Few laps around Waterford Hills Raceway in Michigan

[5.M0NSTER]

Just a few laps @ Waterford Hills. It's a 1.5 mile long track which is rather tight, narrow, and slower than I'm used to. 50mph feels fast in some of the corners here. It's a technical track though, and a good line makes all the difference. And I'm still working on mine Enjoy!

This is with a 2014 GT Track Pack with stock suspension. Car pushed in a few corners, but for the most parts the balance was neutral. Planning steeda sports/koni yellows, panhard, adjustable front sway bar and CC plates for next season. I want to lessen the roll/dive/squat by at least 40% while increasing overall corner grip, keeping neutral balance and maintaining crisp turn in.

https://youtu.be/yWcZCQzw4o0

 

[Norm Peterson]

Any reason for your list not including an adjustable rear bar? Most times, that's where you'd want to be making your last adjustments to get the handling balance right.

You'll probably want to work better tires and wider wheels into that mix before long, and don't wait at all to upgrade at least the brake pads and fluid if (as I suspect) you haven't done that already.


Norm

 

[5.M0NSTER]

Thanks for the tips! I have a theory I'm working with here and would love to hear more educated opinions on this. More on this later.

First, regarding brakes, I'm running SS lines, Motul RBF600 fluid, GT500 cooling shields, and Carbotech XP10/XP8 pads. (I have the 14" Brembos) I'm very happy with my brake setup. At Gingerman raceway I was able to outbake Miata and a Rousch Mustang in April. I have not measured my rotor temps yet, but based on pad deposits I'm guessing I'm right at the edge of 1450 deg F rating of the XP10s. I'm debating switching to XP12 next season.

I have 19x9.5 wheels and 275/40 tires (Bridgestone Potenza S04). When these go I will likely upgrade to 285/35 BFG Rivals.

Now as for Sways. Based on my own experiences and conversations with fellow '14 GT Track Pack guy who races regularly, I'm of the opinion that the rear sway of this car needs to be soft to allow as much grip as possible. I'm thinking that with stiffer springs, -1.3 deg camber and adjustable shocks the roll of the car will be subdued by ~35 to 40%. Lowering and more negative camber will also help eliminate understeer. I think I will need a front adjustable bar to fine tune turn-in performance. I want to try it like this and see if I really need a stiffer rear bar. I know someone with this setup who raves about it, and the guy is a great driver.

My goals are:
1) Maintain neutral balance which the car currently has, or push it ever so slightly towards oversteer
2) Maintain or sharpen turn in
3) Maintain the excellent corner exit manners the car has
4) Increase the overall cornering capabilities. I'd like 1.05g sustained with street tires.
5) Allow for adjustability since I DD the car 7 months out of the year, and do 3-4 track days per year.

 

[Norm Peterson]

Thanks for the tips! I have a theory I'm working with here and would love to hear more educated opinions on this. More on this later.

First, regarding brakes, I'm running SS lines, Motul RBF600 fluid, GT500 cooling shields, and Carbotech XP10/XP8 pads. (I have the 14" Brembos) I'm very happy with my brake setup. At Gingerman raceway I was able to outbake Miata and a Rousch Mustang in April. I have not measured my rotor temps yet, but based on pad deposits I'm guessing I'm right at the edge of 1450 deg F rating of the XP10s. I'm debating switching to XP12 next season.

It's probably my bad for not watching the video in full screen watching more closely for nose dive. FWIW, I'm on XP10's all around, but moving up the XP12/XP10 next time around. Stock GT rotor size but with a little ducting aimed at (but not connected to) a fabbed nozzle in the dust shields

I have 19x9.5 wheels and 275/40 tires (Bridgestone Potenza S04). When these go I will likely upgrade to 285/35 BFG Rivals.

S04's seem to be unusually noisy tires. Decent grip, but they can't help telling you all about it. With 285/35's, you'll want wider wheels, possibly as wide as 11" (285/35-18's on 11" wides in my sig pic). This will sharpen turn-in, guaranteed, because you're stiffening up the softest thing in the path from the steering wheel to the ground.

