2011 Mustang GT track log

[neema]

Recently I did an HPDE at Laguna Seca and I have some observations to share and have some questions. Rather than making a thread for every mod, event I attend, or observation I make, I'll consolidate everything into one log to document the changes I've made to the car and their measured and unmeasured effects. Feel free to contribute with your comments or questions and laptimes (if you have them). I figured this belongs in the corner carver forum mostly because my aim is to improve handling characteristics of the car/driver. The rest of the mods are to support the bad habit.

Just to give some background, I still consider myself green at track events, but I've quickly outgrown the beginner/intermediate groups and look for intermediate/advanced point-by groups.

The car's current setup is seen below:
Suspension:
KW Clubsports (530/350 lb springs; 12.75"/13.5" fender to hub ride height)
ST sway bars (front: adjustable--set to soft; rear non-adjustable)
Maximum Motorsports rod-end aluminum panhard bar
Steeda ball joints

Wheels/Tires/Brakes:
Enkei PF01 18x10.5 et 38 with 1/4" spacers up front
Nitto NT01 305/35/18
Stoptech ST60 Trophy w/ 380mm rotors
Stoptech braided brake lines
Carbotech XP12/XP10 pads
ATE Superblue fluid

Engine/Exhaust:
Airaid intake
Magnaflow catted X-pipe
Magnaflow axlebacks
Cooltech Oil cooler
Fluidyne Radiator

Extras:
Cooltech tow hooks
GT500/Boss differential cover (taller breather)
CS Front valance with brake ducts
Tiger Racing hood
Cobra Jet grille (aka california special grille that's trimmed)


This was my first time trying out a proper "track" pad. The last event I had at Laguna seca resulted in gnarly pad deposits on the front rotors and serious steering shimmy everytime I was on the brakes. That combined with a soft brake pedal led me to alternate between "on" and "off" laps and kind of annoyed me (since the session was only 25 minutes long).

That said, I wanted to prepare the car to withstand a whole session of proper driving without having to soft pedal or back off. What I didn't like is that I changed most of these parts the day before the track event (all at once), so there was a lot that could go wrong. Knock on wood, everything was okay.

First things first, the brakes. I went with stoptechs for 4 reasons: I could get them at a good price, track pads are pretty cheap (XP12s are ~$225), they come with great floating 2 piece rotors, and they are mounted farther inboard than the OEM 4 and 6 piston brembos (they offer more axial clearance between the face of the wheel and caliper). I noticed immediately that the carbotechs have more bite than my stoptech street pads, even when cold. sure, they'll probably wear the rotors quicker and make noise, but that's just a side note. On track, they had a stronger initial bite than the stock brembo setup and for a longer period of time (aka it took them a while to go "soft"), almost all the way until the end of a session. I STILL managed to get a soft pedal and some steering shimmy under braking toward the end of the day, so maybe I need to drive around on the pads while cold and see if I can scrape off any pad deposits. I doubt I've warped the rotors. Maybe I'm braking too long/not hard enough???

Another side note: these calipers are pieces of art. They're machined compared to the standard ST60 caliper and are deceptively light. I should have weighed the setup, but I would feel confident in saying the 15" rotor and bigger 6 piston caliper are lighter or at least the same weight as the stock 14" brembo setup.

Next is the Cooltech oil cooler. I have no oil/coolant gauges in my car, so I'm completely in the dark regarding whether temperatures and pressures are good, but I like to use the whole powerband, so I assumed the worst. I've read claims that temperatures rise precipitously in the upper rpm band with this motor, so I wanted to slap a solution on and not worry about it working hard. I realized the Cooltech setup costs more than both the water-oil Boss cooler and the FRP oil cooler, but I wanted the low pressure-drop Setrab cooler, a thermostat, and greater efficacy than the OEM Boss setup. Installation was straight forward, but I took my time. The only time I felt in the dark during the install was when tightening the Moroso oil relocation adapter to the block. I figured that oil filters are installed hand-tight, so I didn't kill it when screwing it on. No leaks so far and it hasn't moved yet, so hopefully it's okay. I used the powerband all the way up to redline since there are a few spots I was figuring out that were "between shifts" on track.

