Suitable Exhaust For 350 Plus Kw Rb26

[Shaun]

Hi,

Ive recently finnished my 'rb26 into r32gtst' project, but im having troubles with an exhaust that is too loud. The car has got about 350rwkw on low boost setting, and ive currently got a Trust TR Drag 3.5 inch exhaust on it. This exhaust consists of a 3.5 inch metal cat, a hot dog, and then a cannon type muffler with perforated tube straight through it. Its over 100db at 5000rpm and thats WITH the silencer in it. It also drones like a bitch in the cabin.

Ive spoken to a few people in the know, and they ALL say that i wont get an 'off the shelf' exhaust that wont restrict the cars power. I dont want to spend 20 grand getting 350kw and then restrict it with an exhaust, so it seems ive got to go the custom route.

Apparently the best way to go is an oval centre muffler that is glass fibre packed, and uses (3.5 inch) perforated tubing that enters the muffler, then makes a 'U' shape before exiting the muffler. Im not sure about the rear muffler though. I imagine it would use perforated tubing with glass fibre but without the bend in it.

Anyway, my problem is that i can only fit a centre muffler that is 12 inches in length under the car while still maintaining suitable ground clearance. There is no way that a 3.5 inch (or 3 inch for that matter) pipe can make a mandrel bend to sufficiently muffle sound in 12 inches.

Surely there are people out there who have tackled this problem before. Im after a free flowing exhaust that is legal (or as close to), and doesnt attract attention. If anyone with experience in creating such an exhaust can help me (or knows someone who can), it would be much appreciated. Ive found a few people in the Melbourne area, but i think it would be difficult to make a custom exhaust, as i am near Sydney.

Thanks heaps, and sorry for the long post.

Shaun.

[GeeTR]

I almost bought a TR as well. If you want to keep that rear cannon (which would be doing very little sound muffling) then yah, you'll need a custom oval muffler where the resonator is now.

Iv seen good results from Hi-tech and SMB in Sydney (both can offer advice and make one off mufflers on site.

Nizmoid has recently had a system made for a RB of similar power. He ditched the cannon and used an oval muffler at the rear though.

[gtst4d]

Get a new oval muffler at the end with the same size outlet as the inlet and use the cannon as a really big paper weight.

[R31Nismoid]

You can have two mufflers, both straight through, and still be 90-92dB.

Mine is 3.5" all the way.

Check my gallery for some pics - all custom of course

[Rezlo]

I use side in center out magnaflow rear silencers (straight threw pref tube) at the rear and get a regular 304 twin 3" stainless tip and convert it to run 3.5"... Makes the system nice and quiet, doesnt restrict power and doesnt draw the cops (serious problem here in South Africa)

With a side in center out you can get away with using 1.5 90' bends for the full system, above was a 3" system I did for a S13 to shut it up with a 330wkw SR20, its a bad example because its got a lot bends but it gives you the idea

Edited May 4, 2008 by Rezlo

[T88 ON BOARD]

My Gt-r was running a T88 when it came from japan...

It had a 3 and 3/4 HKS Priest Exhaust system, No cat and it was around 100db, it has a oval rear muffler which made it very easy on the ears!...But i changed it up for the Trust TR system although mine was 4'' on special order...

So i reckon if you could use that type of muffler with the rest of your exhaust system that should work?

[Shaun]

I almost bought a TR as well. If you want to keep that rear cannon (which would be doing very little sound muffling) then yah, you'll need a custom oval muffler where the resonator is now.

Iv seen good results from Hi-tech and SMB in Sydney (both can offer advice and make one off mufflers on site.

Nizmoid has recently had a system made for a RB of similar power. He ditched the cannon and used an oval muffler at the rear though.

Hey, thanks heaps for all your replys.

Im not fussed about keeping the rear cannon. In fact, id rather go for an oval or more standard looking rear muffler as many of you have suggested.

GeeTR, im having a bit of trouble finding both Hi-Tech and SMB in Sydney. Do you know what suburb they are in?

I was expecting to have both a centre oval and rear muffler made up, but from what some of you have said, maybe i can get away with just the rear muffler being replaced??

Anymore hints as to which work shops can do this for me without experimenting. I need tried and proven methods, as coin is a bit of an issue!! Ill keep trying the above workshops in Sydney.

