I took a trip to Queretaro, Mexico in my car.

The asphalt on that highway is really good and it has some very large straights, on a couple of them my car did 155 MPH and it felt like it could do more, both times I ran out of room.

I didn't take a look at the tach, but I calculated the Autostick's theoretical top speed and it is 165 MPH, does this car have a speed limiter?

My Powerchip arrives this week, along with the increase in power it's supossed to remove the speed limiter (in cars that have one), I will give ir a try once I have it installed.

The car felt pretty stable at those speeds, but I did notice the hood shaking around quite a bit above 130 MPH, has anyone else noticed this?

 

The limiter is set for 150*, but at those speeds the speedometer could easily be off by five or so.

I've been to the limiter a few times (3) and haven't noticed any hood shaking going on.
Check to see if the hood bumpers (small rubber pads at the front corners) are adjusted evenly and don't allow the hood too much free play.

*At least the ones sold north of the border are.

Matt

 

I think the renntech stuff says something like 186 is the limit once the speed limit is removed.

-marc

 

Wow, 155mph, that is amazing.

I got mine up to about 125 without any hood shaking at all.

The car did start to wander a bit, and that scared the blank out of me. I slowed down to 115 and it felt fine.

Someday I may try 140 or so, but that is really pushing it. I remember it took quite a while to get from 100 to 125.

 

Just an FYI:

Over the weekend I was comparing the satnav's GPS recorded speed with the displayed speed on the dash. Interesting to note that at 120mph GPS, the dash reads just under 125mph.

 

Awww.....I so want to see 160 mph

 

Not that we have gone that fast, but we have compared our GPS Speed with the XF Speedometer - and it is Right On!!

 

Mine's stable right up to 140; No sign of any hood vibration.

 

ive had my xf up to about 146 and thats all the faster it would go, and that was a drag limited top speed for me. the road i was on was not perfectly level though.

 

Hey Crazy Mexican!!
How long do you think it took you to get to 155 :?:

 

Crazy Mexican, good one.

I didn't time my runs, but I can tell you that it didn't take me that long to reach those speeds.

The car just kept accelerating and it felt like it could do more.

I've had cars in the past that could reach those speeds, a Volvo S40 T4 200 HP (you don't have that version in the US) and a Seat Toledo Turbo 210 HP (you don't even have that brand) and it felt just as fast accelerating and it felt much more stable and composed.

I've driven many cars costing twice as much at those speeds and I have to say this car never ceases to amaze me, it drives like a more expensive car, oh wait, it is a more expensive car underneath.

I can't wait to try it once it's chipped!! I'm hoping to see 165 MPH, that would be absolutely amazing.

 

I work for the world's largest aotumotive parts manufacturer, and one of the many things I've built are speedo's.
The higher the speed, the more likely it will be off.
It's sort of an exponential thing, A 1 MPH error at 50 could end up as a 10 MPH error at 100.

Some will be perfect, most will be real close, and a few will be way off at anything over 100 MPH.

Matt

 

Maybe so, but the tach doesn't lie.

 

True. Any tach should be on the money.

There are just too many variables when it comes to figuring actual vehicle speed by measuring trans RPMs. Even tire pressure can change it a bit.
Even an error far too small to notice at normal driving speeds will add up.
Especially when you're going over twice the speed limit!

I hope your chip arrives soon!!! You'll love it!

Matt
-I'm afraid my 150 days are over, they opened the stretch of highway I was using...-

 

Matt,
AWWWWW! Bummer. What highway was that? They're never open when you need them, and I guess they open when you don't want them too!

 

They're adding a lane to I-75 near my place. The whole side was closed off! Nothing says "GO FASTER!!!" than a totally empty freeway!

I've found that the road crews can be very accomodating if you explain how you'd like to check out what your car can do.

Matt