The Roxster gets aero - Porsche 986 Boxster V8 engine swap track car build 33
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- Опубліковано 6 лют 2025
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Nice to see the roxster getting some screen time. We need to see it on track.
Till it blows up.... lol
Jeff
Do it the old way we did in the 70's without CAD or wind tunnels
Tape a coloured ribbon 75mm long, every 100mm up and sideways on your decklid and back window. Repeat on top and underside of your wing. Make it a bold contrast ribbon to your black car, ie a yellow ribbon.
Secure the services of mrs Jeff and a friend. Drive down the road at 80, 120 and whatever legal kmh you can get away with and photograph the car from the back and from the side at the various speeds. If the ribbons lay flat its positive (downforce) and if they lift its negative (uplift) pressure. That way you can see quickly whats happening to the air over your decklid and the wing. If the ribbons on the wing top are up it means you need to increase the angle of attack.
A bit of time to do the ribbons ( if they are in rows you can very quickly see how they are behaving and which row. Turbulance or odd wind flow can be seen by counting number of ribbons from the side or top and dealt with accordingly.
Easy peasy. Try it, you will be surprised.
On the Alfarrarri use black ribbons in 100mm grids that are easily visible.
Easy peasy on road wind tunnel.
Racing a Meisener ohc 1640 Ford Z window Anglia we quickly found the back was "walking" around due to negative pressure at the back window. We made an under floor pan airscoop and plumbed it up behind the back seat area and made a long rectangle outlet behind the back window to introduce airflow and it sorted the problem as well as increasing straight line speed down the back straight by a few mph
Some tape and a camera with someone taking pics from another car.....mobile ACTUAL conditions wind tunnel.....
Hope it helps you a bit.....
That sounds like an epic solution to the Anglia aero issues. Basically turning the leaned back rear window into a big diffuser.
@Jonathan_Doe_ we were broke engineering students without bursaries, working 4 jobs to get our qualifications. We learnt all the hacks and tricks in the book to try do our passions with cars. And we were learning big lessons while doing it
Mmmmm dont remember sleeping too much then......
Thank you Jeff. It was great to see the Roxster back and can’t wait to see it on the track.
Hi Jeff, nice to see the Roxster back again, having so much to do on all projects, that's what can happen.
When this is done, the Franken-hawler as well, then you can move that baby from track to track!
Cheers 👍💪✌
Just heard you'll be taking it out later, that's great news!
Brakes work, the wing should work, shifter cables hopefully are better now as well.
Cheers!
Hey Jeff, well this was a pleasant surprise. I enjoy your work on all your vehicles. Can’t wait to see this on the track. Cheers, mate.
Love Roxster coverage.................so keen to see things progressed.
But along with all the other projects 🙂
PS: I made 2x feet under the rear boot/trunk near that lip- with a large rubber pad on top.
So when the boot closes, and the weight of the spoiler comes down under load, it had even more support underneath.
Easy enough to do - and needed for 100kg +++ support.
You can do the floor mounting option without having to cut the hatch if you make the wing mounts a 2 piece design. 1st section from the floor to right underneath the hatch, supporting the hatch on a horizontal plate with quick release pins on it. Just a couple holes in the hatch for the pins to go through and then the 2nd section with another horizontal plate, with holes to accept the quick release pins, as a foot sandwishing the hatch. This will still transfer the forces to the frame of the car but when you want to open the hatch it's only a few quick release pins and the hatch can be opened without a problem. If you can find somebody who has a virtual windtunnel program for the computer it would make the aero setup fairly easy and tailored to your specific car and aeroparts.
That is actually a very good option.
I was thinking make the hatch a sandwich also, could have two uprights coming from the floor even if wing mounts bolt through bit like with roll cage stuff, 8 bolts to lift the hatch which for a race car in not really a big deal
Hi Jeff, try plasma cutting a couple of aluminium columns that the hatch will close on but make them high enough so that the wing mounts rest on them when the hatch is closed. That will transfer the load to where you want it and still allow the hatch to be opened.
or a simple cross piece with a couple of hood bumpers to take the pressure....
Hey Jeff, I think I saw the channel in the underside of the wing that spans between the struts (likely there for strength) . Think about filling this in as it destroys the laminar airflow exactly where you want it the most. This effectively stalls the wing by detaching the air. As it stands it would produce minimal downforce and mostly just drag.