Thanks,

Shaun.

[Shaun]

You can have two mufflers, both straight through, and still be 90-92dB.

Mine is 3.5" all the way.

Check my gallery for some pics - all custom of course

Hey, how do i get to those pics? The gallery just shows Thailand pics.

Any idea on the construction (internally) of your mufflers?

Thanks,

Shaun.

[R31Nismoid]

I have two Albums - just click the other

http://www.skylinesaustralia.com/forums/ga...-album1130.html

Thats a direct link, there are about 5-6 pics to give you an idea.

Also remember its a HR31, so muffler size/position is different but it'll give you an idea of where to start and the fact you need some pretty hefty mufflers. All mufflers were custom made for my car, so i cant offer much for the construction there

Any exhaust shop experienced in big power should be able to work magic though

[GeeTR]

Hi Tech

344 Bourke Street, (cnr Short St)

Darlinghurst NSW 2010

Sydney, AUSTRALIA

http://www.hitechmufflers.com.au/home.php

SMB

11 Aero Road

Ingelburn,

NSW 2565

http://www.smb.net.au/

[Shaun]

Hi Tech

344 Bourke Street, (cnr Short St)

Darlinghurst NSW 2010

Sydney, AUSTRALIA

http://www.hitechmufflers.com.au/home.php

SMB

11 Aero Road

Ingelburn,

NSW 2565

http://www.smb.net.au/

Thanks mate,

I couldnt get onto SMB, but rang Hi-Tech today and they said they could help me out.

Ill keep researching..............

[Strik3r]

very easy option would be to get a butterfly valve installed..... when putting around town, your effective exhaust size is about 2".. pull a lever, open up the valve and your straight back to 3.5" when you want to fang it (on the track of course).

keep in mind, this is not a strictly legal option....

[SirRacer]

will be interested to see how you get along shaun as im going to be facing the same problem soon.

my car doesnt have sound deadening so it will be much worse no doubt

[benm]

I first r32 came with a jap cat-back that just had a rear oval canon and was so loud I couldn't drive at the same speed for longer than a minute on the motorway without ruining my ears due to the drone. Dropped my car into 'Penrith City Exhausts' and got Eddie to make a new custom cat-back with a centre and rear magnaflow oval mufflers.

Not only was the drone completely gone, but it was no longer illegal and he managed to mount it about 2 inches higher so it wouldn't scrape like the jap exhaust did. All up it cost me $1000 drive away and was very good quality.

[Swiper the Fox]

Shaun, my business partner Dave's dad has an exhaust business in Thornton. They have a lot of experience with imports and may be able to assist you. Give me a call if you are interested.

[FLY12N]

I have a Jasma approved exhaust, 3" flows fine and sounds great without being too loud. Definately worth having a look into Jasma approved items.

[R31Nismoid]

^^ Yeah but 3" isnt going to handle 350rwkw.

You need something special to make power and be quiet @ those kinda flow levels.

[Shaun]

^^ Yeah but 3" isnt going to handle 350rwkw.

You need something special to make power and be quiet @ those kinda flow levels.

^^^^^^Yeah this is my problem. Its easy to make it quiet, but i dont want to kill my power in the process.

There seems to be plenty of options, however, so ive just gotta find someone with experience in this area to make me a custom exhaust.

Thanks for your replys, ill keep you posted.

Paul, ill give you a ring and get the Thornton shops number.

Shaun.

[Shaun]

very easy option would be to get a butterfly valve installed..... when putting around town, your effective exhaust size is about 2".. pull a lever, open up the valve and your straight back to 3.5" when you want to fang it (on the track of course).

keep in mind, this is not a strictly legal option....

I was talking to X Force about their rear muffler that has a butterfly integrated in the design, and its electronically controlled. When closed, it directs gasses through baffling in the muffler (quiet), and when open, its a straight through design. Their 3.5 inch oval muffler is being developed now and should be ready in 2 - 3 months.

Idealy, id like an exhaust that flows the power and is quiet (the holy grail), but alternatively this option might be ok.

[Gts-t]

Hey shaun,

I think u could look at some off the shelf options such as trust PE2 and the kakimoto regu 06&R. Pretty sure they will flow 350rwkw and still be quiet. I have the PE2 and its not that much louder than stock

GL