Cowboy6622

Hey guys. I suspect a big part of it could be that its a former Hertz rental i think its detuned. With the factory 2.73 gears it was 6.5 on the factory track app. I went to a 3.27 i got in a deal where i helped a buddy put a 3.73 in his 02 gt and that got me to 6.2. Then an airraid cai i got in a deal from a friend who also sold me. Shock tower brace got me a 6.1.

That was that until last week. I wore out the factory Michelin high energys and had come to enjoy autocross. I knew i needed wider than a 17x7 so got a set of 19x9 19x9.5 off a gt performance package with new perillis, then put new hawk hp plus brakes on.

NOW i do 0-60 in 6.9 and the fuel muleage is down 4 mpg.

Did i royally screw with the computer? Do the brakes cause that much drag? Are the tires that soft and wide?

I got a tuner and talked to Bama. He suspects a tune issue so he is sending me a blank tuner to figure out what the codes on the computer are, and go from there. I hope a tune fixes this.

Has anyone rlse heard of any bizarre issues like this and what caused it?

JimC

Bigger wheels will add weight so performance will drop typically. Also, did you adjust the computer for the new tire size? That will throw off both your MPG and your speed.

JJHoover

wider tires causes more drag as well

Cowboy6622

But the books say the car should get 5.4 or something 0-60 and it was never there in the first place.... and I seriously doubt the tires and wheels would slow the car by a whole second. I've never seen more than a tenth or so.

I'm thinking rental car tune.... see what happens when the tuner gets here.

Chromeshadow

These can be programmed with the Key to be in the Valet mode, any chance that is the problem?

Cowboy6622

So far as i can tell no. It has my key, but i had tobget another key made at Ford for like 120 bucks and the car shows two administration keys

JimC

So you changed tire size but have not adjusted for the different tire revolution per mile then? That will also throw everything off - speedometer isn't reading the right speed so you show 60 but could be going faster or slower depending upon the tire difference.

Cowboy6622

The difference is like .8 mph at 65.

David Young

My 2011 automatic with 3.31 gears, 100% stock ran 6.1-6.2 0 to 60 times. With a tune it ran around 5.6-5.8 seconds to 60mph. Just something to give you a little to go on.

I'm in the high 4's now

ucinn

I have a 12 vert with tune and CAI with 2.73's and am doing a 6.1 with 93 race tune..gears and driveshaft are next. Ive got 19X8.5/19X10 staggered. The wheels aren't going to cause that much of a difference. It actually helped me because I can't break the invos loose like the stock wheels. I would try getting a proper tune for the changes you have made and go from there.