Bye-bye 245 / 45 / 16... Hello noob alignment

[Discseven]

Originally Posted by bpu699

How do you plan to bend the struts? Adjustable camber plates are available.

Bo

Darrin first suggested strut bending being a solution. But he does not know exactly how it was done. He has provided contact info to his mechanic. TY Darrin

Originally Posted by darrin

My mechanic in Denver (Jim at Eisenbud's) "solved" the problem I've had with inside front tire wear by slightly bending the front struts (apparently my front suspension was at adjustment limits too). Apparently a common solution for them and I've seen MUCH more even front tire wear since then with no perceived effect on stability/steering effort/etc.

Originally Posted by darrin

Unfortunately, I didn't personally witness what they did -- you might want to try calling them -- Eisenbuds-Fine Service of Porsche, Mercedes, Audi and VW 303.825.0322

[Bill Verburg]

Originally Posted by Discseven

TY for diagram. Rear is 245 / 55. Without thinking about effect of increased diameter, surly I've self adjusted way I drive to compensate to a degree. Will now apply a more studied sense to performance and comment later on this.

Ok here's the results for 245/45 vs 245/50(per the receipt)



There's additional degradation due to weight further from the axis of rotation but it's difficult to quantify w/o a dyno

[wwest]

Originally Posted by Discseven

Would like to call them. Pls PM me their number and who I should speak with. TY Will. LOL on quiet. That is a concern after I get the car set up to make them last!

What size are they? I might be interested.

Very nice on charity

OMNI Brake and Alignment, four two five 823-1511

Off of 2001 C4, 18", factory standard.

[JAR0023]

Someone mentioned the Scruggs pamphlet. Well worth the time to track down a copy. It helped me a great deal. I've completed exactly one home string alignment and 20k miles later I'm still seeing nice even tire wear. Strings can be tedious but if you are careful and diligent you can get your setup just as good as a high dollar machine.

Another tire option is out there now. Toyo Proxes T1R is back out in 245/45r16. The hitch with the T1R is the front. Front option is 195/55r16. You'll lose half an inch in section width and height. I'll stick with the RE-11s. I've gotten almost 18k out of the rears (they need replacing) and the fronts have a ton tread left.

FWIW my alignment specs are close to what Pete Z recommends. Daily driver with some hooliganism thrown in.

Front - 1/16" total toe in. / .6 degrees negative camber. / caster around 5.8

Rear - 1/32 - 1/16" total toe in. / 1.2 degrees negative camber.

[Trackrash]

A couple of things. Negative camber may increase IF you have worn strut inserts or other worn suspension components. Bent struts can make the problem worse as well.
The lower the front goes, the more negative the camber.
There are offset ball joints, not sure if they can make more positive camber.
On my '71, I used a strut brace to force my shock towers apart. I was able to get zero camber with my car lowered.

[rattlsnak]

245/55? That's a Nascar tire! Huge! I had to run 245/50s once and it looked way out of place.

[Flat Six]

Originally Posted by darrin

keep in mind that your larger diameter rear wheels will cause your car's gearing to become taller, which could affect its perceived performance.

Don't forget that the taller rear will increase forward rake, which effectively lessens caster . . . .

[Discseven]

Originally Posted by Bill Verburg

Ok here's the results for 245/45 vs 245/50(per the receipt)



There's additional degradation due to weight further from the axis of rotation but it's difficult to quantify w/o a dyno

Interesting chartographics Bill. TY. Have not been out yet since this realization so am curious to see if I can sense it.

[Discseven]

Originally Posted by JAR0023

Someone mentioned the Scruggs pamphlet. Well worth the time to track down a copy. It helped me a great deal. I've completed exactly one home string alignment and 20k miles later I'm still seeing nice even tire wear. Strings can be tedious but if you are careful and diligent you can get your setup just as good as a high dollar machine.

Another tire option is out there now. Toyo Proxes T1R is back out in 245/45r16. The hitch with the T1R is the front. Front option is 195/55r16. You'll lose half an inch in section width and height. I'll stick with the RE-11s. I've gotten almost 18k out of the rears (they need replacing) and the fronts have a ton tread left.

