997 GT3 track day silencers

[braddo]

Especially given that Brands Hatch is yet another track bringing in stricter noise limits, are there any GT3 owners here using bolt-on silencers to widen their choice of track days?

Searching through threads a while ago, someone linked to this:

http://www.actproducts.co.uk/product/si06-porsche-...

Does anyone here have one? What's it like and how effective is it?


My standard car was tested at a bit over 103db at Brands (aircon off, clutch in). I haven't tried the vacuum cap trick yet to get a lower static noise test reading. Anyone know how much difference it makes?

I really want to be able to do Brands Hatch GP!

[braddo]

S1MMA said:

Hi, I've done the vacuum pipe trick (Laguna seca mod as they call it in the states). Gets it down to about 101ish. I was also 103.6 static at Snetterton recently without Laguna seca mod.

From what I've been reading, the best and most cost effective thing we can do is fit downturned tips, this makes a good difference. Think some of the 911 racing cars have downturned tips.

There are a few products around, or a local place can weld these up for you I'm sure. Search for them.

Thanks, that's useful stuff. I'd like to think if a 911 gets close to the 101 static limit at Brands that they'd show a little flexibility. At least that would get you on track...

I know a small fabricator not far from Brands so I might see what they quote for a pair of slip-on downturned tips.

[braddo]

wtdoom said:

Thank you matey . I love her so much too , a dream really . The team looks at it as we are temporary custodians of her until we pass her on to the next custodian . It's a piece of history to me and I pinch myself every time I get in it . I promise you she will never be wrapped in cotton and imprisoned in a bubble . She will be raced and swap paint with gt40's etc regularly . If we are ever testing in the uk etc would be team RSD's pleasure to host you .

Here's a Twitter account for her if you are interested: https://mobile.twitter.com/brumos_rsr95 , Neil and rob will update it as he prepares her for her next race at Paul ricard in early October . Dino vids , testing vids etc . They will do the works , will be proper nerdy beardy st .

Dammit, I really didn't think there was ever going to be a reason good enough for me to get onto Twitter, but...

Amazing how small the 'prototypes' are - imagine a 991 RS in the photo near your car.

[braddo]

ttdan said:

These are worth a look. Knocked about 4 to 5 db off a GT3 with an x pipe fitted, so 110 ish to 105 ish. When used on a standard rear box with the vacuum mod it was ~100 at Goodwood static.

http://www.decibeldevil.co.uk/

Do they fit straight out of the box?

[braddo]

nxi20 said:

I've been using these on my 996 GT3 track car for a couple of years now. They work extremely well and are a quality product; I've not had any trouble getting on at Brands GP (101dB) or Castle Combe (100dB)...

Good to know, thanks.

I like the idea that this product reduces noise by more length and silencing, rather than noise 'restriction'.

It seems that if I want any chance of going to Brands, aside from opening up more options like Bedford and quieter days at Snett, Goodwood etc, I'll have to take the plunge.

Does the product cool down relatively quickly that you can take it off at the end of the day, give it some time (half an hour?) and then it's cool enough to transport inside the car (e.g. wrapped in towels or something?)? Or would you need to leave it on for the drive home?

[braddo]

adbett said:

braddo said:

I know a small fabricator not far from Brands so I might see what they quote for a pair of slip-on downturned tips.

Who's the fabricator near Brands? I might have a similar need for my 996 they could help with!

Solid Fabrications, based around Orpington. He did some work on my old AMG Merc which I was happy with.

[braddo]

I had a look at the standard tips on my vanilla 997.1 and they are 79 or 80mm.

I think I'll get in touch with ACT next week.

[braddo]

I measured the circumference of standard 997.1 tips and it was 252mm = 80mm diameter. Product ordered from ACT.

[braddo]

Update - I ordered the silencers from ACT Products - build quality seems good (not the prettiest welding but who cares in this context). The fit was spot on.



My standard 997.1 GT3 read 103.4 at a sunny spring day at Brands. I had a track evening at Snetterton this week and with the new exhaust add-on it read, err, higher than 103, which failed the static 102db test for the evening!

So, some annoying inconsistency with noise readings even amongst MSV-owned tracks. Had to do the 'Laguna Seca' mod of plugging the exhaust valve vacuum, after which the noise gentleman gave the all-clear.

The drive-by was 92db (like Brands). Immediate black flag for noise and unless you can show them a physical mod, no chance of getting back on track.

I removed the exhaust valve plug and started very tentatively - but didn't trip the noise meters. A crazy-loud supercharged Civic didn't seem to trip the meters either, so it's all rather uncertain how loud my car and how its reduced noise will translate to somewhere like Brands.