997 GT3 track day silencers

[p5hrr]

I fitted these into straight through pipes

[jimmyslr]

I recollect that this type of thing, in slowing down the exhaust gasses, could have a detrimental effect on the engine. Does anyone have better insight into that?

[nxi20]

The Supertrapp solution above is sure to introduce some extra back-pressure into the exhaust. The exhausts that were linked to by the OP do not introduce any significant back pressure because they do not have any real restriction to gas flow and serve the added useful purpose of firing the exhaust noise directly down into the track.

An engine is an air pump; if the intake or exhaust is restricted, it impacts on the efficiency & capacity of the pump; it will negatively affect peak power & usually with a restricted exhaust it will run a little hotter due to the exhaust being unable to loose as much heat as it would if unrestricted. It shouldn't do any actual damage though assuming that the engine itself has sufficient cooling capacity.

Edited by nxi20 on Sunday 29th May 21:14

[hunter 66]

Here is a picture of them ...... worked really well difficult to see but small attachment onto the pipe and then adjust the fin until sound right simple

[hunter 66]

Another picture of car rear

[Paul_M3]

When researching this before, I saw solutions of DecibelDevils and 'Downturns'.

The engineer in me thought the obvious thing to do was combine the two.

Decibel Devil + 90° bend off ebay =



A nice easily removable silenced downturn.

I'm afraid I can't give any values, but there is a noticeable reduction in noise.

[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?

[nxi20]

braddo said:

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?

Totally cold within half an hour. I use mechanics gloves to remove after 15 mins or so & leave them on one side. I stick them in the frunk when I've finished all the other end of day chores.
I suspect that if spotted by the BiB, you might get a pull on the way home as they probably contravene Construction & Uses due to being very hot & exposed to pedestrians brushing past. I've never driven on the road with them.

[adbett]

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!

[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.

[CTO3]

hi all,

have ordered a set of these so i can do more donington 98dB days

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

had a quick google and measurement of the standard tailpipes on my car (2007 997 gt3 rs) and seems to be just above 80mm, but actproducts have said the ones they had for standard are 90mm, will this be for sharkwerks tailpipes? (88mm according to the sharkwerks website, also says 81mm std?)

not near car to get a more accurate measurement, anyone had these for 997 gt3?

thanks in advance

[Cunno]

CTO3 said:

hi all,

have ordered a set of these so i can do more donington 98dB days

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

had a quick google and measurement of the standard tailpipes on my car (2007 997 gt3 rs) and seems to be just above 80mm, but actproducts have said the ones they had for standard are 90mm, will this be for sharkwerks tailpipes? (88mm according to the sharkwerks website, also says 81mm std?)

not near car to get a more accurate measurement, anyone had these for 997 gt3?

thanks in advance

80mm is correct for standard tips, 88mm either M&M system or other aftermarket system

[CTO3]

Ok cool, cheers matey! Will get on with the order!

[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.

[S1MMA]

interesting. I did Snetterton in my standard 997.1 GT3 earlier this year, and it just passed the static test without laguna seca mod, and didn't trip a drive by all day.

[Murcielago_Boy]

Scuderia sell a motorsport tailpipe which reduces volume. I've not fitted it myself, as my GT3 is well gone, but they reckon it knocks off around 5dB.