I did see that. I assume the guys who built it put that in for strength with no idea how the wing actually worked. I will put some tape over it for now and hope that will work.
Watching a guy at the moment Jeff , who is making a Metro 6R4 Group B rally clone using the underpinnings of a Boxster !! . It has involved a lot of shortening
Irish lad, it's quite interesting
You can tape some string length’s top and bottom covering the wing and use tour go-pro to video if the wing looks to be stalling or theres even flow over both surfaces 👍
My favourite channel gives us an extra vid. Nice one mate, thanks!
I have an idea. What about mounting some short towers in the boot, that just touch the bottom of the rear wing mounting points, but don’t bolt them together? They would just touch when the boot lid is closed. That way the weight could be transferred to the chassis, but you’d still be able to open and close the boot as needed.
I can't see for sure on my little screen, but I think the wing might be around the wrong way, on my little screen it looks like the flick up is window side not at the back of the car.
I was thinking the same thing.
Nope, he has it the proper way. The centre is angled differently than the ends because the air off of the hatch is arriving at a different angle than the air at the sides, so the angle of attack of the wing is different. A copy of a very common design. Of course, the channel on the bottom is counter productive to it working properly.
Good to see Roxy back!
It´s actually beginning to look pretty cool. I hope you will clean it all up in the end, and award it a paintjob. Maybe an opportunity to share some of your paintbrush skills?
Actually it could be fairly easy to mount through if you space the bottom rear mount such that the bottom bolt is over the metal lip underneath, then just use a long bolt (with a rubber on the end) with a corresponding perch underneath such that when closed, the bottom mount bolts contact the perch... Easy peasy, but not sure I explained in a way that makes sense. That would avoid all the faffing around, transmit the load, and still be able to use the hatch normally.
Hey mate nice work but i think the original uprights looked better been angled back rather than virtical, hopefully I'm still going to get my Sunday morning fix
Cool! been a while since we got some Roxter content!
Pleased to see a bonus instalment and the Roxter to boot!
Good to see the 986 back!
G'day,
Mr Jeff.
I rekin it's always good seeing work being done on the Roxter. It's come a long way since you've had it on your channel.
The rear wing certainly looks the business i hope it performs well.
You mentioned being a race car it's gotta look like a race car. What about getting the Roxter Wrapped in vinyl. In a Home built by Jeff colour scheme. I'd certainly chuck in a few $ to help.
So thanks for sharing ✌️ Peace from Melbourn / Pakenham 3810
I think the best aero for the front might be a duct to bypass air through the front storage compartment. Seen it on some race prepped boxster and caymans. Micha Charoudin drove one and has a walk around of one.
Porsche themselves have taken this approach on the new GT3 RS. It’s basically “free” downforce, because it can actually reduce drag by cleaning up the airflow at the windscreen base.
Let's go and shake this down! I'm sure it will be quite "entertaining" with all the unknowns of this project!
Sorry Jeff, I know this is a family friendly show, but when you introduced the episode, I heard "Porn neglected Rock Star" and only thought, Dang! That's a shame for all those old aging Rock Stars! Enjoy all the videos/cars/content, thanks Jeff!!!
Lol, and there I was thinking the original uprights looked nice, and just to replace the mounts to the wing from the flimsy screw system.
They were at the wrong angle.
You should bolt the wing to the chassis. Any amount of pressure on the engine cover could cave it in.
Nice (well not the car, but the work you've done) looking forward to seeing it on track .. how much faster do you recon it will be compared to a regular coxter ?
It may be worth remembering that the wing will also produce drag and even at 100 mph there will be that additional substantial rearward force. The nett aero vector may not go through the uprights at all. There may actually be a torque trying to rotate those uprights off the back of the car. Bootlid fixings should really just be for show.
The roxster is my favourite series, it deserve some proper areo, just buy the cayman cup aero kit
Mid week Jeff. Awesome.
The finest Chinese 😂😂 love that comment
Cool Aerobar, car looks better, don't eat it Jeff😁
About time a boxster episode :)
Friday bonus content, will I still get my Sunday fix 😂
You know viewing figures are down when Jeff puts out a 'mid week' video. It's tough atm. Figures are so low, we feel the need to react with more content.
Nah it's probably all the wet weather, so less fires to put out. Give it a month when all the night time flue fire calls start and he gets run raggered and he gets the bags under his eyes. ❤
Agree
Glad to see it though. Even digging the rust repair on the Ford.
