himself

In another thread, there was a statement that a GT3 stock suspension is not "matched" to Hoosier R6s. There was some mention of R6 spring rates not being matched to the suspension, and not maximizing grip levels.

This got me thinking, and I realized I have no idea why this is true, or even what it means.

Can one of the suspension/setup/tire gurus please explain to the class what this means? Should I be using a less sticky tire? Do I "need" to upgrade something to be better matched?

Thanks!

-td

Veloce Raptor

IMO, it's not true. But you have to prepare yourself for more body roll & quicker wear of bushings, etc.








Professional Racing and Driving Coach

Bob Rouleau

Nonsense. A stock GT3 works well on Hoosier R6, 18 inch Michelin Cups (the real ones not the N rated street version).

You need a proper alignment though. Neg 2.5-2.7 in front neg 2.4 in back.

Perhaps whomever gave you the advice meant real racing slicks and I would agree with that. But DOT R compounds were made for the GT3

Best,

U4EEAH

That's absurd. Perhaps they meant cannot fully exploit all of R6's grip, which is true, a full race setup will get more out of them. Far softer versions of the 911 than GT3's will benefit from R6's, just can't get all their potential.

Paul 996

Ditto,

TD, thanks for jumping in the other thread, I had already given up.

I do just love the "facts" provided by all the experts.

911SLOW

There is no sane person that would argue that the 996! gt3 springs of 225 F
550 R and suspension are not an ideal match for the r6 which is not a simple n-spec dot tyre but mach closer to slick. And that the suspension was not designed for such tyre or slicks of course.

To take full advantage of the R6 you need to match the suspension.

Here is the thread. https://rennlist.com/forums/996-foru...for-996c2.html

Veloce Raptor

.....

himself

At what level of grip do negative side effects start manifest themselves?

-td

FredC

Incredible.... I agree with you VR, this one is tough to let slide by...

himself

This is turning into a giant debacle - which was not my intent. *sigh*

-td

911SLOW

This is a good question. The simple answer is probably when grip "overpowers" the suspension..

To find the optimal spring rate you need a good driver and a track and perhaps the right equipment. For example Cargraphic spent 6 days in Hockenheim with 3 engineers from HR and Marc Basseng driving to develop this spring kit mainly for 996 gt3 drivers that use Michelin cups or equivalent semi slicks and not the street ps2 tyre that the 996 gt3 suspension was designed for.
I happen to own one of the test sets, it still has the test tapes on the springs and all. It worked. But because I have upgraded again, I can lend it to you to try it yourself.


John

911SLOW

Also note that Porsche never installed a Dot tyre to the 996gt3.
It only used the average Nspec corsa system which is more of a street tyre than semi slick on the 996gt3RS which btw again had altered spring rates compared to the gt3 to compensate.

John

beentherebaby

Tires have a spring rate based on both carcass design and air pressure. Tires can be designed for a wide or narrow targeted vehicle application. There are series specific tires to match the basics of the cars in that series. There are DOT series tires to match production car based suspensions used for HPDE and Club racing purposes.

Tuning the suspension of a vehicle to optimize the tires performance is ideal but that does not mean that for instance an R6 won't function just fine on any number of vehicles with an OE suspension because the tire design is not model specific. The OE suspension may not allow you to take full advantage of ANY tire if it is not optimized for the application. Stickier tires can induce greater vehicle roll with OE suspensions and result in undesired suspension geometry changes.

Where the rules limit suspension changes there are occasions where one tire performs better on certain models than another for a variety of reasons. The only means to tell is to test. When in doubt test.

dan212

I personally would not run Pilot Cups on the street, but the stock GT3 suspension is absolutely fine for MPSC (Pilot Cups).

The stock 996/GT3 suspension is great for Pilot Cups. I have friends who run Hoosiers on stock suspension. The only thing I would advise before heavy track use is upgrading the toe/drop links (very inexpensive). This has zero effect on handling performance and is considered just prudent a safety upgrade that has no negative effect on street use.

Out of the box, the 996/GT3 is a marvelous track car. Aligned as much as the stock arms will allow its a joy to drive off and on the track.

By all means use the "real" Pilot Cups on the track. The only reason I don't suggest them for street use is the wear rating (which is why they are sticky) and the very shallow tread which makes them less than ideal (safe) on the street in the rain. Changing the suspension wouldn't make a difference in that regard.

I drove my 996/GT3 on the track with stock springs/shocks etc for two years with Pilot Cups and had a blast. I knew stiffer would be easier and maybe faster to drive, but wouldn't make ME a BETTER driver.

I did finally changes springs and shocks, solid motor mounts, shock mounts etc etc. Car rides like a brick on the street but is much easier to drive on the track. I love the change, BUT changing the suspension didn't make me faster. I still had to be a better driver. The stock suspension had forced me to be smooth and then appreciate what the stiffer settings communicate and let me do.

So my advice is get your car decently aligned and enjoy one of the greatest cars to drive on the track. Out of the box it is amazing.. Have fun!

Bull

+1. All that is needed is a proper alignment and you are good to go.