Track Day Exhausts
Discussion
I got busted at Bedford today with my "Extra Quiet" Silencer fitted. It measured 103Db(A) Static!! With a bit of effort, we managed to get on track and with some judicious lifting at the right place, never tripped the drive by meter, but 103 is ridiculous for an extra quiet silencer and I don't like the prospect of being sent home for being too noisy. I'm guessing that the silencer is knackered, but unlike proper stuff, it isn't repackable, so does anyone have any suggestions before I invest some hard earned cash with Radical?
Try Wayne Jackson at JAC in Hucknall, Nottingham. He's just done a track day one for my PR6. lovely job. He'l re pack it and make it so the end cap can be removed to re pack in the future. And can even mirror finish polish for you.
Top quality work and a top bloke to deal with.
Jacksons Automotive Components
Unit 7, Plot 1, Wigwam Lane
Hucknall
Nottingham
NG15 7SZ
tel: 0115 9635556
Top quality work and a top bloke to deal with.
Jacksons Automotive Components
Unit 7, Plot 1, Wigwam Lane
Hucknall
Nottingham
NG15 7SZ
tel: 0115 9635556
just fitted my repacked by wayne track day silencer, its a pig to do so wayne told me its a three bypass system seam welded all over the place, don't think he would recommend doing it a again.
Fitted it this evening and with my dBa meter it showed 98dBa at 1 meter inside of the unit with the rear clam off, so should expect about mid 90's at the track.
Cheers wayne for a great job
Fitted it this evening and with my dBa meter it showed 98dBa at 1 meter inside of the unit with the rear clam off, so should expect about mid 90's at the track.
Cheers wayne for a great job
take back my previous comment, my repacked one failed its noise test yesterday at 107.7 dBa at .50mtr, I borrowed one from Phil cooper this just about passed the static test at 105 but later in the afternoon I got black flagged at 106 on drive by.
Ive now took deliver from radical one of their track day silencers fitted it and this is showing 107 static with my own dba meter, so the question is the radical silencer fit for purpose or am i doing something wrong???
Ive now took deliver from radical one of their track day silencers fitted it and this is showing 107 static with my own dba meter, so the question is the radical silencer fit for purpose or am i doing something wrong???
baja1969 said:
take back my previous comment, my repacked one failed its noise test yesterday at 107.7 dBa at .50mtr, I borrowed one from Phil cooper this just about passed the static test at 105 but later in the afternoon I got black flagged at 106 on drive by.
Ive now took deliver from radical one of their track day silencers fitted it and this is showing 107 static with my own dba meter, so the question is the radical silencer fit for purpose or am i doing something wrong???
Unless the tester at Radical is profoundly deaf, I think the description of their "extra quiet" silencer is somewhat more than a little optomistic!Ive now took deliver from radical one of their track day silencers fitted it and this is showing 107 static with my own dba meter, so the question is the radical silencer fit for purpose or am i doing something wrong???
Has anyone had any success with the Muffler that Merlin sell?
baja1969 said:
...... but later in the afternoon I got black flagged at 106 on drive by.
Mike, that is bonkers relative to an SR3 and suggests to me that the problem is with the noise metering rather than the exhaust. Did you ask to see the equipment certification/calibration proof?That said, I think that everyone trackdaying a Radical needs to have a 'get out of jail' SuperTrapp in their tool chest, even on a 105dB Static day; you certainly can't rely on that Extra Quiet Silencer; whether brand new or not, some do and some simply don't.
Agree there. 106 on drive by cannot be right. Unless they meant that the drive-by noise "equated" to 106 static?
Re the quiet cans. That just seems a bit of a lottery really. You always have a supertrapp thingy around for track days. Used the Merlin one which takes about 2db ish off. Also needs some "economy" when describing the rev limit I suspect!
Bert
Re the quiet cans. That just seems a bit of a lottery really. You always have a supertrapp thingy around for track days. Used the Merlin one which takes about 2db ish off. Also needs some "economy" when describing the rev limit I suspect!
Bert
splitpin said:
baja1969 said:
...... but later in the afternoon I got black flagged at 106 on drive by.
Mike, that is bonkers relative to an SR3 and suggests to me that the problem is with the noise metering rather than the exhaust. Did you ask to see the equipment certification/calibration proof?That said, I think that everyone trackdaying a Radical needs to have a 'get out of jail' SuperTrapp in their tool chest, even on a 105dB Static day; you certainly can't rely on that Extra Quiet Silencer; whether brand new or not, some do and some simply don't.
baja1969 said:
Any idea where i can get one just in case my fall back plan doesn't work.
