raked v. level & two-2s v. 4-the-same

[oasis]

What are the handling characteristic differences between a raked car versus a level car? ... and a car with larger rear tires than fronts versus all four tire being the same?

My situation: I have a 1971 1302 -- currently stock, but nearly ready for first GL mod. That mod will include MaXX struts or Kerscher struts, four-wheel disk brakes with 5x100 bolt pattern and these wheels (just purchased):
BBS RX-II (16x6½ et 42) wheels for VW
Also, my intent is to keep the stock fenders. (I'm keeping my post to American terms and spellings for consistency.)

Two of the wheels came with 205/55-16 tires. I was told to use 205/45-16 tires on the front. Although unwanted at first, the two supplied tires are in surprising very good condition and are actually closer in total diameter to the stock tires than the 45 series tires.

I'm trying to decide whether to go with 55s all around which (I'm guessing) would sacrifice some lowering up front*; go with the 55s in back and buy 45s for the front; or something else while also deciding whether the car should be extra lowered up front or kept level. (* maybe 55s won't work at all)

Important footnote: I am looking for better handling, not necessarily the best handling. While I realize this means a trade-off in harshness -- which is perfectly acceptable -- I do not want a total trade-off. Since my driving and riding experiences have been limited to Supers in stock condition mostly, I do not know how to quantify what I want.

[beetle1303]

the first thing to say is that your speedo readings wont be accurate.
If you want to keep as much as accuracy as possible you should go with something that has a similar perimeter. I havnt fitted my other wheel/tyres yet, but i have a quite stiff front end (1303) and stock 165/80r15 tyres and the car is really bouncy over speed bumps though and feels like hell is approaching when tried to pushed to the limit.

I believe that going with the 45s will give you better handling but they will be much more unforgiving compared to the stock tyres. meaning that the car might understeer in slippery conditions easier due to stiffer suspension and less (stock,anything you have in the boot but not added) weight to make it work...

Hope this isnt to frustrating

Chris

[oasis]

My tires say 165-r-15 (I added the dashes). I was told stock tires were actually 78 series. Anyway, the tire calculator site can be set for 80 or 75, so the conversion for 205/55-16 tires would be: 70 MPH reading is actually 68.58~70.38 MPH ... close enough for me. Now, I'm assuming the speedo is reading the rear wheels but I don't know that to be a fact. The 45 series tire is a smaller circumference.

Part of me would like the same size on all fours, but I'm concerned of rubbing the tires on the front if I stick with the 55s and lower the front -- even mildly.

So I guess a different query would be: Would 205/55-16s fit under stock front fenders when lowered 1½-2 inches? If not, would the understeer be more pronounced with 45s up front and 55s in back? 205/45-16s on all fours would be too screwy for the speedo (64.13~65.81 when reading 70).

[beetle1303]

About clearence the only thing that i can tell you for sure is that my mechanic is currently (about a year now) is running 225-40-18 tyres at the front on his 1303 and tyres rub on the springs ONLY at full lock or nearly at full lock, which is a matter only when manuevering in tight spaces. This is caused because he has stock fenders up front and the use of adapters would make things worse. point is that even is his car goes over a speed bump while steering there isnt any tyre rub. the car is lowered about 1 1/2"-2" and he is using a 3 bolt setup as 1302's and early 1303's.

What i told you before about understeering prob doesnt have to do only with the tyre's height (ie 45, 50 etc) but with the rest of the suspension setup, lowering etc. 1.5-2 " isnt that lowered in my opinion though. Not that i would go further than that


Chris

[rip]

frankly I'd go with the 55 series tire all around. Simply for the ride quality, 45's are going to be harsher, not to bad, but still... As for the understeer problem well I havn't messed with supers much. But I know if you tighten up the rear you can create a little bit more oversteer, or loosen the front up.

I don't think 205 will have serious clearancing issues, but again havn't really looked at supers. I'd use them as stated early you'd only have lock to lock problems.

I'd go with a level stance because of the way it looks, don't know if there is a big difference between stances, except for at really high speeds (95+). Keep asking that one hopfully somone more knowledgable will reply.

rip

[oasis]

I'm going to go with the 205/55-16s on all fours first.

I just got the MaXX strut kit, disc brakes, stress bar, front and rear anti-sway bars, camber+ adjust kit, and other stuff which is included from TopLine yesterday. I'll see my shop tomorrow and make an appointment. We'll see how the initial set-up goes, and tweak away if necessary.

[Supa Ninja]

Sounds like Oasis has finally been completely turned to the dark side . The Maxx struts with minimum lowering setting is going to put you pretty low to the ground. Try that first let the suspension settle for a couple of days and see if you like it.
The rear I would adjust it one outer notch. The speedo is powered by the front left wheel so it may be off a lil, you'll still have a idea of how fast your going.
I recommend for you to go with the 55's all around cause it sounds like you're not going it a whole lot and if you fill in some of the wheel well with tires it will look a lot better. If front tire rub becomes a prob then I'd go with the 45's.

