gchristofi

Trying to book my first ever trackday (), so went to the Bedford Autodrome for a sound check. Their noise limits are 101 db static and 87.5 db drive by.

Stock car with the exception of a g-pipe recorded 105 static (measured 0.5m from exhaust) so now considering my options.

I have previously run a cup pipe with standard secondary, but when the original secondary silencer became very rattly, I put back the original primary silencer and added a g-pipe instead. I have read previous posts stating that cup bypass is quieter than a g-pipe but don't fancy forking out £6-700 for a new secondary silencer. So am considering a silencing exhaust tip as a possible solution.

has anyone here got 1st hand experience with the 'Will Norman MHP' exhaust tip mentioned in other threads on this forum? Will it help me reach my 101 db target from the 105 my car is producing right now?

Anyone used this alternate product from DANSK?

http://www.design911.co.uk/fu/prod55...rt-Porsche-964

Jamie Summers

I've got one of the Will Norman tips and it "does what it says on the tin". Running a standard tip with decat and cup pipe my car was typically 107-108 db, with the Will Norman Tip it is 104-105, and with the extra removable insert it is 98-99 db (use this just for static tests and remove for track driving - drive by noise is not a problem for 964s)

Jamie

rosssavage

I have a decat and cup pipe fitted. Did my first track day a while ago at Bedford and was about 108, so failed the static test but the drive by was fine.

I've just got a the Will Norman tip and although I've not done another track day yet. It's much quieter and with the baffle in it's a big difference. Not the cheapest thing and not the best looking but I'd be gutted if I'd paid for a track day and was not let on because of noise.

Mark J

D'oh all this is confirming i made a wrong move when i bought the cat bypass recently to go with my cup bypass. The last thing i want is to be restricted on future track day events
And having to fork out yet more money on a silencer tip sounds crazy talk ! Blinking nannying noise police..grrr.
How the heck do RS and GT3 cars get by on their numerous track events ? Surely they are louder than a mildly exhaust tuned 964 ??

I am actually considering selling the as-yet unused or fitted cat bypass now.

rosssavage

I know what you mean, it does seem a bit wrong.

Fitting the decat does change the sound (even with the silenced tip) in a good way. I don't do loads of track days so I might even just put the tip on for track days as it only takes a few minutes to fit. I guess after a while you will know which tracks you can get onto but could be expensive finding out. I know that (without the silenced tip) I can get onto Bedford. I will fail the static test but be fine with the drive by.

gchristofi

Think I'll give the 'Will Norman' tip a go. From Jamie's post looks like it's good for a ~ 3db reduction without the insert.

Jamie, is the insert v. easy to add/remove inconspicuously?

Ross, you got onto Bedford running 108 static??

Jamie Summers

Yes, the insert is very easy to fit / remove, just two small allen-head screws.

Jamie

gchristofi

Thanks for the info Jamie. I just called the retailer of that Dansk product. Was told that it also came with a removable insert .... a lot less $$$ so considering trying that instead. Would be good to know if anyone here has tried the Dansk product and can offer feedback?

airfan

Have searched for further info on the Will Norman exhaust tip but can't find it?

Turbo Jonny

here is the contact details from the favourable article in Porsche Post
september 2007 -

normster@talktalk.net tel. 07894 066479

rosssavage

yeah managed to get onto Bedford. Got a red sticker and had to do a couple of drive by's with an instructor driving my car but passed them all fine. To be honest it was my first trackday so didn't know what I was doing. I'm sure someone else can answer this but I think most tracks won't let you on if you fail the static test??

For me Bedford was good for my first one. Felt if I got it a bit wrong it would have been fine. Although I missed the sighting laps because I was doing the drive by's and then decided to not slow down for the bend at the end of the straight on my first lap. My passenger had to change their pants

boxsey911

Pics of the Will Norman tip:

This is with the extra bung inserted for the static test:



Here's the insert removed:



Without the insert the tip looks pretty normal and reduces the db by enough to stop drive by meters being tripped.

Jamie Summers

By the way, the insert fits flush, it doesn't stick out like in Boxsey's picture. The picture just shows it pushed in half way !
The latest versions of the insert have two "tabs" welded on to the end so it can be secured with allen-screws rather than just a "push fit" as per the early prototype.

Jamie