Bomber

I wish i had an extra bit of room up front - there is bugger all room for this thing:



Still - the whole car is one big R&D exercise - so why not eh?

AlexF

another MGF fan

AlexF

that the issue I have - just worse...

vibrating_cake

okay i know im a newbie to passionford but....
boot mounted radiators, VERY good idea, freeing up space for a large intercooler up front where the radiator used to be, with adiquate heat shielding (for the turbo) and a nifty oil cooler controlled via thermostat would keep things nice and coool.

anyway, back to the design, i'd like you to look up "ground effects" on cars, and diffusers/splitters

diffusers are the big things on the rear of most DTM cars, *runs around and looks for pics*




the purpose of the diffuser is to control the travel of air from the bottom of the car, up to meet the air that runs over the top of the car.
this creates less drag and reduces natural lift of a car.

now, here we have a situation which includes fast flowing air thats going underneath the car and past the boot floor anyway.

with reference to picture 1, whats that centre section you ask, blocking flow.
well, add a radiator there, no need to have the rad mounted internally in the boot, have it mounted externally under the rear of the car in a large diffuser.
for 1, this reduces drag and lift
for 2, this is a place of fast flowing air

problems being stonechips, so a grill would need to be manufactured to protect the rad.
heat when sat, fans must be added if the car is to be used on the road, in traffic jams etc.
and suspension travel must not "bottom out" on the rad, or this could cause a big ass leak.


either that or mount the rad in the centre of the boot facing vertically to the back of the car.
cut loads of holes in the bootlid centre and find a way to get air into the car, naturally the air will flow out into the vaccum caused behind the bootlids vertical face as it always does, this also reduces drag and aids flow to the rad, win win.
its also safer

GARETH T

Bomber

by all means have a go,,, but be prepared to do a fair bit of trial and error to get the temps right! as your playing with a Mk2 fiesta,,, buy a shitter and cut that one to bits and test before doing you own

keep us informed as well

Bomber

Thats not tight...





I feel your angst! There is no room for anything

GARETH T

vibrating_cake

diffusers are only 10% of the underfloor aerodynamics

Turbosystems

iTrader: (5)

no mgb fan it's my age

Bomber

Its a mk1 - so 2" shorter in the 'bay than a mk2.

So double

GARETH T

that engine looks great all together! how much BHP you looking at?

vibrating_cake

just a thought not for aerodynamics sake but they look cool and the upward lip could be used to mount 1 or 2 not so tall rads in, horizontally in an area of lots of flow of air

AlexF

yours has all the bits on the engine!

Mines missing a few parts:

IC
Alternator
Exh down pipe

oh and the rad



Alex

Bomber

Well that one blew up at Field Motorsport when they were live mapping it! (they built it). They used a brand new Focus block - that blew a 1" crack in cylinder bore wall on number 1. Upon inspection there was a casting defect in the water jacket - so it was either new block (again) or fit liners - i chose to fit the liners and never have to worry about it again.

So its all built up with a new inlet (i think me and Gus are having the same inlets) and Nikasil liners. It has Focus WRC rods and Pistons in it.

But I have got Christians old tubular manifold, Tial gate and T3/60-1 (.70 cold side - .48 Hot side, 360 blades and a Stage 3 shaft) to go on during the winter time when its garaged.

I was told it should be on the Dyno today ... but I don't believe things until I see them.

In its original form i was told by fields that it would be well over 300bhp - but now i can run some serious boost anything is possible.

Happy times!

AlexF

so about 200bhp then

GARETH T

i mapped a MK2 fiesta last week with big BHP and i must say,,, its fuckign stupid quick

Bomber

250 - 260 bhp ATW would be nice. But tbh i'll be happy just driving the damn thing.

Bomber

Ginges one?

Luca

iTrader: (2)

im thinking - stick the thing in the roof - game set match lol


Options are endless with this, the bst option i feel is to vent the air out of the rear of the car with the rad being complety encased as to keep air flow at its best the air should force / suck itslef out.

The flow under the car mainly is cool air... other than from heat from transmission exhaust and turbo which vents underneath.

With the set up similar to a rs200 with roof vents to intercooler this set up could be fiasable too.

Like we have said , trail and error is the key to the game.

Im liking the thought of all the room up front for a large intercooler but this rear mounted rad situation is rather more complex than first thought.

