3.2 Carrera track widening
Thread Starter
AutoX
Joined: Aug 2010
Posts: 12
Likes: 0
From: Ann Arbor, MI
3.2 Carrera track widening
I have just acquired a "plain vanilla" 87 911 with the OEM 16x6 front and 16x7 rear Fuchs wheels. I do not want to change the OEM tire size, but I want to increase the track width to the extent possible with the standard body (no fender lip rolling).
Would anyone know how much can I move the outer surface of the tire out (e.g. if I were to use hub spacers with the existing wheels, what size spacers would I need), front and rear, without fouling the fenders in full jounce? The car is not lowered and has the OEM springs and anti-roll bars.
I prefer to do this with 16 x 8's in the rear (smaller offset) if I can find any, and small spacers front and rear.
My rough measurements based on curb position are about 10 mm in front (20 mm track increase) and 20-25 mm in rear (40-50 mm track increase), but I have no way of verifying no fouling under jounce.
Thanks!
Yoram
Would anyone know how much can I move the outer surface of the tire out (e.g. if I were to use hub spacers with the existing wheels, what size spacers would I need), front and rear, without fouling the fenders in full jounce? The car is not lowered and has the OEM springs and anti-roll bars.
I prefer to do this with 16 x 8's in the rear (smaller offset) if I can find any, and small spacers front and rear.
My rough measurements based on curb position are about 10 mm in front (20 mm track increase) and 20-25 mm in rear (40-50 mm track increase), but I have no way of verifying no fouling under jounce.
Thanks!
Yoram
Rennlist Member
Joined: Feb 2004
Posts: 12,312
Likes: 10
From: Roseville, CA
If you just look at the static number of wider OE wheels, you end up with an inch on each side by mounting a 911 7" wheel in front, and an 8" in back. Is the front 7" at the ragged edge of rubbing, without rolling the fender lip? Sure, especially with a 225/50 tire. At the rear, a factory 9" is about 1/2" wider on frontspacing than the 8". So ultimately, keeping your wheels, about 3/4" in front, and up to 1 1/2" rear. But it's sure going to look funny.
I haddah Google dat
Rennlist Member
Rennlist Member
Joined: Nov 2008
Posts: 11,501
Likes: 5
From: Fresno, CA
I don't understand the question. I have a stock narrow body '84. With 7"s in the front and 9"s in the rear, the tires pretty much stick out of the bodywork as much as you'd want it to. Even with 205s, the fronts look like truck tires. I think the main difference between 9"s and 8"s is the rim width on the back side of the wheel.
Edit: OK, sorry....I see now that you have 6" in front, and 7"s in the rear. What you should do is move the 7"s to the front, and buy 9"s. No spacers. If you go with 8"s, then you still will not need spacers, and due to the narrower wheel, I think it would look funny to have the skinnier wheels moved much further out, plus your outer rim will be practically outside of the fender.
Edit: OK, sorry....I see now that you have 6" in front, and 7"s in the rear. What you should do is move the 7"s to the front, and buy 9"s. No spacers. If you go with 8"s, then you still will not need spacers, and due to the narrower wheel, I think it would look funny to have the skinnier wheels moved much further out, plus your outer rim will be practically outside of the fender.
Burning Brakes
Joined: Jun 2009
Posts: 1,211
Likes: 163
From: Bay Area, CA
My '85 is stock, with 16 x 6+7's, and the only mod being turbo tie rods. I'm happy with it this way, but given your question you might want to consider lowering the car to the "Euro ride height." As far as I know, the Euro cars were set lower, and the car was designed for that height, but in the US, they were set higher due to bumper safety regulations. You'll still need the same clearance whether it's lowered or not, but the look of the car will be affected by lowering as well as by changing wheels + putting in spacers.
Rennlist Member
Joined: Feb 2004
Posts: 12,312
Likes: 10
From: Roseville, CA
It's marginal. A 15mm offset 9" gives you just under 4" frontspacing. An 11mm 8" is just over 3 1/2". (Now if you want to throw in '86 944 Turbo Fuchs into the mix, it all goes weird. But a 23mm offset 944 T rear 8" works great on the front of a torsion bar 911, with a 15mm offset 9" in the rear. Tire fitment is a bit tricky on the front, if you're not hacking things into a track car.)
Thread Starter
AutoX
Joined: Aug 2010
Posts: 12
Likes: 0
From: Ann Arbor, MI
Gentlemen, thanks for the good inputs. My intent is to keep the original tire sizes for the street, therefore rather keep the stock 6" and 7" wheels (not easy or inexpensive to get hold of 8" OEM Fuchs, as I am finding out...).
So the question remains: How wide a spacer can I use if I keep the rims and tires as is front and rear to prevent rubbing?
