Traction Trouble

[willrc]

I have a 2007 Mustang GT. It has a Power Stop Big Brake Kit, AMR silver wheels 19x10 &19x8.5, Continental extreme contacts tires, BMR suspension kit, Koni struts and 2 inch lowering springs, 3.73 ring and pinion, and a True Trac differential etc... So, I've run it at Gingerman Raceway a couple of times and the rear wheels grip the track fine however the front tires are sliding thru the corner at the same time. I can't fit wider tires in the front so why not run stickier tires up front? I know you don't want to get to a place where the front tires are grabbing and the rears are breaking lose, but the rear tires are wide enough I have no trouble with traction back there.

 

[Mad Hatter]

Most of us run with square tires sizes such as 315/30-18's, its good size on all four corners. 2" in drop can lead to all kinds of odd quirks in your handling. Koni Yellows?? BMR Adjustable sway bars?? What position is it in?? To stiff up front will give you understeer.

with only 19x8.5 wheels up front, its most likely too little rubber on the road for starters..

 

[EF1]

I have a 2007 Mustang GT. It has a Power Stop Big Brake Kit, AMR silver wheels 19x10 &19x8.5, Continental extreme contacts tires, BMR suspension kit, Koni struts and 2 inch lowering springs, 3.73 ring and pinion, and a True Trac differential etc... So, I've run it at Gingerman Raceway a couple of times and the rear wheels grip the track fine however the front tires are sliding thru the corner at the same time. I can't fit wider tires in the front so why not run stickier tires up front? I know you don't want to get to a place where the front tires are grabbing and the rears are breaking lose, but the rear tires are wide enough I have no trouble with traction back there.

Wheels sound like a drag race set up. Skinny fronts will push in corners. Like Mad Hatter suggested you can tune suspension to minimize it but you really need wider front wheels for road course.

 

[KazarS197]

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I agree with @Mad Hatter - more rubber up front. I'll add with a 2" drop I would definitely get an alignment and max out front camber with focus on the toe at zero to minimal toe out and maxed castor. With an 8.5 in wheel you can max out at with 255 tires. If that size is too big now maxed out camber will give you more space on the outer fender and might help with tire size. If you still have room with a 255 then match up the 19x10 up front and - more rubber and rotatable for tire life.

 

[blacksheep-1]

295s are the minimal upfront on a 10 inch wheel, also I would question whether you have enough camber. Once you address that, we can go from there.
also when you say "BMR suspesnion kit" what exactly does that include?

 

[KazarS197]

295s are the minimal upfront on a 10 inch wheel, also I would question whether you have enough camber. Once you address that, we can go from there.
also when you say "BMR suspesnion kit" what exactly does that include?

Ya - my post looks weird. I was trying to say if after he gets an alignment and if he has room with the 8.5 in wides up front with 255 then get another pair of 19x10 for the front and match the rear tire size.

 

[willrc]

Ya - my post looks weird. I was trying to say if after he gets an alignment and if he has room with the 8.5 in wides up front with 255 then get another pair of 19x10 for the front and match the rear tire size.

front sway bar link, MOOK80899, front strut bellows, Front strut bearings, front sway bar link, stabilizer bar, orange Koni struts with 2-inch lowering springs, engine and transmission mounts, and a rear sway bar. And once it was lowered a front 19x10 would not fit. the front and rear tires are Continental Extreme Contact DWS06 PLUS, Fronts are 255/40zr19 100xl, rears are 285/35zr19 99y. The rear tires never slip cornering while the front are sliding. I'm thinking about buying some Michelin Pilot sport 4s for the front tires.

 

[willrc]

front sway bar link, MOOK80899, front strut bellows, Front strut bearings, front sway bar link, stabilizer bar, orange Koni struts with 2-inch lowering springs, engine and transmission mounts, and a rear sway bar. And once it was lowered a front 19x10 would not fit. the front and rear tires are Continental Extreme Contact DWS06 PLUS, Fronts are 255/40zr19 100xl, rears are 285/35zr19 99y. The rear tires never slip cornering while the front are sliding. I'm thinking about buying some Michelin Pilot sport 4s for the front tires.

