Jump to content
SAU Community

Recommended Posts

Hi all,

i am onto my 2nd Skyline, and I have to say that I am really enjoying the lower in-cabin noise with the stock exhaust compared to the last car. The last R33 had a Hitech catback which was good, but I now realise it also raised the background noise a fair bit. :):(

With the new car, I have replaced the turbo pipe, and it has a 3" Cat. Since it seems important to give the exhaust gases as little resistance as possible until they have cooled, I was wondering what effect it would have if I changed the pipework from the catback to 3" in mild steel, then let the pipe taper to fit the stock GTR rear exhaust?

I am hoping that the larger pipe volume reduces the resistence, and lets the exhaust gases cool before entering the stock rear box where it now is less of a bottleneck on the system.

Any one with experience in exhausts have an opinion?

Thanks

Ned

Link to comment
https://www.sau.com.au/forums/topic/25945-3-pipe-to-stock-exhaust/
Share on other sites

HI Silver 33,

My reason for keeping the stock exhaust wasnt cost related, but I probably will get a 2nd hand exhaust this time, however since you never know how it will sound until you stump up the cash and get it fitted, its still a lucky dip.

I dont mind a snarl at higher revs, so long as its inaudible at commuting, and highway cruising speeds.

Ned

Hey Ned,

I understand your dilema.

I too have a 3" dump off the turbo upto the cat but have a stock exhaust from the cat back.

I use to have an exhaust from Hi-Tech on my previous car and the exhaust note at cruising speed also got to me., which is why I have not upgraded the cat back exhaust. I like the quietness of the stock system but I'm sure there is alot of ponies to be had by replacing it with a more free flowing system.

If I was to upgrade, a Jap cat back system that is JASMA approved would be the only systems I would consider.

One of my friends brothers has an R33 GTS-T with a Jap system. I've only been in it once and it was very quiet - could not believe it. I'll see if I can get the brand and model.

It's a good idea to increase the size of the pipe off the dump as it allows the hot turbulent air to to get away quicker.

There is a slight gain to be had in power and response but it isn't massive. You will also get a little more noise/resonance over stock.

BTW JASMA cat back systems are the shit. I've had two now, a 65mm Kakimoto which was very quite until pushed hard and now a brand unknown 80mm cat back which is quiter than the 65mm system. There is still a bit of background noise at freeway speeds though.

Hi BH DAve,

I had heard that the JASMA exhausts were good but as akeenan points out there are a variety of them which all can have the acreditation mark so long as they meet the reg's (not all related to noise levels I understand).

I'm still interested in the lareg pipe to stock exhaust, if anyone has experience?

Ned

Noise is actually one of the main considerations in getting the JASMA plate.

A JASMA stamped exhaust is the Japanese version of an ADR compliant exhaust, except JASMA is an independent association. It isn't going to get the tick if it doesn't meet all the requirements, such as build quality, noise output, emissions, and probably others.

It's a fair bet your TRUST system was getting old and worn out akeenan (and no I'm not having a go at you) but exhausts do get louder over time as the steel wool/fiberglass packed in the mufflers starts burn off eventually.

If someone does have a brand new JASMA stamped exhaust thats noisey as hell then I would like to hear about it, I won't argue about it if I'm wrong.

Cheers

Dave

I had a full N1 system (just a big pipe, small muffler) and it was bloody loud - gave me headaches.

I got a heap of quilting material from spotlight, and lined the boot and behind the rear seat - that made it alot more bearable and only cost about 5 dollars for the material and same for some spray glue.

I decided to get a quiet system, to avoid any attention from the plods, so went out and bought a Nismo dual muffler 80mm cat back. It is alot quieter, but still barks in anger:)

The other big difference I noticed though, was a very prominent loss in power, and more lag - my car felt very sluggish and lethargic, but it was quieter.

Bottom line is, performance has a price, not always just dollars.