Now as for Sways. Based on my own experiences and conversations with fellow '14 GT Track Pack guy who races regularly, I'm of the opinion that the rear sway of this car needs to be soft to allow as much grip as possible. I'm thinking that with stiffer springs, -1.3 deg camber and adjustable shocks the roll of the car will be subdued by ~35 to 40%. Lowering and more negative camber will also help eliminate understeer. I think I will need a front adjustable bar to fine tune turn-in performance. I want to try it like this and see if I really need a stiffer rear bar. I know someone with this setup who raves about it, and the guy is a great driver.

My goals are:
1) Maintain neutral balance which the car currently has, or push it ever so slightly towards oversteer
2) Maintain or sharpen turn in
3) Maintain the excellent corner exit manners the car has
4) Increase the overall cornering capabilities. I'd like 1.05g sustained with street tires.
5) Allow for adjustability since I DD the car 7 months out of the year, and do 3-4 track days per year.

My thoughts on bar adjustabilities is that the thinner rear bar will have finer adjustments than any front bar, and will have far less effect on overall roll stiffness (meaning less effect to whatever camber you might want to set). If you start out with a mid setting on the rear bar that's close to the OE rear bar rate, you have the flexibility to go either way. Keep in mind that the overall effect of your planned spring swap includes both understeerish effects (more front roll stiffness) and oversteerish effects (less roll and camber change). You've got about a hundred more HP to play with than I do, though . . .

On adjustability for swapping between track and DD . . . I'm betting that tweaking anything other than shock settings will get real old, real quick, and you'll just leave the bar(s) at your track setting(s).

My car also splits duty between track time and year-round daily stuff (though me being retired means that "daily driving" is mostly just where I want to go instead of being mostly where I have to go ). All I play with are the damper settings (track, daily me only, and sometimes still softer settings for when my wife is along for the ride). Near as I can tell thus far, I need to pick up about another second/minute to run even with the SS Camaros.


Norm

 

[claudermilk]

I essentially have you intended setup. Steeda Sports/Koni yellows/Vorshlag CC plate. No bars yet. I've also swapped to SS brake lines, Motul600, XP10/8 pads on track. I next need to set up brake cooling ducts. Finally, I have 18x10 AMRs with RE11As on them (I ran S04s on the street & a few autocrosses). I have also put BMR LCAs and relo brackets on.

For track duty, I set the camber at -2.75 and bump up the damper rebound stiffness. I basically see the results you are aiming for.

 

[5.M0NSTER]

Thanks Norm, good stuff here!

I think I get your point on rear sway, your view is that it's needed to adjust possible to softer setting, rather than needing it to stiffen roll resistance. That's a good way of looking at it. Since the rear bar is 2x the rice of the front I was going to go that route first, and see if I need to get the rear as well.

And yes, dampers are the only things I plan to adjust street to track. Right now I have my XP8s in the back permanently, and I swap the XP10s on a week before/after my events.

As for tires, 285/35-19 is approved from 9.5-11 wide rims. I'm planning on sticking with my 9.5s. Yes, at the track the S04s speak loudly.

Claudermilk,
thanks for the input! Glad to hear your setup is working out as intended. Wow, 2.75 deg of camber is huge! Do you notice any understeer on initial turn in before the car rolls and grips?

 

[SlowJim]

Some springs are actually designed to work with the stock rear sway bar. Maximum Motorsports comes to mind.

 

[csamsh]

You're gaining nothing by using a big tire on a small wheel other than deceased feel at the limit and probably some instability from the tire wanting to roll over. I'd really, really try to find some room in the budget for 18x10's, or look for a 265 or 275 that would fit the 9.5's better. Every big size rival I've ever seem runs wide, I would want a 10.5 at least for a 285 rival. The 295's are wonderful on an 11" wheel.

