Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

N/A Quiet 2.5" exhaust

Thread Tools
 
Search this Thread
 
Old 01-11-2012, 11:22 AM
  #1  
Junior Member
Thread Starter
 
tblackey's Avatar
 
Join Date: Sep 2011
Location: Aliso Viejo
Posts: 81
Total Cats: 34
Default N/A Quiet 2.5" exhaust

Just finished getting the motor rebuilt by Rebello. 208hp at the crank. I'm looking for a 2.5" free flowing exhaust that will hopefully pass Laguna Seca sound. Any ideas?
tblackey is offline  
Old 01-11-2012, 11:40 AM
  #2  
Elite Member
 
JasonC SBB's Avatar
 
Join Date: Jul 2005
Posts: 6,420
Total Cats: 84
Default

2.5" 5x11x22 Magnaflow.
JasonC SBB is offline  
Old 01-11-2012, 11:51 AM
  #3  
Elite Member
iTrader: (41)
 
rharris19's Avatar
 
Join Date: Jan 2006
Location: Seabrook, TX
Posts: 2,417
Total Cats: 20
Default

Originally Posted by tblackey
Just finished getting the motor rebuilt by Rebello. 208hp at the crank. I'm looking for a 2.5" free flowing exhaust that will hopefully pass Laguna Seca sound. Any ideas?
Is this an NA motor or turbo?
rharris19 is offline  
Old 01-11-2012, 11:55 AM
  #4  
Newb
 
12pack's Avatar
 
Join Date: Jul 2011
Posts: 1
Total Cats: 0
Default

"N/A Quiet 2.5" exhaust"
12pack is offline  
Old 01-11-2012, 11:57 AM
  #5  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,179
Total Cats: 1,130
Default

prebuilt or DIY? Jason's suggestion is just a muffler.

If you have the money for a 208hp N/A motor that was professionally rebuilt, I'd suggest FM's, although it's only 2.25". Or try Enthuza, they have a good selection of budget systems. Next try goodwin racing, they have a good explanation of their systems, including loudness and power. Just checked though, couldn't find it. Might be on racing beat's website.
curly is offline  
Old 01-11-2012, 12:00 PM
  #6  
Elite Member
iTrader: (41)
 
rharris19's Avatar
 
Join Date: Jan 2006
Location: Seabrook, TX
Posts: 2,417
Total Cats: 20
Default

Enthuzas stainless 2.5" racer exhaust should be below the limit. I don't know anyone with that exhaust, but it should work.

http://shop.enthuzacar.com/product.s...4&categoryId=4
rharris19 is offline  
Old 01-11-2012, 12:59 PM
  #7  
Newb
 
Rogue_LE's Avatar
 
Join Date: Aug 2011
Location: Propwash 16X D/FW, TX
Posts: 31
Total Cats: 2
Default

I have had a Enthusa on my N/A 93LE since like 2001.
Very pleased with it.
It sounds great, and is not too loud.
Rogue_LE is offline  
Old 01-11-2012, 04:17 PM
  #8  
Junior Member
 
one-niner's Avatar
 
Join Date: Sep 2010
Location: Denmark
Posts: 80
Total Cats: 1
Default

If a cat is required, how about the "RoadsterSport Midpipe with Catalytic Converter and Resonator" sold by Good-Win-Racing and GoMiata? It's 2.5" and there should be plenty of choices for both headers and mufflers to go with that.

- Tom
one-niner is offline  
Old 01-11-2012, 06:23 PM
  #9  
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 3,143
Total Cats: 174
Default

First of all, I would not cheap out on an exhaust if you went through so much trouble to build such a well prepared N/A motor.

Start out with what your header options are, and forget about the off the shelf headers like the Racing Beat 4:1. That header is not designed for 200+ hp N/A motors. I think 949 still has a racing header, or you can contact Jesse Prather Racing. They do all out N/A Miatas, and have some insight as to what exhaust you will need.

