Exhaust fabrication to meet Track Day regs.

[cantfindausername]

I was sound tested at 110db last night at Brands Hatch. I've got a custom manifold, downpipe and center section, all in stainless, and then a Dep2Pro back box.

Is it possible for me to get down to the trackday regs with a custom back box?

Does anyone have any recommendations as to who to use?

Thanks,
Ant

[larry93]

can you not get a bung to fit it to get it down we did that for totb and sailed thru

[cantfindausername]

How much power would be lost by sticking 2 of them up the exhaust?

[sanchi]

I'm still trying to find out some info but a few local places to me are clueless. I think you may have to compromise by creating a separate track exhaust as it might be easier than to chop up your dep 2. But I'm still looking into it...

[sanchi]

Bingo here you go mate,

http://www.simpsonraceexhausts.com/page5.html

and funny enough they are around the corner from me and didnt even know!

[steve b]

I was sound tested at 110db last night at Brands Hatch. I've got a custom manifold, downpipe and center section, all in stainless, and then a Dep2Pro back box.

Is it possible for me to get down to the trackday regs with a custom back box?

Does anyone have any recommendations as to who to use?

Thanks,
Ant

Its easy to quiet cars down, you simply need a decent sized box with enough wadding in it. I had Hayward & Scott make one for my old MR2 dropped the noise with its fitment from 108dB to 88dB.

My MX5 was 98dB so I cut open the back box, restuffed it and its now down to 88dB. I posted a how to on here when I did it.

You don't want bungs as they effectively make your nice big free flowing exhaust a peashooter, the bung for my old Apexi hyabusa knocked 3psi of boost off instantly.

[cantfindausername]

Thanks mate, have sent them an enquiry. I got a quote from a place in Cardiff for £290 all in for a twin silencer, single exit system which they say is < 100db.

I'm ok with having to swap to a specific track exhaust for the odd day here and there.

[cantfindausername]

I was sound tested at 110db last night at Brands Hatch. I've got a custom manifold, downpipe and center section, all in stainless, and then a Dep2Pro back box.

Is it possible for me to get down to the trackday regs with a custom back box?

Does anyone have any recommendations as to who to use?

Thanks,
Ant

Its easy to quiet cars down, you simply need a decent sized box with enough wadding in it. I had Hayward & Scott make one for my old MR2 dropped the noise with its fitment from 108dB to 88dB.

My MX5 was 98dB so I cut open the back box, restuffed it and its now down to 88dB. I posted a how to on here when I did it.

You don't want bungs as they effectively make your nice big free flowing exhaust a peashooter, the bung for my old Apexi hyabusa knocked 3psi of boost off instantly.

Yeah I want to steer away from bungs as much as possible.

Having spoken to one exhaust fabricator they say that the problem with the Dep2Pro is that the silencers are stubby. The best for silencing are long.

May drop H&S a line too.

[Bender Unit]

A tail pipe bung shouldn’t cause power loss as long as it’s designed properly.

My exhaust is getting louder so I am going to make a new bung. The basic idea is to simply turn the tail pipe into a silencer. I have 2 bung ends which match the internal bore of my exhaust pipe (2.5) the idea is to weld some perforated tube between the 2 bungs and then wrap with wadding. This then slots down inside the tail pipe – essentially making a silencer in the tail pipe.

It shouldn’t cause any restriction as its essentially just another silencer and the gas can flow through it just as easily as the other exhaust boxes as I haven’t reduced the internal bore of the internal pipe work – however with the extra wadding in the tail pipe it will absorb a lot of the noise. The diameter of the tail pipe can make a real difference to the exhaust dB,.

That’s the plan and I will find out on the weekend – have a DB meter so will test.

[cantfindausername]

Sounds like an interesting idea.

Be dure to keep us posted with results. Pics would be good too

[sanchi]

Just got off the phone to simpson race exhausts... and they sound very good, very well telephone mannered (Definitely DID NOT sound like your average powerflow garage lol).

They told me they are only open for customers on a Saturday so I'm going to pop around then to get them to have a look to see what they can do to bring the db level down. Will update after Saturday...

Sanchi

[LimeyMk1]

www.powerspeed.co.uk seem to be a well informed bunch as well, not too far from you either Anth. I'm considering taking the V6 to them for manifolds etc.

[cantfindausername]

I'd be interested to see what Simpson Race Exhausts says. I sent them an email and all I got back was

> Message Received: Sep 14 2009, 12:29 PM
> From: "Simpson Exhausts"
> To: "'Anthony Onions'"
> Cc:
> Subject: RE: Exhaust enquiry
>
>

Hi



The link doesn’t work mate, can you retry again please

Clearly the copy and paste function escapes them. Hopefully their welding skills are better than their computer skills.

Still, i sent them back an attachment so hopefully see what they can come up with.

I used Powerspeed for making my downpipe and screamer. Wasn't overly impressed with the work for the money to be honest.

[sanchi]

I'd be interested to see what Simpson Race Exhausts says. I sent them an email and all I got back was

> Message Received: Sep 14 2009, 12:29 PM
> From: "Simpson Exhausts"
> To: "'Anthony Onions'"
> Cc:
> Subject: RE: Exhaust enquiry
>
>

Hi



The link doesn’t work mate, can you retry again please

Clearly the copy and paste function escapes them. Hopefully their welding skills are better than their computer skills.

Still, i sent them back an attachment so hopefully see what they can come up with.

I used Powerspeed for making my downpipe and screamer. Wasn't overly impressed with the work for the money to be honest.

Oh dear lets hope so... I'm going to see them hoping they are good... But will update soon as I have been...

[LimeyMk1]

I used Powerspeed for making my downpipe and screamer. Wasn't overly impressed with the work for the money to be honest.

Shame. Think I'll have to pay them a visit to see what their quality's like, got any piccies of their work?

Other than that i've heard good things about Stealth Systems in Southampton.

[cantfindausername]

The work was ok. But I might be expecting more for my money.

Here is the down pipe.

[petbeemer]

We do custom exhaust stuff, never had problems with track db noise but it is getting tighter dependant where you go!
Used to own TubeTorque in Macclesfield

[cantfindausername]

What would you recommend for the back end of an MR2?

[petbeemer]

What would you recommend for the back end of an MR2?

how far are you wanting to get it down?

[cantfindausername]

Currently 109.8db, tested last week at Brands.

Would like to get it < 100 ideally.