Jump to content
SAU Community

Recommended Posts

Hey guys,

I have got a boost T ready to hook up but I want to get an exhaust done first. I have been recommended by others to get a 3" turbo back exhaust so I booked in my car for a quote. The exhaust guy said that 3" is too big and will be too loud (I don't want it loud. just performance) and suggested that all I would need is to take out the cat converter and run a straight 2.5" pipe through from where the cat was. The rest of the stock pipe is 2.5" but it changes to a 2" half way down which he recons is all I need to take out in order to get some good performance. :wacko:

Getting told millions of different things. It is cheaper to do the 2.5" obvously, but is it worth it?

Some help and/or experience of different exhausts would be great thanks!

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/
Share on other sites

Go 3", add in an extra resonator and you'll be fine. Best of both worlds.

BTW, did a professional exhaust fabricator advise you to take out the cat on a street car?

I'd be heading to a different exhaust shop if I was you...

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5416127
Share on other sites

Sounds like the guy you are talking to is a tool. Depending on where you are, there are massive fines for running no catalytic converter.

3" all the way but spend some decent money on a good quality rear muffler. You could run 5 inch all the way, it's the rear muffler that will determine 85-90% of the sound that comes out of it

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5416298
Share on other sites

Sounds like the guy you are talking to is a tool. Depending on where you are, there are massive fines for running no catalytic converter.

3" all the way but spend some decent money on a good quality rear muffler. You could run 5 inch all the way, it's the rear muffler that will determine 85-90% of the sound that comes out of it

His location says NZ so I am pretty sure they are not required by law to run a catalytic converter.

As everyone has said, bigger the better, the type of muffler will determine most of the sound. 3" minimum.

But yeah guy is still a tool, my 3" exhaust is super quiet. Depends on the mufflers

Edited by Harey
Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5416621
Share on other sites

If you don't have to have a cat, if that is correct, do you have to have mufflers?

If not, does the exhaust have to exit past the diff?

If not, I would honestly have a side pipe exiting just after the trailing edge of the passenger door

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5416779
Share on other sites

Cat is not currently required in NZ. There is a noise limit.

To OP: get the three inch now or you will be doing it again later. Also find another exhaust shop. With the right muffler at the end you will not be too loud or if you want you can stick in a resonator in the middle.

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5417012
Share on other sites

3" or bust!

A proper 3", with two decent mufflers, will not be loud at all.

Under 90dB which is very quiet.

Many thanks guys,

Depends what you mean by "quiet"

I got a 3-4 inch tip on the back at the moment and it rumbles. It only gets my ears going slowly up a hill. 90dB unless I am mistaken is rather loud. I've got a little bubby expected early next year so I want it to be soft on his/her ears... but I want performance as well :)

cheers

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5417273
Share on other sites

A mate has a very young child, and shes often in his gtr. As soon as ge goes around the block he says she's asleep. Stockish GTR with a kakimoto exhaust.

He's been doing this for ages, I think his girl is about to turn 2yo

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5417579
Share on other sites

I'm not expecting it to be quiet. I want a rumble... :) but I just don't want it loud enough to get my ears...or the little one's.

What ive reccomended above mate, trust me, will not be loud/drone or annoying.

Anyone of the Vic guys thats seen my car will tell you that you don't even notice it.

@ 2000rpm, no stereo and tiny bit of throttle, i can't even hear it and my car has all the sound deadening removed.

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5417919
Share on other sites

ive got a r34 GTT i was wondering if anyone knows if you can get extractors with a 3inch outlet .. ive got from the catback back 3inches but turbo to catback is just stock. i want to hole thing 3inch.

Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5421117
Share on other sites

ive got a r34 GTT i was wondering if anyone knows if you can get extractors with a 3inch outlet .. ive got from the catback back 3inches but turbo to catback is just stock. i want to hole thing 3inch.
You can get up to 5in if you want!
Link to comment
https://www.sau.com.au/forums/topic/334260-25-or-3/#findComment-5421266
Share on other sites

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


  • Latest Posts

    • OK, next the shroud needs to come off and there are a couple of tricks. Firstly, there is a loom from near the passenger side headlight to the fans, coolant temp sensor etc and there is no plug to undo.  In my case I was OK to leave the shroud on top of the engine so I just undid the passenger side fan plug and about 10 of the clips which gave enough free wire to put it aside. The fan plugs were super tight, the trick I used was a small falt screwdriver to push down on the release tab, then a larger flat screwdriver to lever the plug out of the fan unit....be careful with how much force you apply! If you need to remove the shroud altogether for some reason you will have to deal with all the plugs (tight) and clips (brittle)....good luck. I removed all of the clips and replaced them with cable ties that I will just cut next time. Also, in the Red Sport / 400R at least, the intake heat exchanger reservoir hose is bolted to the shroud in 2 places with 10mm headed bolts; so remove them (the hose stays in the car; no need to undo it at the t fittings down at the radiator lower mount. Once you've dealt with the HX hose and the wiring loom, there are 3x 10mm headed self tappers holding the top of the shroud to the radiator; remove those.   The shroud then lifts out of the bottom mounts where it sits on the radiator, up and onto the engine out of the way. Simples
    • Ok, disregard my “rate them” comment, sorry for my unrealistic input
    • OK, now we are ready to get started. You need to remove the air boxes on each side for clearance. The cover is straightforward, undo the clips on the top and lift the front cover out of the rest of the housing. If it is tight you can remove the air filters first. The rear section of the airbox is trickier. On each side you need to remove the Air flow meter wiring which is held to the airbox with a clip; you need to get behind the clip on 2 sides if you want to remove it without breaking it - unclip the harder side and pull on the clip with medium force, then unclip the easier side and it should pop out The airbox is held onto the intake hose with a spring clamp; you need to get a flat bladed screwdriver behind the spring on both sides and pop them outwards. When you have got them in the right unclipped place they will stay there and the airbox slips out pretty freely. Put a rag in the intake to prevent anything getting dropped in there, and also to prevent you seeing that the turbo seal is leaking oil (as they do). Then. The top of the radiator is held by a steel plate, it is secured by 2x10mm and 2x12mm headed bolts . Remove them and remove the plate Also grab the bushings that hold the radiator to the plate on each side so they are not lost!
    • Next, remove the upper and lower radiator hoses, both are held with a spring clamp. While you are under there, tackle the Auto Trans cooler lines.  Again both are held on with spring clamps, and as mentioned above you should cap them on the radiator side with an 8mm cap, and on the car side loop them with a length of 8mm pipe - this will stop you losing a dangerous amount of AT fluid during the rest of the job If you've been meaning to add a sender for AT trans temp, this is a great time to do it; put a sender fitting into the passenger side line as that is the inlet to the cooler/radiator.
    • Next you need to remove the intake duct (as with pretty much every job on these cars), it is a series of clips you gently remove with a flat bladed screwdriver. They do get brittle with time and can break, and I have not found a decent quality aftermarket one that fits (they are all too soft or flimsy and don't last either) but the nissan ones are a couple of bucks each (ouch).  Once the clips are off (either 8 or 10, I didn't check) you lift the intake duct out and will see the reservoirs Undo the line into the radiator side cap (some bent needle nosed piers are awesome for spring clamps) and then remove the 4x 10m nuts that hold both in place.  I didn't get these pics, but remove the line under the radiator reservoir (spring clamp again) then remove that reservoir. Then you can get at the intake reservoir, same thing, spring clamp underneath then remove it. BTW This is a great time to put in a larger (+70%) combined reservoir that AMS makes..... https://www.amsperformance.com/product/q50-q60-red-alpha-coolant-expansion-tank/ They also make an Infiniti branded and part# version if that is your thing
×
×
  • Create New...