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it really comes down to the choice of mufflers. simply make sure it has a big centre resonator and a big oval rear muffler (no cannons). it may be worth looking at a twin system something like a twin 2.5 or 2.75" system may be another option to look at (or even twin 3"), as you will be able to get muffler with good noise attenuation in those sizes.

How about a custom system with two centre resonators/mid mufflers? Also twin tip big oval rear muffler?

I am in the UK, so please nothing made only in Oz, no offence :devil:

Looking for a track day exhaust for an R33 GTS-t on an RB26 engine running 280 degree cams and 2860 -10 turbos, so it's a bit vocal at the top end. Has to be 100% sure of passing all UK track day noise tests, I don't care WHAT it sounds like, it just has to be very quiet and with as little restriction as possible. As an example an HKS Hi Power Silent is FAR FAR too loud, I need something as close to stock noise levels as possible. Thanks. 102 Db static, at about 4000 RPM needed absolute tops.

Would you be better off with less aggressive cams and a normal (performance) exhaust like a HKS Silient?

Just thinking laterally a bit.

My Noise RB was fixed with a fujitsubo, my quiet RB already had a fujitsubo. Different models, both slightly louder than stock (3.5inch), if that still isn't good enough get another resonator welded inline. http://www.nengun.com sell them internationally AFAIK.

^ problem with quite a large number of Jap 3.5" exhausts - they aren't really 3.5" at all.

They have step downs to 3" near the mufflers/resonators etc to keep the noise down which hurts performance etc.

Buy the Racepace Mufflers themselves, get them posted to you and then get a local place to make up the piping in between. Done.

I agree 450rwkw -10 turbos with a 3" exhaust sounds interesting. By interesting I mean crap.

I hear what you are saying re a locally built one off, but past experience has shown some one ofs fail miserably in the noise department, so many companies are into huge bore systems and massive exhaust tips it's hard to drum into them that I want *QUIET*, modest pipe sizes for ground clearance and still more silencing, and care not a hoot about looks or "that special sound". I just want to tip up at any UK circuit KNOWING it will pass the noise tests, even if it's 70 BHP down on its potential. Thanks. Any contact info for the RacePace system for sale, or RacePace themselves?

http://www.racepacemotorsport.com/

If someone wants quite system with good flow this is what would i recommend.

It's custom made SMB oval muffler 3.5" in/out ,rest of the piping is custom 3.5" and I also used hotdog from my old Kakimoto that we chopped up.

It's very quite (dare to say 90-92dB) and there was no noticeable power loss,in fact power went from 466>482rwhp but I can't say it was due to mods to exh. system coz runs were not made on the same day(1st run 6 months prior).

I'd be guessing you wont be 90-92dB @ 5100rpm... My 3.5" has 2 mufflers, the larger of the two is bigger than your single one to start off with and i could only manage 91 :)

Would be good if you could go and get it tested so you know rather than guess. Sound level is very hard to estimate.

Hi, I am the original poster from way back :) The car has what I believe is a Fujitsumo system (is that how it's spelt?) and a fairly big slience where the cat would be. On 280 degree, 10.5 mm lift cams through Garrett 2860 -10 turbos with the smaller turbine size option, it makes between 95 and 98 Db @ .5 meter away from, and at 45 degrees to the tailpipe, on an RAC MSA noise meter, tested by RAC MSA scrutineers here in the UK. I am sure a freer flowing system could unlock more power through less back pressure, but I am am adamant I will not go to track days wondering if the thing will pass a noise test or not, nor have to spend hours packing borderline re packable silencers every time it goes anywhere :) I will try and get a photo of the old system that I found for it, the car should be on the ramp today or tomorrow, I am only going by hearsay as to the make, maybe someone will recognise it? It will need replacing before too long, although it's still pretty sound (pardon the pun...) at the moment. Thanks for the replies.

Edited by Chris Wilson

Yes, inhouse.

Any idea how much roughly a legal custom exhaust (dump, front pipe, cat, catback) would cost from the likes of racepace? Lets say it's expected to flow between 300awkw to 350awkw.

Hi, I am the original poster from way back :) The car has what I believe is a Fujitsumo system (is that how it's spelt?) and a fairly big slience where the cat would be. On 280 degree, 10.5 mm lift cams through Garrett 2860 -10 turbos with the smaller turbine size option, it makes between 95 and 98 Db @ .5 meter away from, and at 45 degrees to the tailpipe, on an RAC MSA noise meter, tested by RAC MSA scrutineers here in the UK. I am sure a freer flowing system could unlock more power through less back pressure, but I am am adamant I will not go to track days wondering if the thing will pass a noise test or not, nor have to spend hours packing borderline re packable silencers every time it goes anywhere :) I will try and get a photo of the old system that I found for it, the car should be on the ramp today or tomorrow, I am only going by hearsay as to the make, maybe someone will recognise it? It will need replacing before too long, although it's still pretty sound (pardon the pun...) at the moment. Thanks for the replies.

cool. sounds like a fine solution. it's spelt Fujitsubo btw. :)

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