DIY Turbo Discussion greddy on a 1.8? homebrew kit?

more restrictive muffler = quicker spool?

Old 11-26-2006, 03:08 PM
  #1  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Question more restrictive muffler = quicker spool?

I don't get it, but I swear my turbo is spooling quicker with a turbo style muffler now than it was with the flowmaster style (chambered) muffler. I was going to datalog a run to verify it, but my clutch failed before I got there. I swear I saw 15psi for instance where I would have had 13psi max. before. Explanations? - rob
m2cupcar is offline  
Old 11-26-2006, 03:41 PM
  #2  
Senior Member
iTrader: (1)
 
UofACATS's Avatar
 
Join Date: Mar 2006
Location: Tucson "it's 110º" Arizona
Posts: 1,017
Total Cats: 0
Default

How is it determined that the new one is more restrictive? I thought the chambered style was more restrictive
UofACATS is offline  
Old 11-26-2006, 03:49 PM
  #3  
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
Default

isn't a turbo style chambered also?
y8s is offline  
Old 11-26-2006, 03:58 PM
  #4  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Well I use those terms losely. Think of a flowmaster vs. something like a dyno max super turbo. The turbo style usually runs through a series of tubes, changing the exhaust direction. The chambered keeps exhaust flow going straight through, just around various "walls".

chambered:

turbo:
m2cupcar is offline  
Old 11-26-2006, 04:05 PM
  #5  
Junior Member
 
Dange's Avatar
 
Join Date: Aug 2006
Location: Colorado Springs, Co
Posts: 81
Total Cats: -1
Default

a flowmaster is more restrictive, esp, on a 4cyl, engine. the exhaust has to hit basically 3-4 "walls" before leaving the muffler, think of as if you put 3-4 u bends in the exhaust. and as you know exhaust doesnt like to change directions..
the turbo style is 2 perforated cores on each side of the muffler exhaust enters goes through the perforations through a "gap" and then back through the other tubes perforations. though the exhaust has less problems going through the perforations the soundwaves have a harder time thats how that works oddly enough having nothing to do with turbo..
the flowmaster is all designed around the pulsewaves bouncing them off eachother canceling out the higher frequencies and amplifying the bass.. they definately flow better than stock but its more show(sound) than go definately more backpressure than a "turbo" style muffler

go get a nice magnaflow/borla straight through muffler i think enthuzacar.com has the borlas for 109 each and you can find the magnaflows even cheaper than that.. route your exhaust as straight and short as possible and watch the near instant boost! turbos hate backpressure. the whole reason they work is high pressure on the engine side+ heat and low pressure on the exhaust side and is cooler. another benifit is with a good flowing exhaust you can see an addition of around 1-2 psi in some cases



EDIT: hmm you posted the graphics right as i was typing
Dange is offline  
Old 11-26-2006, 04:08 PM
  #6  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
Default

turbo muffler should be less restrictive. The one you posted isn't a traditional design. it usually has core travels throughout the entire space instead of straight through. but they still usually flow high CFM ranges +400 and the exhaust flow doesn't run into any obstructions.



what brand did you get?
Braineack is offline  
Old 11-26-2006, 04:59 PM
  #7  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Hah. Well that's good news to me. I've got a hooker turbo- though I HAD to get the offset/center setup because I've got the exhaust coming straight out the back. That's how most of the offset/center designs work. Add to that there's only 13-1/2" of space to shove it in and I'm limited to what will fit. Fortunately hooker makes their turbo mufflers 13" long instead of the standard 14". The idea to go straight out the back happened when my Miata was rear ended. The bumper skin was scraped up so I figured that was the time to try it. It was easy with a 2-1/4" exhaust, but now I'm stuck using a more restrictive muffler (that the turbo design above) to get it to fit.

My exahust is 3" from the wastegate housing exit to the tail pipe, with two bends- a 90 coming down from the turbo, and a 90 going back to the rear. I'm running a cat, resonator (glass pack) and this new turbo muffler. I'm still amazed that the flowmaster style muffler doesn't flow as well as a "turbo" style muffler. Maybe I've been watching to much SpikeTV? But the way the turbo spooled up, I'm a believer.
m2cupcar is offline  
Old 11-26-2006, 05:08 PM
  #8  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
Default

I bet it sounds better too. I put a $20 turbo muffler on my altima.
Braineack is offline  
Old 11-26-2006, 05:15 PM
  #9  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

That "flowmaster" was WAY loud. My wife got in the car for a ride back when I was only running 8psi and that muffler (way quicker than anything she's rode in)- I got on it and the first thing she said, "Your car is LOUD". Never mentioned anything about the acceleration. I'm amazed at how much I can hear the turbo now too. I only got a taste of this quicker spool and my clutch fragged on me! At least that's what I think it is.
m2cupcar is offline  
Old 11-26-2006, 06:18 PM
  #10  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Yeah- straight through doesn't get any better. The two factors that sent me to this turbo muffler now is the 13" can length AND the $25 delivered price. You can't buy a 3" muffler for cheaper than that and it looks about the quality of a dynomax (yeah, I know that's not say much). - rob
m2cupcar is offline  
Old 11-26-2006, 06:57 PM
  #11  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,892
Total Cats: 399
Default