I felt dumb for installing 5w-20 (Mobil 1) oil in the car again, but it's what I had at the time. Next time around, I'll go with at least a 5w-30, especially since it's near 100°+ almost all summer where I live. What's nice is being able to run an extra ~1.5 quarts of oil with the cooler. I ran even a little more oil to make sure there's something there for the sump to pick up on a hard corner, so the car had just under 10 quarts in it. Good for long oil change intervals!

To go with the oil cooler, I swooped on the old Fluidyne 2-core radiator blowout they were having ($250 for a big burly radiator!) and threw that in. Might as well, no? The stock radiator looks like a puny A/C condenser, so anything is an improvement. To tie things together, I installed a cobra jet grille (wide open) and Tiger Racing hood so the extra air has an outlet.

The enkeis are nothing new on these cars.. Many people have ran them and that's why I went with them. If the car was slammed in the back, there may be some rubbing issues with vertical compression, but I don't have my car super low, so I didn't have any problems all weekend. I wish I had a scale, because they were noticeably lighter than any other wheel/tire combo I've had on my car, even with heavy 31lb 305/35 NT01s.

Tire pressures were at 33 psi cold and about 38-40 psi hot. They felt pretty good to me and the car finally showed some signs of neutral understeer. Didn't have time to heat cycle them and I didn't want to shave them, so we'll see how they last. Temps were relatively even across the width of the tire, but some pictures indicate I could use more camber (I ran 2.1°). The tire size is brand spankin new, and I think it works well for mustang fitment. Just trim the swaybar endlink stud about 5mm-7mm, buy some billet spacers, and you're good to go. The pic below is pre-spacer.

Behavior of the car was pretty good. I did a crappy job of bedding in the pads (I probably didn't slow down enough) and couldn't get them to "green" fade. Any advice on this? After speaking with a friend who is a BMW club racer, he said to ease into the pads on each corner, progressing from a moderate to a very hard pressure over a period of 2-3 laps, then bedding in is done. Maybe I should try this next time.

Still, I was braking too early in most parts of the track and couldn't get my braking points down. I've noticed that the car takes more pedal input than others (Miata, BMWs) to get the same level of braking, even with race pads. Anyone else have the same concern? This is both with Brembos and the stoptechs, although the stoptechs feel firmer in the pedal (both use braided lines)

The tires definitely slow the car better than my 285/35/20 R888s did, but that's probably due to the lighter wheels and more aggressive pads. The car was comfortable with corner entry, but would wag it's tail out a couple times on hard corner exit. I presume this can be cured with some relocating brackets and stiffer bushings on the rear axle? It felt almost as if compliance in stock bushings were making it step out and come back in. If I could solve this issue, corner exit would be awesome. Maybe I can dial out compression in the rear.

That said, I consistently got 3-4 seconds quicker per lap on average. My quickest lap with Brembos on 19's with 285 Kumho XS tires was a 1:45.4. This was an outlier--I must have nailed the line and braking points and had a no-traffic lap. With the new brakes/wheels/tires, the quickest was a sloppy 1:43.8. Most laps were 1:44-1:45 There's still a ton of room for improvement with braking.

Next outing will be August 25! I'll have pics up from the last event soon. GoPro died after the first session, so nothing to show from inside the car unfortunately

 

[HEMI LOL]

great write up! thanks for the good info.

 

[Philostang]

Great looking car!

Couple of quick things to note. First, it's a Mustang. Don't expect it to brake like a Miata, it's an unreal expectation. You can bolt on this or that, but you're still left with basic physics and a car that is 1,000 lbs lighter is not going to require the same level of brake input. Oh, you might try running a titanium shim on the back of the pads. Stoptech uses (or used to use) only aluminum pistons which are not the best for high-heat applications (still can't figure out why they don't go to stainless). Anyway, I run Stoptech calipers and use the shims to help w/resisting heat transfer to the fluid. Can't say they made some huge difference (I never felt I had much trouble in the first place, but got the shims as insurance), but something to consider at their nominal cost.

