4722 replies to this topic

[Nev]

Where do you buy your exhaust pipework from Nev?

 

All over really, mainly looking online.

 

Am still waiting for the Chinese flapper valve to arrive, it's been over 6 weeks now...

[CocoPops]

Where do you buy your exhaust pipework from Nev?

  All over really, mainly looking online.   Am still waiting for the Chinese flapper valve to arrive, it's been over 6 weeks now...

Not trackable? Who was the courier? I assume it was cheap?

[Nev]

 

 

Where do you buy your exhaust pipework from Nev?

  All over really, mainly looking online.   Am still waiting for the Chinese flapper valve to arrive, it's been over 6 weeks now...

 

Not trackable? Who was the courier? I assume it was cheap?

 

 

It's trackable: "still in transit" from China. It has another 12 days to arrive supposedly before I can launch a complaint.

 

On a more positive note, the weather is actually sunny enough to dry the roads up for a change. I might actually get out in Nipper this afternoon to welcome my dad back home, after a long stay in hospital. He was an auto-mobile engineer trained in the late 50s in London and then was in charge of many of the high profile cars (like embassy fleets) in Bombay where he owned a large workshop.

 

So I have him to partly blame for my unusual interest in things mechanical.

 

I still use some of his dusty old auto engineering books, it is surprising how advanced and in depth they go, often focusing on matters that you rarely hear about these days like nitriding and sleeve valves.

 

 

Edited by Nev, 02 March 2017 - 10:48 AM.

[Nev]

Hoo-bloody-raah, the Chinese flapper valve has finally landed on my doormat, after 2 months and 3 days.

 

It looks really quite well made. The bushes are well sealed and smooth to operate, the actuator is firmly mounted and the valve seals very well. I need to connect the nipple to a bike pump to see at what pressure it will open. The advert said it will open at 14 PSI, which is way too high for me as I need it to open at about 2 to 5 PSI.

 

[ditonics]

Everyone likes a flapper. I take it your want the valve to open automatically under boost rather than the switched route (cruse mode, race mode etc)

[Nev]

Everyone likes a flapper. I take it your want the valve to open automatically under boost rather than the switched route (cruse mode, race mode etc)

 

Yep. I've just popped into the garage and hooked it up to a bicycle pump with gauge. It seems to open quite progressively over several PSI, maybe cracking open at about 4 PSI and fully open by about 10 PSI. 

 

Luckily, I think this means I won't need to attach an opposing spring on the hinge to counterforce the over strong actuator.

Edited by Nev, 08 March 2017 - 12:23 PM.

[chris_uk]

that looks quite well made.. 

 

looking forward to seeing how this goes.

[Nev]

15 hours of work, 1 burn and 1 cut later and silencer #6 is finally getting there. I've stuffed it so full of noise diffusing stuff (SS scouring pads and glass fibre wadding) I wonder whether the bloody car will even be able to start.

 

I am expecting this one to be 1 or 2 dB quieter than the last silencer when cruising + idling (due to the extra chamber and more strict routing of gas. However on boost (with the bypass valve open) it will likely be a noisier. We shall see in a day or 2, fingers crossed.

 

With the extra valve and pipework this thing is really quite heavy, I haven't had it on the scales yet but maybe 15 Kg.

 

 

 

Edited by Nev, 14 March 2017 - 04:56 PM.

[ditonics]

Tesco: So how many scouring balls are you after sir...... Have you tried the valve in anger yet?

[The Batman]

wouldnt worry about weight if it works

[hairy]

Interested to hear this thing running Nev

[Nev]

Interested to hear this thing running Nev

 

Me too, it better be bloody quiet!

 

Just measured it's weight on the scales: 12.7 Kg.

 

For people unaware of the design I won't have the extra weight of the dogleg bend & cat & pipework, so that must save approx 6 to 8 Kg. Overall I bet my system isn't any heavier than OEM, and bean in mind mine will flow about 300% more gas, at a lower expected back pressure.

Edited by Nev, 14 March 2017 - 10:27 PM.

[siztenboots]

so the big visible opening was the input then

[Nev]

so the big visible opening was the input then

 

Nope, those pics above are with the top of the whole carcass not yet in place and the exhaust tailpipe stub showing. The inlet opening isn't visible in the last pics, it's more apparent here (top right of the carcass), where entry into the silencer is in a straightish line from under the sump (thus eliminating the entire pipework area where the cat is contained usually)

 

Edited by Nev, 14 March 2017 - 10:46 PM.

[ChrisS1]

Your welding looks like its coming along nicely

[fezzasus]

Welding is improving massively, however your design isn't. You can't expect to push exhaust gasses through loads of wadding and expect low back pressure.

[oakmere]

It does have a clear path through now when the valve is open👍. Still think the basic design could have been better using chambers like the N/A box. Though this would be more complicated to produce. Wish I had a welder and the skills.

Edited by oakmere, 15 March 2017 - 10:03 AM.

[fezzasus]

It does have a clear path through now when the valve is open👍. Still think the basic design could have been better using chambers like the N/A box. Though this would be more complicated to produce. Wish I had a welder and the skills.

 

But if it only works with the valve open, that defeats the purpose of building the silencer.

 

Chambers aren't that complicated to produce, they just tack weld in place. Nev has already built on chamber to separate the perforated pipe from the outlet.

[Exmantaa]

Maybe you can simply adapt this: http://www.ebay.co.u...hYAAOSwdGFYx~N0  

[Nev]

Bolox, I forgot to order any 10 mm steel rod in order to make the hanger brackets. This will cause a 2 or 3 day delay

 

Was hoping to go for a spin into Wales this weekend, as it is actually SUNNY here !

 

Edited by Nev, 15 March 2017 - 12:38 PM.