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Location: Cambridge, MA
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37 - 40 vs. 45 - 51.5
what a difference these numbers make! I swapped wheels today. Here's the scoop:
Set 1 originally on car 7x9x17 Cup IIs with spacers Kumho Vicotracers 225F/255R 45 lbs each front wheel, 51.5 rear Set 2 now on car 8x9x15 Fuchs Old Comp T/As 225F/245R 37 lbs each front wheel, 45 rear The difference in unsprung weight is 16 lbs up front and 23 out back. What a change! Car feels significantly more agile and definitely quicker, pedal response is great, the car really jumps now. I loved the way the 17s felt on the car, very solid, but the 15s make it feel like you can move it around more. Can't comment on absolute stick, roads are pretty cold, some wet areas, and the Comp T/As are old technology, so it was just some sporting fun today. After (top pic) and before (bottom pic): 
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Tru6 Restoration & Design Last edited by Shaun 84 Targa; 02-06-2005 at 03:32 PM.. |
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02-06-2005, 03:18 PM
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Location: Galivants Ferry, SC
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Isn't that "After and before? " .........
???? Wil
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Wil Ferch 85 Carrera ( gone, but not forgotten ) |
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02-06-2005, 03:27 PM
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Sorry, yes, after and before.
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Tru6 Restoration & Design |
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02-06-2005, 03:30 PM
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Location: renton wa
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the other way Right?
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1987 911 carrera targa 1969 911 T still working on this one other oldies 1968 honda mini trail 50 ko model free bee came in boxes 1981 CR 250 R basket case rebuilt and running |
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02-06-2005, 03:30 PM
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Crusty Conservative
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Lookin good, Shaun!
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Bill 69 911 T Targa, 2.4E w/carbs (1985-2001) 70 911 S Coupe, 2nd owner (1989- 2015) 73 911 T Targa, 3.2 Motronic (2001- ) |
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02-06-2005, 03:54 PM
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Both look nice, but isn't it wonderful that our "outdated" Fuchs still have redeeming values? ( that they look great too isn't a bad thing either !!)
Wil
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Wil Ferch 85 Carrera ( gone, but not forgotten ) |
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02-06-2005, 04:25 PM
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drag racing the short bus
Join Date: May 2002
Location: Location, Location...
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Huh? 37-40 vs. 45-51.5 - I thought you were giving some sort of bizarre Superbowl score.
 Your weight experiences say a lot for the smaller Fuchs. I've heard some say the weight doesn't matter between large and smaller wheels on a 911, but nevertheless, first-hand experience helps. This is one reason why I'm hesitant to go to larger wheels. BTW, I don't believe that there's a lack of tires out there for 15-inch rims. I see plenty of rubber available for those wheels. I'd like to hear what you gain or don't gain on the track. Didn't you once post that you were able to break traction while using 16-inch rims? Hey! Philly just scored!
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The Terror of Tiny Town |
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02-06-2005, 04:33 PM
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there is definitely a difference in how the car feels.
Here's my round-up on wheel-tire experience: 17 inch Cup IIs with Victoracers: better tire than I am a driver, once hot, these things stick like 2-stage epoxy. don't expect to find the limit of these tires 17 inch Cup IIs with Pilot SXs: best tire I've ever driven on. extremely predictable, long lasting, stick like glue. better tire than I am a driver, never found the limit of the tires 7x8x16 Fuchs with SO3s: never liked these, squirmy at the limit although they did break away predictably, just not cleanly. 8x9x15 with the T/As: not enough data, but love the lightness. the only street tires that will work with hte 15s in this configuration are Dunlop 8000s, pretty much an AVS100 as I've heard them explained. When the T/As wear out, I'm getting some Avon slicks and hand-cutting some grooves in them. The Pats will come back. No worries there.
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Tru6 Restoration & Design |
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02-06-2005, 04:42 PM
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Team California
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OMG, at first I thought that you were refering to tire pressures.
 Thanks for the "butt-dyno" report on the lighter wheels. That is a good place to lose weight. 
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Denis |
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02-06-2005, 04:46 PM
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drag racing the short bus
Join Date: May 2002
Location: Location, Location...
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Yeah, tires for 15x9s might be a little difficult to find, but slicks - if they'll work - pretty much leave everything else blushing.
Oh, you're right. Pats just scored. 7-7. Boring game, though.
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The Terror of Tiny Town |
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02-06-2005, 05:02 PM
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218lb Lap Timer
Join Date: Sep 2004
Location: Livermore, CA
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What's the asphalt-to-wheelcenter distance change between the 15 and 17-inch wheel/tire setups. A shorter distance will enhance butt dyno results... The car will definately feel more torquey...
Nice ride, Shaun... Cheers!  Jojo
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Jojo '84 3.2 Carrera Coupe '00 Jeep Grand Cherokee LTD "If everything seems under control, you're just not going fast enough" -Mario Andretti |
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02-06-2005, 06:56 PM
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Rear diameters
255 40 17 21.02 245 50 15 19.82
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Tru6 Restoration & Design |
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02-06-2005, 07:33 PM
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Hmmm.. Those diameters are bit suspect. Might check that.
impressive weight difference though. Are those factory cupIIs?
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Chuck Moreland - elephantracing.com - vonnen.com |
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02-06-2005, 07:37 PM
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Quote:
A is section width in mm B is Aspect ratio C is wheel diameter in inches =(A22*B22/100/25.4)+C22 Yes, a set of polished factory Cup IIs with Wheel Enhancement spacers measured together. FWIW, an ealier set of standard painted/cleared OEM Cup IIs with the Pilots were a good 2-3 lbs lighter per wheel.
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Tru6 Restoration & Design |
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02-06-2005, 07:43 PM
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it looks like you've only added one tyre sidewall height not two
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Cheers, Ryan 1969 911E (historic racer) 911ST replica (tarmac rally) |
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02-06-2005, 07:47 PM
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Back in the saddle again
Join Date: Oct 2001
Location: Central TX west of Houston
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Yep, those would be tiny tires since the stock 16" tires are ~25" tall. I think Ryan's got you set straight. I'm surprised there's not a bigger weight difference going to the 15" Fuchs. Those TA's must be heavy tires.
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Steve '08 Boxster RS60 Spyder #0099/1960 - never named a car before, but this is Charlotte. '88 targa  SOLD 2004 - gone but not forgotten
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02-06-2005, 08:19 PM
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So did you put the 15x8s that normally came on the rear on the front? I was wondering if this would fit. I was thinking of moving my 8s to the front and getting some 16x9s for the rear since the 15x9s are unobtanium and there are a few more tire options.
Looks great.
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erik.lombard@gmail.com 1994 Lotus Esprit S4 - interesting! 84 lime green back date (LWB 911R) SOLD RSR look hot rod, based on 75' SOLD 73 911t 3.0SC Hot rod Gulf Blue - Sold. |
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02-08-2005, 08:15 PM
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They both fit. Rolling fenders is necessary though.
Even though I love this set up, and can just stare at the car for hours now, the 9s are going up on eBay soon.
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Tru6 Restoration & Design |
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02-09-2005, 08:42 AM
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1970 Porsche 911S 2.2l MFI