Its something i have to do and feel function should always superseed fashion.Its just the flowing of air to the rad thats crucial - getting rid of it out the back is the easy part. The naca ducts in rear side windows will aid in pulling air through also.

I do think that up front most of the rads temps is due to heat soak from engine and turbo....

Thankfully a friend knows a guy running a golf mk2 with a 20v t in it who is developing a rear mount rad also... So i shall make a call him to and get some snaps

GARETH T

yes mate,,, the big ginger cunts one

Luca

iTrader: (2)

Gearbox is the key to it mate light car and power dont mix to well.

I have quaife box now and 235 bhp 790kg.....

cannot get it to wheelspin at all.. which is great..

Double that with the new engine and we could be having problems..

Bomber

I want to use an MTX75 box

But i'd need to see about the Cable linkage, driveshafts and Hyd. clutch.

First things first though - and thats the Rad!

AlexF

a piece of 2" pipe and a duct will flow SOOO little air compare to what you need...

think of the entrance and exit space a std rad has on a MODERN car - what gives you an idea of the areas required.

Alex

Bomber

Agreed.

But what about the increased capacity of the cooling system? Will that not help to dissipate the heat more efficiently?

AlexF

Only to the extent that the extra water will absorbe a greater amount of heat than before - once its hot you still need to cool it down.

Air flow is the key - hence modern cars having rads that are totally boxed in. With many BMWs they use both a electrical fan AND a mechanical fan due to both the number of rads (water, air con, oil etc etc) and the requirment for air flow even when traveling slowly or with hot ambiant conditions.

I can't offer many solutions as I havent styarted my LET mini project yet. But I will face the same problems you do.

So far I am considering put the rad flat in the boot and scooping air from under the car up and out the boot lid itself. BUT I don't need to consider aero-dynamics greatly, its a brick to start with!

Alex

Luca

iTrader: (2)

Be interesting to see the underneath shots of this set up...

with 800+ bhp ( so we are told ) this set up works..

Luca

iTrader: (2)

THE old set up seems somewhat different but love to find out how the air gets to the rad.

Bomber

I would say that it almost 100% uses a windage tray/scoop from underneath the car.

smitsturbo

theres a lad on here just put his in the boot, (i'll find pics in a min)

im also very interested in doing this to mine becouse of space issues

Luca

iTrader: (2)

THIS MAKES FOR A GOOD READ

http://autospeed.drive.com.au/cms/A_2159/article.html


Explaining high pressure low pressure

Bomber

Also as a side point is it worth investing in a decent oil cooler - might that help bring down engine temps?

WD Pro

Nice bay

Does that cam sensor have its connector laying flat ? if so, whats it off as I could do with one.

Based on the MKII escort designs trying to exit air though the boot lid would be bad, through the rear panel would be good - more so with a lip spoiler on the rearmost boot edge.

There is a great book by Simon Mc Beath (sp ?) that has loads of good info and diagrams on air flow and air pressures - DT sell it but it is printed by Haynes

Bomber

Yep its flat, when its back i'll get the Part Number off it for you. but i'm 80% sure its a Puma Cam Sensor.

WD Pro

Hope you remember as I wont

roop

iTrader: (1)

i looked into this once and researched into putting the car in a wind tunnel,i found a company that does some work for f1 cars,ended up being Ł500 an hour!but the m.d. was very helpful and had a lot of time for me.
cutting a long story short he said putting the rad anywhere other than the front of the car takes the ram effect away,so i explained to him i was prepared to have any kind/position of vents to make this work,problem is whether its an external or internal vent the air will always want to go around it meaning the air that does go down will effectively stop at the rad.
i opted out of this in the end but possible solutions include running fans all the time or creating some sort of scoop under the car to basically draw the air through the rad,although air underneath has a turbulance effect so trial n error would be needed.
the only advantage to this conversion is the increased water volume!

PF Dave

Just a couple of 'hopefully' helpful / interesting stories.

When I went over to Norway in 2004 to feature Stian's blue WRC Escort it had a carbon fibre enclosure around the rad in the boot. Air was drawn in through a scoop underneath the boot floor up through the rad and then out of the tailgate... all enclosed in effect by the carbon surround.

To keep everything looking mega-neat, as Stian always does, he cut some holes and meshed them behind the number plate. First time he let loose up the road at around 100mph I think it was, the carbon enclosure actually shattered into little pieces! Turns out there was masses of air getting in, but not enough getting out and the pressure build up destroyed the enclosure!

