Reducing drag on old-shape sedans

Looking at two old-shape sedans where drag was reduced a lot. Note that my most recent aero book (replacing the one shown in this video) can be found here - www.amazon.com/Vehicle-Aerody... or Amazon in your country.

[@tiitsaul9036]

I was literally about to suggest this very topic to cover. Thanks for sharing. Bmw e30 m3 had raised boot lid as well and lots of aero changes from standard e30. I always thought why they raised the boot lid. Now I know.

[@MQN8R]

Great video. Really considering under trays for my 1985 Subaru Vortex. Always enjoyable to learn more about reducing drag. 👍

[@magnusdanielsson2749]

As always very interesting. 👍

[@JulianEdgar]

Thank you - spread the word!

[@canadianmarauder1923]

Ya got me thinking about radiator ducting and hood vents now. There is a plastic air deflector that’s attached under radiator on my 03 marauder. Would like to leave it off and install full front lower air dam. Need more air through rad too cause I have to install trans cooler and another heat exchanger for the blower. I’m more worried about keeping underhood temp low than anything else. I’ll have to experiment. Loved this topic Julian

[@averyalexander2303]

Very interesting, I never realized the rear spoiler made such a big difference to drag! I just picked up a trunk deck from a Honda Civic Hybrid for my standard 2005 Civic sedan when I was at the junkyard the other day since it has the cool little spoiler built in and is a direct bolt on. I wonder what effect that will have on downforce/lift, I imagine not much either way.

[@JulianEdgar]

Easy to measure the pressure change on the boot/trunk lid - no guesswork needed.

[@m_a_t_t6098]

Do the radiused front wheel arch include any other parts that you can't see from the outside that you know of on the Peugeot or on the insight? If I got a spare fender and tucked that part of the fender in would it be replicating that mod for testing? Also good to see some numbers about the rear window/trunk area. I've been running an extension (untested), but have been thinking about switching to a separation edge setup when I get free time.

[@JulianEdgar]

I am not certain what the indented part of the fender achieves. But I have two guesses. (1) Flow reattachment after the wheel is improved because of the curved surface. (2) Airflow out of the engine bay (the Insight, at least, has a large opening through to the engine bay in in the inner fender) better attaches itself to the side of the car because of the more gentle radius.

[@Propzie]

Is there anything that can be done with a land rover? About as close to throwing a brick down the road that you can get. I personally have a 90 pick up so would something as simple as an angled tonneau cover be effective?

[@JulianEdgar]

Yes an angled tonneau cover is likely to be quite effective. Also, full undertray.

[@Propzie]

@@JulianEdgar I've been thinking over ways of doing undertrays but the diffs and linkages get in the way, the only feasible place would be side undertrays and maybe some form of diffusers. I think the topic of pickups and work vehicles is quite an interesting one as often they are needed for offroad use but on road they are pretty atrocious when it come to MPG.

[@Mister5MasterToJa]

Do you have a video on hatchbacks?

[@JulianEdgar]

My book covers drag reduction approaches on all car shapes - www.amazon.com/Vehicle-Aerodynamics-Modification-Development-alternative/dp/B0C87VYVL8 or Amazon in your country.

[@lauriedooker1031]

Does those old boot buckets really help much ? Does anyone have any information about Ute aerodynamics?

[@JulianEdgar]

What is a boot bucket? There's plenty of info on ute aerodynamics. What do you want to know?

[@lauriedooker1031]

@@JulianEdgar I’m working on a Porsche 914 and to my mind the basic Ute shape after the b-pillar is Aero problem for these models . Would a boot aero ‘ bucket ‘ like on the old broke commodores raised boot take away the rear lift ? Thanks Julian for you message and while a 914 isn’t a aero car I’m still interested in improvement .

[@JulianEdgar]

@@lauriedooker1031 It would be much better to follow what was done in another of my videos - kzbin.info/www/bejne/l4m6eoV_YpySf9E - and add a 944 type rear spoiler

[@lauriedooker1031]

@@JulianEdgar a boot bucket is a slang term form a raised spoiler connect on both side that run at the same hight as spoiler sack to the rear window C-pillar Creating a area shaped like a wheel barrow inside or bucket shape that holds air. Peter Brock commodores.

[@user-kz7et7xj6k]

А я то думал, я одной такой ерундой занимаюсь!) успехов!

[@JulianEdgar]

Удачи

[@lauriedooker1031]

Sorry , can’t understand your written language .🙏

[@Mart77]

4:32 - hi, i'd like to know more about how flow separation around the rear window enhances the overall drag reduction

[@JulianEdgar]

Reduced suction peaks at edges

[@Tore_Lund]

Ahh, 80' cars. When compression was higher because NOx was not a concern yet. That helped fuel economy too.

[@crankhandle]

My petrol toyota prius has nearly 14:1 compression from factory 2zr-fxe

[@Christdeliverme]

Saying this lovingly. Go check out comparable engines from the 80's to 2010's and up.

[@Tore_Lund]

@@Christdeliverme how would I get access to a lineup of comparable engines from the 80' to 2010? I presume You are questioning my claim of higher fuel efficiency in older engines? You do know a 2CV from 1939 could drive 30 km per liter? Likewise the 18-45 HP engines in cars common in the 80' all got 20- 25 km per liter. Modern cars can't do that.

[@kamiljj6809]

i dont belive in reduce drug for Holden.

[@JulianEdgar]

No, I am not much into reduce drug either.

[@archygrey9093]

lmao