one. the only 2,5" they have is with two pipes. the single one is 2,25... Damn

And 3" is custom order USA, no other options. the question I keep asking myself is: Do I need a 3" exhaust after a 2,5" Begi DP for max 270rwhp (in the future)?

Last edited by miatadaxdriver; 10-25-2013 at 11:54 AM.
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Old 10-25-2013, 01:34 PM   #37
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I have no idea what a shop near you would charge, but I imagine it would be less than getting an entire exhaust shipped from Artech. Is there anyone in your area that does custom exhaust work?
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Old 10-25-2013, 02:56 PM   #38
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Nope, and if so totally unaffordable. In Europe it really sucks to buy parts for two reasons.
- to expensive
- mostly non existing

Everything I search for but can't find => Buy in the USA

I bought wheels, turbo kit,clutch, stickers,gauges,spoilers and so on
The only thing that really sucks are the import taxes and customs (In Europe)
The rule for Europe (Belgium in my case) is quite simple: add 33% to the value of your order and that's the price it will cost
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Old 10-25-2013, 03:07 PM   #39
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Right, but you can buy the big 5x11x22 magnaflow and have it shipped to you, then have Joes Exhaust Shop weld it up for you. That way you add 33% to $120 instead of $1200.
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Old 10-25-2013, 03:22 PM   #40
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Quote:
Originally Posted by thenuge26 View Post
Right, but you can buy the big 5x11x22 magnaflow and have it shipped to you, then have Joes Exhaust Shop weld it up for you. That way you add 33% to $120 instead of $1200.
Most of the exhaust systems I saw, cost about $450 to $600...
$1200 what am I missing?
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