Resonance patch

steveO
Posts: 80
Joined: Mon Oct 01, 2018 2:08 pm
Location: Calgary

Re: Resonance patch

Post by steveO » Sun Sep 05, 2021 3:17 pm

Hi Andy,

I think I will do your mod with 2mm plate. Should have done it sometime ago.
Sound deadening will only change the frequency of a vibration not remove it, but still worth doing. The tunnel is the main structural member of a Triking so I am going to try the flexing test and loosening and retightening of the drive train.
I have been practicing my puddle welding fitting new floors to my MGB so welding on the Triking will be a doddle, must remember to disconnect the electronics first.
Steve

Simon.gk
Posts: 31
Joined: Tue Feb 16, 2021 4:42 pm
Location: Nova Scotia, Canada

Re: Resonance patch

Post by Simon.gk » Mon Sep 06, 2021 4:55 pm

So now I have a lost of suggestions as to how best to tackle the resonance issues. I can live with the present level of noise as it is not a constant and, I suppose, I could always go slower.
This does open the door to the next part of the noise questions. I have reverse megaphone Norton style silencers and in general use, just puttering about, they are ok. If I actually exercise the Guzzi motor they are really loud, almost approaching the dreaded Harley level according to others.There is a strong rasp on the overrun and I wondered if that was contributing
I do like the look but used to love the sound of the Lafranconis on my Le Mans and am wondering if going that route would be both quieter and help with the resonance.

My Lotus manual states the following: Noise and vibration are a normal and necessary feature
of a mechanical device such as a motor car. The nature and extent of such noises, including brake squeal, engine and exhaust noise, gear whine, knocks, rattles and wind noise will differ from car to car, with the level of acceptability being determined by the Company.


Maybe I should worry less and just enjoy the journey.

DSU475
Posts: 66
Joined: Wed Sep 26, 2018 4:23 pm
Location: Worthington, Leicestershire.

Re: Resonance patch

Post by DSU475 » Wed Sep 08, 2021 10:19 am

SteveO

Hi Steve,
I gave the precise dimensions to a local engineering company, who used their laser cutters to do the job for only 18 of our English pounds. The plate also provides a stronger mounting surface for the prop shaft cover. I would happily give you the dimensions, but not sure if MY plate would fit YOUR car ?

Kind regards,

Andy.

steveO
Posts: 80
Joined: Mon Oct 01, 2018 2:08 pm
Location: Calgary

Re: Resonance patch

Post by steveO » Wed Sep 08, 2021 3:34 pm

Thanks Andy,
Think best to measure my car as all hand built.
Thinking of getting a piece folded so it covers both top surface and extends down the sides some what.
Will need to take account of the centre bearing, but can mill the base down to compensate. Also thinking folded angle might work along the top edges of tunnel will stiffen, but the handbrake slot is so close to the edge it would weaken the angle and defeat the objective so a plate across the whole top surface as you did is the way to go. Did you extend it down the sides?

Did you ever sort out your fuel sender?

Thanks
Steve

DSU475
Posts: 66
Joined: Wed Sep 26, 2018 4:23 pm
Location: Worthington, Leicestershire.

Re: Resonance patch

Post by DSU475 » Thu Sep 09, 2021 8:46 am

SteveO

Hi Steve,
I had considered a fold on both sides, but as you say it would be awkward on the prop shaft side because (on mine anyway) the top plate overlaps the vertical plate by about 1cm. I decided that a flat plate fully welded at each bulkhead and tacked along both sides would be more than sufficient, this has proved to be the case.
The sender unit is still a work in progress, no-one has been able to identify it, partly because it was originally modified to suit the tank. I've tried parts supply specialists for Triumph, Mg, Lotus etc. I have a number of options (1) I could remove it, blank off the hole and fit the later Triking unit that mounts to the top (2) Leave the original sender in place, still use its fuel delivery pipe, but fit a generic sender to the top of the tank (3) Have the original sender repaired.
I am currently looking into having it repaired.

Regards,

Andy.

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