Exploring Aerodynamics of Type 1's

[67rustavenger]

So since there is an existing thread on what it would take to cruise at 100MPH and accelerate to 120MPH to keep with the Lambo crowd.
https://www.thesamba.com/vw/forum/viewtopic.php?t=732702

I thought that it would be a fun exorcise to start a discussion on the subject.

Some of us, that have driven an ACVW over 100MPH. Experienced the extremely light front end feel. Fn scary sometimes!
Not to mention the instability when a side gust of wind shoves the car across the roadway.

So would tubbing the bottom of the car help with high speed stability?
Would tubbing the the bottom create cooling issues? Let's say tub it to just before the bottom of the engine. That hot air has to go somewhere.

This might be interesting. Let's see what you smart guy's can come up with.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[jpaull]

Great topic.

Adding weight and lower then stock is first. My green 60 that is lowered some, has a heavy cage integrated all over, and geared for high speeds cruises at 100 comfortably. The little 1679 does struggle at 105 and quits pulling though. I also installed the 12 gallon tank for more weight. Sway bars, tight suspension, new shocks, all help. Same size tires and car is level at all 4 corners.

It doesnt help when people have a hot rod rake with big tires sitting high in the back.

[calvinater]

Jpaul , what brakes on that 60?
_________________
"Albatross"!

[Ohio Tom]

lower the whole car as much as is safe.
Add an air dam up front.
Add all the Castor you can. I run 6deg in my drag car.
One hand on the wheel at 130mph.

[jpaull]

[74 Thing]

Keep the air from going underneath!

[Glenn]

My 74 has more than enough power and gearing to get over 100mph... trust me i've been there.

Front lowered 3", rear lowered 1", larger front anti roll bar and added rear bar.

I remember before the front end would lift above 80mph.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

[W1K1]

I have one of the kamei superbeetle spoilers on mine, it takes away that floaty feeling at high speeds on the highway

_________________
http://www.thesamba.com/vw/archives/manuals/jim_martin_engine_build.php

1973 super
1965 squareback 1500E
1971 bay window westy- subi swap

[Wreck]

There is a little on spoilers and whale tails on this page , Whaletail 4 has most of the info on handling .
It's old from the early 1990s when the big fibreglass mud guards and whale tails were still quite popular in Australia .
http://www.clubvw.org.au/oldart012

[nextgen]

I agree, with keep it level and low. My old story. My bug has 195 60 on rear and 195 50 on front. 2" dropped front spindles , disc front and rear.

Heavy front sway bar front and rear (removed). After I built the T-4 this is the same engine I drive now 30 years ago. I thought I would see what it can do, one night took it on the NYS Thruway and waited at a on ramp till the traffic was way ahead of me then hit the gas. At 65 it blasted to over 100 in seconds, maybe 105. Then the steering got real light and I felt I was going to loose control, so I took my foot off the gas and it just kept going!!!!!! I was catching up to traffic and started to freak. I kept gently pumping the brakes and just made it into traffic .

What the heck, then I spoke to some of my friends in Europe by snail mail and they said it was common if I used the heavy Bus Flywheel. Yep, It was a 210mm and stock.

Still use that flywheel and actually love it but never go over 90. 75 80 is my limit.

Keeping up with traffic is my goal. I like turning heads with the way it looks.
_________________
email: [email protected]
The TYPE IV UPRIGHT CONVERSION MANUAL
BEETLE MAGNETIC DEFLECTOR SHIELDS
LETS TALK DUBS https://www.youtube.com/results?search_query=joe+cali+ghia https://letstalkdubs.libsyn.com/ep-200-joe-cali-ty...qI3xJTCzjs

[Eskamobob1]

Gah. I realy wnat to get into this one, but I dont have time to write for the next few days :/

Honestly, I recomend anyone seriously interested in improving handling and high speed stability of beetles contact FJ camper over on STF. He is probabaly the guy with the most experience in high speed T1s outside fo drag that is still active in the community

Long story short of improving ground effect though is that you need to create laminar flow under the car. That means a dead flat under tray (much, much flatter than a stock beetle pan) and a propper diffuser. Any turbulent flow you get from ramming the air into the engine will propagate further forward under the car, so without a stall limiter (probabaly not the term for cars, but basicaly something that sections the flow such that your laminar boundary has a limit on how far back it can move) you would not want to use a scoop from a purely aerodynamic perspective. Because venturi effect is so hard to control on ground cars dont even think about playing with it. When implemented improperly you can create varriable downforce rates that chance so drasticaly with minor bumps its far more dangerous than even the death wobble o suppers. The promary concern with road cars is moving the air around the outside of the wheels. A splitter will help with this (especialy if lowered slightly), and FJ camper has had benefit from insalling a low profile wedge facing the front of the car infront of thr rear wheels as well. Just by cleaning up the under car flow and creating less turbulance you will increase down force, but it wont be where the majority of it comes from unless you very majorly give up general drivability.
_________________
'74 - front disks/lots more work to do

[67rustavenger]

[old_man]

[74 Thing]

Interesting read about the whale tale Wreck!

A Kamei spoiler in the front and Herrod Helper in the back. Good tires, front a rear sway bars, good shocks, caster shims, and a good alignment-I guess I am thinking about handling at speed. Lighter brakes and wheels help too.

[halfassleatherworks]

Just overlay a profile of a type 1 with a Airplane wing and you will see why a beetle will fly above 50 MPH.
_________________
Halfass Leatherworks*****GOT LEATHER Made to order Leather crafts, you can find us on that face book thing

Belts, wallets, mouse pads, drink coasters, Engraving, most things made in leather.

personal items if you want it in leather in Reno Nv, *****

[oprn]

[Wreck]

[modok]

Rake also puts the windshield at a steeper angle which isn't helpful.

I've always wondered what position is best for a rear wing or spoiler.
Maybe it is midway down the rear window?

[Eskamobob1]

[slalombuggy]

Bob Stahls 150mph competition coupe. All steel body. 700lbs of ballast

My 57. Glass front end with splitter that extends 12" under the front. Rear wing. 2000lbs at the line. 4" narrowed link pin beam with internal sway bar. IRS rear, 3.5" torsion raise, lowered one outer spline. Rear sway bar.