The stepping out in the rear thing is where I'd put most of my attention. Without being there with you in the car it's hard for anyone to say what might really be happening, so take whatever we say with a grain of salt.

Your car info didn't say anything about what lateral locating device you are using. Are you still on the factory panhard bar? That stepping-out/then-settling would happen a lot to me when I was on the factory pahnard (though that wasn't from power delivery as much as from bumps in the road). The description you gave sounds different from just getting loose in the rear (either from too much power application or from LCA bushing compliance), especially if the car caught itself w/no correction on your part.

If you were catching it and she came into line in short order, then maybe you're better off looking into the LCA bushings (and likely relocation brackets w/the power you have). Just to lay out options, at the rear spring rate you're using you may want to look at that rear sway bar. Pity it's not adjustable. I'd at least try throwing on the OEM bar (or better, one of the really small V6 bars, I think you can get them cheap these days). If you soften compression in the rear and it seems to be helping but not enough, put the OEM bar back on and see what it's like.

FWIW, I suspect the real gains in time you'll see will still come from getting off the corners better and not so much from braking. Sure, you'll gain time by not over-braking, but that will pale in comparison to what you'll gain by being able to get out of the corner better.

Last thing, oil: 10w40 is what most of the 4.6l crowd would run (not sure about the heavy-track-use 5.0 guys).

Best,
-j

 

[Apex50]

To correct oversteer, shouldn't he try tightening the front sway? Solved my problem, with whiteline adjustables, front and back.

 

[SoundGuyDave]

You use swaybar tuning to correct gross over-/under-steer characteristics on a steady-state corner, like a carousel or skidpad... Also, a stiffer front bar achieves the same result as a softer rear bar, but in a different way. The more bar you run, the less net grip you have on that end of the car. In an oversteering car, I would rather add grip at the rear, than take grip away from the front to get the balance, if you follow.

From the description, this sounds more like a dynamic issue, so I would also be looking at reducing bushing compliance. It could also be that some "retraining" of the right foot is in order, but that's tough to diagnose without being in the car or at a minimum getting video of the action from inside the cockpit. John (Philostang) is on the money with his comments.

 

[Roadracer350]

Great looking car!

Couple of quick things to note. First, it's a Mustang. Don't expect it to brake like a Miata, it's an unreal expectation. You can bolt on this or that, but you're still left with basic physics and a car that is 1,000 lbs lighter is not going to require the same level of brake input. Oh, you might try running a titanium shim on the back of the pads. Stoptech uses (or used to use) only aluminum pistons which are not the best for high-heat applications (still can't figure out why they don't go to stainless). Anyway, I run Stoptech calipers and use the shims to help w/resisting heat transfer to the fluid. Can't say they made some huge difference (I never felt I had much trouble in the first place, but got the shims as insurance), but something to consider at their nominal cost.

The stepping out in the rear thing is where I'd put most of my attention. Without being there with you in the car it's hard for anyone to say what might really be happening, so take whatever we say with a grain of salt.

Your car info didn't say anything about what lateral locating device you are using. Are you still on the factory panhard bar? That stepping-out/then-settling would happen a lot to me when I was on the factory pahnard (though that wasn't from power delivery as much as from bumps in the road). The description you gave sounds different from just getting loose in the rear (either from too much power application or from LCA bushing compliance), especially if the car caught itself w/no correction on your part.

If you were catching it and she came into line in short order, then maybe you're better off looking into the LCA bushings (and likely relocation brackets w/the power you have). Just to lay out options, at the rear spring rate you're using you may want to look at that rear sway bar. Pity it's not adjustable. I'd at least try throwing on the OEM bar (or better, one of the really small V6 bars, I think you can get them cheap these days). If you soften compression in the rear and it seems to be helping but not enough, put the OEM bar back on and see what it's like.