FWIW my alignment specs are close to what Pete Z recommends. Daily driver with some hooliganism thrown in.

Front - 1/16" total toe in. / .6 degrees negative camber. / caster around 5.8

Rear - 1/32 - 1/16" total toe in. / 1.2 degrees negative camber.

Yeah... got email for Scruggs and phamplett is supposedly here in Pelicanworld somewhere but haven't dug it up yet.

TY for specs you're running JAR. Am curious how you DIY calculate "o.6 degrees neg camber?"

[Discseven]

Originally Posted by Trackrash

A couple of things. Negative camber may increase IF you have worn strut inserts or other worn suspension components. Bent struts can make the problem worse as well.
The lower the front goes, the more negative the camber.
There are offset ball joints, not sure if they can make more positive camber.
On my '71, I used a strut brace to force my shock towers apart. I was able to get zero camber with my car lowered.

Track... my car is lowered (until new tires!) Looking at top of my struts, do you know if top can be pushed (further out) against car? There's about 1/4" space there.

[Discseven]

Originally Posted by Flat Six

Don't forget that the taller rear will increase forward rake, which effectively lessens caster . . . .

TY for input Flat. Neg ramifications of larger tire size... definitely increasing. Am pondering the evil I have done.

[Trackrash]

Originally Posted by Discseven

Track... my car is lowered (until new tires!) Looking at top of my struts, do you know if top can be pushed (further out) against car? There's about 1/4" space there.

It's hard to tell from the picture. But it is worth trying to push them out as far as you can. Look under the fender, as the strut mounts can hit underneath as well. I took my strut mounts off and squished them in a vice to make them thinner, in an effort to gain more adjustment. Every little bit helps.
Make SURE everything is TIGHT on your front suspension. I once found I had a loose wheel bearing and that made it seem like I had negative camber on one side. A loose strut insert can cause the same effect.

[Discseven]

Originally Posted by Trackrash

It's hard to tell from the picture. But it is worth trying to push them out as far as you can. Look under the fender, as the strut mounts can hit underneath as well. I took my strut mounts off and squished them in a vice to make them thinner, in an effort to gain more adjustment. Every little bit helps.
Make SURE everything is TIGHT on your front suspension. I once found I had a loose wheel bearing and that made it seem like I had negative camber on one side. A loose strut insert can cause the same effect.

Nice crush move Gordon. TY on input.

[KTL]

Toe is easy with a set of toe plates from Longacre. Here's the Scruggs book. Send him some money as a thanks.

Toe Adjust Techniquest

How does the 205/55 look/fit on the 16x8 front? 205 on an 8 in. wheel is stretching that tire a bit. Typically a 205/55 is recommended for a max wheel width of 7.5 in.

I am willing to bet your front toe is currently a mess with tires that have inboard shoulders like you show. That inner shoulder wear is typically not what an old 911 will show. These old 911s have one heck of a time getting any decent amount of negative camber. Tires that look like that either have a boatload of negative camber or a ton of toe-in. So I suspect that is toe related or a badly bent strut. I've tracked 911s with a group for about 10 yrs and the stock-ish ones always have a ton of outer shoulder wear on the fronts, with not a lot of inner wear. My point of mentioning the track driving is that it accelerates tire wear and shows you what kind of wear you could expect to see after several thousand miles of street driving.

[Evan Fullerton]

Barring any wild deviations from stock, proper alignment specs are always going to be a moving target and driver specific. The stock Porsche alignment specs are designed around reasonably spirited street driving. Drive like a Grandma or some aggressive canyon work or spirited track use and poor tire wear will result. Uneven tire wear is the nature of the beast for a sports car. If your getting more them 10k miles out of a set of higher tread wear street tires on any Porsche with a factory alignment, your doing ok.

You can back off the specs for longer freeway tire life but when driving spiritedly, performance will suffer. There is no magic alignment setting, it is all about matching it do the drivers requirements and the rest of the suspension set up.

