554 replies to this topic

[Muncher]

I just splashed out 59p on a db meter for the iphone, it's supposed to be reasonably accurate and well calibrated but it only goes up to 105db...

[Muncher]

Chris is taking the silencer back on the 27th and is increasing the length at both ends to make it as long as possible (which will involve cutting holes in the ends of the existing heatshield). It may also be increased to 7 and a half inches.

[techieboy]

I just splashed out 59p on a db meter for the iphone, it's supposed to be reasonably accurate and well calibrated but it only goes up to 105db...

Wow. Really pushed the boat out there!

Be interested to hear just how accurate it is though. I've got a Maplin db meter somewhere in the house which I really must dig out one of these days.

Chris is taking the silencer back on the 27th and is increasing the length at both ends to make it as long as possible (which will involve cutting holes in the ends of the existing heatshield). It may also be increased to 7 and a half inches.

Have you decided it's too loud then? I'm beginning to think that the diameter of the silencer is the key thing for noise output levels with these exhausts. It's about the only thing we haven't yet been able to try with the Piper system.

[Muncher]

Chris is of the view that the length rather than girth is the key. Will be interesting to see what db readings I can get out of it, it's not silly loud all the time, in fact at times it is very quiet. I am rather thinking of what it's going to be like with a lot more gas going through it. It certainly isn't too quiet (though I haven't owned a VSE). He also confirmed the primary which is close to the water pipe is actually further away than it looks.

[techieboy]

Tried a number of different configurations including 7"x24" and 7"x29" main silencers and still not sufficient silencing to be track friendly at stricter circuits. At this rate, I'll need to go back to an OEM cat and pre-cat to add a bit more silencing to the system.

[PiperRS]

Chris is of the view that the length rather than girth is the key.

I would agree with this also

Nice looking system Chris has made. His work is of a very high standard so these will be a nice option for customers.

Well done.

Kind Regards

Garry Curley
Race Product Development Dept

[alanoo]

My 2Bular is honestly equivalent in terms of noise to the standard silencer when normally cruising (= silent), has a pleasant not loud sound at mid throttle, but I am actually concerned if or not it will lead to noise issues at WOT. It is not LOUD, VERY far from a VSE/Komotec or Larini, but these are just WAY too noisy on track so... I really don't consider it is loud, it just makes some fair amount of noise (I am very sensitive to annoying noise I must say), but I have no idea what the guys at the tracks will say (even in France, there is now some not fun restrictions)

[Muncher]

Just did two static tests at 4500 rpm, 1m away 45 degrees...

96db


Trying to carry out a haphazard drive by test resulted in 98db. Most of the time in the car driving it was over 100db.

[PiperRS]

Just did two static tests at 4500 rpm, 1m away 45 degrees...

96db


Trying to carry out a haphazard drive by test resulted in 98db. Most of the time in the car driving it was over 100db.

Could you do the static test at 0.5m distance. This is the normal testing distance for most UK tracks

Kind Regards

Garry Curley
Race Product Development Dept

[NickB787]

Jon did mine and it came out at 88 static on idle and about 94 at 4500rpm Pleased I will take it to bedford though and see what they say.

[Muncher]

Mine's going back on the 12th instead now for a few changes, including making it repackable.

[MAXR]

Mine's going back on the 12th instead now for a few changes, including making it repackable.

That's the best way! Jim at 2ubular is still not happy with designing & building a repackable silencer as he only uses 0.8mm S/Steel for lightness. Most exhausts makers tend to use 1.6mm, which is stiffer, but much heavier.

[Muncher]

I got my sister to check it today at 50cm, she seemed to think it was 100db but I don't think that's accurate as the iphone was reading over 90db due to a bit of a breeze without the car even being started.

[The Batman]

i have a iphone, and its a wank phone! if it works as good as a £100 one then why would it be 59p! if you want an accurate reading go to a track and get them to test you as without that information i dont know who would buy it for track!

[Muncher]

i have a iphone, and its a w4nk phone! if it works as good as a £100 one then why would it be 59p!

if you want an accurate reading go to a track and get them to test you as without that information i dont know who would buy it for track!

Chris has got a proper meter so is going to check it when he has it back. The iphone is a fantastic device though, I don't agree with that, it's only 59p as all you are buying is a simple bit of sftware, there hardware is already there.

[The Batman]

na its crap and can he test drive by then? if so to him and hope the new longer backbox works

[Muncher]

na its crap and can he test drive by then? if so to him and hope the new longer backbox works

Drive by is always a bit subjective though I guess, are there any standard conditions for that?

My Dad just brought home a DB meter from a guy at work.

0.5m and 45 degrees...

92dB at idle
107dB at 4,500rpm with a bit of wind

[The Batman]

now chris gets to have a go at all the fun that garry is having, trying to knock 9/10db off

[RobNA]

107dB at 4,500rpm with a bit of wind

That is REALLY loud!

[Muncher]

now chris gets to have a go at all the fun that garry is having, trying to knock 9/10db off

Yeah, some of the race teams which he makes exhausts for have quite strict noise limits so I'm pretty optomistic.