? What is the value of the screen opening at the rear of the S2?

[RonPNW]

In the middle of major fiberglass work and wondering if I should block / cover the screen at the rear of the S2 (I have a 70).

With the screen the air definitely goes into the screen from the back of the car (the wake). Despite this anything in the rear trunk gets cooked and the gel coat in my trunk box has cracks everywhere. This is with 1/2' insulation under the trunk box. What is the situation on the TC where the rear is blocked / covered. Does that create a stronger flow under the trunk? Does the TC have the same issues with a hot trunk? Has anyone tweaked the airflow in that area to get more cooling onto the exhaust system?

Or just live with it?

Thanx
Ron

[Pfreen]

I have not noticed an issue of of the trunk insert overheating on my tcs.  In fact,  glued trunk carpet on he inset many years ago.

[bjthomp]

I'm a strong advocate for "just live with it." It is what it is.

[Richard48Y]

I recall seeing a "Tuft test" of the rear deck area, but not one for the rear opening.
I have also seen post here that leaving the luggage box out improves flow.
With all the cameras available now perhaps someone could update the issues?

[jbcollier]

The rear opening, unfortunately, allows engine compartment air exiting through the cover vents to flow back in.  I wouldn't glass it in though.  Just fit a clear cover.  That way you maintain the stock appearance and solve the air recirculation issue.

[GavinT]

I have also seen post here that leaving the luggage box out improves flow.

That's what I found, too (S2).
I have no hard data on this but the engine room does seem to run cooler when the luggage box is absent.

Also, the airflow immediately behind the rear bumper seems to be turbulent or perhaps more or less static. I expect we've all seen the 'staining' that happens to the bumper from the exhaust.

Combine all this with the fact that it seems a leaf on the engine cover vent won't blow off till a decent speed is reached leads me to think the rear airflow on these cars is quite complicated.

[Richard48Y]

Anyone tried a rear Diffuser?

[TurboFource]

This one has interesting air extraction from deck lid….

[Richard48Y]

Looks like he went all-out, much of the rear panel removed and a big diffusor in its place.
I do have a spare rear deck lid so may see about modifying one for days of more demanding use.

[TurboFource]

Another Europa…

[Bainford]

Is it just me, or does anyone else think that a wing mounted to the flimsy engine cover is just useless boy-racer bling? How much downforce could an unsupported rear deck effectively deal with. Not much, I imagine. Whenever I see this, I doubt the validity of any other aero 'improvements' that may be fitted to the car. Pretty effective drag generator, though. Am I off base here?

[BDA]

Well, it isn't just you. I don't like wings on street cars (I don't really like them on street cars modified for racing but I give them a pass since wings are probably actually useful for them). My opinion is they are the new fins from the fifties but as you point out there isn't much structure for the wing to push against in the event that it actually does something. If there were modifications to adequately support the pressure from a working wing, I would still disapprove. Is there really a need for more downforce at the back of the car given the speeds it's likely to go? Back in 2020, a Europa with a BDA tricked out for endurance racing was for sale on BaT and it didn't have or seem to need a wing.

[Richard48Y]

I do somewhat wonder if a "Truck bed" wing be at all effective to counter the returning air flow issue?
That should be simple enough to test.

[TurboFource]

Surely they put a rear spoiler on the Circuit Wolf car for more than “aesthetics”    (just kidding…..)

[Clifton]

Most, nearly all cars with wings are for show.

I looked at a lot of CFD on cars before venting my radiator in the front and sealing off my rear deck lid on one side.  Wings do provide some downforce but if nothing is done on the front it will create lift on the front. A small front spoiler isn't enough. GRM magazine has had a few CFD articles with everything they did and the numbers with every mod.

The rear of the car has turbulent air. If there is a direction of flow, it would be most likely in as the top of the deck has negative pressure. I have an intercooler and air filter 100% sealed off from the engine compartment on one of my deck vents. I used compressible rubber seals like on the doors to seal it. I have an air temp sensor on the intercooler outlet and air filter inlet and two K type probes on a dual  channel thermometer (under $30 on Ebay) that I moved around while testing. The only way I've been able to get enough cool air near ambient is with a bottom scoop coming up from the gas tank and sealing that off too.

Insulation on the bottom of the deck would only work well if it has a radiant barrier facing the heat source like a thin reflective foil with an air gap between that and the deck lid.The air gap could be a foam. Like any heat shield, the barrier needs to be spaced off both parts.  You can buy adhesive lined foam insulation with a metallic mylar film pretty cheap.