I'm back in a 911 and some 15x7 tire rub/shock questions on a hot rod

[MrBonus]

So I've decided I'm done with non-Porsche toys. I tried to think my Lotus could be a 911 and while it is an amazing little machine, it isn't where my heart is at.

Fortunately, I had the opportunity to purchase a very nice '71T hot rod with a very punchy 2.7 out of a '77.

The shocks are definitely in need of replacement and it's wearing some old 196/65/15 P6000s on a set of 15x7 Fuchs that I will be replacing. I note on hard turns they do lightly rub the outer rear fender wells. I have read 500 threads on this basic issue but do you think going to 205/55/15s will remedy this issue? I'm noting the big, bulbous sidewalls seem to be the culprit of the rubbing more than the top of the tire, so I'm hoping a half inch of height shaved off and smaller sidewalls will remedy the issue.

Also, I think the car is wearing uprated torsion bars of some sort and a set of tired Konis. Shall I replace with HDs or Sports?

It's great to be back! The car otherwise drives like a dream.

[Jonny042]

I would say, at first glance, I wouldn't change a thing!!!! A little rubbing on the inside is no problem IMO. But you you could add 5mm spacers in front without much trouble to lessen it perhaps.

[MrBonus]

Originally Posted by Jonny042

I would say, at first glance, I wouldn't change a thing!!!! A little rubbing on the inside is no problem IMO. But you you could add 5mm spacers in front without much trouble to lessen it perhaps.

Sorry, I clarified the rubbing is in the rear fenders! Also, thank you.

[jpnovak]

I think you need some rear negative camber. This will pull in the top of the rear wheels/tires and give you some more clearance.


The front quarter picture almost looks like you have positive rear camber. Though this could just be angle of photography.

Beautiful car!

[MrBonus]

Originally Posted by jpnovak

I think you need some rear negative camber. This will pull in the top of the rear wheels/tires and give you some more clearance.


The front quarter picture almost looks like you have positive rear camber. Though this could just be angle of photography.

Beautiful car!

Hah, perhaps. I just went to the garage and there is very little negative camber if any at all. Thank you!

[jpnovak]

Can you tell where it is rubbing?

Is it rubber on the lip? This means the tire is too far outboard. Too much camber is usually the top reason. Could also be too wide spacer (if any) , too wide wheel (or offset), or too wide tire.

Is it rubbing further up on the underside of the fender? This means that you do not have enough spring rate, the tire is too wide or the tire is too tall. Or a combination. The 65 series tire is quite tall.

Is it rubbing on the front or rear edge? This could be incorrect toe settings.

[MrBonus]

Originally Posted by jpnovak

Can you tell where it is rubbing?

Is it rubber on the lip? This means the tire is too far outboard. Too much camber is usually the top reason. Could also be too wide spacer (if any) , too wide wheel (or offset), or too wide tire.

Is it rubbing further up on the underside of the fender? This means that you do not have enough spring rate, the tire is too wide or the tire is too tall. Or a combination. The 65 series tire is quite tall.

Is it rubbing on the front or rear edge? This could be incorrect toe settings.

It has clearly been doing it for quite some time (as noted by the paint burn). It doesn't look too severe based on the condition and age of the tires. The 7s are quite wide, but the 65 series tire is really quite tall, and it looks like the contact/rub is the upper bulge of the sidewall, which is why I'm hoping a wider but lower 205/55 tire will fix the issue.

[MrBonus]

Also, I'd rather not change the wheels because frankly, they just look fantastic.

[Bill Verburg]

Originally Posted by MrBonus

It has clearly been doing it for quite some time (as noted by the paint burn). It doesn't look too severe based on the condition and age of the tires. The 7s are quite wide, but the 65 series tire is really quite tall, and it looks like the contact/rub is the upper bulge of the sidewall, which is why I'm hoping a wider but lower 205/55 tire will fix the issue.

