TTurbine

I just read how Manthey's M600 GT2 shaved about 1 second off the stock GT2 tire specs by going with wider rubber in the Hockenheim on the same 600 hp car...

Since im running an identical power package im speculating that i might benefit from this setup?

The specs are as following...

265/30 ZR 19 Front
345/30 ZR 19 Rear

Do you think its worth going that far for better traction? any possible disadvantages with this setup ? Slower acceleration times? top speed? More understeer due to wider tires?

I understand the front tires will stick out which will possible increase drag , but if i go with this setup i will install there wheel arches... which has about 7 kilos extra down force..

Car is driven 12 times a year at the track...

thoughts greatly appreciated..

Moe

10 GT3

Stock or aftermarket/wider wheels? Those sizes are good for 9.5" wide front wheels and 13" wide rear wheels. If you aren't going with wider wheels, then no.

TTurbine

Ive checked with tire rack MSPC is availble in 345 and will fit 11.5" - 12" wheels
and 265 in the front will fit with 9" wheels..

10 GT3

Yes they may fit, but they won't handle well. Remember that all that tire now flexes on the rim when you enter a corner. It slows in turn-in as the car will not turn-in until all that sidewall flex is complete. A 325 tire on a 12" has a section width that is 13.2" versus 13.8" for the 345. The end result is almost 1" of additional sidewall flex before the car turns in. The only way to compensate is to add more tires pressure. This reduces contact patch and grip, hence completely negating the whole reason why you want a wider tire. Finally, those wider tires also weigh more adding more weight to the worst place: unsprung weight. You will be adding 4 lbs a corner as the 345 weighs 32 lbs versus the 325 that is 28 lbs.

There is absolutely no advantage to over tiring a car unless you are going for wider wheels. Don't believe everything in those specs. A 345 is optimal for a 13-13.5" wide wheel. Both Vipers and Enzos use that size on 13" wheels from the factory. Have you noticed that the spec on a Sport Cup 305 is speced for as wide as a 11.5" wheel. Yet, Porsche OEM puts this tire on a 12" wheel with only a 12.5" section width. Stretching the tire allows you to run less pressure gaining contact patch/grip and maintaining turn-in/handling.

TTurbine

I guess i stick with stock rims and tires for the mean time , untill i find wider wheels ,
Do you think it will be worth while having wider wheels and tires ? or as they say stock works best ?

Z06

If your looking into quicker laap times it can be done in chassis set up!

Lower 15 mm with bunp steer adj arms
Aggresive Alignment
2 piece solid rear control arms
DA Shocks/ with proper spring rates
This is a big part of the Manthey 600 to get those lap times!
I used Cargraphic Bilstein DA Shocks from the Tuner shootout, realy great and easy shock to set-up!

Z06

One more thing, if there is a reason to go with wider tires it's for more front end grip..not the rear!

When considering a set of larger front tires the front to rear ratio in diameter is important, do a search this it's a regular topic.

Do you have a second set of lighter than stock rims and if so do you have a R tire?

TTurbine

Z06 , I mainly track it with the corsa's , im aiming to get them on there limits first ( track time ) As i am a fairly novice driver , then i will use hoosiers with a dedicated track rims ,, im thinking of using the Manthey BBS rims any thoughts?

Step 2 im planning to install Mantheys KW suspension.

My alignment is -2.4 camber front and -2 rear , and max toe in the rear..

My LSD at the moment is being sent over to Gaurds for a 40/60 rebuilt. i Was basicaly tracking it with an open diff for some time ,,, no wonder my inner tire tread got worn out fast!!!

This is the tracks layout , as you can see is the reason i want more rear end stabilty

Freak997tt

Guys

Will those tires fir fine on stock OEM 997 GT2 wheels?

http://www.moderntiredealer.com/Chan...ot-a-drag.aspx

Freak997tt

Here is more info about new nitto NT05R tires

Tread Depth: 6.3

Inflated Overall Diameter: 27.36"

Dimensions Overall Width: 13.43"

Approved Rim Width: 12-13.5"


WILL THEY FINE ON STOCJK OEM 997 GT2 RIMS?

Z06

Are the Manthey BBS magnesium wheels in the proper size's? when I first saw them they were smaller than stock and cost mega money!

I chose the Champion RS98, very light with proper offset and width, plus for the price of the Manthey BBS you could get two set's of champion wheels!

For damper/shock I chose the Cargraphic (Euro Tuner Shootout) Race DA Bilstein shock.
These were dialed in by the Bilstein engineer's using the Motec data system at Hockenheim and the Ring.
They were originally on the Land RSR.

Have you compared the lap times at Hockenheim betweeen the Manthey and Cargraphic?

It took me zero time to get things dialed in!

With the Traqmate data system I have seen 1.6's g's with the stock MPSC.... i have no idea how accurate is the Traqmate.
Will soon install the Racelogic VBox lite.

If you did decide on going with the Cargraphic Bilstein set-up, tell Thomas S to get the same set-up as me...6th Gear Racing.

10 GT3

Moe,

I also believe you have your facts incorrect about the Manthey M600. It did not have the wider tire sizes you indicated. The Manthey M600 went faster with the following modifications:

1. Monoballs on upper front mounts with 1 additional degree of caster
2. Manthey/KW coilovers
3. 19x9.0 (.5" wider than stock) and 19x11.5 (.5" narrower that stock) wheels with stock size tires (235/325)

They make a lot of comments about how much lighter the BBS wheels and the benefit with less unstrung weight. From the article:

Freak997tt

StrekStrekStrekStreker forum

TTurbine

Z06 , Cargraphic Hokenheim times are much faster than Manthey's but that was on there 997 tt with awd... Those are damptronics correct?
Dont you think there is any downside since they were developed for the 997tt?

I found this one in cargraphics site..G97330291303GT2ALS
CARGRAPHIC Air Lift Suspension
P97 GT2
Motorsport suspension
997 GT2 BILSTEIN
Setting TUNER GP/TRACK
external reservoir
with AIRLIFT KIT FA
Operation via remote or switch
Price: 8.995,00 EUR /5

I assume yours is without the airlift?

I just checked out the Manthey BBS , there just too narrow...
I think i will go with the champions...

TTurbine

GT3 , Heres the translated part from the Sport Auto article talking about the M600 they had for the test....

"Yet the cheering falls at the first contact with the Small track in Hockenheim Not too frenetic from. While the moves M600, equipped with identical tires, the lap time of the Series GT2 by four tenths of a second handle. Easily go out of hand the progress 1.09,3 minutes, however. The impressive Einlenkpräzision the result that in the border area with an agile rear not only to be expected, but all too often is to handle well. Only with the delicate ride on the limit it is clear that the Hinterachsbereifung given the sharp rise in conditions sometimes feels overwhelmed.

And only with a newly stocked combination of special Michelin Pilot Cup tires is the fragile system of the sharpened 911 GT2 then again according to rights. The front end 265 and rear 345-millimeter-wide 19-inch wheels complete the package perfectly. And not only to the extent that the M600 is burning with fantastic 1.08,4 minutes, a new sports car's best time in the Hockenheim Motodrom."