To scoop or not to scoop?

[Dr. FrankenRex]

I paid less than Ed for a real one

[Keke]

[Eddie_r32]

So took the car out last night and she still flies, nothing negative about the performance to say at all. If I was to fit again I would look at trimming the "exhaust" about 5mm as it is pushing on the bumper a bit too much.
I would prob get the dremel and trim the l bracket up so the bolts can slide forwards and back in the l bracket, fix to car wity just those, test fit bumper and then do final fix, if that makes any sense!

[nightfire10]

So took the car out last night and she still flies, nothing negative about the performance to say at all. If I was to fit again I would look at trimming the "exhaust" about 5mm as it is pushing on the bumper a bit too much.
I would prob get the dremel and trim the l bracket up so the bolts can slide forwards and back in the l bracket, fix to car wity just those, test fit bumper and then do final fix, if that makes any sense!

Is it any better ? Sound better ? Is it worth doing basically

Sent from my SM-G930F using Tapatalk

[Eddie_r32]

I it's now quieter for me as I had an Aem screaming away, for 100 quid and a couple of hours of your time I'd say it's worth doing, may feel more benefit going from stock intake to this than I have going from Aem to this

[New Duke]

Pics again

Hi Eddie,
Looking at your pics I wondered if you did anything to fill the gap between your new scoop and the airbox housing? I've expertly annotated one of your photos to make it easier to explain.

My understanding is that the stock airbox (which I've never had) slots around the VFAD meaning that even when the VFAD is removed and the ram scoop is fitted to line A, then the stock intake extends out to line A anyway. Meaning that there is a seal and all scoop air enters the intake. That's what the Racing Beat instructions suggest anyway.

But on our aftermarket intakes the gap between lines A and B is left as a cavity with the VFAD removed so some airflow can escape under the car and not make it into the intake. Do you have any plans to sort that? I'm looking at options ranging from chopping up a VFAD and sticking a section of it in there to plug the gaps, to taking measurements and having some plastic ducting custom made.

Or... I may just leave it. So curious what you though about it, if it bothered you at all!

[Eddie_r32]

Nice 'tache

I have been thinking about this, I will join them up next time I have the car in bits. I think I may use some neoprene sheet, bit of velcro and some cable ties.

I'm sure there is a better way but I think it would work ok

[Eddie_r32]

I used the original VFAD housing/hose

P6230386.jpg

A tab made of duct tape allows you pull it back to seal with the original airbox

P6230387.jpg

Where it's held by a couple of stainless self-tapers

P6230388.jpg

You can also remove the clip for the vfad vacuum hose, which makes removing the airbox much easier*

P6230389.jpg

*This is also a great tip for all 192 owners, who don't have a vfad but they do have the clip that gets in the way.


See also viewtopic.php?f=30&t=44692

[Eddie_r32]

Anyone who takes the plunge, 2 of these are going spare for a voluntary contribution

[NeMFO]

Ok, I would welcome your thoughts on a plan that I have been hatching. I now have two front bumpers and am considering butchering the tatty one to have as a track day bumper with brake cooling ducts and a ram air opening straight in front of the stock air box.

Please feel free to check my maths but I have calculated that our engines ingest approx. 3,900 litres of air during 9000 revs (1300cc x 3000 as we get one bang per revolution so 3 revolutions for full displacement have I got that right?) which is presumably at slightly less than atmospheric pressure because it is sucked not pushed into the engine. I'm no engineer but I have read that turbos deliver around one atmosphere (14psi) of boost so I was looking to double the available air at high speed because I was a little disappointed with the top end at Bedford. I believe that I would be covering 213,333cm per minute at 80mph so an intake with an area of 37.5 cm2 (5cm x 7.5) would give me 8,000 litres per minute.

I'm sure there are some practical considerations to address, (sealing the intake tube, not blowing the air filter out and anything else you might want to suggest) but is this a stupid idea?

[delta0]

There is a ratio between the rotors and the elliptical shaft that means the rotors spin less than this. The rpm is measured at the shaft as it is for a conventional engine.

[350matt]

a good measure of how much air the engine is consuming is the MAF sensor
flat out it reads 220g/sec


so 220 grammes / sec = 6 cubic feet / sec = 360 cfm & 25 lbs/min = 13.2 kg/min = 792 kg/hr = 0.22 kg/sec

so to actually boost over this amount air to get some appreciable ram effect will need a substantial scoop and over 100mph

[warpc0il]

Most "ram air" systems don't provide enough positive pressure to qualify as forced induction.

How they increase power is by reducing some of the parasitic loss, normally referred to as "pumping loss" which is the energy that it takes to suck the charge into the engine.

Even the slightest positive pressure means that the engine no longer needs to suck and all that energy is available to drive the wheels.

This is a slight over-simplification but sufficient to understand the advantages.