If I can't run a wider tire up front, I thought I could compensate with a stickier tire.

 

[KazarS197]

front sway bar link, MOOK80899, front strut bellows, Front strut bearings, front sway bar link, stabilizer bar, orange Koni struts with 2-inch lowering springs, engine and transmission mounts, and a rear sway bar. And once it was lowered a front 19x10 would not fit. the front and rear tires are Continental Extreme Contact DWS06 PLUS, Fronts are 255/40zr19 100xl, rears are 285/35zr19 99y. The rear tires never slip cornering while the front are sliding. I'm thinking about buying some Michelin Pilot sport 4s for the front tires.

Are you talking about mixing tires front and back? Having different tire properties around could get you in a hell of a situation. It might be OK in a straight line but around bends in my opinion I would not do. What if the fronts actually hook and the rears don't? There are too many factors to concider - operating temperature, different tread, age of tire with hardness, air pressures ( does one tire do better at a different hot pressure), side wall roll plus probably others - that's all I could quickly think of. Where are the 19x10s hitting up front? What about rolling the fenders? Sorry, I know it's work and a pain. Are you able to put a 19x10 upfront and take a few photos where you have clearance issues? The guys here have been through many suspension and wheel setups. There might be an economical solution.

 

[blacksheep-1]

If I can't run a wider tire up front, I thought I could compensate with a stickier tire.

That's a false economy, true mustangs tend to be pushy, but pretty much everyone on TMO has managed to factor most of that out. If you do 2 compounds, then you can't rotate tires, and while 2 compositions will throw a band aid on it, it won't last long.
Also, I think the 19x10 wheels will prolly fit, the fenders just need some love in the form of a bead roller, or maybe a baseball bat, either one.

 

[xr7]

Can't imagine 19 x 10's not fitting. I have 18 x 11's all 4 corners. Still on the original front struts, Ford racing springs, maybe dropped the front about 1/2" , a 20mm spacer, ARP long studs and Vorshlag camber plates, running max camber and have not opened up the strut tower hole, yet. I'm running a tall tire, 295/40-18 Falken 660's, no fender rub and only lightly rubs the fender liners at the inside front of the tires at full lock.

 

[willrc]

I'm new at this and I suppose there's a good reason why people don't mix different tires together, and you've given some good reasons. The tires I have on now are pretty much done after just two track days. My son says driving lessons would be money well spent, and with my lack of experience I'm sure that would help. Thank you, guys, for taking the time and effort to offer your advice, I'm pretty sure I'll regret not taking it. But with the large aftermarket brakes upfront I can't put 18-inch rims back on again. And with the 2-inch drop the front tires I have don't rub but there is no way 19x10s would fit without rolling the fenders. And it's still a fairly nice-looking car, so I really didn't want to do any body work yet, and I'm not ready for it to be a track only car yet. So, it seems my options are fairly limited, with my current budget. I want to thank you all again for your advice, I'm sure in the future I'll be more likely to take it. Don't give up on me guys. Thanks!

 

[Dave_W]

orange Koni struts with 2-inch lowering springs

That's probably part of the problem. Two inches is way too much drop on the front, as it changes the angle of the lower control arm and on a McStrut suspension changes the roll center too much. Plus, with that much of a drop, either the springs are stiff to keep you of the bump stops, or you're riding on the bump stops all the time. And the Koni Orange isn't valved stiff enough to handle much of an increase in spring rate.

Continental Extreme Contact DWS06 PLUS

That's an all-season tire. Just tread squirm is going to give you issues if you're pushing hard.

