seanks

When fitting a FMIC and obviously removing the TMIC. Got me thinking that the air flow from the Scoop may well adversely affect the flow of air in the engine compartment, reducing the efficiency of the FMIC?

If that's the case is there not a replacment for the Scoop (bit like EVO) to improve the flow? To act as an exhaust from the engine. Or how about all FMIC Scoobs fit Sport bonnets?
Just a thought as the Scoop is a bit of a signature trademark of the Scoob but...

StickyMicky

fit a reverse scoop

ets are doing them now

dooluck or doluck from japan have been doing them for a while

my mate says the bottom half of his windscreen stays dry when on the move in the wet with his reveresed scoop, so i asume they work?

richiewong

fatmanscooby had something like that on his Type R

http://bbs.scoobynet.co.uk/showthread.php?t=411835

FB Tuning

iTrader: (30)

I've got a hybrid on my car, and have kept the bonnet scoop in place.

Air passing through the scoop cools the last section of hard pipe before the throttle body, which is obviously beneficial.

Fuzz

but it pressurises the engine bay....

If it does that then less air will travel through the FMIC in the first place.

I think the classic shape needs to keep some sort of bulge on the bonnet to look right but a backward facing scoop or lifting the rear of the bonnet will help.
Something I have yet to try out but it is on the list.


Andy

StickyMicky

crap pic



but this car has the reversed bonnet vent which i spoke of

FB Tuning

iTrader: (30)

I really don't think that's the case...

Surely the downdraught of air through the scoop is helping to draw air ingested at the front of the car backwards through the engine bay?

Anyway, the air passing through the intercooler at the front of the car then has to travel through the aircon condensor (if fitted), then the radiator, and then it will 'hit' the front of the cambelt covers, stopping dead in it's tracks. IMO this is the major restriction.

The bulk of the air can then only travel up or down - If your undertray is removed, most of it will just go down and exit under the car.

If the undertray is still fitted, and the air is then travelling over the top of the engine, the negative pressure created under the bonnet, infront of the scoop will assist the air's passage towards the rear of the engine bay and down the sides of the gearbox tunnel

It would be interesting to rig up some sort of airflow sensor behind the front mount and do some tests with and without a bonnet scoop

Has anyone monitored charge temps with/without the scoop?


Richard

360ste

iTrader: (1)

I am in agreement with richard that the airflow through the scoop causes a slight vaccum over the top of the engine assisting airflow. When I fiited my FMIC I thought that the engine would run slightly hotter due to the air going through the intercooler first. Wrong it actually runs cooler even after a good booting. I am actually looking at a GRP bonnet with RS Turbo (sorry for swearing on scoobynet) style bonnet vents to aid airflow further.

Steve

tath

on a related point, anyone know if you can get carbon fibre bonnets with no scoop?

VAL113R

I have a classic wrx with a fmic

The car is a 93 and I fitted a facelift front end including a sport bonnet.

I had the car mapped by Andy F last week and the car seems fine with the sport bonnet. I was a little worried about heat and the induction kit at first, but it seems fine.

At the moment the car is red with a yellow bonnet, blue grille and green bumper ! It's away in the garage getting painted now so will take a few pics when I get it back.

I quite like the sport bonnet. The car becomes a "sleeper" as such as most people will assume it is a 2.0L N/A

cheers

Cret

Why not get a section made so that instead of the scoop just sending air into the engine bay you could instead have ducting to direct it at a pod filter as a really good cold air supply?

On the legacy for instance the scoop already is ducted sort of like this because the 'intercooler' (chargecooler) is water cooled so the air from the scoop is directed over to one end of it and onto the turbo chimney.

Warwick-hunt

heres another if not the same one, certainly an interesting idea

RaymondH

I asked this question ages ago and Bob Rawle, I think it was, replied saying that tests had shown that intake charge temps were significantly lower with the scoop open than they were with it blanked off. I compromise now and blank the scoop off in winter to keep the crap off my shiny bits and replace the blanking plate with a fine wire mesh for the rest of the year.

FASTER MIKE!!

does'nt it cool the turbo?

mickywrx

iTrader: (29)

does'nt it cool the turbo?


I believe it does but i could be wrong. And i don't know how to do the quote thing but thats another story.

StickyMicky

it helps cool the turbo, yes

mickywrx

iTrader: (29)

wooo hooo, i got something right. I am the genious that i keep telling wor lass i am.

mgcvk

Reverse scoop looks completely terrible.

cookstar

iTrader: (6)

When i do take the plunge and get a fmic i will retain the scoop and place an oil cooler in place of the tmic.

Functional and looks cool.

chrome

if you do that cookie- make sure you put some mesh or something over it to protect the oil coller rows from incoming debris/birds..
I know of two cars that killed their engines when they decimated their oil coolers due to no protection!

Jake

Thought it sounded like a good idea until I saw the pic! what a mess.

StickyMicky

Fangoria

iTrader: (1)

Fuzz

Can you explain how having the scoop with an FMIC pressures the engine compartment and is thus a disadvantage

With the engine temps of my car there would be no way that I'd be stupid enough to either reverse the Scoop or blank off - I like temps to be as low as possible in the engine compartment and the Scoop does that job relatively nicely - without it my engine and intake temps would suffer badly!

cookstar

iTrader: (6)

Hadnt thought of that, but its not going to be for a while yet, will need lots of thought before doing the job me thinks

harvey

iTrader: (48)

Thinking that no scoop would improve aero dynamics after fitting a front mount, I did a series of experiments. This included the blanking off, of the existing scoop, the complete removal of the scoop and blanking off and the reversing of the scoop.
Rather than bore you with great detail, the conclusion was that under bonnet temperatures would rise signifigantly if the scoop was removed, blanked or reversed.

I also found that temperatures would rise if the under plate was removed although I carried this work on and made an improved design underplate from carbon fibre which is now on one of my cars to cater specifically for the needs of that engine bay installation.

I investigated air flow over and under the bonnet in some detail.
On the O/E system, air comes in at the front, through or round the radiator and from between the headlights and bonnet and then over the engine and down the transmission tunnel.
The biggest source of heat is from the turbo exhaust side so it is best to insulate that but keep the compressor side cool and retain an ambient temperature air feed to remove excess escaped heat. The scoop on the O/E set up does this well.

Anything that interferes with the flow path above, is probably a bad thing.
Removing one or other or both blanking plates to open up the vents on the bonnet also results in an increase in under bonnet temperature, much against what many people believe and might first be thought. The top of the bonnet is a low pressure area so you are not letting air in but pulling air out which must disturb the intended flow path.

There is an exception to this however when you make a cold air divider. If the filter area is supplied with adequate cold air from the front or underside of the car, using for instance a large brake duct to feed cold air to the filter, then removing that part of the blanking plate that is in the cold air divided area only, result in encouraging cold air to flow into the area and over the filter to exit by the exposed louvers.

All very interesting and I doubt it adds a lot of power but there are some installations I have seen that must result in high under bonnet temperatures and that must be a bad thing.
Keep it cool, keep it safe.

StickyMicky

do the wrc cars run with the side vents (much larger in size) open?

or are they a purley cosmetic thing?

if they run with them open do they blank the centre one off?

coulty

oh and why do mitsubishi evos have a mesh so that the air goes through their fmic and out the bonnet?

seanks

This was Haldours car at TOTB on Sunday (pic from Mr. Palmer), pretty much sums up what I was thinking?

FMIC with louvered escape vents in bonnet as per evos?

StickyMicky

are they wheel trims

seanks

Yup, had some light weight kevlar tie-wraps holding them on good and tight 8D