Exhaust & Intercooler Routing Suggestions? Mid-engine

Posting this in the general discussion section to get a little more traffic compared to getting buried in my building thread.

I'm at a crossroads with my Europa where I need to decide on exhaust and intercooler arrangements.  Longitudinal mid engine, VW 1.8t.

As it stands right now.

The intake on top is the one I'll be using. In a most basic sense, both the exhaust and charge pipe need to run to the rear, then I'll need to squeeze a muffler an intercooler in there, snaking around the exhaust and shift linkage.

Starting with the exhaust, I think it wants to run underneath the shock cross to give the shocks and charge air pipes some room.   The muffler can be longitudinal or transverse.

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In reply to Brotus7 

The car will be an autox and track toy, so it'll need a decent intercooler with good airflow.  Ideally I don't want to cut exterior scoops in the body which has me leaning towards air to water (knowing full well that an air to air with good airflow is better, I just doubt that I can get the airflow). 

That said, do any of you guys have experience with air to air ICs in locations with crap for airflow?

In reply to Brotus7 :

Yes, and it's amusing to watch air inlet temps go from ambient to 150+ degrees F in about five seconds.

Water-air is the best bet IMO.  Put the heat exchanger where air can get to it.

Is there a way to have the intercooler laying down, pulling underbody air?  I'm picturing an F1 diffuser kind of situation.

Small car, you are going to be using every square inch.  I like the fore and aft muffler, because it leaves the other side of the transaxle open for boosty stuff.

Will there be any vents on top? If so, I'd put the intercooler flat with the trunk/hood and use puller fans to suck outside air down and out the back. If the intercooler is mounted vertical on the back panel, it might pull in hot engine air, probably right off the muffler.

If no upper vents, I'd do like Streetwiseguy said and lay it down on the ground with puller fans grabbing underbody air upward.

I like the transverse muffler, keep it as far from intercooler as possible, but I'd like it more if it was 1-in-2-out so you can do wide-apart dual exhaust!

Is it running/driving? I haven't seen your particular build thread, but I would defer final packaging for those particulars as long as humanly possible - the devil's in the details, and the devil melts when it touches super hot exhaust in a super narrow packaging. 

I wouldn't cut scoops into the body, I'd cut it into the deck lid.   

Sometimes 'ideally' is best off taking a back seat to functionality, especially when you start talking track reliability. Perhaps something along the lines of a snorkel tall enough to get into the free air stream mounted to the deck lid, some ducting that seals to the bottom of the deck lid and the face of the intercooler, and maybe an intercooler with the inlet and outlet on the same.

So something like this up top:

...And this below:

It's not like the general idea is entirely without precedence:

In reply to Driven5 :

Some things are only meant to be done once. 

Point the muffler down at an angle and get it as low as possible?

In reply to Brotus7 :

I’d put the intercooler right in front of that mesh opening, then drop the muffler just below it. 

Muffler as high as possible (heat rises). Since this is a turbo car do you really need a muffler?  With the turbo you probably don’t need a muffler that is that large. Probably need something more like a resonator.   

Intercooler as low as possible pulling air from where ever you can get it. 

Thanks for the feedback guys.

The more I looked at it in the garage today, the more it seems that the muffler wants to live North-South, which means the next decision is for the muffler exit - do I go up and thru the mesh (think barking flames at waist height) or notch the fiberglass and drop it below the rear of the car.  

Looks are deceiving, the muffler is only 14" long.  This muffler has pretty good reviews from guys with turbos - so we'll see if I went overkill nor not.

With respect to scoops and ventilation - there are 4 oval vents in the engine lid, pretty close to the rear window.  Not sure if they are for catching air in, or for letting hot air out when not moving.  I'll get some pics tonight.

Air flow through the rear deck vents is bottom up.  That is, the air exits the vents on top of the deck lid.

Did you consider a NACA duct on the side?  The Type 47's had that.

Dr. Hess said:

Air flow through the rear deck vents is bottom up.  That is, the air exits the vents on top of the deck lid.

 

Did you consider a NACA duct on the side?  The Type 47's had that.

This is why I was suggesting keeping the IC low. As for exhaust just put a turn down on it at the back. 

Air-to-water doesn't have any inherent performance disadvantages vs. air-to-air, in fact they can work around packaging limitations that air-to-air can't and tend to be the best-performing option in practice because of that (if used with a dedicated radiator!), the only downsides are weight and cost.

What a great build!

More photos.

Rog