Good luck, you'll love the set-up!
Nick

[Dennis]

A raked stance (nose down) on a car can cause handling problems if the caster of the front wheels is not adjusted to bring it back closer to vertical. Caster is the angle formed by the vertical centerline of the ball joints and the floor pan. The greater the change in this angle, the more unpredictable the handling characteristics become. The use of caster shims between the lower beam tube (on a std type 1) will help to bring the caster back to vertical. I'm not familiar with any methods of correcting caster on a Super, but I'm sure there is a way to address the problem.

[Chris Percival]

toplineparts.com sell caster fix bushes, that simply mount the anti-roll bar further forward.

[oasis]

Caster fix kit and the Flip-it bump steer kit come (actually came a couple of days ago) with the listed products above -- I forget what comes with what off the top of my head.

It's my understanding the MaXX struts used to be a 2½-inch drop at the first setting, but the newer struts are actually two inches or maybe a fraction less depending on the car's starting point. My 1302 has a pronounced nose-up look like models in the original brochures, so I imagine mine will be two inches.

I opened all five boxes yesterday and copied all of the installation literature which came with all of the parts. I delivered the copies to my lead mentor at the shop I frequent. As luck would have it, he was out sick yesterday.

Ironically enough, the TopLine printout for the struts still list 2½ inches as the first setting. I looked at the struts. I don't know exactly where I should measure with the units not on the car, but I'm hard-pressed to see two inches.

The rear settings will be interesting. From what I read, one notch may be too much of a drop.

If I remember correctly, there is a 1½- to 1¾-inch difference between the front and rear distances if measuring the current top of the tire and bottom of the fender (wing). Assuming the MaXX struts at the first setting lowers the front two inches, I would only be looking for a ¼- to a ½-inch drop for the rear. If one notch is more than that, I'll have a lowered nose-up stance -- not what I would be looking for.

Although quite pricey and although I received mixed reviews about them, I may bite the bullet and get adjustable spring plates for the rear if minor adjustments are necessary.

If 205/55-16s work, the speedo will not be that far off at all. The actual speed at a 70 MPH reading would be 68.58~70.38 MPH. (I listed a range because the calculator can compare a 75 series tire or an 80 series tire, and it is my understanding stock Beetle tires are actually 78 series. That being the case, a 70 MPH reading would be 69.66 MPH.)

I'm very excited about my first step to the Dark Side.

[rip]

oasis

as far as I under stand it, because I don't think any one had said it. The raked stance is better.

this is because with the nose down it doesn't allow for much air to flow under the body. This is often easy to understand, but the reason behind the higher, than front, rear end is so that little bit of air will enter will now be exposed to a larger volume, under the car. This larger volume is a decrease in pressure, thus a down force at the rear of the car is created.

The problem here is that the slope of the rear of the car is already shaped like a wing and the air is flowing very fast over the rear of the car, as compared to the underside, which creates lift. So I don't know if this will help alot.

But adding a wing and the raked stance should help.

[ECBug]

I read an article by an old racer that said on his super he kept the front end 1 inch higher than the rear and it handled better, I thought I read it hear but I cant find it. Oasis, didn't you get the kamei spoiler too? If so I would try to go level and a rear wing. JMHO

[oasis]

The stance of the car is slightly raked. The TopLine MaXX struts are at the first setting. The rear's stance went unchanged.

I did order a Kamei spoiler through the SBO! group buy. They haven't arrived yet so I don't have mine.

The car currently resides at the shop. The original plan was to take care of everything on a weekend. I'm not going into everything -- partly because of my penchant for producing long-winded posts, and partly because there is a whole lot of nothing going on. Some work was done during last week between customer's cars which needs repairs. I wasn't there for that. I'm not even sure I've been fully updated. (My schedule has been very full and I was away.)

The car looks good but at some point, I really need to drive it. At that point, I can give a comprehensive update, tweak anything that needs tweaking, and just plain move on with my project. I also promised a report on a shop in Manassas, Virginia, but I'm not showing up there without The Cruiser.

If the rear needs any lowering, I'll probably go with adjustable spring plates. They are pricey but I can't imagine more than a quarter-inch adjustment would be necessary. Any more than three-eighths of an inch may produce a nose-up stance. I already experienced that and at 68 MPH, a punter like me can feel an uplift.

[Wally]

Originally Posted by ECBug

I read an article by an old racer that said on his super he kept the front end 1 inch higher than the rear and it handled better,

IMHO, I tend to agree because more than aerodynamics, the caster of your car makes more difference in handling than the slightly changed airflow.
Nose down: less caster, hence the existence of caster shims on a standard.
Nose up: more caster, thus better straighline handling and straightline driving at high speeds is the most challanging in a bug, just like with that other rear engined car: the 911...

Nose down only looks better, but drives worse. Again, just mho.

Regards,
Walter

[oasis]

Great. All that money spent, and it's going to drive worse?! Maybe I can wait to drive it. Maybe my immediate circle was right; I should have kept it stock. So far, this has been more humbling than enjoyable.