When you get your header selected, than decide on what rear exhaust to run. Racing headers often do not have the same bolt up location and flange as off the shelf headers. 949's header may have that ability, but you will have to look into it.

I personally would build a rear exhaust that was a straight through design if you are building a race car. It will have the least restriction and lightest weight. You may not need it to exit the rear of the car, but you will have to check your rule book on that. From there, it is simply choosing the muffler that will fit, and meet decible limits.
miata2fast is offline  
Old 01-12-2012, 11:45 AM
  #10  
Junior Member
Thread Starter
 
tblackey's Avatar
 
Join Date: Sep 2011
Location: Aliso Viejo
Posts: 81
Total Cats: 34
Default

I'm using a 4-2-1 right now with the stock flange where the end of the cat would be. Eventually I might get a Stahl header, but not yet. Motor was dyno'd with that header. Xida's are next.

I'll probably just have a new one done with mandrel bends at the muffler shop, but if there was something good off the shelf that would be nice. I want it to be quiet enough to pass a 92db day at Laguna Seca though, and that's not super easy.
tblackey is offline  
Old 01-12-2012, 12:26 PM
  #11  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
Default

Xidas > any exhaust.
Braineack is offline  
Old 01-12-2012, 12:41 PM
  #12  
Senior Member
 
Miater's Avatar
 
Join Date: Aug 2010
Location: Arl. Texas
Posts: 936
Total Cats: 27
Default

You have a local muffler shop that has a mandrel bender!?
Miater is offline  
Old 01-12-2012, 12:42 PM
  #13  
Senior Member
iTrader: (12)
 
sbrian2's Avatar
 
Join Date: Nov 2005
Location: Murfreesboro, TN
Posts: 595
Total Cats: 3
Default

Burns stainless muffler, light and quiet but will cost you. You'll have to fab the rest.

BTW, are you the same guy that had the LS swapped FD?
sbrian2 is offline  
Old 01-12-2012, 11:53 PM
  #14  
Junior Member
 
fwMiata's Avatar
 
Join Date: Jan 2005
Location: Fort Worth, Texas
Posts: 237
Total Cats: 1
Default

I ran a FM turbo exhaust (duals on mine) with a highflow magnaflow round resonator after the cat for a long time N/A and it was very nice and mellow.
fwMiata is offline  
Old 01-13-2012, 08:51 AM
  #15  
Junior Member
Thread Starter
 
tblackey's Avatar
 
Join Date: Sep 2011
Location: Aliso Viejo
Posts: 81
Total Cats: 34
Default

Originally Posted by sbrian2

BTW, are you the same guy that had the LS swapped FD?
Yep. 1.33 at Laguna, Shooting for under 1:30 this year with bigger motor and more tire.
Attached Thumbnails N/A Quiet 2.5" exhaust-p6020616.jpg  
tblackey is offline  
Old 01-13-2012, 05:59 PM
  #16  
Senior Member
iTrader: (12)
 
sbrian2's Avatar
 
Join Date: Nov 2005
Location: Murfreesboro, TN
Posts: 595
Total Cats: 3
Default

Originally Posted by tblackey
Yep. 1.33 at Laguna, Shooting for under 1:30 this year with bigger motor and more tire.
Awesome, love the car. I co-drive Dan Chadwick's (Tweakit Racing) autocross car and him and I helped build Brent Dalton's LS1 FD. I also believe I helped a buddy of yours, Chris Coffee (sp), by letting him test fit some control arm on one of our cars.

Good luck with the Miata build, I can't wait to see how it turns out knowing how your FD is.
sbrian2 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
04-12-2021 04:21 PM
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM
Corky Bell
Prefabbed Turbo Kits
18
11-22-2016 09:01 PM
Big_gumby
Meet and Greet
80
10-05-2015 04:06 PM
Goldwar
DIY Turbo Discussion
2
09-29-2015 09:20 AM



Quick Reply: N/A Quiet 2.5" exhaust



All times are GMT -4. The time now is 08:10 PM.