Recollect we got ours from Demon Tweeks; we had ours welded onto a reducer spigot pipe (also from DT I think) to make it easy and very secure to bolt it onto the end of a R Quiet Can.I'll reference/measure it all up tomorrow and ping you a message with all the details.
Cheers
Trev
I have a merlin muffler and had to use it last time I was out on track to get it under 100db. I have a radical quiet exhaust which measured 105db that time (early march). Took it back for a retest after getting it hotter and it was even louder so I used the muffler and suddenly it was at 100db. I noticed the noise test meter was set on "max hold" mode. The problem with this is that if the exhaust pops at all it pushes it over the max limit easily. So it's down to the skill (or more accurately sense) of the noise tester to ignore such readings and look at the average figure.
I have three options for additional silencing at the moment. I bought a stainless Y pipe from an eBay seller and had the end flared so it slip fits over the quiet silencer tailpipe with an exhaust clamp, and cut two slots down it to allow the clamp to work. This enables me to split the gases at the exit so the noise meter can't measure both exits at the same time as they face away from each other parallel to the rear of the car. The effect is small but nonzero.
The second configuration is one merlin muffler straight on the tailpipe. Knocks a couple of db off.
The third configuration, which I've never used, is the y pipe with a muffler on each end.
It's all done with exhaust clamps so isn't what you'd call beautiful nor is it light but it'll get me out of a hole if needed. I rather suspect the full setup doesn't do much for airflow at the rear either.
I do think though that on a radical the biggest problem is that the exhaust is so close to the engine that much of the noise being picked up is coming from upstream of the silencer, and I think the engine cover does little to limit the transmission of that noise outside of the car.
I have three options for additional silencing at the moment. I bought a stainless Y pipe from an eBay seller and had the end flared so it slip fits over the quiet silencer tailpipe with an exhaust clamp, and cut two slots down it to allow the clamp to work. This enables me to split the gases at the exit so the noise meter can't measure both exits at the same time as they face away from each other parallel to the rear of the car. The effect is small but nonzero.
The second configuration is one merlin muffler straight on the tailpipe. Knocks a couple of db off.
The third configuration, which I've never used, is the y pipe with a muffler on each end.
It's all done with exhaust clamps so isn't what you'd call beautiful nor is it light but it'll get me out of a hole if needed. I rather suspect the full setup doesn't do much for airflow at the rear either.
I do think though that on a radical the biggest problem is that the exhaust is so close to the engine that much of the noise being picked up is coming from upstream of the silencer, and I think the engine cover does little to limit the transmission of that noise outside of the car.
Well I've certainly thought about it, but obviously not done it yet. However, my "quiet" radical exhaust is showing signs of having no packing material left as there's lots of loose material in it when you tip it upside down.
What do you mean by "in the nineties" - are you talking close to 91 or to 99? I'm guessing the latter.
And on what car and engine combo? And is it repackable?
I have a day proposed for 25th of this month where I'd need to be under 100db so thinking about options. I've always managed it in the past but I now have a different engine so it may be a bit louder this time.
What do you mean by "in the nineties" - are you talking close to 91 or to 99? I'm guessing the latter.
And on what car and engine combo? And is it repackable?
I have a day proposed for 25th of this month where I'd need to be under 100db so thinking about options. I've always managed it in the past but I now have a different engine so it may be a bit louder this time.
Edited by ric355 on Monday 7th April 19:58
I have used various levels of avoiding the truth, to claim anything up to about 8000 rpm being my rev limit, so have been tested at anything up to about 6000rpm.
I struggle to believe that free revving an engine can ever be a good thing to do, so revving it at nearly 8000 seems to lack mechanical sympathy. Maybe I need to get over myself and just get on with testing it at various different speeds!
I struggle to believe that free revving an engine can ever be a good thing to do, so revving it at nearly 8000 seems to lack mechanical sympathy. Maybe I need to get over myself and just get on with testing it at various different speeds!
After doing tests on a few different exhaust combinations I'm now of the opinion that the exhaust system isn't the problem, with the correctly packed and probably muffled exhaust silencer the exhaust is well within the noise limit, i think the issue lies else were IE noise from the engine bay, my previous car the PR6 had no issues with noise tests with the big R track day silencer so why would the SR3 be any different, i think its down to the extra space in the engine compartment not absorbing the engine noise/frequency and its this that is tripping the noise meter over the required noise limit.
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