Bear in mind that manufacturer recommended widths are generally not aimed at racetrack use.

 

[5.M0NSTER]

Some springs are actually designed to work with the stock rear sway bar. Maximum Motorsports comes to mind.

I just looked at MM set, and I just saw that their street and track set comes with CC plates, LCAs for the rear, springs, shocks, and front sway bar, but not the rear. Thanks for pointing this out.

The drop of the springs it a bit too aggressive for my intended use, but for southern states this seems like a great kit!

You're gaining nothing by using a big tire on a small wheel other than deceased feel at the limit and probably some instability from the tire wanting to roll over. I'd really, really try to find some room in the budget for 18x10's, or look for a 265 or 275 that would fit the 9.5's better. Every big size rival I've ever seem runs wide, I would want a 10.5 at least for a 285 rival. The 295's are wonderful on an 11" wheel.

Bear in mind that manufacturer recommended widths are generally not aimed at racetrack use.

I see your point. I find myself in a dilemma here though. My car came with 3.73 gears with the Torsen diff (Boss rear end for the Track Pack cars). It also came with 255/40-19 tires which are 27.05" tall. And while I LOVE the torsen, and L O V E the acceleration the 3.73 gears provide on the street, I've found that at the track this setup results in gearing that is too short. In other words I run out of gear (hit my 6800rpm limit) with 100 yards left to the brake zone. It is super annoying.

So my temp solution was to go with 275/40-19 which is 0.7" taller, and effectively "extends" my gears my 2.5%. It's been working out well, but particularly when I'm done with my suspension mods I will need more grip.

And anything in the 18" rim category is shorter than 27" thus further exacerbating my problem.

So my solution was to go with 285/35-19 on my current wheels. I can't fit an 19x10 up front without rubbing or spacers, and I don't want to do that. So I'm afraid I have to take a trade-off in handling. My question now becomes this:
Will I have more grip out of a Potenza S04 in 275/40-19 on a 9.5 rim, or out of a 285/35-19 BFG rival on the same rim? I'm guessing it's the latter dues to compound.

 

[kcbrown]

And anything in the 18" rim category is shorter than 27" thus further exacerbating my problem.

Yep. That's why I stuck with 19" rims. It's not like tires aren't available at that size or anything, at least until you start looking for used racing tires or something...

So my solution was to go with 285/35-19 on my current wheels. I can't fit an 19x10 up front without rubbing or spacers, and I don't want to do that.

Actually, I think you can.

While I have to use a 3mm spacer up front with my Forgestar F14s in 19x10 (I have a 2014 Track Package car as well, and we originally thought they'd fit without spacers, but I suspect there are slight variations in the caliper design or something that resulted in them not fitting for me), the Forgestar CF5 is supposed to fit without any issues. Talk to Vorshlag. They'll hook you up. And a 3mm spacer is no problem at all, really. Vorshlag has those as well (high quality ones, I might add).

So I'm afraid I have to take a trade-off in handling. My question now becomes this:
Will I have more grip out of a Potenza S04 in 275/40-19 on a 9.5 rim, or out of a 285/35-19 BFG rival on the same rim? I'm guessing it's the latter dues to compound.

Probably the Rival.

I was running S04s on mine since I got the car in late 2013. I eventually got to the point where I was putting too much heat into them. So I switched to RE11s recently.

While the built-in G meter doesn't seem to be showing higher values than what I was getting before (despite having the camber maxed out at -2.2 degrees on my stock springs), the grip feels a little more consistent now, and I'm pretty sure these tires don't get greasy as easily, if my recent experience at Thunderhill is anything to go by.

 

[csamsh]

yeah.....19x10's go just fine up front. So would a 19x11. Or an 18x11.

Change your gears. It's easy/cheap and the 3.31's are really a lot better for track stuff.

 

[claudermilk]

Claudermilk,
thanks for the input! Glad to hear your setup is working out as intended. Wow, 2.75 deg of camber is huge! Do you notice any understeer on initial turn in before the car rolls and grips?

