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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.

Shame you dont want Oz made, there are at least 2 companies making high flowing exhausts to DB levels (eg custom).

You should mention what the DB limit is that you're trying to reach :devil:

Racepace...hands down, end of story, close and lock please mods.

Personally had a drive in a 440+ KW at the treads R33 GTR that sounded and idled like a brand new stocker.

I know of one for sale too...

Edited by Swiper the Fox

I don't want anything bigger than 3 inch, even if kills some power. I need to be practical about this :devil: I do mention the desired Db figure in my original post. Details of the noise test are 102 DB at 0.5 metres from the exhaust tail pie, measured at 90 degrees to it, at 4000 RPM. I would consider buying from Oz if the postage wasn't an absolute killer and i was sure the system would meet my needs, so can you let me have a link to these Racepace systems please, and the one for sale? Thanks.

If you cant get something custom made locally 3.5" or 4" (i have been looking for quiet large exhaust systems) you can see if racepace will make up and send you over a system, but all of the jap etc systems i could find had a little hotdog and a canon on the back that does practically nothing to the noise level.

  • Like 1
I don't want anything bigger than 3 inch, even if kills some power. I need to be practical about this :ermm: I do mention the desired Db figure in my original post. Details of the noise test are 102 DB at 0.5 metres from the exhaust tail pie, measured at 90 degrees to it, at 4000 RPM. I would consider buying from Oz if the postage wasn't an absolute killer and i was sure the system would meet my needs, so can you let me have a link to these Racepace systems please, and the one for sale? Thanks.

If you currently have a 3" exhaust system on the car you can fit an off the shelf 3" straight through offset > centre oval muffler (16" deep x 11" wide x 6" high) my exhaust with that muffler on the rear and a hotdog in the middle is 92db @ idle (45 degrees and 50cm from the exhaust tip) and 89db @ 3500rpm.

If you want something off the shelf the Kakimoto Regu 06&R has a decent sized mid muffler and a canon on the rear, if that is not quiet enough you can get the rear muffler changed by an exhaust shop to a larger item to take more noise out of it for a relatively small cost.

I don't want anything bigger than 3 inch, even if kills some power.

Erm 3" and 450rwkw+ worth of turbo do not mix at all well mate.

You are going to need 4". Even 3.5" is really asking a lot for that type of setup.

Anyway 102dB @ 50cm, 4000rpm = should easily be doable.

My Racepace exhaust is 91dB @ 5100rpm - 3.5". This is around 50cm from the exhaust tip as well.

I had a Futjisubo one. I daresay quieter than stock. Was slightly bigger than 3" too. Too bad I sold it and didn't get model =/

It just had rediculously huge end muffler and resonator - so big I couldnt fit a whiteline swaybar cause it was in the way.

Just get a local one made up with huge resonators?

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?

man, how did you build a track car without using google at some stage of your build?

Curtesy of google

http://www.racepacemotorsport.com/main.html

Pretty sure this is the right one, correct me if i am wrong boys/girls

Edited by s2d4
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?

So simply tell them you want 4" with the two biggest mufflers money can buy?

As i said above about the sound requirements - they are realistically NOT that harsh at all.

102dB is pretty lenient mate and gives you serious flexibility to move about.

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?

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.

If you currently have a 3" exhaust system on the car you can fit an off the shelf 3" straight through offset > centre oval muffler (16" deep x 11" wide x 6" high) my exhaust with that muffler on the rear and a hotdog in the middle is 92db @ idle (45 degrees and 50cm from the exhaust tip) and 89db @ 3500rpm.

If you want something off the shelf the Kakimoto Regu 06&R has a decent sized mid muffler and a canon on the rear, if that is not quiet enough you can get the rear muffler changed by an exhaust shop to a larger item to take more noise out of it for a relatively small cost.

I'm pretty sure this will do the trick if my TI-R blew 92.5dB. They're one of the best sounding, good looking and quietest aftermarket exhaust for sure.

  • 1 year later...

You will need a full twin system. You want the maximum cross-sectional area coupled with sufficient wall surface area to provide sound dampening.

A 2 x 2.75" system would suit you well. Cross-sectional area equivalent to 3.8", surface area equivalent to a 2.75" (but doubled obviously, although this cancels out).

Ta-da.....custom exhaust twin 2.75" with decent resonator/s and muffler/s.

HKS has the N1 full-dual (prob too loud), 2 x 3" apparently.

post-23086-0-11218100-1307436553_thumb.jpg

Kakimoto has one in 2 x 2.75" but again too loud (they say 103db with stock turbos!)

post-23086-0-95497500-1307436952_thumb.jpg

However you can see the possibilities, the Kakimoto system has minimal resonators and mufflers, so making a quieter custom system would be no issue.

Edited by simpletool

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