Jump to content
SAU Community

Is It Possible To Have A 3" Exhaust And Still Make Power?

Mid_Nite_R33
 Share

Recommended Posts

TiTAN Grand Master

TiTAN

Posted
Posted

R31 nismoid is making around 300kw and has a legal exhaust, my car is 92db and makes over 300kw.

ask an exhaust place to make you up an exhaust with the biggest straight through mufflers they can fit.

Mid_Nite_R33 Mentor

Mid_Nite_R33

Posted
  • Author
Posted
R31 nismoid is making around 300kw and has a legal exhaust, my car is 92db and makes over 300kw.

ask an exhaust place to make you up an exhaust with the biggest straight through mufflers they can fit.

Awesome, I heard magnaflow muffler are the quietest, any others?

cheers

NYTSKY Grand Master

NYTSKY

Posted
Posted

The Kakimoto Regu and Trust PE2 are the quieter exhausts out of the Jap ones, im sure there are others.

Or like has been mentioned get an exhaust shop to make you one. My friends 700hp 25/30 sounds stock. 4inch dump with 3 1/2 exhaust with big mufflers.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Yes it's possible...

I'm just over legal, ~91dB with a 3.5" exhaust (it'll be good for 350rwkw). 3" can be made legal, plenty of people have done that on the forum.

My mufflers are fully custom (hand made) etc. So it wasn't cheap, but then to keep the fuzz outta your hair these are the measures we have get to today :woot:

There are some off shelf Jap ones that are under, I'm not sure what their names are though.

Basically just get a custom 3" made and have 2x the biggest possible mufflers installed + 4" cat. Should sort you out.

Mid_Nite_R33 Mentor

Mid_Nite_R33

Posted
  • Author
Posted

to put things into perspective, im making 250rwkw now and might be increasing to about 280 soon,

I have a 3" turbo back exhaust atm, I was thinking of leavin the first section of the exhaust as is and maybe having a 3.5" catback made up implementing the largest 2 mufflers, that way the extra 0.5" diaemeter will make up for the restriction of the mufflers......

Anyone know any exhaust shops in inner melbourne that could look after me?

cheers

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

280rwkw = 3" is fine.

Straight through mufflers really should not post much restriction at all mate, so i'm not sure what you mean about the extra half inch alleviating restriction...

Mid_Nite_R33 Mentor

Mid_Nite_R33

Posted
  • Author
Posted
280rwkw = 3" is fine.

Straight through mufflers really should not post much restriction at all mate, so i'm not sure what you mean about the extra half inch alleviating restriction...

I thought that the mufflers may restrict so gotta increase diaemeter...

Who should i head to for this in melb inner suburbs ??

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Well they do restrict, but you ain't talking massive amounts mate.

280rwkw you need -

1x 3" piping, mandrel bent. A little bends through the system as possible

2x 3" straight through mufflers, largest possible you can get under the car

1x 4-4.5" Hi-Flow cat

Just get it done in mild steel and it'll be nice and cheap. Turbos make enough heat to keep rust @ bay.

As for where to get it done - NFI mate, i don't use anyone inner city.

discopotato03 Grand Master

discopotato03

Posted
Posted

Personally I think the greatest gains are from being larger in the first 1/3 to 1/2 of the exhaust system .

The gasses are pretty hot out of the turbo on full load so giving them some volume to expand into seems to work .

The gasses cool and contract (increase in density) quite quickly and you can afford to go a bit smaller in tube size toward the rear half of the exhaust system . Usually the cat and mufflers are back there anyway so 3.25 or 3" mufflers should be reasonably easy to fit .

Cheers A .

Mid_Nite_R33 Mentor

Mid_Nite_R33

Posted
  • Author
Posted
Well they do restrict, but you ain't talking massive amounts mate.

280rwkw you need -

1x 3" piping, mandrel bent. A little bends through the system as possible

2x 3" straight through mufflers, largest possible you can get under the car

1x 4-4.5" Hi-Flow cat

Just get it done in mild steel and it'll be nice and cheap. Turbos make enough heat to keep rust @ bay.

As for where to get it done - NFI mate, i don't use anyone inner city.

Ok, why the 4.5" cat? cant i just retain my 3" high flow cat?

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

CAT's are restrictive. Just have a look @ em :woot:

Such tight honeycomb blocks are the enemy of good flow... so hence get a larger CAT and help the process along.

Car is still legal and emissions will be good so there is no real downside.

I would hedge a bet that if you had a 3" hi-flow cat on there and then dropped it for the next dyno run - you'd see a power increase :D

Hell even with my 4.5" CAT i can feel a difference in or out... It's not a massive difference but it's noticeable.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • jez NF
      The Evolution Of "night Fury"

      By jez NF · Posted

      Waaay ahead of ya....(evil laugh!!) Will show the fitment and spec details later when it isnt as rainy !
    • wizlb
      Flex Fuel Kit Workshop

      By wizlb · Posted

      Thanks Dose.....    I appreciate it!!
    • Dose Pipe Sutututu
      Dose's Sometimes DIY and Pay Someone Home & Boat Improvement Thread

      By Dose Pipe Sutututu · Posted

      I'll probably be putting the shit box back on the dyno again soon, I want to dial in the closed loop boost control properly. I'll have a camera facing the car/motor for fun too. Just note, there are essentially 3x 10AN inlets going into the catch can and 1x going back to the intake pipe. Most of the time the catch can "return" to the sump actually is the crank case breather, pushing air out.
    • Piggaz
      Ogura orc1000f vs Osg tr2cd vs Osg r3c experiences, max torque/max hp?

      By Piggaz · Posted

      I have the R3C with a Nismo slave and by no means does it behave like a stocker, it ain’t THAT bad. On take off just give a bit more throttle than you would say a coppermix and it’s fine. It will not slip though.   
    • uchoa
      Yet another RB Neo misfiring thread after reading all the others.

      By uchoa · Posted

      Okay. Final round of testing done. Got a friend to hook up a fancy scanner to the car and we also ran some compression and leakdown tests, she is healthy.  The MAF was definitely the culprit. So for future reference anyone with similar issues that find this thread. I suggest the following steps, in order of affordability:   Check your spark plugs for any fouling, replace plugs if they are bad or re adjust the gaps making it narrower (0.8mm would be good). Check every coil's resistance with a multimeter. It can be done by probing the IB and G pins on the coil pack. Resistance should be around 1.4 (+/- 0.1) Ohms Check the MAF. If you have Nissan connect or a good scanner with the 14 adapter it should allow you to see the voltage on the MAF reading should be around 1.1 - 1.2V when car is idling. But if you don't, buy a new MAF from Amazon and test, then return it. (For instance, I got a Chinese one for $40 that was reporting 1.3v on idle). If you still have scanner, you can run tests on the injectors to see if they are working, just remember to unplug the fuel pump fuse/relay and have no pressure on the line. Then listen for the noises that the injectors make. Clean/replace injectors as needed. Once you find the issue and fix, order thousands of dollars worth of OEM parts to refresh unrelated things (Optional)   PS: Thanks to the absolute legends of this forum for the responses and help to someone that went a bit over their head. (me)
×
×
  • Create New...