Not really. Also keep in mind, I am running AMR 18x10s with RE11As at 275/40-18.

You're gaining nothing by using a big tire on a small wheel other than deceased feel at the limit and probably some instability from the tire wanting to roll over. I'd really, really try to find some room in the budget for 18x10's, or look for a 265 or 275 that would fit the 9.5's better. Every big size rival I've ever seem runs wide, I would want a 10.5 at least for a 285 rival. The 295's are wonderful on an 11" wheel.

Bear in mind that manufacturer recommended widths are generally not aimed at racetrack use.

I notice this swapping between my street setup & track setup. I also have the OEM 19x9 (Brembo car) and have 285/35-19 BFG g-Force Sport Comp 2--they are squeezed on the wheels & look nice & beefy. However, compared to the track setup they are noticeably less responsive. I give up 0.1" from the street setup, and about 1.8% from the OEM POS Pirellis.

I also have the 3.73 gearing handicap (seemed like a nice "upgrade" when buying the car--oopsie). The tire size doesn't really noticeably make my gearing problem any worse. In an autocross I probably hit the "do I shift or breathe it" decision point 10-20 feet earlier on the occasional long straightaway. On a track day, I still have more in the car & am inching up to where I'll run out of gear, so not a problem there yet. I will very likely swap to the normal 3.31 gears when I eventually throw a T-2R in there.

 

[mrfatride]

nvm i just figured out my own question.

 

[fast Ed]

Out of curiosity, what's a good lap time around Waterford these days? I was there in the early 90s in my Fox, and seem to remember getting to the lower 1:20s was a decent lap.

It's a fun little track, would love to get down there again sometime.


cheers
Ed

 

[13726548]

How about rear upper and lower control arms? I haven't seen these mentioned yet?

 

[Norm Peterson]

Rear lowers and the upper aren't nearly as in need of upgrading out on a road course as they are at the drag strip or jumping away when the traffic light turns green. Easy rolling starts to get out there, and I would guess rarely as low as 2nd gear once you are. And you aren't powershifting either.

Not to mention that the poly/poly bushed arms that most people probably think of first are not exactly the hot tip where hard cornering is involved.


The only reason I have aftermarket rear LCAs on my car is because the bushings in the OE arms were beginning to deteriorate (FWIW, they're now Currie Currectracs, each arm has one spherical that's not a rod end). The UCA is still OE.


Norm

 

[13726548]

For a car that already has decent shocks & springs, and wide tires, what would you recommend as a next modification? It feels as balanced it can be, with some induced oversteer coming out of corners.

 

[csamsh]

Define "decent" and "wide"

How much do you want to spend

What is your seating situation?

 

[Norm Peterson]

More seat time. You'd probably benefit from things like firmer suspension bushings, more aggressive alignment, and a little fine-tuning of the suspension geometries . . . after you can actually suspect by the feel that such things are holding you back.

Otherwise, brake pads & fluid and a better solution to venting the rear axle than Ford provided come to mind.

I don't know what you've done so far, not even the current tire size and wheel width (which may themselves have a little room to grow).


Norm

 

[13726548]

Define "decent" and "wide"

How much do you want to spend

What is your seating situation?

Decent as in Koni STR.t struts & Tein S tech springs on 255 width tires. I've got 9.75" width wheels though, so there's definitely room to grow.
I'm happy with the way it drives but aside from wider tires and coilovers I'm wondering if there's anything else I left on the table.

More seat time. You'd probably benefit from things like firmer suspension bushings, more aggressive alignment, and a little fine-tuning of the suspension geometries . . . after you can actually suspect by the feel that such things are holding you back.

Otherwise, brake pads & fluid and a better solution to venting the rear axle than Ford provided come to mind.

I don't know what you've done so far, not even the current tire size and wheel width (which may themselves have a little room to grow).


Norm