Regarding the cabin ventilation system, how about doing a smoke test? It works on the engine, why not the cabin? Fill the cabin with smoke, turn on the heater blower motor and close the doors. See where the smoke comes out.

If the side scoops are blind, they might possibly be opened and a light sheet metal or fiberglass ductwork attached to them to direct air through a hose to the area you want. I often used flexible stainless hose, similar to what might be used on truck exhaust systems to direct air to rear engined kit cars. I got out of that business in the 90's but still have 2 lengths about 4 feet long.

I once even used gutter downspout mounted to the bottom of a VW based replicar to capture and direct air back to the engine fan. We put a poly hose to downspout coupling on the front end of each downspout to capture air and force it into the downspout. Stopped the engine from overheating.

quote Originally posted by Liberty: The ONLY air flow to the back comes from a fan under the front hood and goes through the two aluminum tubes that are about 1" diameter in the back.

The source of air for the trunk wall cooling tubes is from the back top of the passenger side wheel well. The is an intake and fan on the right side of the trunk that turns on when the radiator cooling fan turns on.

Does the custom bodywork fit tightly to the sides of the rear window, or is there a small gap?

Looking at the pictures you have posted, it is difficult to see your exhaust routing, but I do see the trunk side(rear) exhaust manifold flange, the turbo connection and the EGR. It appears that some of the crossover pipe from the window side (front) manifold is also visible.
In reading your exhaust routing description, I am having some difficulty in envisioning the true exhaust routing.
Could you post some pictures so that we may better assist you with this problem?

ogre, thanks for the reply and your input again =]

fierofool, I vape (for the time being, trying to quit smoking) so I could blow some clouds in there and see where it goes, interesting idea, thanks! Equally thoughtful idea on routing the air through the side scoops to somewhere directly useful instead of just flowing in. Thanks for the ideas.

olejoedad, Yes, the body fits tightly to the rear window all the way around... it's one piece as far as I can tell, no gaps. My apologies for the lack of strong pictures to portray what we've been pondering. I will take some good pictures and draw a picture of the exhaust system for clarity. It is very cramped back there so I understand not being able to see everything. I have a school thing to attend for my daughter and will be back around 11 eastern. I'll get the pictures up then. For now, I'll try to explain it. A picture is worth a thousand words... I'll try not to make it that long =] This will be from the perspective of standing directly BEHIND the car looking down at the engine assuming the bonnet was removed. There are two exhaust manifolds, one in front (towards cabin) and one in the read (towards tail). The exhaust is directed to the DRIVER side out both of these manifolds. The front travels along the back and turns on the front left corner of the engine and heads directly toward the turbo. The back one travels along the back and attaches to a flange just before the turbo. At this joint is the turbo and EGR and just past this joint heading towards the tail is the down pipe. It travels nearly perpendicular to the rest of the exhaust system (straight towards ground) and meets a Y about 2 feet down. The Y goes left and right and they both bend slightly up to the single tail pipes on each side. Again, the person who built this kit didn't know Fieros well, as this exhaust system is the worst design ever. Routing pretty much everything right under all the sensitive electronics....

Your exhaust is following the stock routing from the manifolds. The crossover pipe has been modified or replaced to mount the turbo; the OEM crossover connects the two manifolds above the transmission and then drops down in front of the transmission to go to the cat.

The routing you have is common with turbo installations. You need to wrap the exhaust and install some shielding to control your heat issue.

quote Originally posted by Liberty: fierofool, I vape (for the time being, trying to quit smoking) so I could blow some clouds in there and see where it goes, interesting idea, thanks! Equally thoughtful idea on routing the air through the side scoops to somewhere directly useful instead of just flowing in. Thanks for the ideas. ....

I've never used the method, nor even seen the equipment needed to do the job, but it's often suggested here to do a smoke test on the engine when trying to find a vacuum leak. That's what I was referring to, but I suppose that your method would work by exhaling 2 or 3 hits into the cabin, judging by the clouds I see come out of the windows of some vehicles.

Check your email. Sent you one.

Here is a picture of the rear window:


Here in this picture you can see the front manifold exit and the pipe that leads to the manifolds junction:


Here you can see the previous pipe leading to the junction, the EGR, the turbo and down pipe:


And finally the Y portion of the exhaust which is AFTER the Cat. This split has two mufflers and two tail pipes (tips out of picture):


I have found THREE locations that I can either use the existing bolt, hole or mounting point. I can make a heat shield that would run from the front left of the engine to the cat. I think I'm going to remove the entire exhaust including manifolds, clean them up and wrap them.... maybe even coat them. I think that plus the heat shield should greatly reduce the heat issue. Not sure how/if possible to wrap the turbo, still looking into it. Perhaps I'll just beef up the heat shield in that area.

Send me a PM with your email, I will send you some pics of the Flow Thru Ventilation discharge point on a bare spaceframe.
That area is missing on your car, it has been cut out to provide for the back side window.
You should be aware that removing that area of the spaceframe significantly weakens the spaceframe in rollover situations, hopefully the builder installed some structural reinforcement.