The Cal-look Lounge

So me and my Dad were out for a ride last Friday visiting with Steve Walker, aka nlvtinman.  On the way home  there is a long sweeping left turn fallowed by a stop light.  The speed limit is 40mph and we were around there, not speeding.  As we approached the intersection the light switched to yellow.  We had a decent amount of space to make up but I stayed the course.  A car coming in the opposite direction made a left in front of us so I was hard on the brakes.  The front tires immediately locked up causing us to carry on straight instead of fallowing the slight left in the road.  I let off the breaks, downshifted into second and back on the brakes.   This time they locked again and I was forced to make a quick right turn at the light to avoid rolling into the intersection.  

What's up with that??  135r tires must be too small, I guess, and need another look.  I had been wondering if the drums with metal woven shoes were enough but I guess if you can lock them up on dry roads than the brakes aren't the parts that need attention.
Anybody have advice for a possible upgrade or were the stars just aligned?  I have never had that happen before anyway.

Taylor

its down to grip, you have the best brakes in the world but if the tyres cant grip..... 135 is skinny too.... stickier rubber and or wider fronts would help

What air pressure do you run in your 135s, Taylor?
It's all about contact patch ... 22 or so psi would be max for the fronts.
Still, 135s are mighty slim.

TxT

Taylor,
Had the same problems before with 135’s.  I hated them and upgrading to a 145 looked ridiculous to me, it’s just a cm wider…    So I recently upgraded to 175/65/15 tires.  These tires are the exactly same height as a 145, so it looks good from the side!  No skinny too low smart tire look.  I ‘ve chosen for a Pirelli cinturato to stay in the theme, all though it’s a newer looking tire it isn’t too modern.  It’s a frequent size because the new mini coopers run them.  So I guess you can find them also pretty easy in the states.
I’ll never go back!   

Taylor,
How was that for a wild ride...Glad to read that  you are not talking about needing some bodywork to be done on your Dad's car.
Did you both head for the TP when you got home, there had to be some in your pants.

Steve

HMMMMM    I'm about to put new fronts on my car, found firestone F560 145's for 73 bucks thanks to a tip from Pep but after seeing Daryl's wide fronts the other day and now reading this along with Texas Tom's recent postings of wide fronts and my struggles driving around on my M&H's lately the thought of a wide patch is appealing. Heck maybe this falls into Jim's post of things to come....is the day of the 145 being the go to coming to an end? Big decision to make don't know if I can make the change from tradition but it seems a logical choice.

As for you question Taylor I'd say 135's are the main issue. I too run drums all the way around and although I do feel it's a risk they are for the most part adequate. There have been a few instances where fade has come into play but for the most part they keep up with what I need.  

I use a brake bias adjuster to keep the brakes balanced in a hard braking situation.

I think the biggest advantage in modern tires is the technology, not necessarily the extra width.

What shocks are you using? Weight transfer is also a very important factor.   

I'm doing what SOB did, adjust the brake bias. Make the rear tires work for a living. The optimal breaking is somewhere between free rolling and fully locked, this suggests to me that bumpsteer will also take away some breaking power.

Jon; Am I correct in thinking that SOB used bigger brakes in the rear, but no bias adjuster? I am setting up my oval with 60s brakes in the front and T3 in the rear and hope to achieve what You are describing.

yes better brakes at the back will help 'unload' all the braking power from the front, but non the less the 135's are not optimal. i had 145's on my type3 and that is way too skinny, now i opted for a To#¤ta prius tyre 165/65/15 pretty low profile, 165/70 would be ideal, but i like the look and the improved braking was the biggest benefit. also rake, isn't helping on our cars either.

Bendik; Yes he used beetle disk brakes in the front and type 3 drums in the back, but also a bias adjuster. I actually found his actual break system in my barn on Sunday. I havent touched the adjuster, want to try it out first.

Drums have more tendancy to lock up than discs, so a disc upgrade will definitely help.

I ran into this problem many times, braking hard and going straight.  What does one recommend for those 3-1/2 inch wide wheels?  A friend of mine mounted 165s on his.  I swear it looks odd.  I currently have 125s on my 3-1/2 inch wide wheels, I say it looks perfect, sidewall is not bulging out like how it would with 135s and 145s.

Lower the front tire pressure to 18psi, psi is all about axle weight.

OK guys, thanks for all of the suggestions.   

1.  Steve, it wasn't really that scary just surprising.
2.  I had the fronts at 24psi, ill lower it to 18-20.
3.  Front shocks are lowered oil shocks.

Maybe some wider fronts will be in order.

Nice thing about decrease in rolling radius is you increase leverage to the brakes vs a higher aspect ratio, with all else remaining equal

upgrade to disc brakes buddy !

Kinda reminds me of a guy who wrecked his split window 35 years ago !! I saw it spin and years later
met the driver......One wacky Steve Walker  !!!   :D

is it a wide 5 setup? as i understand it, the wide 5 T3 drum has a built in hub but the 4x130 needs a hub also....?

Is this so?
I always toughed decreasing front tire pressure will cause a tendency for more understeer during cornering.
So better braking but worse steering... :-\

I know... I know who needs to corner, but if you like daily driving with your looker...