My guess is 10mm, maybe 13mm front, 25mm in the rear. Any experience supporting or refuting this?
Thanks,
Yoram
So the question remains: How wide a spacer can I use if I keep the rims and tires as is front and rear to prevent rubbing?
My guess is 10mm, maybe 13mm front, 25mm in the rear. Any experience supporting or refuting this?
Thanks,
Yoram
Banned
Joined: Apr 2009
Posts: 977
Likes: 2
Yorman,
Do yourself a favor, save for the Fuch 8's in the rear and keep your 6's up front if you want to cheap out. Put a 205 on the front and lower your car to euro height and you will achieve what your looking for. The spacers will look stupid with 7's in the rear as the rim lip isnt wide enough.
Do yourself a favor, save for the Fuch 8's in the rear and keep your 6's up front if you want to cheap out. Put a 205 on the front and lower your car to euro height and you will achieve what your looking for. The spacers will look stupid with 7's in the rear as the rim lip isnt wide enough.
Trending Topics
Thread Starter
AutoX
Joined: Aug 2010
Posts: 12
Likes: 0
From: Ann Arbor, MI
Rereading all inputs...
Ken,
Thanks a bunch. I am tending to follow your figures conservatively and use 13 mm spacers in the front and 28 with my stock 6"/205 and 7"/225 wheels/tires. You think this set up would look funny? Why? I cannot visualize the problem. Is it because the brakes would look tucked too deep behind the wheels?
Ricster and Oldskewel,
You guys planted a seed regarding lowering the car... But similar question for Ricster as for Ken: Why would the spacers look stupid? Because the brakes would be burried too deep inside?
Thanks again,
Yoram
Ken,
Thanks a bunch. I am tending to follow your figures conservatively and use 13 mm spacers in the front and 28 with my stock 6"/205 and 7"/225 wheels/tires. You think this set up would look funny? Why? I cannot visualize the problem. Is it because the brakes would look tucked too deep behind the wheels?
Ricster and Oldskewel,
You guys planted a seed regarding lowering the car... But similar question for Ricster as for Ken: Why would the spacers look stupid? Because the brakes would be burried too deep inside?
Thanks again,
Yoram
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Drifting
Joined: Nov 2003
Posts: 2,981
Likes: 2
From: Virginia
Why do you want to increase the track?
It sounds like its a cosmetic issue.. cosmetically speaking, the larger "dish" of the 7,8,9 in wheels will look SOOOO much better than just pushing your stock wheels out. The stock 6" wheel has almost no dish at all to the wheel lip.
Also, if its cosmetic only, have you considered aftermarket Fuchs wheels? http://www.automotion.com/wheels-and-tires.html offers "fakes" in 8 and 9" for about $250ea compared to the $1000-2000 people charge for real.
It sounds like its a cosmetic issue.. cosmetically speaking, the larger "dish" of the 7,8,9 in wheels will look SOOOO much better than just pushing your stock wheels out. The stock 6" wheel has almost no dish at all to the wheel lip.
Also, if its cosmetic only, have you considered aftermarket Fuchs wheels? http://www.automotion.com/wheels-and-tires.html offers "fakes" in 8 and 9" for about $250ea compared to the $1000-2000 people charge for real.
Rennlist Member
Joined: Jul 2002
Posts: 16,557
Likes: 94
From: Bend, OR
If you want performance, there is no substitute for wider rubber. If you want looks, go with spacers and call it a day. As I recall, you can use 1" at rear but as noted, fronts can get tight. Maybe 7mm.
Banned
Joined: Apr 2009
Posts: 977
Likes: 2
Ricster and Oldskewel,
You guys planted a seed regarding lowering the car... But similar question for Ricster as for Ken: Why would the spacers look stupid? Because the brakes would be burried too deep inside?
Ugly as sin, on spacers...trust me. It looks awkward. I think its probably the dish of the 7's in the rear. I work for a Porsche dealer and can say I have seen the spacers and it just looks..weird. Pony up or save up for 8"s and you will not regret it...trust me. I have 8's on my 86 carrera and it looks awesome. Lowering a car is a must also to get the right stance. I put the 8's on last year when I was putting on new rubber...I had put the bridgestone re-01R tires that tire rack had a deal on, well once I put them on my new 8's the car's stance looked way too tall, when it looked fine with the 7's in the rear. See the slippery slope here? So I decided to re-fresh my suspension with new rubber, sanders bars and lowered...corner balanced, and aligned. I must say it feels as if its on rails. So you get the look and performance all wrapped up in one.
You guys planted a seed regarding lowering the car... But similar question for Ricster as for Ken: Why would the spacers look stupid? Because the brakes would be burried too deep inside?
