windshield

[euromodder]

Originally Posted by Frank Lee

People still think the hood/windshield junction is the problem

The main benefit of a shallow windshield angle, is the equally shallow transition angle to the roof .
It'll help the streamlining beyond the windshield-roof transition.

[Clev]

Originally Posted by CFECO

Nissan Murano rear glass looks good, though the glass is not laminated windshield glass = not legal for use as one. Has a wiper already built in though.

Yeah, I'd avoid using rear hatch glass as a windshield. I get rocks bouncing off my windshield at least once a month that would shatter a back hatch at freeway speeds.

[kach22i]

Originally Posted by euromodder

The main benefit of a shallow windshield angle, is the equally shallow transition angle to the roof .
It'll help the streamlining beyond the windshield-roof transition.

How about an equally angled hood leading to the windshield?

Previa Thread

[aerohead]

Originally Posted by Patrick

Muffildy, if you're gonna go all-out, use the rear hatch glass from a 1984 Camaro:

Patrick,I have one of these for the T-100 for demonstration purposes only,as it is 'safety glass',but not 'laminated safety glass.'
They won't even let me,or anyone else run one of these at Bonneville.Glass shards all over the course should they break.
And State Inspections won't pass them for passenger vehicles as they're not DOT rated for windshield service.
RATS!!!!!!!!!!!!!!!!

[aerohead]

Originally Posted by muffildy

yes, this is an all out project
none of the unibody will be re-used, we are going to be bending/welding a completely new body and attaching it to a tube frame chassis.
the 1984 camero rear window is a good idea, only problem is that the camero is 72 inches wide, which is 6 inches more wide than the miata; since we are using the A-arms/differential etc that would mean i would need to get longer CV joints which can be pricey; do you know of a similar rear window thats made for a 66 inch wide car? If i used the insight front windshield i would be at 66.7 wide instead so between 66 and 67 would be good. 68 might be pushing the CV joint issue.
also a 3000 dollar windshield is out of the question - budget is not that big.

The Dodge Viper has as good a windshield as we're likely to run across.About $600.Check the dimensions.

[Frank Lee]

Originally Posted by kach22i

How about an equally angled hood leading to the windshield?

That affects the windshield/roof transition how?

[CFECO]

Less of a sharp edge the air has to break over. IF the template is the ideal, then the rounder and smoother we make the front of the car the better the rear will work, yes? If one took a vertical flat plate and the rear was the template from max camber, would "that" be just as good as the full template? If the windshield is of no matter, why do the better aero cars all have laid back windshields? Prius...

[Frank Lee]

Rumpler.

Less of a sharp edge the air has to break over.

The angle of the hood/windshield has no influence over the angle of the windshield/roof. The ws/roof junction is the important one, and angle has less to do with it than how generous the radius at the junction is.

If the flow is decent as far back as the A-pillars/windshield header it doesn't matter what's going on ahead of them.

[CFECO]

Rumpler, .28 so? It follows your template in plan view, if it was template in side view, it would be really something.

"If the flow is decent as far back as the A-pillars/windshield header it doesn't matter what's going on ahead of them."

Prove it. Vertical flat plate with template rear = full template, I don't think so.

[Patrick]

Here's what Hucho (1987, pp. 133, 135, 136) has to say about windshield angle:

As the windshield becomes flatter, the aerodynamic drag decreases. ... From all these data it can be concluded that the direct influence of windshield inclination on drag is only moderate. The effect is assumed to be more pronounced the more the flow is routed over the windshield.

Windshield inclination angles of more than 60 degrees are not practical because of light diffusion. In addition, large, highly inclined windshields lead to increased solar heating of the passenger compartment.

Two effects are responsible for the favourable, though moderate, influence of a highly inclined windshield on drag. First, the excessive speed in the area of the A-pillar is reduced so that the momentum loss occurring at that point is smaller. Second, the deflection of the flow at the transition from the windshield to the roof is weaker. The low pressure peak occurring there is therefore smaller and the positive pressure gradient in the remaining flow is less steep. Hence the momentum loss in the boundary layer is lower, allowing greater pressure recovery in the area of the rear end. . . . Therefore, even if a strongly inclined windshield does not contribute to a local drag reduction, it helps to improve the flow over the rear part of the car and thus to reduce the overall drag.