Front Differential Chewed due to incorrect wheel/tire se up
Registered User
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Onibas, just get appropriate tires for your 997 wheels
and bolt them on without spacers. They should work
just fine that way. The techno spacer is just to
accommodate the the narrower sport-techno wheel.
Your 997 wheels aren't narrow.
and bolt them on without spacers. They should work
just fine that way. The techno spacer is just to
accommodate the the narrower sport-techno wheel.
Your 997 wheels aren't narrow.
Former Vendor
Joined: Nov 2003
Posts: 297
From: California
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Joe,
The Sport Techno wheels are 11x18 as are the stock 996 Turbo. The difference and the need for the spacer is because Porsche uses the same 11x18 Sport Techno wheel on both the narrow body 996 and wide body 996 C4S and Turbo. The 996 Turbo wheel has a 45mm offset, Sport Techno is 63mm. The 997 Turbo wheel is 51mm which would sit inboard of the stock wheel position by 6mm. Many aftermarket wheel manufacturers use an offset around 34mm so the 17mm spacer will be fine as long as the hardware doesn't hit the back of the wheel. By hardware I mean the lug bolts that hold the factory adapter (spacer) on the car.
The Sport Techno wheels are 11x18 as are the stock 996 Turbo. The difference and the need for the spacer is because Porsche uses the same 11x18 Sport Techno wheel on both the narrow body 996 and wide body 996 C4S and Turbo. The 996 Turbo wheel has a 45mm offset, Sport Techno is 63mm. The 997 Turbo wheel is 51mm which would sit inboard of the stock wheel position by 6mm. Many aftermarket wheel manufacturers use an offset around 34mm so the 17mm spacer will be fine as long as the hardware doesn't hit the back of the wheel. By hardware I mean the lug bolts that hold the factory adapter (spacer) on the car.
.
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Lots of racers use Complete Custom wheels. They are
strong and cost-effective. I have a set I've used for
6 years. http://www.ccwheel.com/files/wheelprofiles.php
They can make wheels to custom order with a backspacing
you can specify to within 1/32" for tight clearance applications.
I am running a 9.5"x18" front wheel with 265-35-18 tires.
Joe
strong and cost-effective. I have a set I've used for
6 years. http://www.ccwheel.com/files/wheelprofiles.php
They can make wheels to custom order with a backspacing
you can specify to within 1/32" for tight clearance applications.
I am running a 9.5"x18" front wheel with 265-35-18 tires.
Joe
Thread Starter
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Banned
Joined: Jun 2004
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Well fortunately 245/35/19's Conti 810S Winter Sport Fronts do fit on Cargraphic 19s but it is a case of a hairs width for tyre radius in the arches 
and boy do they look mean, tvm all for your help here and hope you don't have to go here. The moral is don't listen to your Cargraphic distributor when it comes to winter tyre recommendations ...
and boy do they look mean, tvm all for your help here and hope you don't have to go here. The moral is don't listen to your Cargraphic distributor when it comes to winter tyre recommendations ...
Registered User
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From: Colorado
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according to this post as long as there is less than a 0.5 inch differential between front and rear tires you should be ok...?
Here is some advice, i was in your situation a few weeks ago...
235/35/19 - 305/30/19 have a difference rolling diameter of .73
235/40/19 - 305/30/19 have a difference rolling diameter of .20
245/35/19 - 305/30/19 have a difference rolling diameter of .45
I run the 245/35 305/30 combo, only because thats the only sizes with a rolling diameter in a mpsc under .50 difference. I remember speaking to Damon via pm, and IIRC he said it shouldn't be a problem to run 235/35 305/30.
Because of the lack of sizes and cost of tires in 19's, i've been trying to find someone who wants to trade for something in an 18".
I'll let the pros chime in, i hope my advice helps!
235/35/19 - 305/30/19 have a difference rolling diameter of .73
235/40/19 - 305/30/19 have a difference rolling diameter of .20
245/35/19 - 305/30/19 have a difference rolling diameter of .45
I run the 245/35 305/30 combo, only because thats the only sizes with a rolling diameter in a mpsc under .50 difference. I remember speaking to Damon via pm, and IIRC he said it shouldn't be a problem to run 235/35 305/30.
Because of the lack of sizes and cost of tires in 19's, i've been trying to find someone who wants to trade for something in an 18".
I'll let the pros chime in, i hope my advice helps!
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Bottomline: I'm not saying it's ok, it's my only option.
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From: Colorado
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oh, well there has got to be a point where it is ok.
I just found this old thread where they state that a difference of 4% diameter is acceptable from front to rear. That means that on a 25 inch tire you could have the other tire be 26 inches in diameter and you would be ok. So was there more than a 4% difference in the OP's tires, or am I interpreting this data wrong? I don't think I am as they specifically stated % difference in diameter.
https://www.6speedonline.com/forums/...ference-2.html
I just found this old thread where they state that a difference of 4% diameter is acceptable from front to rear. That means that on a 25 inch tire you could have the other tire be 26 inches in diameter and you would be ok. So was there more than a 4% difference in the OP's tires, or am I interpreting this data wrong? I don't think I am as they specifically stated % difference in diameter.
https://www.6speedonline.com/forums/...ference-2.html
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All this technical jargon is very confusing to me. Can someone please tell me if these specs are ok with my 996TT?
Dunlop Sport Maxx GT
19x8.5-FRONT ET55 - 235/35/19
19x11-REAR ET50 - 295/30/19
If it's incorrect, which should I change and to what? Thanks wheel/tire gurus!
Edwin
Dunlop Sport Maxx GT
19x8.5-FRONT ET55 - 235/35/19
19x11-REAR ET50 - 295/30/19
If it's incorrect, which should I change and to what? Thanks wheel/tire gurus!
Edwin
Last edited by M32; Jan 8, 2009 at 09:19 AM.
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From: Houston
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you really should go to a 315/25/19 on the rear. The 295/30 is too tall for your car