It's not the tire size, 235/55/18 is a factory GT tire size, and when I had my 2011 GT, I ran the factory Pirelli A/S 235/55/18's up to 150mph many many times.

If you're going to be driving at those speeds at the drop of a hat (unplanned in other words) than you should be checking your tire pressures regularly.

Since the tires are new, I have to ask, how many miles are on them now? I've always noticed brand new tires feel squirmy at higher speeds until the rubber release agent wears off completely.

Also, the tires you bought are an all-season high-mileage rubber compound according to the Yokohama website, meaning they're not very sticky, so regardless of the speed rating, I would be cautious with that specific Yoko tire model period.

With the ABS feeling you encountered, it could have been just that if the Dynamic Stability Control was kicking in trying to save your butt.

Yeah...

Improving high speed stability
 

Holy shit.

How long did it take to get up to that speed? You had to of been in od right?

It wasnt that long tons of room on the autobahn, i dont know the exact though.

I shifted into 6th alot with 3.73s and boost

The problem is that a base GT suspension is just fucking straight up garbage. WAY too tall, WAY too soft, and WAY too un-dampened, with tires that are WAY too narrow for a 3600lb 400hp car.

A friend and I took a road trip in a 2012 GT auto from Hertz. It had 14k on the clock. At anything over 115 it was a complete disaster. Any cross wind at all would have had us flying off the road. We finally agreed to limit ourselves to 105 even though it had plenty of power for 140+. It was just too hairy at high speed.

You guys going over 120 with any regularity in a stock suspension GT are idiots. Sorry if that's you. You may not have enough high speed driving experience to realize when you're in over your head.

To fix: replace the springs, struts, and wheels/tires with just about anything from the aftermarket.

Agreed. Well said, Danny. The thing about the 5.0 suspension is that the car is heavy and when everything is going okay, the car feels solid and smooth giving a false sense of confidence. The problem lies in when the suspension comes unsettled and it quickly becomes a nightmare.

I think I had my car over 100 once before I dropped it. My F-150 felt more stable at 100 MPH than the car did.

With the suspension setup now, it feel much more planted and stable, but still sketchy as hell when you hit a small divet in the road....thanks SRA!

FWIW, the Brembo GT and Boss 302 suspension is much better than the basic GT suspension I was talking about above.

Details on "old car" and said event. A legal and legit 2 bills is way cool.

Who said anything about doing it 'with any regularity'? And I hardly consider myself an idiot nor do I believe anybody else does who knows me. I have hit 120 twice in the 'Stang and even though it was smooth (as I said in my post), I immediately backed off because I was aware of the dangers of the moment. And I just might have enough high speed driving experience to know when I'm over my head.

Don't take it personally, Danny really didn't mean anything directly at you. He's just a point black type of guy and not one to spare anyone's feelings. Partly because he's an asshole, the other part cuz he's lazy and it just takes too much effort to be polite. I can kind of relate to that. lol

No event I was stationed in Germany from 2007-2012. Driving over there is like driving on racetrack 24/7. Cops dont really patrol the street like here. Sold the car when I left and the motor didnt make it much longer with the new owner. He used if for ring and autobahn abuse. With the suspension I mentioned above and the PS2s it was an awesome combo. I think it would have lasted but for some reason he put the stock plugs in it and played with the timing with the handheld.

When I had it
http://i32.photobucket.com/albums/d2...T/DSC_0524.jpg

New Owner
http://i32.photobucket.com/albums/d2...psca31a6d7.jpg

Don't be too sensitive. The car, as Ford built it, is squirrelly as fuck at high speed. But that's easy to overcome with a few aftermarket parts.

Well alignment scheduled for Wednesday plus them checking out why my gauge cluster goes dead while driving. Service advisor didn't know if I need a 2 or 4 wheel alignment so she wrote down 4