Elephants trunking.

[Chillidoggy]

Removed the convoluted trunking from behind the engine trim panel, air inlet duct and the restrictive steel mesh in order to replace it with something less so. While I’m on the case, thought I might as well reroute the hose and bypass the silencer.

I found the air inlet duct has been damaged, so I’m thinking of manufacturing another from GRP, as I’ve struggled to find any 85mm fittings that might do as a mould. However the trunking has taken such a set, presumably as it’s now 25 years old, that it’ll be an impossibility to get the required bend radii now. It’s solid!

Does anyone know where I could get trunking similar, as at the moment I don’t fancy paying the £120 + Vat from SJs. I’ve had a look, but failed to find any 85mm diameter, only 90mm, but I can make that fit.

 

 

[slewthy]

This any good?

https://www.ebay.co.uk/itm/Flexible-Air-Ducting-Hot-Cold-Transfer-Car-Engine-Intake-Pipe-Hose/270892010458?hash=item3f126c0bda:g:zN0AAOSwMuBcglmq

[Choppa]

No idea on the trunking but would a drain pipe fitting work for the mould?

Something like this

https://www.drainagesuperstore.co.uk/product/flexseal-85mm-to-100mm-rubber-flexible-drainage-drain-pipe-coupling.html

[sailorbob]

Somewhere on the forum, or on LotusTalk, there's a neat replacement for the trunking detailed that bypasses the silencer using a couple of silicone hose bends and an aluminium coupler. I think it was posted by MrDangerUS.

Did you find the rat that feasted on your intake adapter

[Chillidoggy]

I don’t remember seeing that fix, but I’ll see if I can find it. Hopefully the God of the TLF search function will be kind, but I’m not hopeful.

Thankfully, the offending Esprat has long since been banished and with luck, died a horrible and painful death at least equal to the pain I’ve had to endure over the past 6 years of ownership.

 

[Chillidoggy]

Found the thread - I even commented on it. Shows you how the memory is fading, eh?

 

 

[sailorbob]

That's the thread, I couldn't find it. The specific post is this one:

https://www.thelotusforums.com/forums/topic/69227-use-of-ribbed-hoses-and-its-adverse-effects-on-the-intake-air-flow/?do=findComment&comment=786605

 

[RobinB5]

If you focus on any one of the flow restrictive parts in the in the air intake system, you'll be able to identify ways in which to improve that individual item, e.g. corrugated vs. smooth pipes, less restrictive inlet grate etc. However the real elephant in the room, so to speak, is the pressure drop over the air filter which dominates the overall intake dP. If you're going to convert a given ££ into improved flow rate, that would be the place to start. 

[RobinB5]

Forcing air through a porous media to remove particulates will always incur a pressure drop. In theory a cyclonic separation approach might be more efficient (in terms of dP, similar to what Dyson pioneered), found this reference: https://journals.sagepub.com/doi/abs/10.1177/0954407017704879 don't have access to the paper and the abstract doesn't indicate which approach is more efficient (filter vs cyclone). Coupled with the fact that I don't know of any OEM who is looking into this technology does rather indicate it's not worth the increased cost. Interesting nevertheless.

[RobinB5]

Considering the first air filter was introduced 80 years ago, and there hasn't been a fundamental change to that technology since, do wonder if there's scope to consider a different approach.

[tomcattom]

I can't remember what size I used on mine. I'll measure the leftover offcut  from what I bought when I pop out to the garage later if you want.

I didn't have any hoses at all on my S4s when I bought it so I had to measure the two openings to get the right size hose and if I recall I found the air box fitting was marginally bigger than the one up by the filler flap on mine.

[Chillidoggy]

 

17 hours ago, RobinB5 said:

Considering the first air filter was introduced 80 years ago, and there hasn't been a fundamental change to that technology since, do wonder if there's scope to consider a different approach.

K&N? Green Filter? Pretty sure they function differently to a concertina paper filter. Air filtration technology exists, but there are limitations on cost and space.

Thanks for the offer, Tom, but I've ordered the silicone hoses and joiner, they should do the job.

