ditto , liek dave said my m3 felt more stable then my 996 does right now with suspension mods.

 

>> lowered the car to a height I love... <<

I have some experience at high speed and I can say I have never driven a well set up P car that didn't feel really comfortable at 190 + mph.

The part about "lowered the car to a height I love " is suspect. I seriously doubt the height you *love* is loved by your vehicle at high speed. : )

Think about it!


Cheers

R

 

I'm on pss10 and corner balanced, lowered 1.4 inches, and very stable at any speed, very neutral...do this mod or don't go fast.

 

when you do a corner balance do you have to do an alignment also with it?

 

the alignment comes after the corner balance...the problem with lowering the car out of spec (i.e. "to a height I love") is it throws off the corner balance and introduces bump steer (toe might be off also)....both will cause the car to "wander" at speed...the spring change doesn't seem to have helped the car at all...

 

I'm not an expert so anybody correct me...But yes, the corner balance involves small height adjustments and is really part of an alignment as I understand it.

 

just finished PSS10 and H&R bars...much better than stock but still too much float in the front end and the tail still steps out too much. Next step is dog bones and rear toe steer but this still wont solve the front end issues. Any suggestions.

 

I feel bad for you guy's who cannot get this car setup properly.... My car is SOLID, and much lighter then the turbos, find a better shop!

 

A few things that make the steering feel light... front tire pressure too high, front suspension height (relative to rear) too high, and/or stock aero dynamics (on non GTx)... Changing any of those will change the steering feel.

 

I will try to clarify, leave your springs, corner balance and weight bias alone for now.

When you "play" with ride height without respecting the front to rear slope of the car (rake), and if the front ride height is higher than where it should be, it will generate front aerodynamic lift at high speeds since less air Force is exerced on the top of the front bumper (downforce), and more air is entering underneath the front bumper, both result in higher front lift. The incremental air entering at speed under the front bumper due to higher nose has no exit and acts as if someone is lifting the front end, and this creates lightness at speed.

Your car might generate 100 lbs of lift. Cars setup for high speed runs always have additional rake dialled to them up to a certain point were aerodynamic drag becomes too important.

I would check tire pressures first , rake second (at least one degree), toe third, and castor 4th.

Corner balancing will impact your car's behaviour when cornering when there is mass transfer, not in much in straight line unless it is royally screwed up which would be surprising.

As to the 996GT3RS question, it has 4 times more downforce than the 996TT in the rear. And these numbers are at only 125mph, the higher the speed , the much higher the impact of downforce is, it is not linear.

Remember the picture at Le Mans of a MB backwards flipping in the air?

 

What is the correct tire pressure for a set of 19"?

 

My car feels the same. Coilovers would help I bet.

 

What he said, you need proper suspension for high speeds. You can have all the down force in the world but without the proper suspension its useless.

 

Maybe this is old school but I use this method...

Almost every tire has ^ marks where the sidewall and tread meet. I take some corners at 9/10th and check to see if the scrub marks on the tire are just at the tips of the arrows ^ then adjust pressure. This ensures you are getting the right contact patch.

I have 235/35/19 front and 315/25/19 rear and run 38/44psi.

 

You can have the best suspension in the world but have a very wrong rake or toe or castor setting and your expensive suspension is as good as garbage.

Sure it is easy to recommend MOTON and problem solved, only to find out he only needed proper settings $5k earlier!