My 40 series (2 chamber) flowmaster was never loud, and with the turbo it is very quiet. I really do not like loud exhausts at all. I have heard flowmasters are not good for turbo 4-cyl cars but it doesn't make much sense to me and I never saw any proof. Soon I will be redoing my exhaust and using a straight-thru style muffler due to space problems. If I get better spool, great! If it's louder or sounds like ***, it's for sale!
TurboTim is offline  
Old 11-26-2006, 07:17 PM
  #12  
Senior Member
 
boostinsteve's Avatar
 
Join Date: Oct 2006
Location: Honolulu, HI
Posts: 563
Total Cats: 0
Default

I love the flowmaster that I have on there now, super 40 series, I am going to put a cat on it when I get the dp, and that should make it just a mild rumble. Flowmasters are some of the shittiest flowing mufflers as far as performance goes, but you pay for the sound. Although the magnaflows sound wicked as hell.
boostinsteve is offline  
Old 11-26-2006, 07:23 PM
  #13  
Senior Member
iTrader: (6)
 
Kelly's Avatar
 
Join Date: Mar 2005
Location: Sammamish, Washington
Posts: 1,396
Total Cats: 0
Default

Magnaflow for the win.
Kelly is offline  
Old 11-26-2006, 09:07 PM
  #14  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Well I've got datalogs from the chambered muffler and WILL have datalogs after with this turbo muffler. Same map, the only thing changed is going from dino oil to syth. The only thing that might be different is ambient temp- but it was 70f here today and the car felt totally different. So I should be able to make a good comparison.

The chambered muffler that was on there sounded absolutely badass when I was on it- very throaty. BUT the rest of the time, under normal driving, it was just a loud droning, around town or on the interstate. I want something I can take a road trip in and still hear the radio.
m2cupcar is offline  
Old 11-28-2006, 07:40 PM
  #15  
Junior Member
 
Dange's Avatar
 
Join Date: Aug 2006
Location: Colorado Springs, Co
Posts: 81
Total Cats: -1
Default

try unbolting your muffler and take a pass up and down the street and see how much faster that spools, if you like it go get a straight through, the reason the flowmaster was probably so loud is it resonates..ALOT... so you get metric but ton of noise inside
Dange is offline  
Old 11-28-2006, 07:45 PM
  #16  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

I had a straight pipe and that was the loudest- but I never ran any boost when it was that way. I can datalog- that should the difference between the two mufflers since nothing else was changed.
m2cupcar is offline  
Old 11-28-2006, 08:54 PM
  #17  
Senior Member
 
RusMan's Avatar
 
Join Date: Jun 2005
Location: WA
Posts: 504
Total Cats: 0
Default

I have full 3" exhaust with one aspec straight through muffler, it's amazingly not that loud, well at least in the car, outside its way loud, but I thought it would be much louder. It's maybe just a tad louder than my old 2.5" with cat, silencer, and a muffler.
RusMan is offline  
Old 11-28-2006, 09:38 PM
  #18  
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Yeah- I don't know. I saw your exhaust pic and it's very similar to how mine is laid out. I had people saying that I'd only need a resonator if I was running a cat. It was so loud like that, two people couldn't talk to eachother. With the turbo muffler now it sounds quieter than most aftermarket Miata exhausts, which means it'll sound great in a year (or less). I also think one thing that makes it louder is having the hard top on. I think the resonance from that chambered muffler would come through the bulkhead and just bounce around interior. I think the fiberglass goes a long way towards reducing the interior resonance transmitted by the muffler. I know I don't care for as loud a Miata as most, so that's part of the issue. -rob
m2cupcar is offline  
Old 11-28-2006, 09:50 PM
  #19  
Senior Member
iTrader: (1)
 
PaKMaN's Avatar
 
Join Date: Oct 2006
Location: Burbank, CA
Posts: 536
Total Cats: 0
Default

Originally Posted by Wideopentuning
Magnaflow for the win.
Straight piping FTW.

No cats, No resignators, No Mufflers
PaKMaN is offline  
Old 11-28-2006, 10:06 PM
  #20  
Senior Member
iTrader: (6)
 
Kelly's Avatar
 
Join Date: Mar 2005
Location: Sammamish, Washington
Posts: 1,396
Total Cats: 0
Default

Yeah when you can hop in your G35(lucky bastid) whenever you wanna drive something that sounds nice you can afford to go that route.
Kelly is offline  

Thread Tools
Search this Thread
Quick Reply: more restrictive muffler = quicker spool?



All times are GMT -4. The time now is 09:44 AM.