Ugly as sin, on spacers...trust me. It looks awkward. I think its probably the dish of the 7's in the rear. I work for a Porsche dealer and can say I have seen the spacers and it just looks..weird. Pony up or save up for 8"s and you will not regret it...trust me. I have 8's on my 86 carrera and it looks awesome. Lowering a car is a must also to get the right stance. I put the 8's on last year when I was putting on new rubber...I had put the bridgestone re-01R tires that tire rack had a deal on, well once I put them on my new 8's the car's stance looked way too tall, when it looked fine with the 7's in the rear. See the slippery slope here? So I decided to re-fresh my suspension with new rubber, sanders bars and lowered...corner balanced, and aligned. I must say it feels as if its on rails. So you get the look and performance all wrapped up in one.
Thread Starter
AutoX
Joined: Aug 2010
Posts: 12
Likes: 0
From: Ann Arbor, MI
Gents,
Thanks for your insights. It is primarily a performance issue but also a cosmetic consideration.
My main goal is to push up the oversteer limit but not the "cornering stiffness" - not make the car "over-tired" to a point where it is an "on-off" car in public road handling. I will look closer into lowering. My concern with 245-16 rears is that to keep the gearing close to stock you need to use 45 profile, for which the only tire available is the Fusion ZRi. If you go with 50 series you increase the gearing by 3-4%, depending on the tire. I feel that with the stock drivetrain (remember, this is a "plain vanilla" car...) the car is already slightly overgeared in first and second (tend to drop to first in tight corners to not lug the engine), and I don't want to make it worse.
As to the cosmetics, I guess my eye is not well enough trained yet in 911 aesthetic etiquette, so I am not yet aware of the negative aspect of not enough dish or lip, but I may get into it over time.
My last Porsche was an '88 944 Turbo S (which I really miss...) with the gorgeous flat 928-like forged anodized wheels (no dish at all), and I never pondered much the unique world of Fuchs cosmetics...
Admittedly, I did use larger aftermarket 5 spoke cast wheels and tires to track it (I still have them for mostly nostalgic reasons), but that was purely track-performance vs. cost driven.
So... unless I find some 8"s soon, I'm afraid it would be spacers (shudder)... I hope you guys do not excommunicate me for it...
Thanks again and cheers,
Yoram
Thanks for your insights. It is primarily a performance issue but also a cosmetic consideration.
My main goal is to push up the oversteer limit but not the "cornering stiffness" - not make the car "over-tired" to a point where it is an "on-off" car in public road handling. I will look closer into lowering. My concern with 245-16 rears is that to keep the gearing close to stock you need to use 45 profile, for which the only tire available is the Fusion ZRi. If you go with 50 series you increase the gearing by 3-4%, depending on the tire. I feel that with the stock drivetrain (remember, this is a "plain vanilla" car...) the car is already slightly overgeared in first and second (tend to drop to first in tight corners to not lug the engine), and I don't want to make it worse.
As to the cosmetics, I guess my eye is not well enough trained yet in 911 aesthetic etiquette, so I am not yet aware of the negative aspect of not enough dish or lip, but I may get into it over time.
My last Porsche was an '88 944 Turbo S (which I really miss...) with the gorgeous flat 928-like forged anodized wheels (no dish at all), and I never pondered much the unique world of Fuchs cosmetics...
Admittedly, I did use larger aftermarket 5 spoke cast wheels and tires to track it (I still have them for mostly nostalgic reasons), but that was purely track-performance vs. cost driven.
So... unless I find some 8"s soon, I'm afraid it would be spacers (shudder)... I hope you guys do not excommunicate me for it...
Thanks again and cheers,
Yoram
Team Owner
Joined: Aug 2005
Posts: 28,461
Likes: 1,631
From: Cambridge Ontario Canada
.. you will not be excommunicated for spacers .. but you will be excommunicated for not posting a pic of your ride 
BTW I have 7s on the back for spring and fall and 9s on the back fro summer driving with HP tires. so thorhetically ou could go with a 1" spacer ..
however my 9s are 17 inch rims with a stiff sidewall tire .. a softer sidewall tire on a smaller rim may flare out under loadng and catch your fender..
BTW I have 7s on the back for spring and fall and 9s on the back fro summer driving with HP tires. so thorhetically ou could go with a 1" spacer ..
however my 9s are 17 inch rims with a stiff sidewall tire .. a softer sidewall tire on a smaller rim may flare out under loadng and catch your fender..
Rennlist Member
Joined: Jul 2002
Posts: 16,557
Likes: 94
From: Bend, OR
A 911 has a trailing throttle oversteer tendency, no matter what you do. If you are concerned about this, join PCA and get some DE or AX days in. Doing such will teach you how to make use of the 911 design's abilities.