Ideas to reduce exhaust noise

[db484bhpv8]

I intend to be at a standing mile event at Elvington next tuesday and the noise limit is 101db static.
My car is about 105 last tested at 4500 rpm.

So i need a couple of ideas to reduce the level that i can impliment this weekend.
I cant refit my cat pipe. I do have removable tail sections from just behind the box.

[Richard 858]

ACT trackday silencers should do it I'd have thought.

[clive f]

are you using the standard silencer Derek?

[fatboychim]

These fellers should do the job, I've got a pair (of silencers) if you want to borrow them.

https://www.merlinmotorsport.co.uk/knowledge_base_...

[Richard 858]

fatboychim said:

These fellers should do the job, I've got a pair (of silencers) if you want to borrow them.

https://www.merlinmotorsport.co.uk/knowledge_base_...

The ACT ones are similar. I've got a pair you're also welcome to borrow, got them 2nd hand, hardly used and haven't used them myself yet. I'm up at a wedding in Harrogate this weekend and can bring them with me if that's any use.

[jojackson4]

Turbo
May not be ready for next week

[griffdude]

Repack the main silencer? Cut it open & repack with something like this-
http://www.btbexhausts.co.uk/section_details.asp?S...

[Pupp]

jojackson4 said:

Turbo
May not be ready for next week

Or even the week after...

[Richard 858]

Pupp said:

Or even the week after...

...or the week after that.....

[db484bhpv8]

clive f said:

are you using the standard silencer Derek?

My system is full decat with a lovely Y piece and the box is semi sleeved.
So its quite loud.

I just had it confirmed that the test at Elvington will be 105db static 3/4 revs. Maybe they will believe me my max is 4500

I think it will be borderline so just need something in place just in case.
Whereabouts are you Richard? Harrogate is on the way for me. Just wondering if you could leave them with someone near there and io can collect them early on the Tuesday on the way.

[QBee]

Surprised you are even as low as 105dB Derek. Mine is similar except its 5 litres and I have the standard exhaust, and mine reads anywhere between 102 and 108 dB depending on atmospherics, the proximity of buildings and which MSV track is measuring it.

If you fancy a detour to Newark I have a spare standard exhaust we could swap in. I have little doubt that my local garage would loan us a ramp, ditto Willow Sproutscars, who are local.

Alternatively I have a pair of ACT track day silencers you could borrow, like the other guys on here, and could post or courier them to you for a few quid. They knock about 4dB off and soften the sound, and they also convince the track guys that you are serious.

PM me if you are interested in either solution. I will check the price of post/courier this morning, but it will be around the price of 20 miles detour fuel I imagine. Just convince yourself that Elvington is slightly further away.....

[db484bhpv8]

QBee said:

Surprised you are even as low as 105dB Derek. Mine is similar except its 5 litres and I have the standard exhaust, and mine reads anywhere between 102 and 108 dB depending on atmospherics, the proximity of buildings and which MSV track is measuring it.

If you fancy a detour to Newark I have a spare standard exhaust we could swap in. I have little doubt that my local garage would loan us a ramp, ditto Willow Sproutscars, who are local.

Alternatively I have a pair of ACT track day silencers you could borrow, like the other guys on here, and could post or courier them to you for a few quid. They knock about 4dB off and soften the sound, and they also convince the track guys that you are serious.

PM me if you are interested in either solution. I will check the price of post/courier this morning, but it will be around the price of 20 miles detour fuel I imagine. Just convince yourself that Elvington is slightly further away.....

Thanks for the offer Anthony. You are a little out the way but dont be suprised if i am asking for your address on here Tuesday morning and heading your way

[QBee]

You are most welcome, Derek. I can put you up Monday night if it makes life easier. With a little warning I can try to pre-book a ramp at Willow or my friend Nigel's - his restored 1950s Humber is a joy to behold.

My 5 litre, similar spec to yours except for standard exhaust, with ACT cans bolted on is normally around 99-101dB and has never made more than 103dB that being at Bedford on a day when everyone was failing due to atmospherics, even PetrolTed in his Dyson powered Pork Pie GT3RS.

The courier to get the cans to you would be less than £6, two day delivery, if you go for that option. Just need to know by Tomorrow, as to get them to you by Monday means getting the courier sorted ASAP.

I'm 86 miles south of Elvington, half a mile off the A1.

[db484bhpv8]

QBee said:

You are most welcome, Derek. I can put you up Monday night if it makes life easier. With a little warning I can try to pre-book a ramp at Willow or my friend Nigel's - his restored 1950s Humber is a joy to behold.

My 5 litre, similar spec to yours except for standard exhaust, with ACT cans bolted on is normally around 99-101dB and has never made more than 103dB that being at Bedford on a day when everyone was failing due to atmospherics, even PetrolTed in his Dyson powered Pork Pie GT3RS.

The courier to get the cans to you would be less than £6, two day delivery, if you go for that option. Just need to know by Tomorrow, as to get them to you by Monday means getting the courier sorted ASAP.

I'm 86 miles south of Elvington, half a mile off the A1.

Thanks very much Anthony. I think i might get away with 105db now.
It would be a shame for you to go to the bother of posting them and me posting back if i didnt need them or if they didnt fit.
How do they attach btw? I made my tailpipes myself and they are a little larger bore than standard.

[clive f]

not much help as a quick fix, but long term you could open up the silencer box and fit a cross piece, but made in perforated pipe, then pack with wadding, allowing the gases to mix in the cross pipe helps reduce the noise and on the plus side does not cause a restriction or loss of power, a lot of guys with loud classics have been doing this n the states since they have lowered the db on some circuits other there and have found a cross pipe helps cut down on noise but not on power, maybe a perforated version in the silencer will work as well?

[db484bhpv8]

clive f said:

not much help as a quick fix, but long term you could open up the silencer box and fit a cross piece, but made in perforated pipe, then pack with wadding, allowing the gases to mix in the cross pipe helps reduce the noise and on the plus side does not cause a restriction or loss of power, a lot of guys with loud classics have been doing this n the states since they have lowered the db on some circuits other there and have found a cross pipe helps cut down on noise but not on power, maybe a perforated version in the silencer will work as well?

Sounds like a good plan for another Winter job Clive. I also want to squeeze in my remote bypass valve at the bottom of your Y piece. Then i can have the best of both worlds

[QBee]

db484bhpv8 said:

Thanks very much Anthony. I think i might get away with 105db now.
It would be a shame for you to go to the bother of posting them and me posting back if i didnt need them or if they didnt fit.
How do they attach btw? I made my tailpipes myself and they are a little larger bore than standard.

They slide over the standard tail pipes and have a U clamp with a nut on each end to hold them in place. If you have enlarged your tail pipes they won't fit. They only fit the 2.5 inh standard pipes. You can buy them in a variety of sizes from ACT.

They will of course fit my spare standard exhaust.

[Richard 858]

Dereck, I forgot to say, YHM !

[db484bhpv8]

Richard 858 said:

Dereck, I forgot to say, YHM !

I got it thismorning and sent you a text.
Thanks very much Richard.
Our TVR community is the best

Lets hope i can do the Chim boys proud and hit 170

[Richard 858]

No problem Derek, speak Saturday.