Hmmm, still needs more doorstops I reckon.
For balance.
Looks awesome! ❤
Any chance Roxster Wednesdays might return 🙌
When you called it the ugliest Boxster in Australia you were not exaggerating. It can only get better.
Hi Jeff. Nice to see the Roxster getting some Love.
Have you considered getting some 10mm Plyboard and making a front diffuser for the front. 2-3 inches in front of the Bumper would give some good Downforce on the front and with Boxster being flat on the Bottom upto the engine should make it easy to bolt to.
Cheap and effective solution to some great aero.
Front and rear diffusers and a signal green paint job?????😊
Looking forward to what you do for its appearance.
Track time!
Finaly "forgoten" build 😊
I hear Red Bull Racing are looking for a new aerodynamicist ;-)
What about a roll cage?
Nice one
You could screw some door wedges on the front 😂
It's getting close to time to Rock! You might want to think through that "downforce is from the bottom of the wing"- that was very new to me here on the otherside of the world. The top creates downforce by pushing down because the air pressure increased along the front of the wing as the air bent upward to go over it; the bottom of the wing might produce some negligible additions, by creating a slight reduction in air pressure , which would lessen the effect of the wing, so a very neutral bottom is how you get the most downforce with the least drag. Vroom, vroom!
Algorithm algorithm algorithm,
Love the show
Jeff, why are you lugging around a spare tire in a track car?
Just haven't taken it out yet :D
I wonder if Adrian Newey was watching? It looks the business anyway.
If anyone in Scotland is wanting to build a similar Boxster track car, I have just the starting point for you... an ex-sprint/hillclimb car needing a new engine...👍
I was wondering about the Roxter in the last video.
maybe I’m dim witted… but surely you’d have a look at what Porsche has done on the Cayman GT4????
5:29 Chinesium 😂😂😂
Why just not sit on it to test it out :D?
I love this project... jut because it started as something so terrible! :D
Let's Roxster.
It feels like a pedal , like :-)
I'm just here for the fun facts, with Mrs. Jeff. Never any Porsche facts?
We did the Porsche facts in the 911 series ;)
But Je-eff@@HomeBuiltByJeff what about 986 facts? 😊
What about cross loads on the wing? Like a few then cables to keep it from shuttering.
We will see if it needs it
Jeff - You mean the rubber doorstops were not effective aero aids, LOL. OK, now on to the more serious stuff. First, the supports for the wing only need to be able to take the downforce load the wing can generate and as that is a generic wing, my guess is there won't be more than about 100kg of downforce generated at full speed. Your supports should be more than adequate. Second, I believe you should angle the front of the wing into a more downwards position in order to have the leading edge parallel to the ground and not tilted up like it currently is. Trying to remember from my fluid dynamics classes from many years ago, but it looks like your current configuration is going to generate a lot of drag without much downforce. Try varying the angle of the wing during your track day to see if there is any appreciable difference in handling of the car. Weirdly enough, you may even find mounting the wing backwards generates more downforce than the forwards configuration you currently have it in. This is counter-intuitive, but wind tunnel tests have proven this out for certain types of wings. Give it a try to see if there is any difference.
boy racer equipment
👏👍🏻🍺
Hello Algorithm!!!
Get rid of the spare wheel and all the other heavy junk that isn't required in a track car before going.
I can never quite understand the shape of rear wings like that, it looks like it’ll give lift?
Looks like the leading edge is at the back, put the wing on a flat surface and whichever side is higher will be the trailing edge .
That is not even remotely true... It is an aerofoil. That is what determines the leading edge ;)
Considering you build cars and I've built aircraft, I'll defer to your apparent greater knowledge on the matter
@@wukswheels Haha, well then I am obviously not understanding your meaning then ;)
Thats a sedan wing and not a coupe.
Will it make a difference? No. Not really. Will the aero nerds point it out? Yes.
ua-cam.com/video/b1xFgMwurBY/v-deo.html
Hello Jeff. I really like your work... But I think you made the roxster uglyer with that horrible wing. And perhaps slower with the extra drag you ad. Its not easy to understand the effect of the wing without a wind tunnel. Its possible that you ad lift instead of downforce... Just my opinion... Cheers from Portugal
I think that thing was world class ugly
It looks like the leading edge needs to come down more based on that front shape.
@julianedgar