You are correct is believing that the tire height is the issue

a 215/60 which is a tad wider and taller will rub in the same place

any of the following will be ok

205/55 @ ~23.9"
205/50 @ ~23"
195/60 @ ~24.2"
195/55 @ ~23.4"

Additionally Bilstein Sport rear will help, these work well w/ Bilstein HD front

Check T- bars too, 20/26 w/ S or SC sways is a very nice street setup

[MrBonus]

Originally Posted by Bill Verburg

You are correct is believing that the tire height is the issue

a 215/60 which is a tad wider and taller will rub in the same place

any of the following will be ok

205/55 @ ~23.9"
205/50 @ ~23"
195/60 @ ~24.2"
195/55 @ ~23.4"

Additionally Bilstein Sport rear will help, these work well w/ Bilstein HD front

Check T- bars too, 20/26 w/ S or SC sways is a very nice street setup

Thanks, Bill. I think I'll go with the Sport/HD setup. I'd rather not mess with the torsion bars unless I continue to have issues.

[MrBonus]

So it looks like the Sport Bilsteins are only available for the '72 and on cars. I'm stuck with HDs as my sole option.

[Bill Verburg]

Originally Posted by MrBonus

So it looks like the Sport Bilsteins are only available for the '72 and on cars. I'm stuck with HDs as my sole option.

from the current Bilstein catalog for '71 911
Part Number: 24-009676
Series: B6 Performance
Notes:
- Club Sport Version
- Setting: 1800/1645
- For use with M14 lower mounting bolt 24-009676

Part Number: 24-009737
Series: B6 Performance
Notes:
- Rally Version
- Setting: 2855/1400
- For use with M14 lower mounting bolt

Part Number: 24-009751
Series: B6 Performance
Notes:
- Sport Street Version
- Setting: 3365/1645
- For use with M14 lower mounting bolt

Part Number: 24-001670
Series: B6 Performance
Notes:
- Standard Version 1
- Setting: 2385/1330
- For use with M12 lower mounting bolt

Part Number: 24-001694
Series: B6 Performance
Notes:
- Standard Version 2
- Setting: 1965/1330
- For use with M14 lower mounting bolt

Part Number: 24-595452
Series: Motorsports
Notes:
- RSR Version 1
- Setting: 1800/1700
- For use with M14 lower mounting bolt
- Requires additional components and racing springs

Part Number: 24-617321
Series: Motorsports
Notes:
- RSR Version 2
- Setting: 2400/1800
- For use with M14 lower mounting bolt
- Requires additional components and racing springs

[MrBonus]

Originally Posted by Bill Verburg

from the current Bilstein catalog for '71 911
Part Number: 24-009676
Series: B6 Performance
Notes:
- Club Sport Version
- Setting: 1800/1645
- For use with M14 lower mounting bolt 24-009676

Part Number: 24-009737
Series: B6 Performance
Notes:
- Rally Version
- Setting: 2855/1400
- For use with M14 lower mounting bolt

Part Number: 24-009751
Series: B6 Performance
Notes:
- Sport Street Version
- Setting: 3365/1645
- For use with M14 lower mounting bolt

Part Number: 24-001670
Series: B6 Performance
Notes:
- Standard Version 1
- Setting: 2385/1330
- For use with M12 lower mounting bolt

Part Number: 24-001694
Series: B6 Performance
Notes:
- Standard Version 2
- Setting: 1965/1330
- For use with M14 lower mounting bolt

Part Number: 24-595452
Series: Motorsports
Notes:
- RSR Version 1
- Setting: 1800/1700
- For use with M14 lower mounting bolt
- Requires additional components and racing springs

Part Number: 24-617321
Series: Motorsports
Notes:
- RSR Version 2
- Setting: 2400/1800
- For use with M14 lower mounting bolt
- Requires additional components and racing springs

Thanks, Bill. It looks like I want:

Rear

https://www.pelicanparts.com/More_Info/24001670.htm?pn=24-001670-M512&SVSVSI=911E&DID=12989

Front

https://www.pelicanparts.com/More_Info/P36112.htm?pn=P-36-112-INT&SVSVSI=911E&DID=48034

[MrBonus]

Sorry, I'm on Bilstein's site, and all '69 - '71s use the M12 mounting bolt, correct? I don't want to accidentally order the wrong item.

[Bill Verburg]

Originally Posted by MrBonus

Sorry, I'm on Bilstein's site, and all '69 - '71s use the M12 mounting bolt, correct? I don't want to accidentally order the wrong item.

thru '71 the lower shock bolt was M12x1.5x85
from '72 on it is M14x1.5x95

[Joe Bob]

65 series tires are way too tall for spirited carving of turns. 55 or 50 would be a better fit.