Do I need a custom made exhaust?

[gregmacd]

and if so who do you recommend?

I have a \'99 FD she is completely standard at the moment (other than very loud exhaust and PFC) but the reason I chose an Rx-7 over Skylines and Supra\'s etc. is because I wanted a light weight agile track car. I will tune her eventually but only to a maximum of about 360 BHP (@ the fly). I want to do track days, dwyb, Nurburgring etc etc...

As such I am very aware of noise levels and I don\'t want to be constrained at track days. I will pay whatever it takes to get a good exhaust that will let me enjoy myself on Englands various tracks.

What do you all think?

[shaunwil]

Get a good quality backbox. Something like a racing beat or dolphin to quieten it down. Will loose some hp and 360fwhp may be out of reach on stock twins but not by much with a quieter system.

Shaun

[Mattie]

I\'m in a similar position; don\'t want it too loud because of track use etc...

I had an RE-A Dolphin rear silencer and it\'s certainly quiet enough, but it is a baffled silencer and strangles my car too much, so I am now going to try a  custom exhaust with two v.large straight through silencers.

[gregmacd]

Hey guys thanks for the responses.
 
My concern about buying off the shelf is that I\'ll have no way of knowing if I\'ll break the noise limits (98 db in most places I think).
 
I am also concerned about strangling the car too much. Given eventually I want 360bhp.
 
I was thinking that that some sort of silenced mid-pipe + cherry bomb style back box with bung would be the best solution. I also assumed that a good exhaust manufacturer would be able to perform noise tests as they do track side.
 
Is anyone running a tuned track car with an exhaust set up that they know works?

[batman]

cherry bomb what the f**k dude ya got an rx7 not an escort

[gregmacd]

Sorry I thought everyone called those Jap exhausts you can stick a babies head inside cherry bombs :Tongue1.

I\'ve just seen from the Noise Levels thread that I actually need to get down to 95db! Which is 3 times quieter than 98 db (I believe).

Is anyone out there running their Rex on a track?

If not do the Time Attack events have to comply with these same noise levels? If so I\'ll call Whifbitz and ask them what they do with their Rex.

[Mazdarotaryparts]

Hi Grant,

For the fit and forget cat back you are looking for the Racing Beat single tip is one of the very few on the market will handle all of your requirements as a free flowing "quiet" silencer with the biggest plus being that these silencers tend to remove the pitch the Rotary produces but you still end up with an exhust you can hear that is a nice sound  .

A lot of exhausts tend to end up with the stuffing burnt out of the silencer box due to the heat the rotary produces over a piston engine.

With the racing beat you will fit it and not have a problem for years,

The only semi complaint ever was a customer recently who went back to his LOUD exhaust because his Racing Beat was too quiet, but then he did ask for quiet !  

If you would like to follow the link below you will find more info and you can also buy on-line from the link if you wish.

http://www.mazdarotaryparts.com/bfd-ex001-racing-beat-single-tip-cat-back-exhaustb-1178-p.asp

Hope this helps

[gregmacd]

Thank you very much for the information.

Can you provide me with the dimensions please? I\'d like to see if I can get it to line up with my current mid-pipe or whether I\'ll need to replace that too.

Thanks again!

[Mazdarotaryparts]

Thank you very much for the information.

Can you provide me with the dimensions please? I\'d like to see if I can get it to line up with my current mid-pipe or whether I\'ll need to replace that too.

Thanks again!

Hi Grant,

All aftermarket cat-back and mid-pipe pieces that are sold separately are made with the inlets and outlets in  the same positions as standard so this means your mid-pipe will mate up with a Racing Beat cat-back system or any other cat-back you may choose.

Hope this helps

[FD3SNuttah]

i bought an exhaust (which cost me hardly anything on the good old ebay). it might look very loud but actually its very very quiet. i think it is slightly more restrictive than the straight through single box i had before but not much so, however when you warm the car up its MUCH MUCH more quieter! although i havent got a meter to test it..

Saying that tho im able to pull in to my driveway without everyone on my street  knowing that im coming from miles away. in fact its altered the tone so the car is more deeper/rumbly as opposed to rather loud/buzzy

the racing beat is a good exhaust everyone raves about them but mate they cost a fair amount

there is another alternative - HKS (i think) make an exhaust bung which goes in the exhaust and its active so that when you are not giving it boost it restricts noise but when you go full throttle it opens up and is not restrictive at all.

[gregmacd]

I have no problem with the price in that link. Does anyone know if I can just buy a device to measure the noise levels myself?

I\'m being a bit of an old woman about this I know.

[FD3SNuttah]

i just checked the link and your right that isnt a bad price at all that! last time i looked i dont think anyone sold them here and they costed a fair bit to import fro the states.

anyway about the meter they arnt too much to buy

http://www.edirectory.co.uk/pf/88888/mia/d/Digital+Sound+Level+Meter/pid/3859687

[AtomicRex Racing]

We race Rx7\'s at castlecombe which is probably the worst of all circuits in the uk for noise restrictions.  All last year we had absolutely no problem with the most we ever read was 93db, as such when they used to test our car like all other before every practice session they joked at how there was no point in testing ours as we were always well under.  
Our exhaust as said was absolutely perfect and lasted the whole season, however when we took it off for the winter strip down, we could hear that some of the baffling had obviously been blown out as they were a little rattly (spelling).  
With this is mind we have now commissioned a well respected company to make our exhausts for us, both the mid pipe, and back box are completely repacke able.  So if it were to ever be too loud you could simply repack it in the paddock and still get on any track day etc (on top of this you could play around with different materials that you pack it with to tune it to your desired note).  

One thing we were very keen not to do was make the exhaust in anyway restrictive to performance, as simple that would be SILLY!!! :rollin and not beneficial.
Our car last year was running a single turbo GT35/40 which made very good power.

Saying all this we wouldnt want too try and sell anyone something that we didnt have faith in ourselves, this is why all three of our cars this year will be wearing our new shiny exhausts.  

Details and pictures of exhaust should be up in our vendors section in about 10-14 days.  Although if you want to know more please dont hesitate to contact us.

Just to let you know what will be on offer:
-Single turbo conversion manifolds (with an option of having it ceramic coated)
-Downpipe
-Mid pipe
-Back Section (cat back)

[gregmacd]

Brilliant! That\'s great I will definitely be in touch!

I\'m not gonna be doing time attack or anything but I would DEFINITELY buy an exhaust that I knew had been used for motorsport and was able to pass the noise limits.

Thank you very much for your reply btw if you can make the tail pipe 4" slash cut jap style and titanium with that funky blue colour that would be great :evillaugh just taking the ****

[Mazdarotaryparts]

Hi Grant,

If you want the look you require with a big slash tailpipe we sell the lightweight blue tipped 5ZIGEN Pro Racer A-Spec Exhaust cat back that "claims" 90db.

The reason I say "claims" is because from our experiance Rotarys with different engine porting and turbo configurations will give different noise levels, however looking at you projected Horsepower that sounds like you will be staying on the twin turbo set up and stock ports so you should not have too many noise issues with your car whatever your choice.

Hope this helps

http://www.mazdarotaryparts.com/bfd-ex007-5zigen---pro-racer-a-spec-exchaust-systemb-1213-p.asp