 

[RobinB5]

@Chillidoggy, all those filters work on the same principle of forcing air through some porous media that the particulates stick to. Sure, some will certainly be more efficient than others. Only other 2 completely different methods of getting the particles out I can think of is to spin the air so they fly out to the periphery (cyclonic) or electro-static attraction. No idea if either of these has ever been prototyped? 

[Chillidoggy]

I suspect someone has already been there, and James Dyson might have a better person to ask. But as I said, cost and space in a car may well be prohibitive.

Edited July 15, 2020 by Bibs

[Giniw]

On 14/07/2020 at 20:35, RobinB5 said:

found this reference: https://journals.sagepub.com/doi/abs/10.1177/0954407017704879 don't have access to the paper

Sci-Hub to the rescue! (https://en.wikipedia.org/wiki/Sci-Hub)

Here you go! https://sci-hub.tw/10.1177/0954407017704879

 

Edited July 15, 2020 by Giniw

[RobinB5]

1.6% more power, 2.3% more torque compared to a (new) air filter. Although the size of the separator is no bigger than some of the air filter mods I've seen, the fact that it is mounted vertically would present some challenges in the engine bay!  

[Chillidoggy]

This any good?

[Chillidoggy]

The hoses arrived this morning, so I got straight on to the job. I drilled out the rivets holding the intake duct, and trimmed the new stainless mesh which has a much larger open area than the original. I ended up using some very fine wire from the wife’s beading stock to hold it in place, before applying the Sikaflex, offering it up, and re- riveting it.

Then to the hoses. I had to trim more off them than I expected to get them to sit where I wanted, and it was a bit fiddly to get the assembly in place, however overall I’m pleased with the way it looks and I imagine it will be less restrictive than before.

[Chillidoggy]

New inlet trialled today. As I’m still being a little cautious on the new engine (800 miles now), I cannot comment on any performance difference, nor would I without dyno testing. What I can say is the turbo induction sound is now much more pronounced with the driver’s window open. It sounds like something’s being sucked down a drain, which I suppose is not far from the truth. With the window shut however and cruising at the legal speed limit or below it, there was no discernible noise increase.

Moving on, and having carried out hours of internet research, I finally discovered that the rise and fall in turbo noise is known as ‘Turbo Whistle Aural Transience’, or TWAT. I’d recommend anyone keen on inlet modification carry out an extensive Internet search for TWAT. Obviously, there will be those who wear baseball caps back to front who find this kind of Increase in inlet noise addictive, impossible to live without, and yearn to bask in the admiration from their peers that a large diameter red hose brings. In this case the search should be modified to ‘Huge TWAT’. Conversely, those who aren’t really interested in any large increase in turbo noise or hose diameter or more importantly are too old to care, would be well advised to search for ‘Old TWAT‘, or ‘Little TWAT’.

I sincerely hope this information will be useful for those Esprit owners looking to make improvements to their TWATs, or, failing that, as a plausible explanation when the wife stumbles across the internet history files.

 

[jfitz981]

This is a great thread and I asked a similar question in another thread about the possibility of a better turbo air intake solution....I know our engine bay gets extremely hot so it would not be a wise move to simply put a large cone filter on the turbo due to the heat but our air intake piping is so long with so many bends....I just keep thinking there could be a better way (but I could be totally wrong). Has anyone tested or thought to maybe pipe the air intake down and to the left side rear of the car behind the engine with a large cone filter with a protective covering or something like that to reduce the length and bends of the system to get a more efficient system. Or is something like that simply not worth it....

The TWAT search flagged by my parental controls setup for my son....haha....that was hilarious. 

Hope everyone is safe and healthy.

Jason

[Chillidoggy]

Personally, and from and cost/benefit point of view, I think @CHANGESsolution is impossible to beat. The only reason I didn’t do it was due to the wife and I wanting to drive the car as much as possible this year, I’d already rebuilt the engine so spent an inordinate amount of time on the car, and I know I would also have taken quite a while over the inlet job because I’m a pedant.

Check out ‘High Performance Esprits’ group on Facebook and search Peter Harding’s posts, he’s made a beautiful job of it.

 

[jfitz981]

Awesome will do! Thank you

[strat10]

Did I miss where you got the hoses from?

[Chillidoggy]

Link is in this thread.