Roof Spoiler on Pick-Up Truck Cab - Phase-1

[kach22i]

Originally Posted by freebeard

Tell us what we're looking at.

After the angle grinding and tin snipping off the old rust I both sprayed and brushed Permatex rust treatment everywhere, then primed and painted.



The rest was buried in the Pelican Parts thread already posted - did a partial copy & paste below.

Rusty old pickup truck - Razzle Dazzle Camouflage - Pelican Parts Technical BBS

Originally Posted by kach22i

The hi-expanding foam used in hot weather kept shrinking on me, even weeks later - very frustrating.

The low-expanding foam used to fill in the missing or shrunken areas continued to expand weeks after, even after being sanded flush and sealed with a coat of 2-part epoxy.

From what I've read on-line after doing this, 2-part Marine foam is the best product to use.

The foam is intended only as a backer material to fill in the void. I sealed it with epoxy (allowed to harden), covered that with an epoxy mixture using maybe 1/2 the micro-balloon mixture - allowed to harden. Then covered with fully stiff micro-balloon paste. Because the shell of this construction was so strong and stiff, I did not use any fiberglass cloth. Time will tell if this was a mistake.




The tape you see inside of the wheel wells is self-adhesive roof flashing. It keeps the foam from dripping on to the tires.

Should you try this, use thick painter's plastic in lieu of Saran Wrap, the thin plastic wrap gave too much, the foam should be pushed into the metal cavities and not allow to balloon out like that.

I also used a very strong self adhesive mastic roof tape to bond dissimilar materials. For instance, in the wheel wells where I lag bolted on conveyor belt material to prevent salt spray from attacking everything again.



Notice those rear wheel lips are rubber, glued on with black silicone and back taped. Not clean, not pretty but should hold up for as long as this old rig is road worthy.

[ECONORAM]

Originally Posted by freebeard

Wickerbill?

To test you premise you could tuft test the bed gap.

If you look at the newer (Gen 4--2009 and newer) RAM pickups, they have a rubber seal (not unlike door seal material) between the cab and the bed. It's not flush with the side, and doesn't seal the gap entirely, but must do something at least for NHV (noise, harshness, vibration). I tried this once with clear packing tape across the gap of my cab and the bed and bed cover (heard it rattling and squeaking constantly), and for a while with 1/4" foam weatherstripping stacked 3 or 4 layers thick. That did last for a while, but the wind eventually blew it out. I couldn't tell you if there were any mpg gains. Might try it again, with some door seal type material, as I discovered that after my first two test materials.

[kach22i]

Dumping this roof wing here.

1995 Ford Escort RS Cosworth
https://bringatrailer.com/listing/19...rs-cosworth-2/



Is this the same type of car?

1995 Ford Escort RS Cosworth Aero (model for Europe Germany)
1995 Ford Escort RS Cosworth Aero (for Europe Germany) specs review

Drag coefficient (Cw-Wert):

Cd claimed:
0.38

Cd estimated by a-c:

[freebeard]

Is this the same type of car?

Same as what? The thread is Photobucketed all to h*ll.


https://en.wikipedia.org/wiki/Merkur_XR4Ti

I like the Cosworth part from ten years later. I'm looking for some sort of Kamm-back for the Dasher. Maybe this is it, with a box cavity at the rear bulkhead. What do you think of the width of the slot in the upper wing? Narrower?

I wonder if that ducktail was upside down, whether it would it mangle the top of the turbulence and reduce the size of the wake.

[aerohead]

The rally spoiler on the Cosworth raised the drag,from Cd 0.34,to Cd 0.38 and lowered the top speed,from 145 mph,to 140 mph.
The patented,Ford of Cologne,bi-wing spoiler on the Merkur/Scorpio lowered the drag,from Cd 0.34,to 0.32.

[freebeard]

Thanks.

I suspect the increased drag is caused by the duck-tail contour of the upper wing. But it is positioned for maximum leverage.

Suppose the upper wing had the same contour as the XR4Ti part. It would be very similar to kach22i's pickup cab wing with a bigger gap.

[aerohead]

Ferrari said that the C-Pillar winglets directed air down the backlight,then up,over the rear spoiler.It cost them around $200,000 in wind tunnel time just to dial the shape,size,and placement in.
The 1975 Ferrari Cr 25,at Cd 0.256 comes in below the Cd 0.285 599XX,without any of the gee-whiz excrescences.

[aerohead]

Originally Posted by freebeard

Thanks.

I suspect the increased drag is caused by the duck-tail contour of the upper wing. But it is positioned for maximum leverage.

Suppose the upper wing had the same contour as the XR4Ti part. It would be very similar to kach22i's pickup cab wing with a bigger gap.

I'd be tempted to just project C-Pillar flying buttresses out,with their tops following the template,then enclose the top,spanning between the buttresses.Even better,enclose the sides to create a Kamm-box-cavity.
It would create a blind spot,so careful use of mirrors would have to follow.

[freebeard]

Bertone B.A.T.?

[BamZipPow]

Originally Posted by aerohead

I'd be tempted to just project C-Pillar flying buttresses out,with their tops following the template,then enclose the top,spanning between the buttresses.Even better,enclose the sides to create a Kamm-box-cavity.
It would create a blind spot,so careful use of mirrors would have to follow.

Kinda like this on the Toyota T-150?