I really get the look, but not the skinny tires in the front.
I drive with 165/65/15 up front(with discs), brakes good, corners good... also looks good in combination with 195/70/15 in the back... but that is my opinion.

Keep it save

Regards Edgar

I guess it all depends on where you drive and the conditions.

There's no way I'd drive on 135s, but that's a personal decision for me. I quite often NEED minimum braking distances to avoid wildlife and swaying trucks road trains, so I need more rubber and more leverage on it. I also drive on loose ball-bearing gravel everywhere too though, so if I go too wide on the front then it wont dig in for grip, and the front will just slide straight off the road.

I would prefer 195s on the front for the highway, but then it skids on the gravel because the front is too light for the width, 155s on the gravel are great but then it locks up on a wet highway. Between the two is the sweet spot for my conditions.

Yes a wide 5 set up

I agree, with 195's on the front of my old 67 it hydroplaned more than once. I think 185's are the best if your concerned about braking and handling on a daily driver.

SOB had a 5x130 setup, so separate hubs and drums at the back. And homemade (?) spindles up front.

That's probably the disc brake's greatest asset yet few people understand that. A disc tends to offer more modulation than a drum. A drum brake's force increases exponentially whereas a disc brake's force increases in a more linear fashion.

The tread across the 5.50-16 tires on the front of my roadster are only .25" wider than a 135 tread yet I can stand that car on its nose without locking a wheel. Of course weight transfer is much better in my car than a Beetle but that underscores the idea that it's not just the tire size that you're fighting.


You WANT to induce understeer on a Beetle, especially a swing-axle one. They oversteer like crazy. In fact Volkswagen added the front antiroll bar to induce understeer. Reducing tire pressure isn't the best way to induce understeer on an early Beetle but sometimes you have to use any means necessary.

By the way, reducing the front tire width also induces understeer. So if we really worried about inducing understeer then the last thing we'd do is install small tires up front. 

I don't think it's a way to induce understeer at all. Reduce the front tire pressure, front tires have more traction. When the front has more traction than the rear, that's oversteer. To induce understeer and get the front tires to wash out, they need to lose traction. Pump 'em up hard, or add the sway bar.

You're right that reducing tire pressure increases a tread's traction potential; however, that potentially increases longitudinal traction.

Reducing tire pressure also increases a tire's slip angle. Slip angle is the difference between the angle that the wheel points in a turn and the direction that the wheel actually follows. A softer tire is more prone to roll over in a turn and when it rolls over it loses traction. That induces slip angle. Vastly overinflating a tire will also increase its slip angle but you have to get to rock-hard pressure (like maximum inflation pressure on the front of a light car like a Beetle) to get there.

Well if we're going to discuss longitudinal traction, let's not ignore the fact that increasing the tire's slip angle invertedly decreases the rim's fractional width ratio to the bead of the tire versus the swept area of the brake pad caliper shoe. This then transmits the inertia's momentum to the backbone unibody structure of the front leaf torsion beam and affects the tire's contact patch with the road surface, causing further loss of gription. As you can now see, the simple act of discussing reduced tire pressures affects the entire characteristic of the car's handling, and most importantly that the keeping of ... an amphibious mammal for ... domestic ... yeah, that ain't legal, either.

You're just going off on a tangent (get it? the tangent across the tire in a slip angle? Nevermind. It wasn't that funny anyway).


Oh now you're just being oblique. You can be so obtuse at times. 


bwaaahaahaahaa!

fyi...less air not always better.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=2

The next test was run on our test course to confirm the influence of tire pressure on the tire's performance at its limit. While the drivers thought that the properly inflated tires provided responsiveness and predictable handling, they quickly realized that the same tires in an underinflated state left a lot to be desired. The underinflated tires required more steering input to initiate maneuvers and were slower to respond. The underinflated tires also felt out of sync during transitions; instead of moving in unison, the rear tires' reactions lagged behind the front tires, resulting in a detached sensation being transmitted to the drivers.

The underinflated tires delivered acceptable steady-state cornering force once they stabilized on our test track's skid pad, but the car was uncooperative anytime it was asked to change directions. It proved to be over 2 seconds slower around our test course (2 seconds represents about a 7% loss of handling performance).

In other words, the performance that tire manufacturers build in, low tire pressures can take away.

Just goes to show there's always a compromise, especially with these old cars. Lord knows they're not built to go 'round corners at speed!
Though somewhat futile, it would be interesting and maybe a little scary to take a 'Cal-Look' bug to a skidpad ... especially one with 135s!

Perhaps even arrange a comparison between say 135s, 145s, 175/65s ... even if they were all different cars.

I'll give Road&Track a call ...

TxT

The most important sentences in that review: "Adjust your tire pressures as indicated on the vehicle tire placard or in the owner's manual. Check your inflation pressures at least once a month and before highway trips."

Okay, I promise you that I'm not being a smart ass but it's sort of a given that an underinflated tire will not perform as well as a properly inflated tire will. I don't want to presume that you mean that we should overinflate our tires but I have to throw that out there so people don't get the idea that an overinflated tire will perform any better. Because no tire will achieve its best performance when overinflated.

