mk1 vs mk2 rear track measurement.
05-26-2010, 11:24 AM
#16
Nordschleife Master
Sure, a 12" et 35 would "fit" with enough modifications. But your question was based on stock width not modifying it.
I can tell you that running a 315 in the rear of a MkI will absolutely be the worst decision you could make for the track. To give you a data point, I ran the fastest time on track in my GT3 with a 280 rear! I would suggest sticking with either 285 on a 10" wheel or 295 on an 11" wheel with the proper offsets.
Take it from those of us that have run every tire, tire size, wheel, wheel size, etc, than you could imagine. What you are trying to do is not optimal for your car.
So, to follow up my first question now that I know you want to run it for the track, I would ask WHY you want to run that size (i.e., what are you trying to get from it)???
I can tell you that running a 315 in the rear of a MkI will absolutely be the worst decision you could make for the track. To give you a data point, I ran the fastest time on track in my GT3 with a 280 rear! I would suggest sticking with either 285 on a 10" wheel or 295 on an 11" wheel with the proper offsets.
Take it from those of us that have run every tire, tire size, wheel, wheel size, etc, than you could imagine. What you are trying to do is not optimal for your car.
So, to follow up my first question now that I know you want to run it for the track, I would ask WHY you want to run that size (i.e., what are you trying to get from it)???
05-26-2010, 01:32 PM
#17
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I would agree with Dell on this one. I track my mkII pretty seriously with 295 MPSC rears on 11" wheels and 235s on 8.5" front wheels. Already the front-to-rear grip ratio is on the verge of being sub-optimal at certain tracks that bring out understeer (my sig pic notwithstanding). Going with an even wider rear wheel/tire would only make it worse. If anything, next step for my car would be to try to fund a way to run a wider front tire to reduce understeer.
So, what size fronts are you hoping to run? And critically, have you found any rear track tires (with matching fronts) that can take advantage of that extra 1/2 of rear wheel you are trying to achieve? No point in getting creative ($$) with the 11.5" wheel if nobody makes a set of track tires that need that last 1/2" of width, right?
So, what size fronts are you hoping to run? And critically, have you found any rear track tires (with matching fronts) that can take advantage of that extra 1/2 of rear wheel you are trying to achieve? No point in getting creative ($$) with the 11.5" wheel if nobody makes a set of track tires that need that last 1/2" of width, right?
05-26-2010, 01:49 PM
#19
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That's a great plan. But even so, I would stick with 11" rears. You can run 295's or even 305's back there on the 11's and it will be well-balanced with the 265's up front. I would run that setup.
Again, ask yourself what's the extra .5" of rear wheel actually going to accomplish for you? ...and is that worth the hassle?
Again, ask yourself what's the extra .5" of rear wheel actually going to accomplish for you? ...and is that worth the hassle?
05-26-2010, 01:59 PM
#21
Nordschleife Master
That setup is going to be a speed killer for you since you just don't have the power to work those tires properly. But, if you want to run it, nobody but you gets to decide that 
05-26-2010, 02:38 PM
#22
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Also, minor point, but it's not solely a matter of having or not having "the power to work those tires properly", but also of vehicle weight. Assuming this is a relatively normal 996, I would guess it does have sufficient weight to get heat into a 265/295 combo if driven well (i.e. speed carried into and through the corners consistently).
Just sayin'
05-26-2010, 03:28 PM
#23
Nordschleife Master
That's probably true at some tracks, but not every track. Yes, the wider combo will suffer from increased weight, drag and rolling friction, but at some tracks this could be a worthwhile trade-off for increased average speed through turns. (assuming lowest laptime is the objective rather than feel or fun). At other tracks you will be correct.
Also, minor point, but it's not solely a matter of having or not having "the power to work those tires properly", but also of vehicle weight. Assuming this is a relatively normal 996, I would guess it does have sufficient weight to get heat into a 265/295 combo if driven well (i.e. speed carried into and through the corners consistently).
Just sayin'
Also, minor point, but it's not solely a matter of having or not having "the power to work those tires properly", but also of vehicle weight. Assuming this is a relatively normal 996, I would guess it does have sufficient weight to get heat into a 265/295 combo if driven well (i.e. speed carried into and through the corners consistently).
Just sayin'
Just sayin'
05-26-2010, 08:08 PM
#25
Rennlist Member
I'll just tentatively chime in as I hardly post anymore. I have a well developed MK1 and at one point ran 265 front on a 9.5 and a 315 rear (still do in fact). The car turns in incredibly.
Depending on the driver's talent it is not too much tire for the car. And all temp targets were attained for the camber that I run. 3ish front and high 2s in the back.
I did drop the 265 down to a 245 on the same wheel to pick up some straight line speed but kept the 315s as the rears.
I am wearing the rears now 2x as fast as the fronts on this setup where as with the 265s I was pretty even front to back. However, I am driving the car more on the edge so that may be a contributor.
Dunno if this helps.
I would give the offset and size for my rear but I can't honestly remember as this car has been stored the last 6 months. I think it is a 10.5 ET60 and that is maybe 2mm inside the horizontal plane of the fender. Yes the lips are rolled.
Depending on the driver's talent it is not too much tire for the car. And all temp targets were attained for the camber that I run. 3ish front and high 2s in the back.
I did drop the 265 down to a 245 on the same wheel to pick up some straight line speed but kept the 315s as the rears.
I am wearing the rears now 2x as fast as the fronts on this setup where as with the 265s I was pretty even front to back. However, I am driving the car more on the edge so that may be a contributor.
Dunno if this helps.
I would give the offset and size for my rear but I can't honestly remember as this car has been stored the last 6 months. I think it is a 10.5 ET60 and that is maybe 2mm inside the horizontal plane of the fender. Yes the lips are rolled.
05-27-2010, 07:57 AM
#27
Nordschleife Master
05-28-2010, 07:55 AM
#29
Nordschleife Master
Have a Turbo and a MkI CAB as well as a GT3 from a local guy that is coming over to do brakes. Not sure if the measurement from the GT3 would be the same as a MkII non GT car.
