DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Small loud Exhaust vs Large quiet Exhaust (boost threshold better or worst) help

Thread Tools
 
Search this Thread
 
Old 02-28-2019, 12:56 PM
  #21  
Elite Member
iTrader: (4)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 4,648
Total Cats: 544
Default

I typed an exceedingly longer response, but then deleted it all because I'm grumpy. I'm reminded of a quote.



"If folks are left behind [to the fringe of society], bright minds mutate and stagnate. These folks are potential scientists gone wrong and their natural inquisitiveness and rejection to the norm could be a benefit to science if they were more scientifically literate."

In any event, despite the wealth of knowledge accrued from multiple failures concluding in a greatly similar solution, the goal here is fixed and counter to what we generally seek. After re-reading the original post, it's clear that being QUIET [not to be confused with merely tolerable] is of more importance than performance, and that's the OP's prerogative. I'd be interested if the OP should just carry on with the experiment as it's justification is preordained and report back if he truly achieved a whisper quiet, albeit castrated, turbo Miata.
psyber_0ptix is offline  
Old 02-28-2019, 01:22 PM
  #22  
Supporting Vendor
iTrader: (1)
 
turbofan's Avatar
 
Join Date: Sep 2010
Location: Lake Forest, CA
Posts: 7,951
Total Cats: 1,004
Default

^ what he said.

Also, I realize you're looking for more concrete information, like "you will spool 200 rpm sooner with a 2.5" Magnaflow compared to a 2.5" thrush turbo muffler." However, that information is of very little use to the general forum membership because most (all?) Of us who have used the recommended suitcase Magnaflow have been satisfied with the results.
turbofan is offline  
Old 02-28-2019, 01:35 PM
  #23  
Senior Member
 
Schroedinger's Avatar
 
Join Date: Apr 2016
Location: Atlanta
Posts: 790
Total Cats: 188
Default

I would summarize the priorities thusly:
1) be almost free.
2) be a very specific type of quiet
3) make a poorly performing turbo setup perform minimally more poorly.

Stated that way, I can see why we’re all having a hard time relating.

Last edited by Schroedinger; 02-28-2019 at 04:25 PM.
Schroedinger is offline  
Old 02-28-2019, 05:21 PM
  #24  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,651
Total Cats: 3,011
Default

You will not experience deep tone with that tiny obstructive muffler after a turbo. When you really try to put some volume through it, it will sound like a Crown Victoria or an Electrolux vacuum cleaner, take your pick.

From my decades of personal experience I can tell you many of those mufflers are smaller diameter tubing inside than outside. They commonly are expanded from a smaller size at the tips for mounting. What you see and the cute little representative picture is not always what you get. And with the little tiny case length you have very few perforations in the pipe for the gases to pass through. With that type of muffler you want a very long case for any appreciable flow and you want to hope like hell they actually perforate most of the pipe and not just a few inches of it. Again, it is so the manufacturer really doesn't care about your performance. Neither do the Guatemalans who built it.
sixshooter is offline  
Old 02-28-2019, 05:52 PM
  #25  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

I literally laughed out loud at 11.5psi @ 4400rpm. OP, that is atrocious.

Literally anything you do will be better than your current setup. If you insist on sticking with that shitty $25 muffler, it will still be better than what you have now. The Magnaflow that literally everyone on this forum uses is better still, and will also still be quiet enough for you.

If you actually cared about spool, you would dump that 2871R clone and get a geniune used Nissan turbo.

Last edited by Savington; 02-28-2019 at 06:13 PM.
Savington is offline  
Old 02-28-2019, 05:59 PM
  #26  
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 10,917
Total Cats: 2,201
Default

Originally Posted by Savington
I literally laughed out loud at 11.5psi @ 4400rpm. OP, that is atrocious.
Wanna race from a rolllllllll bro?
concealer404 is offline  
Old 02-28-2019, 06:22 PM
  #27  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,651
Total Cats: 3,011
Default

Originally Posted by concealer404
Wanna race from a rolllllllll bro?
I do I do I do! Pick me pick me!
sixshooter is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Dawsunny
Meet and Greet
4
09-22-2019 08:47 AM
InitialM
Build Threads
6
02-19-2019 03:09 PM
Blkbrd69
WTB
0
07-04-2018 03:23 PM
Zoot
Miata parts for sale/trade
11
05-31-2017 07:35 PM



Quick Reply: Small loud Exhaust vs Large quiet Exhaust (boost threshold better or worst) help



All times are GMT -4. The time now is 04:32 PM.