Shortly after you'll see in pics that he opted for additional 'outlets' in the boot lid which worked well, certainly well enough for three days abuse at the Gatebil events, but I don't think he was ever quite happy with it.

When the car was rebuilt after the crash, air was taken from the rear-quarter windows through the air-ducts which as far as I can remember was in addition to the scoop in the boot floor.

Then it was rebuilt again for Leif and painted silver but it's still undergoing further tweaks, but at Gatebil a few weeks back it was running without the enclosure and Leif was understandably having cooling issues after around 3 laps of use.

The Rallycross boys have been doing it for years, especially over there and for some reason it seems to always work well in Mk1 and Mk2 Escorts as well but there's certainly more science to it than cutting a hole in the floor and hoping there's enough air coming in and able to get out again!

Good luck with your project though... I might have to do it in the Ka yet as space is very, very tight!

smitsturbo

PF Dave
what about tom scarlets rs turbo did he have any issues with it??

Luca

iTrader: (2)

I have been thinking about this constantly today and must say that all your words of widom and encouragement have spurred me on to see this through.

There are factors that need to be tested but its all to do with vacum...

A scoop system mounted under the car where the Fiesta mk 3 fuel tank would normally sit will force the air underneath the car to flow at a gradual pace up into the boot area where a rad will be placed at a 45 degree ish angle. This rad will need to be encased.

1 to reduce temps and further heat soak in the boot area.
2 to keep the vacum effect (sealed compartment).

the air flow will then via two fans constantly running aid the air flow to leave via vents in the rear tailgate/ valence - which ever is feesable.

The Naca ducts as in escosracer - car and leif neilsens will be ajoined to the sealed vacum box and keep air going to the rad.
I origianlly thought this was feeding the rad cool air. But due to aerodynamics and flow of air in this area it would not flow enough to cool a rad.

However these ducts in the rear quarters as not scooping air they are the vacums. The vacum caused by the air rushing under neath through the scoop box into the boot sealed box will pull air through these window vents and basically pull more airflow over the rad.

Obviusly all theory at moment, until i can speak with one of the norweigan crew.
It sounds to me - although un-trained and just plain hopefull a pretty good way to make it work.

If any one saw the scoops on my sunroof to direct cool air onto me during track time this could work for the rad too if nice carbon ones were made for the rear roof section....

vibrating_cake

so your saying a vent under the car would push air up, and vents in the window will pull air up, therefore your using the rear quarters as exits for air? aswel as the boot, why not use the roof, the roof has a lot more clean fast flowing air compared to anywhere behind the rear of the car!
in through the roof out through the suction of the bottom of the car, both have fast moving air.
whats stopping you pulling the intakes up to under the seats, up the natural upwards directions where the rear seats used to be in the centre of the car and back out the wheel arches?
think about wheel arches, the ph1 clio's used to use "clio turbines" which were wheels shaped like turbines, dno if they worked to move air from under the car to the outside but why cant this idea be used here, using motion of the wheel to suck air out to the outside world.

or on the window front again, modify the rear windows to open INWARDS (it can be done) encase these up into 2 separate rads! and back out the rear A pillar window, or boot sides below the window.
here you would ensure a higher area of intake-exit of the air flow, and it means not having to ruin under-floor aerodynamics.

theres many ways around this, trial and error will show u the right way.
as someone has already said, get a shitter and play with the bodywork till you find something that doesnt overheat, then scrap the thing and make something nice for your own car

Luca

iTrader: (2)

No no - the rear quarter windows are for air flow going in and down to the rad but in theory with the vacum being created from underneath in the sealed box the air coming in the rear windows will be greatly increased.Therfore being pulled in.

To create good air flow there has to be room for that strong air flow to go otherwise the air will fill up the area and stop flowing. The exit therfore is as important as the intake.

Im beginning to like the idea of using the roof perhaps not as a main feed but possibly to add to the flow.

The underneath were the rear seat section is would be a good area yes, i can come in just behind the Pro alloy fuel cell and arch the airflow over the rad and back through to exit the lower region of the boot lid/ rear valence.

Looking forward to this going to take some practice too, and i think i need to get this sorted before i sling the cvh for the zetec as im going to have more problems to rectify before i even start.

If anyone has contact details for the Gatebil Escos boys i would be