 

[blacksheep-1]

@willrc
FWIW, there's nothing wrong with being "new at this" we all were at some point. In the future, you may want to stick with a particular brand, such as Ford Racing. their parts are mad eto complimnet each other and work together. Those suspension packages can be bought together, or in singular parts. cortex and other build similar packages for these cars.
I'm beginning to think the 2 inch springs might be the issue, especially if they ae not a "name" brand or a "lowering only" type of spring. @Dave_W might be right, it could be riding the bump stops which means it will push like a train.

 

[KazarS197]

@willrc. Don't get discouraged. I did nothing other than changing oil on cars till I got my mustang 10/2020. It took me weeks of studying information here and 8ish months of ordering parts and working on the car here and there to get is where I wanted. It does take cash. Took me a year to catch up. The good news is it gets better over time, like the second year. Remember the goal is to have fun and be safe on the track. Part of the fun is the satisfaction of working on your own car. Patience you'll get there.

Edit: There's other things you can do while getting your Mustang ready. Grab your son and head out and watch some HPDEs, sit in on the learning sessions, watch instructor in car videos, study your track, find member in car vids here: https://trackmustangsonline.com/threads/track-time-videos.1617/page-67#post-301900
It doesn't cost anything but time, fuel to and from the track and sunburn. Most track rats are great people. Who knows you may run into one of us and get offered a ride. My wife and I made friends with guy the took her out all day in his vett until I got passed off. Once your ready you will have an instructor in your car. Keep an instructor in your car as long as you can to maximize learning.

 

[TMSBOSS]

Instruction is a very good idea. The two things which will make the most difference in performance are tires and seat time. Seat time will progress much faster with quality instruction.
I have run 19-11” wheels up front on my Boss With 305s.
which wheels are you running? Back space and barrel clearance for big brakes varies greatly with different wheels.

 

[willrc]

That's probably part of the problem. Two inches is way too much drop on the front, as it changes the angle of the lower control arm and on a McStrut suspension changes the roll center too much. Plus, with that much of a drop, either the springs are stiff to keep you of the bump stops, or you're riding on the bump stops all the time. And the Koni Orange isn't valved stiff enough to handle much of an increase in spring rate.

That's an all-season tire. Just tread squirm is going to give you issues if you're pushing hard.

I don't know enough to have an opinion on what you said. Other than to say that the struts and springs were designed to work together to make the 2-inch drop work together supposedly. But it sounds like they can cause other issues according to you. Thank you for the advice.

 

[xr7]

If your front suspension control arms are angling downward from the wheel end to the frame end you have drastically changed your roll center.
You need to get the Boss 302S Owners manual. This is the manual for the factory race cars, it has specific measurements for what and where to measure for setting up the chassis.
I have it in a pdf file, I just don't know how to attach it here.

 

[Mad Hatter]

I don't know enough to have an opinion on what you said. Other than to say that the struts and springs were designed to work together to make the 2-inch drop work together supposedly. But it sounds like they can cause other issues according to you. Thank you for the advice.

A really simplified way is to just take a look under the car at the angle of the front control arms. if they are pointing up from the engine towards the wheel.. The car is lowered to much for the struts. Many springs are made for the street racer look, not so much for actual handling. Never mind that 2" drop in the rear will change the angle of the rear LCA too much. You will have traction problems as well.

Seen a lot for mustangs turn up at the track with slammed suspensions only to find that the cars are slower then they were in stock form.

The fun part sorting everything out and then you start seeing your driving improving and your lap times dropping. Thats what TMO is here for!

 

[willrc]

Instruction is a very good idea. The two things which will make the most difference in performance are tires and seat time. Seat time will progress much faster with quality instruction.
I have run 19-11” wheels up front on my Boss With 305s.
which wheels are you running? Back space and barrel clearance for big brakes varies greatly with different wheels.

They are AMR "Silver Wheel Rear Only (05-09Mustang) and 19x10 and AMR "Silver Wheel 19x8.5 (05-09Mustang). These were the third set ordered, American Muscles website said the previous two rims would fit and didn't, but they did eat the shipping costs, until we found these that actually fit.