Effectiveness of the 75/76 Laguna Nose?

Hey guys, was just curious. Is there ANY data out there regarding just how much the slant nose reduced drag on those cars? I've been unable to find concrete data on the aerodynamics of the G3s (surprise surprise), with the best being a pathetic guestimated cd slapped onto every model regardless of blunt or slant nose, or even coupe/sedan/wagon.

If there are hard numbers out there, awesome. But I'd even be interested in hearing about differences in NASCAR times and speeds for comparison. Pretty much anything that can suggest just how effective the slanted nose actually was.

Happy early Easter, everyone!

Good question.

Published data comparison from the 1970s? No.
Did the factory develop this nose to improve aero at high speed? Sure, they did comparison in a wind tunnel, and the product is what you see on '75-76 Lagunas.

Did they typically distribute this data to race teams?
Probably not in the mid 1970s because the teams wouldn't have known what to do with it.
Today, teams are much more advanced, technology is more advanced (and costs less) so data is more readily available today.

What is the CD of the Laguna nose, and how does it compare to other vehicles?
I don’t know.
You could have a nose digitally scanned, and then compare it with some matlab sims to other makes.

Unless you will be building a Bonneville top speed car or running high speed trials on a closed course, I am not sure what the need would be for this type of analysis.
You could do some simple comparisons from the Laguna through the evolution of the Monte Carlo SS to the Lumina, and beyond to see how aero has changed.

This would make a cool magazine article.
If you could find someone to fund the analysis, I could supply some cars and even do some of the testing.

Thanks -

I guess I'm just the guy who likes to know everything inside and out. It would be interesting to have some data to compare and contrast with the other G3s. How much gas could the nose possibly save you on long trips? How much higher of a top speed would swapping to the slant nose gain you?

There's no question it should be more effective, but by how much?

There's not really any plan I'm cooking up, I'm just interested in the information itself. On paper, the biggest thing holding the G3s back aerodynamically are the large frontal areas and blunt noses. But still, there are plenty of older cars with great aerodynamic properties that have just as large if not larger frontal areas. Many of the G3s have a very slick shape once air can get past the nose and swoop across the windshield and down the back. A lot of them even drop down dramatically in the rear to create a smaller void behind the car trying to suck it backwards.

There are a lot of other factors of course, like ride height, air flowing into the engine bay, drag underneath the car from exposed parts, or even the sharp angles where the top meets the sides. Still, it seems plausible that a slant nose Laguna could have really exceptional aerodynamics for a muscle car without looking quite as blatant about it as something such as the Daytona Chargers. With very minor work of course - blocking some of the grill off and lowering the car just a hair.

I'm not cooking up any ideas for a build over here, I just find the whole thing interesting and largely overlooked by the "stuff a big block in it" crowd.

I'm sure the slant nose made some slight improvement for aerodynamics as did the spoilers they used in racing. One thing is for sure though, they kicked butt in Nascar back then. People forget just how good these A bodies were.

For a street car, you will feel a big block much more than you will notice any aero mods...

It was evidently good enough to get the Laguna banned from the track back in the day.

jerry46765 wrote:For a street car, you will feel a big block much more than you will notice any aero mods...

And if I already have a street car with a small block that can't go any faster without trying to take off from the ground?

Personally, I've got a 77 Malibu and then a 73 Laguna. The 73 is keeping its original nose and has some tricks unrelated to this thread in the works to keep the nose down on an oval or road course and of course reduce drag. However, the research and various testing that went into that is why I've been so curious about the slant nose. I have no plans to swap to it and never will - I just don't care for the looks and I don't think I'm giving up any aerodynamic advantage with the plan I already have.

So really, you can take this topic at face value. I'm merely curious.

I've often wondered that myself, how to improve the aerodynamics of these cars. They are good from the A-pillar back due to the tear drop shape, but that bluff front will be a problem

I've thought about blocking the grill off, since mine gets plenty of air under the bumper, and sealing the core support up. I'm more interested in improving the gas mileage with what it came with over swapping in EFI at the moment.

There's absolutely no reason to not improve the aerodynamics IMO unless you are super thrilled with how they look bone stock so I'm with you on that.

Blocking the grill off works but doesn't solve the issue of drag any. My solution on the 73 is to have a flow through design that just lets the air right on in and then shoots the majority of it back up and out of the hood into the airstream.

Two huge drag points are the fender wells and the underbody. I have a partially completed undertray I was fabbing up for the 77 I'm giving to the 73 instead but even just lowering the car a bit and giving it a front spoiler will prevent a lot of that air from coming in under the car. Even worse is that the body itself sits kind of high on the frame so there's even more stuff to catch wind on.

The wells are tricky to fill perfectly but doing so - or at least getting your tire out further with some backspacing - will help a TON. Unfortunately, the stock wells also bulge out at the top, exposing a ton of tire which just creates more drag. Two approaches to the problem are cutting out the wells to be taller, more round, and so they don't bulge out - NASCAR style - or to simply use fender flares. The big problem some people will have is that this will dramatically change the appearance of the car to seem way more high performance which not everyone wants.

Bumper tucks also provide drag reduction since they stick out past the sides of the car and thus increase the frontal area for air to smack into.

Your basic approach for minimal money, work, and alteration of appearance would thus involve partially blocking the grill and sealing the core support as mentioned, fab up a simple chin spoiler and flat black it so it doesn't really stand out, backspace narrow wheels outward so it's a bit more difficult for air to come into them and slow you down, and finally drop the car as much as you can/you think looks decent. Highway mileage would noticeably improve especially with an overdrive.

Seems like a place is needed to run at very high speed numbers to prove any aerodynamic difference. Places like that are harder to find these days around here....too many cops etc, too bad too..