Came across this video tonight, just by chance. No Earth-shattering new info, but I found it interesting.
What was most interesting to me was earlier today @CarloM (a 2+2 owner) was commenting on the exhaust soot/discoloration on his rear bumper. This video mentions that.
RobY
Interesting, thanks for posting that. I’ve seen the 0.40 to 0.44 number before and although that is high by modern standards it was quite good when compared with other cars dating from 1961.
Hi,
Yes. And what I always find amusing (having a masters in arts only, and not science) is how people seem to forget that it’s a relative figure, not absolute.
It’s a factor that will give you the resistance when you multiply it with the surface area if the car’s cross section looking from the front
So if a VW bus or ANY modern car has a much better Cd value, the total drag / resistance may still be higher, take a look at the total cross section area of any E-type vs any other car. 
That’s also why there is so little room inside. 
Cheers!
Ps. Malcolm Sayer sure knew how to calculate! 
Great video, thanks. It would be a nice follow up to see the impact of a bloviator.
Rick OBrien
65 FHC in FL
I’ve seen this before and although I kinda agree with the overall conclusions, especially with the exhaust smell on the 2+2, the tests shown look to me like he tested a model of the SII (the windscreen rake) so didn’t show the closed headlight and S1.5 cars. Mainly I think his adaptation of the model to the coupe was bloody awful and not really close to the real thing, and in aerodynamics small changes can make huge differences.
Oh yeah. My other vehicle…
Cd of .52 with a frontal area of 3.17 meters².
Many an owner has destroyed their engine by driving as fast as it could (which is considerably faster than it should).
A Subaru engine swap allows both…
I wonder if Malcolm Sayer had second thoughts about the windscreen angle he chose for the E-type. It seems like a more acute angle would have reduced drag, but perhaps his experiments didn’t show this?
Racing oriented E-type variations went for more acute angles (as did the 2+2, but I don’t believe that was aerodynamically provoked.)
Dave
The Mercedes I believe had a cD of .36 or so. It was evolved from their contemporary race machines and emphasis was placed on low drag and minimizing lift.
As far as I know, aerodynamic testing played no role in the design of the C1 Corvette. I doubt the imperious Harley Earl would have allowed aerodynamic concerns to impact any element of his styling that he thought important. I believe the cD of the C1 is something like .50. (interestingly, the C2 was better, but the C3 Corvette regressed to the same figure as the C1.)
The 250 GTO probably has the most advanced aerodynamics of any of these. In addition to minimizing drag, through their use of the Kamm tail they actively countered aerodynamic lift as opposed to just minimizing it.
Actually, Malcolm Sayer didn’t realize this (apparently he was unaware of Wunibald Kamm’s work) and thought the tail spoiler was for the purposes of deflecting exhaust fumes! (note that it’s the chopped tail that is responsible for the Kamm effect, not the flip up spoiler though.)
Dave
Nor in the Chrysler Superbirds.
drag and minimizing lift…
Having experienced very light steering, lift, at around 9mph, I had considered fitting an air dam under the E’s chin.
Having finished my multi-year rebuild/refurb, I refitted ALL of the under shields that had been missing. The problematic light steering/lift is no longer evident! Apparently they were there for a reason other than keeping things clean!
Sayer knew. The C5RK Cunningham car not only incorporated a Kamm back, it was actually designed by Dr. Kamm and built by Bob Blake. That was 1952. Not only was the E-Type developed after Cunningham was absorbed into the Jaguar family, it was a design which Cunningham was promised when he signed on. So “didn’t realize” doesn’t sound right. “Not invented here” is much more plausible.
And I thought I was the only one. Makes one wonder about the 150MPH claims in the old days.
They did a fair bit of “fettling” to get there: no bumper beads, no mirrors, 2.88 diff, and a VERY well-tuned engine.
Thanks for sharing Rob, I was pleased to see that Jerry Mouton had posted a comment (Youtube) on the video 6 years ago.
Cheers,
LLynn
Hi,
Nope, professor Kamm found out (as most classic sailing boat enthusists know) that you can “fake” the long sweeping rear end by intriducing a small lip to the cut.
It reduces drag and does not provide any “downforce”. It just eliminates the swirls that would cause drag and unstability at high speeds.
Cheers!
Yup, but “6162 RW” achieved much more as documented by a German Auto, Motor & Sport test in 1962.
IIRC they recorded over 156mph on Italian highway measured by radar, both ways average.
And it had bumpers, normal windows, steel rear door etc. But maybe it wasn’t as well written as the English mythology?
Cheers!
Hi,
You probably mean 90mph?
The steering is light, but just fine. For fast driving you need to have the underpanels fitted correctly and wheel angles as per ROM.
At 120-130mph you get used to it. It’s a bit like flying low. 
I was more worried about the light feeling rear end, although I had three passengers and luggage. Any side wind on the Autobahn made the rear feel really like it was lifted. I’ve heard those who have driven 911’s made before 1976 (no Carrera RS or 930 Turbo) without any rear wing or lip, that beyond 120mph the rear starts to feel light. The vacuum behind the car is lifting it, like an aeroplane wing.
Cheers!
Hi,
The one and only factory Low Drag Coupe was penned by Sayer.
And the factory rebuilt the German importer Peter Lindner’s race car, a Lightweight OTS to a Low Drag Coupe as well. Lindner raced it several years at Reims, Nürburgring, Montlhéry etc. He died in it in the Paris 1000km race in Montlhéry killing a race marshall as well. The car has been rebuilt by CMC in the UK.
Cheers!