A tire that maintains the most surface contact with the road achieves its greatest traction. But not even that can be taken at face value: a grossly underinflated tire (like a dragster slick) will achieve the most surface area...until it enters a corner. Laterally loading a grossly underinflated tire will cause the tire to deflect. The tread surface of a deflecting tire loses contact area with the road and therefore loses traction.

Conversely, a grossly overinflated tire will not achieve sufficient contact area with the road in any situation. You see physical evidence of that on 3/4-ton trucks. The vehicle manufacturer specifies only one tire pressure, the one that lets the tires bear the most weight. However, without the weight bearing upon them (empty truck) the tires will not comply sufficiently to maintain contact area. The middle of the tread wears prematurely which indicates that the tire does not achieve sufficient surface contact area.

I know that people have a hard time believing it but the seemingly low tire-pressure settings that Volkswagen recommended are within the range that lets the tires achieve the greatest contact area in most situations. Remember, tire pressure and load capacity are intimately related. Also remember that an ACVW is uncannily light--the front especially. So you can't draw any comparisons to the pressure settings that 'normal' cars have.

Sure, you can usually alter a vehicle's performance by manipulating its tire pressures but take care. For example, increasing front tire pressure makes a car turn in harder because it induces oversteer...which is a death sentence for a swing-axle car. And whatever you do, resist the urge to inflate tires to the maximum pressure indicated on the sidewall. That's merely the pressure required to make a tire bear its maximum load which is often greater than the weight of the entire vehicle.

That would be so awesome. Most enthusiasts live in blissful ignorance as to how poorly cal-look cars really handle. Volkswagens are already prone to oversteer and swing-axle Volkswagens really prone to WICKED oversteer. Lowering the nose induces even more oversteer. Eliminating the front antiroll bar induces even more oversteer. The stiff torsion bars and dampers that some racers favor induce even more oversteer.

The tiny front tires induce understeer but as we've experienced that's at the expense of traction. The narrowed beams and spring-rate increase that result both induce understeer but certainly not enough to compensate for the stance and swingaxle issue.

I'm not knocking Cal Look. I just want people to understand the consequences of their actions. I giggle a little every time someone observes how well their cal look car handles.

This braking and handling situation, or to be more accurate: the LACK of Both ... is the exact reason I moved to the 175 & 185 width front tires on my car. I did not pick them to satisfy a 'look', but rather a need.
The sidewall height is the same as the skinnier tires in question here, but the handling and braking is Far Superior.
Granted, I do have a set of M&H front runners on my track wheels that do occasionally see some street miles, but those things brake and handle about as well as pencil erasers ... then again, I'm still running those 4-piston Brembos! LOL

I would HIGHLY recommend at least trying a set of 175s ... same size tire as on a new-style stock Mini when they came out (don't know if they're still the same or not). I know they do also make the 175s in a shorter 55% aspect ratio, but I just don't dig the look or the ride.

On the other side of the coin, When I used to autocross my '67 I was running 155s and 175s. Never had a problem with over or understeer and didn't use any aftermarket suspension "upgrades".
It's only problem was being overpowered! ;D 8)

TxT

I'm not knockin' it because in some cases oversteer is fun but your results suggest that your car did in fact suffer an oversteer problem. In that particular application it worked in your favor. Racecars usually work better with slight oversteer. They turn in harder. Cars that oversteer a lot tend to do better on tight AC tracks (remember when swingaxle Manx buggies slaughtered the competition in gymkhana?). It likely would've been a different story on a longer, faster track. You might've ended up looking from whence you came!

Most people usually translate excessive oversteer as 'too much power.' Oversteer is the result of the vehicle transferring too much weight to the outboard rear tire (jacking on a swingaxle) and causing the car to go 'loose' (another term for oversteer). That's why you can reduce oversteer by fitting a wider rear tire, bumping the rear pressure just a little bit to bear the greater lateral load, or as VW did in '67 widening the rear track. Lowering the rear and/or raising the nose so the car sat level or slightly nose high would've gone a long way to reducing the oversteer and converting more power to acceleration. Of course that wouldn't be very cal look but it underscores the mayhem that Cal Look creates.

I don't intend for this to get into a handling discussion but this information may help explain why these cars act this way when we do these things in the name of aesthetics. Hopefully reality will scare off some people so the scene doesn't get watered down with copycats who don't get it, so to speak. 

Although your discussion of the potential causes and effects are interesting, the problem in this case was the car simply had too much power and when abused, yes, it would oversteer. Did the same with 185s.
There's a line you must observe, cross it and you've gone too far. That's the difference between a good driver and a perhaps one that's fun to watch. I was neither, but did have an occasional glimpse of both ;)

TxT

I've sent some pb's with Tom in the past and he really convinced me to try the 175/65's.  Like mentioned above: the sidewall height is exactly the same as a 145!!  Your car will become a REAL driver.  Try it, please!
I even like the look more, it's more in proportion now, when I look at photos of my previous "setup" : 135's and 205/70's it just looks silly and stupid.  Okay, start flaming now!  ;D
My point is, it really creates a whole different car.  I'm a huuuuuge fan.