4722 replies to this topic

[FLD]

Have a look at the Birchills catalogue Nev, they supply parts at a sensible price.  Do be careful when ordering though, you need to be specific as they are really arsey about returns.

 

Nice welder, looks just like mine

[Ormes]

Welder... hmmm... nice... I want

[Mopeytitan]

That design looks fairly familiar... Remember if you ever need anything give me a shout I'll see what I can get you. :: same goes for welding if you want a hand I'll make sure I'm free.

Edited by Mopeytitan, 24 July 2015 - 05:01 PM.

[CHILL Gone DUTCH]

Welder

Yesterday I finally got round to buying the welder + gas I've been promising myself for 3 years or so. I bought an R-tech one based on good internet feedback, 2 year waranttee that is actually upheld, a couple of recommendations from people I know and the fact that the company is local to me.






Some of my first aluminium welds:



The objective is to learn some man skillz and to build a few miscellaneous things like a breather tank and importantly an exhaust that can get noise down below 105 dB, ideally below 100 dB.
 

 
Exhaust Design
 
This is my initial design/experiment made from 3" tube and sheet steel. It differs in design from any standard exhaust box for the VX220, this will reduce extra unnecessary pipework (weight) and make the gas flow round less bends.

Entry into the box will be perpendicular to the box, this eliminates 180 degrees of extra bend (where the OEM system routes via the cat into the side of the OEM box). On initial entry into the box the stream will be split by a Y-pipe with the top and bottom split mounted on a vertical plane. Then internally, the 2 paths of exhaust gase will travel down perforated pipes with bends, one path higher up in the box and one lower down in the box. This will naturally lead to the tailpipes which will exit the box in the standard config.

I plan to make the box very long, fairly wide and deep, such that it has a large volume. There is an option to possibly fit an electrically controlled butterfly flap and straight through pipe from the inlet Y to one of the tailpipes. This would yield almost no noise cancellation, but the maximum power, noise & flames. A switch could be mounted on the dash to open/close this config. The issues are I don't know if I can trust the longevity of these electro-mechanical butterfly flaps and also it will make the car run lean as there will be less back pressure (perhaps this can be dynamically mapped with some enrichment "flag" when the bypass switch is activated).

My design/thinking is the advtanges of this design are:

1. That splitting the exhaust into 2 flows internally will halve the exhaust gas speed giving more time for waves to bounce out.
2. Two paths (roughly a mirror image of each other) might help cancel out noise waves.
3. There will be a lot of perforated pipework (much more than any usual straight though box).
4. Box ends will be resealable, perhaps double skinned as the gas will be striking the ends the most.
5. Bends in the box will be made from sectioned perforated pipe (probably).
6. All internal pipes to be wadded.



If you have some useful input/suggestions, please fire away....

Nev as you not putting any back boxes in why don't you just run it straight out as straight as possible as all I can see is restriction in the design
Maybe it's diffrent on a turbo
But I no if noise wasent a issue I would be running it straight as possible the only reason I don't is to accommodate silencers and back boxes ??

[darronwall]

noise don't matter,its not like its going to see a track is it?

 

[Kieran McC]

I have a gasless welder it does most jobs apart from aluminum, You do need a Argo gas welder to weld aluminum

[turbotoaster]

its interesting your struggling with noise so much while being turbo'd as that acts as a natural silencer, you have seen mine which is basically bolted to the turbine housing and its 94db static noise test and no issues at all with drive by, my friend said it was one of the quietest cars on track at oulton.

 

what size is your current exhaust that your having problems with, are you sure all the baffles are still intact?

[stu8v]

My Larini measures 101db Again on a vxt. I can see me having to replace it soon...

[oakmere]

Chill That picture is the back box well the inside of it anyway😂

[CHILL Gone DUTCH]

Stupid me Lol I thought that was something else lol

[Nev]

Welding 1.5 mm aluminium is tough and has taken quite some time to even vaguely achieve. However, my basic skills (mainly adjusting the welder settings to suit the material) are coming along:





With some bodging, grinding, filling + painting, the first offering to Nipper is a new bespoke breather tank with internal baffles. This will (sadly) be replacing the pickle jar breather tank he has had for the last year or so:

Edited by Nev, 26 July 2015 - 01:07 PM.

[Ormes]

Nice RIP pickle jar.

[Nev]

Woe woe woe, the pickle jar is now out and the shiny new blue breather tank is in; in fact it looks too shiny for my engine bay. As I feel this is a sad day, I may keep the pickle jar as a memento on the mantle shelf in the lounge, just to remind me of it's gloriously functional splendidness !

Edited by Nev, 26 July 2015 - 07:04 PM.

[Zoobeef]

Where did my post go from earlier!?

 

I don't think you should grind off the welds on ally. (May be wrong, I'm not a weldist)

[Nev]

Where did my post go from earlier!?   I don't think you should grind off the welds on ally. (May be wrong, I'm not a weldist)

I have a special subroutine to eliminate your postings, it must have crashed and let your last one on accidentally You are right about grinding welds in general I am sure, but on a glorified tin can like this I don't think it affect it as it has almost no pressure/stress on it. My next thing I have to fork out for is a chop saw of some sort. Ideally I want a cold saw, but in practice I'm likely to get a friction/grinding disc saw as they are way cheaper to buy and fit new discs. Once I get that I will be in a position to section up bits of exhaust pipe.

Edited by Nev, 26 July 2015 - 07:36 PM.

[Mopeytitan]

[quote data-cid='1806584' name='Nev' timestamp='1437938709' post='1806584']Where did my post go from earlier!?
 
I don't think you should grind off the welds on ally. (May be wrong, I'm not a weldist)[/quote]
I have a special subroutine to eliminate your postings, it must have crashed and let your last one on accidentally

You are right about grinding welds in general I am sure, but on a glorified tin can like this I don't think it affect it as it has almost no pressure/stress on it.

My next thing I have to fork out for is a chop saw of some sort. Ideally I want a cold saw, but in practice I'm likely to get a friction/grinding disc saw as they are way cheaper to buy and fit new discs. Once I get that I will be in a position to section up bits of exhaust pipe.[/quote]



My post had gone aswell!!! Grrrr!!!

Edited by Mopeytitan, 26 July 2015 - 09:18 PM.

[Nev]

My post had gone aswell!!! Grrrr!!!

Yea, my subroutine also victimises owners of very loudly painted cars LOL

[Mopeytitan]

[quote data-cid='1806643' name='Nev' timestamp='1437979992' post='1806643']My post had gone aswell!!! Grrrr!!![/quote]
Yea, my subroutine also victimises owners of very loudly painted cars LOL[/quote]

Fair enough, I get that

[FLD]

I got one of these Nev.

http://www.chesterho...dsaw-4100-p.asp

I took it off the stand and mounted it on wooden blocks on the bench top.

[Nev]

I got one of these Nev. http://www.chesterho...dsaw-4100-p.asp I took it off the stand and mounted it on wooden blocks on the bench top.

Hmm, a few questions if you don't mind: 1/ Any idea roughly how many chops through 3" steel pipe a band would do before it got blunt? 2/ How much are new bands please? 3/ How accurate is the mitre, can you measure it within 2 degrees reasonably easy? 4/ Is the clamp big enough to cope with gripping 89mm tube? Thanks.