4722 replies to this topic

[Nev]

But is that actually due to air demand or a poorer filter support than an OEM airbox would provide? The fact that it's collapsed at the edge rather than caused the filter to rupture in the middle would suggest that it has insufficient support.

 

It wasn't braced prior to that picture (an oversight on my part), since then I have braced the filter from inside in the centre of the pannels and it hasn't collapsed since then, so I think my wooden box didn't clamp the pannel edgess as well as OEM.

 

My new design will be made from the plastic housings of actual OEM airboxes, so collapse shouldn't happen. This said though, I am still intrigued to know how much delta pressure drop there is accross the 2 pannels. Am hoping to get out tonight and find out if the roads dry up a bit.

Edited by Nev, 09 March 2016 - 03:24 PM.

[Nev]

Just done some calcs again (based on oxygen to power ratio rather than CC). Balpark @ 8000 RPM it uses around:

 

== 780 cubic feet of air per minute (thats the volume of a small room)

 

== 1.3 million litres of air per hour == 1.6 Tons of air per hour == 62 Lb/sec (which is off the map for my mid sized turbo)!!

Edited by Nev, 09 March 2016 - 03:44 PM.

[Arno]

But is that actually due to air demand or a poorer filter support than an OEM airbox would provide?

 

Yup.. An OEM airbox basically 'captures' the foam edge in a groove in the cover and then tightens that cover down hard on the bottom so the filter is in effect 'suspended' in the filter cavity. The foam edge being constrained is what lends it it's strenght, but the filter by itself is quite 'floppy' and lacks strenght.

 

Nev, your setup in itself is good, but I'd scavenge around on some scrapyards for old Vauxhall airboxes and cut-and-shut those together while keeping the filter clamping systems of the airboxes intact so the filters are properly supported in their frames.

 

Usually they are made of ABS plastic which 'plastic welds' pretty good with a simple high power soldering iron and offcuts from the boxes you take off as 'filler'. That way you could re-create your current filter housing from OEM style parts.

 

Or... Dig around in a scrapyard for an air cleaner unit from a lorry. Massive filter filter units built for 16+L turbodiesels so they can handle the airflow.

 

Bye, Arno.

[oakmere]

Go with the Lorry airfilter Nev. It would be in keeping with the inventive nature of the car.

[Nev]

Managed to get out on the motorway this morning. Though it was a bit crowded I managed to get a squirt up to 6500 RPM with heavy engine load. Much to my surprise the needle on the vacuum gauge didn't budge at all. I'd prefer to do a full 8000 RPM pull to check, but it looks like my double pannel filter setup is sufficient for the air demand.

 

Now to fabricate something out of these 2 NA airboxes (very kindly supplied by FLD, thankyou again Matt):

 

 

 

Edited by Nev, 10 March 2016 - 10:25 AM.

[siztenboots]

from memory working on HVAC, filter dirty pressure sensor was about 20pa new, 100pa dirty

[fezzasus]

Most trucks tend to use cartage type air filters, however they're likely better for packaging and typically high quality so worth investigating.

 

Example: 

 

https://www.bisonpar...ir-filter-15543

Edited by fezzasus, 10 March 2016 - 10:40 AM.

[Arno]

Now to fabricate something out of these 2 NA airboxes (very kindly supplied by FLD, thankyou again Matt):

 

 

That should do nicely

 

The frames provide the anchoring for the filters. No chance these will collapse from any pressure.

 

Bye, Arno.

[VXT Tim]

That rusty clip is making my eye twitch and shoulder raise all on its own

[CocoPops]

That rusty clip is making my eye twitch and shoulder raise all on its own

FLD is a fan of rusty clips and cultivates them specially.

[Nev]

I've looked into a truck airbox setup about a year ago, it is defo viable as it's fairly cheap & easy to buy + install. The issue is also about packaging, as I'd like to be able to use as much of my boot as possible ideally. With the 4" clean-air pipework going there as well in the next few weeks there will be barely space to even put a jacket and bag of climbing gear.

 

MrApex came round this morning (many thanks Simon) and helped me swap out a couple of ball joints on my O/S/F. One of these had a worn thread and the other was a bit worn on the joint, am keen to get out on the road and see if it's helped firm up the mild vibration I've had for a few years now. I also need to return the Nitron from that corner for a refub as it has dumped its oil everywhere.

 

 

 

 

 

 

[Nev]

The latest airbox is built. I need to either build a shroud around the entrance to each with a 3" pipe into each, or possibly find 2 existing NA airboxes and utilise the shroud side of those and install a 3" pipe into those instead.

 

 

The cardboard approx. show where the shroud would need ot be with 3" pipe in the centre:

 

 

[Nev]

I've finished making the airbox, it took quite some time, all the glueing and filling of the asymetric plastic to 4mm plywood, with 2 x 4" inputs (squeezed to ovals to help reduce the unit size) and a single 4" output to feed the inlet tract. It's surprisingly light and bonded with black accrilic which will hopefully cope with the temps in the boot.

 

I have some 4" flexi tubing on the way to me, once that arrives and the weather forecast looks like rain for a couple of days I will take the rear clam off and install it all. I am hoping to route the 2 input flexi tubes via the boot and over the N/S/R arch liner, so that the air from the N/S ear can feed the 2 pipes. Thats the plan, but am not sure there will be enough room for 4" pipes, so might have to recude them down to 3".

 

Once again, many thanks to Matt (FLD) on here for providing the 2 OEM airboxes for free, to get his project going.

 

 

 

Hopefully once installed, it will stop the poor airfilter trying to suck in the prodigious amount of dirt the car seems to pick up around its back end:

 

Edited by Nev, 18 March 2016 - 03:23 PM.

[VXT Tim]

Round of applause for the level of dirt

[hairy]

Round of applause for the level of dirt

 

Blimey Nev, you been driving Nipper through a slurry pit?

[FLD]

Looking good nev. Exactly what I had thought it would be.

[Nev]

 

Round of applause for the level of dirt

 

Blimey Nev, you been driving Nipper through a slurry pit?

 

 

Not particularily, I does seem to get rather dirty, probably becuase I drive it on country roads I guess. Probably only 2000 miles or so since I washed it, might treat it to a sponge down when the wether gets warmer.

[CocoPops]

Most of it is probably the soot you're kicking out? The vx also very susceptible to a low pressure area there, hence it all sticks to rear clam.

[hairy]

It looks like a Moonland though!

[Nev]

It looks like a Moonland though!

 

The silver lining ?!

 

The girlfriend is complaining, she's just washed a load of our clothes and is complaining that my her knickers smell of oil and fumes due to contamination from my garage/driving clothes. I told her to "enjoy" my signature smell !