I just got a Fujitsubo Power Getter (3" pipes) it's not too loud (although I love loud exhausts) but depending on how I drive it the noise varies. If I take off slowly and change gears early it is quiet. If I punch it, the noise peaks at about 2500-3000rpm then drops off again. When freeway driving there is no drone. It also depends on the res and muffler (and the tip). I though the Hi-Tech stuff was supposed to be quiet (and legal) :confused:

Originally posted by BHDave

A JASMA stamped exhaust is the Japanese version of an ADR compliant exhaust, except JASMA is an independent association. It isn't going to get the tick if it doesn't meet all the requirements, such as build quality, noise output, emissions, and probably others.

It's a fair bet your TRUST system was getting old and worn out akeenan (and no I'm not having a go at you) but exhausts do get louder over time as the steel wool/fiberglass packed in the mufflers starts burn off eventually.

If someone does have a brand new JASMA stamped exhaust thats noisey as hell then I would like to hear about it, I won't argue about it if I'm wrong.

Cheers

Dave

Dave, i got a brand new Trust 4" cat back (and now have a full system). It was tested at 108dB... I wouldn't take too much from the Jasma approval in terms of noise levels :)

ronin09 i was waiting for your reply :)

It's a fair bet your TRUST system was getting old and worn out akeenan (and no I'm not having a go at you) but exhausts do get louder over time as the steel wool/fiberglass packed in the mufflers starts burn off eventually.

i dont mind if people have a go at me :D i believe the exhaust wasnt too old either but i guess icould be wrong. but i dont believe a straight pipe with a huge cannon muffler, this cannon muffler being about 5 inches wide with a couple of holes around the inside would be able to make the system quiet "er"

In general, most 3" system would be loud. They can all be JASMA certified as I think JASMA's max db limit is still higher than our EPA standard. (One exhaust shop even laughed & called me crazy to have 3" system - they say I better have a 500HP car with that!)

However, you can do visual inspection to save you some headache later. Just by looking at the design, any canon style muffler (such as Apex'i N1 style) would likely be a bit loud unless you chuck in a tail silencer.

Non canon style muffler would be a step quieter, such as Trust MX (have one on my car) with a proper mid resonator and end muffler section like stock ones except for a 114mm tip. HKS Super Dragger would be in this category too IMO.

Some other exhaust would even be quieter and only sounds a bit louder than stock. I can't think of many but on top of my head would be something like Nismo Weldina, Kakimoto (heard one before - very quiet) or Fujitsubo

Hope this helps.

PS: Ronin, which Trust exhaust you got? Do you know which model, as there are many varieties and some are louder than the others.

I think I know which one it is... that'll be the same design with Apex'i N1 & GT Spec.

They'll obviously be louder than Trust MX. Do they come with tail silencer like N1 & GT? Maybe that'll cut the noise down a bit.

Originally posted by rs73

..... (One exhaust shop even laughed & called me crazy to have 3" system - they say I better have a 500HP car with that!)......

:bahaha: those old school guys just woundnt have a clue, obviously time to run a mile if you hear that.

With so many good second hand exhausts around these days - I bought a Nismo cat back that retails for over $3000 for $700 and it was in near new condition and excellent quality (even has a carbon fibre surround on the tip, gotta love the rice touches:D) - its hard to understand why you would buy a aust made exhaust only to pay more and get less.

Originally posted by rs73

Some other exhaust would even be quieter and only sounds a bit louder than stock. I can't think of many but on top of my head would be something like Nismo Weldina, Kakimoto (heard one before - very quiet) or Fujitsubo

I agree there. My Fujitsubo Power Getter is not too loud for an exhaust with 3" pipes and a 4 1/2" tip.

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


  • Similar Content

  • Latest Posts

    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to it's full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so damn hot in there, that made it all the more easy to remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. I was standing there looking at the car and said 'f**k it'. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
    • Also playing with fire if they start to flow more air down low than what the stock twins can. It's not even up top you need to worry, it can be at 3000rpm and part throttle and it's getting way more flow than it should.
    • Any G40/1000 or G40/1250 results out there?  
    • You still want a proper tune on the stock ECU though. Stock tune + stock ECU with GT-SS/-9s is probably playing with fire if you're running more than stock airflow/power.
×
×
  • Create New...