Before pulling the trigger on a MA Shaw or Getty unit am checking for one here. The rear end gets light over 120mph
Maybe running 305/35's or 335/30's ra-1's in the back isn't helping?

 

Acropora

Since you have stock body, you should not be feeling the car light in the rear up until 150mph at least. I am not sure what the fat tires have to do with it?

I have a feeling you are still suffering from alignment problems, corner weight and/or ride height (rake), the GT2 wing without front lip will only make your understeer worse IMO.

 

Do you have an S spoiler in front?

 

You need the RSCS front splitter (GT2) inorder to run that tail as Jean says. However you can run the splitter without the tail. The front splitter requires the normally aspirated nose as well. So this is not a bolt on piece for the turbo cars. I did this conversion awhile back. It looks great and the added downforce is much greater than the S lip.

 

Should have mentioned a GT2 splitter is sitting in a box from iborrel, NA front end coming in soon from Canada.
Running stock front/rear pieces currently. Still waiting on the bolts for the GT2 tilt kit. Alignment is -2 camber all around, toe is 2mm in up front (turn in definitely was less noisy w/ more toe out previously). 1mm toe in for the rears, still fiddling w/ the compression/rebound settings on the shocks. Sway bars are in the middle setting. Rake is same as RS height difference front to back. Corner weight is well... not perfect yet.

 

Something is not right, I regularly drive over 120MPH on the track and have never had the slightest feeling of the rear getting light.

 

Brad,
Are you saying that the rear feels light on the straights, or at 120mph in high speed corners.
Not unusual in the corners, it needs more downforce. Need to balance the front with the right splitter. Mine is not for sale, I suggest Getty, or try FVD Germany. Willie Brombecker FVD actually provided the wings to Porsche, and he is amazing at finding the right parts.

 

Good point by JJayB, I assumed it was in straight line.

My problem with my car and the GT2 wing is that I need more donwforce in the front in high speed corners. I am working on a large CF straight lip that will be fitted under the front RUF bumper and protruding by 2 inches to the front to solve it.

Good to see you changed and went with same camber all around

 

jean i say got with the n-a front bumper cover and the GT2 / RSCA 3 piece splitter. I reinforced the 3 pieces with an aluminum straight lip.

 

Andy

The N/A bumper with the GT2 front splitter is not enough for timed sessions at the track IMO. It is a great street combo or for good straightline balance and DEs.

My GT2 EVO front bumper had a very nice front lip that extends quite a bit, the car was handling very well, it was night and day in the fast corners that had a change in camber vs the RUF CTR2 bumper.

It depends greatly on driving style and car setup for instance JJayB manages to be very fast with his combo.

I like my car to have an oversteer character. it took me a lot of time to set up the suspension but it was sure worth it, easily 2 seconds per lap.

Acropora BTW I would by an original GT2 wing, the others are pig heavy, I could not believe the difference in weight when I checked one out.

 

where can one get an OEM GT2 wing ? I have a carbon fiber one from MA Shaw currently

 

That my friend is a tuff call, check with Viper Bob he use to have one, maybe he knows of another.Sonny.

 

Andy,

If you have a CF one - you wont need an OEM one (other than having it of course!) I am sure they arent much heavier?

Simon.

 

Thanks for the pointers, need to look at the suggested aero options before pulling the trigger. Really like the look of the stock front/rear is the only reason I've been hesitating.
The car wants to rotate a bit too eagerly when trailbraking above 80mph but is great when braking straight. This seemed to worsen when going from shaved 335/30 to full tread 305/35 ra1's.
Didn't feel ready to go over 120mph on the back stretch of midohio this past weekend after nearly going off at 150mph before. Just going slow till the aero and suspension are worked out.

 

You certainly gave up a ton of rear grip with that tire change!