That said, bent struts are a common thing and may be a cause of not being able to achieve alignment goals. At typical ride heights with un-bent stock parts, between 1 degree negative and 2.5 degrees negative appears to be the normal range most cars can achieve. Ride height, bushing age/quality, and chassis differences affect on which end of the scale any particular car falls and/or ability of exceed the boundaries of this range.

[Discseven]

Am having to eat my rear tire size as given. It's not 245 /55. It's 245 / 50. You guys must have thought me insane with the 55.

My Bad. My apology.

Here's front/rear size confirmation.




Went back to TirePlus today and asked what their "policy towards a customer who didn't like their tires was?" They said they'd replace all provided I bought the replacements from them. Damm nice. They got a new, dedicated customer. Gonna sleep on it.

[SilberUrS6]

Originally Posted by Discseven

Am having to eat my rear tire size as given. It's not 245 /55. It's 245 / 50. You guys must have thought me insane with the 55.

On my 16x8 + 16x9 combo, I have 205/55s on the front and 245/50s on the back. As it turns out, the speedo is dead, nuts on at all speeds up to 75 (the highest I went over a time course). But, as I have said before, not all tire makers measure their tires in the same way. My experience with Kumho is that they are narrower and have shorter sidewalls than the nominal size would suggest. The speed trials bear this observation out.

[Discseven]

Originally Posted by KTL

Toe is easy with a set of toe plates from Longacre. Here's the Scruggs book. Send him some money as a thanks.

Toe Adjust Techniquest

How does the 205/55 look/fit on the 16x8 front? 205 on an 8 in. wheel is stretching that tire a bit. Typically a 205/55 is recommended for a max wheel width of 7.5 in.

I am willing to bet your front toe is currently a mess with tires that have inboard shoulders like you show. That inner shoulder wear is typically not what an old 911 will show. These old 911s have one heck of a time getting any decent amount of negative camber. Tires that look like that either have a boatload of negative camber or a ton of toe-in. So I suspect that is toe related or a badly bent strut. I've tracked 911s with a group for about 10 yrs and the stock-ish ones always have a ton of outer shoulder wear on the fronts, with not a lot of inner wear. My point of mentioning the track driving is that it accelerates tire wear and shows you what kind of wear you could expect to see after several thousand miles of street driving.

Again am going to correct REAR tire size as I initially posted. Excuse = senility. Here's larger images of 205 /55 / 16 front and 245 / 50 / 16 rear. And TY for input Kevin.

[Discseven]

Originally Posted by Evan Fullerton

Barring any wild deviations from stock, proper alignment specs are always going to be a moving target and driver specific. The stock Porsche alignment specs are designed around reasonably spirited street driving. Drive like a Grandma or some aggressive canyon work or spirited track use and poor tire wear will result. Uneven tire wear is the nature of the beast for a sports car. If your getting more them 10k miles out of a set of higher tread wear street tires on any Porsche with a factory alignment, your doing ok.

You can back off the specs for longer freeway tire life but when driving spiritedly, performance will suffer. There is no magic alignment setting, it is all about matching it do the drivers requirements and the rest of the suspension set up.

That said, bent struts are a common thing and may be a cause of not being able to achieve alignment goals. At typical ride heights with un-bent stock parts, between 1 degree negative and 2.5 degrees negative appears to be the normal range most cars can achieve. Ride height, bushing age/quality, and chassis differences affect on which end of the scale any particular car falls and/or ability of exceed the boundaries of this range.

Good commentary Evan. Makes perfect sense. TY

[Discseven]

Originally Posted by SilberUrS6

On my 16x8 + 16x9 combo, I have 205/55s on the front and 245/50s on the back. As it turns out, the speedo is dead, nuts on at all speeds up to 75 (the highest I went over a time course). But, as I have said before, not all tire makers measure their tires in the same way. My experience with Kumho is that they are narrower and have shorter sidewalls than the nominal size would suggest. The speed trials bear this observation out.

Take a look at larger car pics just posted above. Size is yours Eric... but for manufacturer deviations. Did you roll front fenders?