v8 coupe project

[Henka]

Ahh.... OK, you used a engine from a auto car. That explains it all.

As for handling - well, there you are - you tried it and liked it - go for it!

As for trying - I agree, I was just curious and wnated to know what your thoughts were.

[Keeper of The Kitten]

Wab, what's the plan for air feed to the rear mounted rad? Are you getting Naca ducts in the sides and a rear facing grill, or maybe more discreet intakes and a full time fan system? Apart from the extra weight of feeding the water from the rear to the front (and back) I quite like the principles of shifting weight to the rear.

Henka is right, the polar moment will be very similar with all the weight at the extremities - though I think it might be marginally better as the rear overhang is a little less than the front. However I think the goal here is to bring the weight distribution more towards 50/50.

In some respects a car with higher polar inertia is a lot more forgiving to drive at the limits, if it starts to breakaway it will be more gentle than with, say, a mid engined car with a very low polar moment - they will spin like a top if they let go.

__MDC__

[Azman]

I have seen it today and boy does that beast fill that engine bay. That is going to be one hell of a piece of kit when it is done......

[WabTheKing]

if you look at the boot floor in a coupe it is split into 3 sections, the two sides and the middle, the two sides sit very low down,

so what im planning to do is to cut through the bottom of these wells and make some forwad facing ducts to catch air forced underneath the car

then this is going to be piped into an area infront of the radiator, (all enclosed)

this will then be pulled through the rad with 2 BIG *** fans which will accelarate the air through a venturi style vent in the rear bumper

[AndyP]

Improved weight distribution AND ground effects, like the way your thinking

[Keeper of The Kitten]

Seems reasonable as a solution to me Wab - if the air is quite free flowing it will be ok, but I hope you don't drive on too much gravel as it will be thrown up under the car and into any forward facing intakes (not a problem with forward facing intake at the front of the car because it is not ingesting much that is thrown up from the ground). Intrigued to see the result of your work!

@Andy, lol!!! Ground effect is when aero elements are in close proximity to ground, like a single seater front wing, conversely it also works for aeroplanes when landing or taking off (bigger wings get ground effect from a greater height). So it works both ways up! As for Will's car it would need to be very low, say 3" from the ground for a venturi to work at speed. Fan assisted traction works but only when sealed to the ground as per the Chaparral 2J or Brabham BT46B.

I can just imagine Will sucking gravel off the ground and blowing it in the face of following cars!!! Just don't puncture the rad dude!

__MDC__

[WabTheKing]

could work with co2, back to the future here we come!

[volcano rs]

shouldn't be problem if you use a mesh no stones can get through that

[vonbeck]

looking good wil,if i had a hat i`d take it off to you good luck and keep us all up to date

[WabTheKing]

these are the style ducts which will go in the floor, 11"x9" with 2x3" exits

air passing under the car will be sucked into the void created by these assisted by the fan behind the radiator

[Keeper of The Kitten]

Ah, looks like a slightly modified Naca opening with twin ducts feeding from it. Sensible idea. I remember being told these work better towards the front of a vehicle, but with fan assistance they ought to work properly. As for mesh, don't fit anything immediately in the opening of a duct as that is the least efficient way, better to fit something much further away, a short distance from the radiator - and ideally put some angle towards the corners in so that any debris like stones, grass cuttings, etc, gets pushed into the corners and doesn't block the main core "window" area.

__MDC__

[Keeper of The Kitten]

How big is (are) the radiator(s), and how many of these ducts are you intending to use? Just wondering if a pair (=4 x Ø3" pipes) would be sufficient.

__MDC__

[BRY]

An 80 for sale in Germany

[volcano rs]

An 80 for sale in Germany

and you would think the s2's didn't have enough room to work on ?

[WabTheKing]

How big is (are) the radiator(s), and how many of these ducts are you intending to use? Just wondering if a pair (=4 x Ø3" pipes) would be sufficient.

__MDC__

well if you look at how much of your radiator on an s2 for instance is actually exposed to air flow, it isnt a massive amount then once you have it going through theres no where for it to easily flow where as the design im using should in theory have more air flow through the radiator or atleast the air will be moving quicker

i have 2 x 11" fans pulling the air through a approx 2ft x 1ft 1.5" rad not sure what the CFM of the fans is

following some advice from jamil on electric water pumps my idea with this is to put the pump below the rad in the boot so that the pump is fed by gravity, this will be turned on and off by a thermostatic switch near where the normal engine thermostat would usually be, the fins on the rear of the standard pump will be removed so this will then become just a pulley which will also reduce load on the engine and may even give a slight increase in power

the water will be piped along the transmission tunnel with soild stainless steel tubing and fed into the boot, rad thermo switch will work as normal with a manual overide incase of emergency