Make your own tiny vortex generators and get better flow attachment on the side glass. Note that my most recent aero book (replacing the one shown in this video) can be found here - www.amazon.com... or Amazon in your country.7
I did this on my 4x4, I noticed rain stagnating on the window, making it hard to see, and hard to crack the window down a little. I did the same test and instantly noticed a difference! Even less noise! One area that was still turbulent was around the weather shield!
You should have a 3d printer, especially for those small things. i know a knife and a little wedge might be quicker but much more variation possible with the 3d printer
I remember explaining why I cut in half a formula 5000(?) Aerofoil, before mounting it under the car, either side of the tail-shaft and bolted to the inner sills- it was partially to overcome the lift of the notch back windscreen, but I really wanted it to cool the twin Brooklands mufflers I had fitted under the boot floor. I also put a plywood panel, from a chin spoiler, to the front crossmember, and was amazed by the difference, mate. Love your videos- good to see an Australian presenter, mate!
Really glad to find this video and your channel, Julian. I will try this on my 80 series Landcruiser side mirrors. Love Autospeed and have been reading it since the early 2000s - it definitely shaped my thinking in regards to cars.
Thanks, but in terms of aero, AutoSpeed is a long time ago indeed. www.amazon.com/Vehicle-Aerodynamics-Modification-Development-alternative/dp/B0C87VYVL8 or Amazon in your country.
Thanks! I can see these tweaks becoming very popular with electric vehicles. Wind noise is a lot more obvious with the absence of a noisy combustion engine, and every skerrick of efficiency helps range. Great idea. 👍
Thank you Julian, your videos are so interesting. On my 2016 Suzuki Jimny, I discovered by accident that reducing the air flow between body and mirror reduces noise noticeably. Had a different mod in mind but I'm going to try this immediately. I started our researching how to reduce heat build up in the Jimny's engine bay and now your videos are enlightening me :-)
Instead of a nice rounded A pillar, newer cars have sharp edges to guide rain water over the car instead of onto the side windows. I could see this helping with wind buffeting. There are small spoilers for sale to help with this.
No, the sharp A-pillar edges actually make buffeting (and drag) worse. It's a topic I specifically cover in my most recent book - www.amazon.com/Vehicle-Aerodynamics-Modification-Development-alternative/dp/B0C87VYVL8
I always wanted to ask you whether you knew about VG's. If only people would realize how valuable this content of yours is. (For free). We put VG's in front of aircraft wings, staggered and angled at about 20 degrees with remarkable effect of lowering the landing speed yet not affecting the cruising speed.
VGs or channel guides? I’m more inclined towards referring to these as the latter in this case: there might be a pressure bubble on the forward facing side of the mirror housing that you’re helping back into the significant flow around/past the A-pillar- showing it where to deflate to. Regardless, this is an awesome little tweak!
Apparently a mirror on a stalk is better. 89 Toyota Supra had a wing type mirror, the 90 had a notch in it to make it more like a stalk. 15 Fiat 500e has a mirror on a stock that angles up from the door at about 45°
Small things like this may not be easily measured, but enough of them together can have noticeable effects. Mind the pennies, the pounds/dollars/euros mind themselves! I’d love to see some throttle stop testing done in a car that has been “treated” and then with the treatments removed - even on a car like the Insight, I wouldn’t be surprised if there was a 5km/h (or greater) drop in top speed without the treatments.
I don't have a monopoly on testing - if you think they will give an improvement, do some testing yourself. I have done that testing, and they made things worse on the Insight. All covered in my Veloce book.
Julian Edgar thanks. I’ll click that link. The unscientific testing of my initial mod is working out really well so far - I’m on track for somewhere in the range of just >100km extra range from my tank. And the road feel is different steering wise (crisper and more precise) but I do have to change my driving habits - I need to get on the brakes sooner & harder coming to a stop: my car seems to have developed a strong affinity for coasting
@@michaelsillymoose5556 I haven’t gone full front undertray yet , but blocking the lower radiator inlet (below the front bumper) has helped: I’m not certain if it’s completely aerodynamic (helping the airflow go under the car), or if reducing the airflow past the radiator and into the engine bay helps keep the engine in closed-loop fuel delivery, but the positive aspects I mentioned above are definitely occurring. This stuff works.
hi, I have a Toyota C-HR and there’s a noticeable wind noise at both rear mirror at highway speed, can you please make a video on … perhaps where is the sound are from and how people can use VG to reduce it. Thank you really like your vids.
It is dependent on the car. In some cars the vortices may match the frequency transmission property of the glass and so noise will increase. In other cars, the reduction in flow separation will make the car quieter.
interestin as I have the same mercedes. have you done any tail modifications or rear glass. during rain it looks like water is staying still at the rear glass, it's not going up or down.
Amazing! What gains would you say that such a little difference on flow at that area would make? Like less 1 or 2 Nm of drag at 100 or 200km/h? Less 0.001 CD? I have no idea! Should be very hard or impossible do actually tell just by the way if looks, but you may have an idea based on previous tests or calculations :)
@@JulianEdgar Would you think these changes might affect airflow further down the line, and perhaps negatively as the engineers didn't account for the modified airflow when designing the rear of the car? Anyway, congrats on the amazing collection of videos! I use them to modify my Hyundai Ioniq EV, which must now be one of the most efficient cars on the road (I think). I'm averaging 115wh/km at mostly highway speeds.
@@JulianEdgar because I have the fabrication skills of an earthworm. Anyway, I'll buy your book and see which ones I'll have the patience to fabricate myself.
I understand your point, but nearly *all* car modification requires mechanical skills, including fabrication. Aero is even more the case, because so few workshops (any?) specialise in road car aero modification. Neither of my books cover in detail making cheap vortex generators - honestly, if you can cut a steak, you can make these rubber ones!
@@JulianEdgar what the result? I've tried the vortex before watching your video. All of sudden youtube recommended this video to me. My car is installed just one vortex and as far as im concerned it works effectively around 70% . Still have smaller wind sounds when car hits cross wind Do you think I can reduce the noise a little more if I apply 2 instead of 1?
Some toyota models also have these: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4Bmhuq38EYI.html, seems like they stole some more of your ideas :)... the video focuses mainly on stability, and also touches upon underbody airflow and strakes. i'm still skeptical about how much effect a single vg can have on vehicle stability. But your tuft testing certainly puts these in a positive light. Interestingly i've also seen stick on examples sold on ebay, in both clear and translucent red, marketed as "anti collission wind noise reduction spoiler". They are likely "inspired" by the toyota ones. the shape looks about the same. I'm tempted to get some for testing. I wonder how a row of vg's accross the A pillar would effect overall airflow, given the A pillar vortex pretty much determines a large part of the airflow over the rest of the side windows and possibly the wake.
I have tried (on the Insight) a row of small vortex generators on the A pillar but the results were much better using turning vanes (ie guides) on the pillars. If you look closely, lots of cars have small vortex generator-like bumps on them (ie not just Toyota), especially around the external mirrors.