FWIW, I suspect the real gains in time you'll see will still come from getting off the corners better and not so much from braking. Sure, you'll gain time by not over-braking, but that will pale in comparison to what you'll gain by being able to get out of the corner better.

Last thing, oil: 10w40 is what most of the 4.6l crowd would run (not sure about the heavy-track-use 5.0 guys).

Best,
-j

Ok I have a question... Why 10w40? I use Mobile 1 5w30 and never had a problem. Not trying to be an ass i was just wondering why 10/40

 

[SoundGuyDave]

Specific to the 4.6L 3V motor, I happened to bump into a Ford powertrain engineer a while back, and we were discussing oil weights in racing applications. The conversation went kind of like this:

ME: "So what weight oil would you recommend for heavy track duty?"
LITTLE BIRDIE: "Ford recommends using only 5W-20 oil in the 3-valve (shaking head). We would NEVER recommend something like 10W-40 (nodding head) for racing."

Draw your own conclusions. Yes, the clearances in the engine are quite tight, but we can pretty much disregard cold-temp performance for a "race" application, and the higher viscosity of the 40-weight will give better lubrication at higher temps and loads on the rotating parts. At least that's what I took away from it all. I don't think you'll have issues with the 30-weight, and that's probably just fine for a dual-duty car. For a pure track machine, though, I'll stick with the 10W-40 Amsoil synthetic.

 

[neema]

You use swaybar tuning to correct gross over-/under-steer characteristics on a steady-state corner, like a carousel or skidpad... Also, a stiffer front bar achieves the same result as a softer rear bar, but in a different way. The more bar you run, the less net grip you have on that end of the car. In an oversteering car, I would rather add grip at the rear, than take grip away from the front to get the balance, if you follow.

From the description, this sounds more like a dynamic issue, so I would also be looking at reducing bushing compliance. It could also be that some "retraining" of the right foot is in order, but that's tough to diagnose without being in the car or at a minimum getting video of the action from inside the cockpit. John (Philostang) is on the money with his comments.

Bushings is what I was thinking too. I'll edit my first post as I forgot to mention I have a MM panhard bar with rod ends (so no compliance there). It could very well be my right foot as well. I was trying harder and harder to find the threshold of the tires in certain corners and the cambered mid-speed (3rd gear) turn 5 is where this mild issue really sprang up. It may also be the suspension bottoming and bouncing off the bump stops. I'd say I'd increase some rebound so they settle, but rebound is almost maxed out up all around. I have Cortex LCAs and relocation brackets waiting to go on. We'll see how they change things.

 

[neema]

Pictures from last friday

Below was the corner that I had trouble staying on full throttle.

There are tenths to be had in the corkscrew

 

[SoundGuyDave]

Your problem corner.... is that T3 at Laguna Seca?

 

[neema]

Your problem corner.... is that T3 at Laguna Seca?

Negative, it's T5 at Laguna Seca (heading up the hill). The car behaves pretty predictably in T3

 

[neema]

I've made a few changes to the car since its last event. I'll post a more thorough update soon, but for the time being, I figured some of you may want to see some pictures.

In short, relocation brackets and lower control arms are fantastic. They're the only mechanical suspension changes I've made to the car and the car has much more traction on corner exit than before. Tire temps were 2-3 psi lower than last time (hot pressure of 36-37psi), so that may be a contributor as well. Negative camber was was changed 1° to 3°. Oil is Mobil 1 10w-30 (it's hot in California) filled a little bit past the max point on the dipstick. A Moroso pan may be something to change in the future--I have nightmares of oil starvation mid corner and throwing a rod. Gearing and tire size leaves the car in near-redline scenarios at many points on track.

Brakes are still giving me issues. I turned the rotors and wirebrushed the pads on all four corners and I still have a vibration issue when braking. There was a hard spot on one front rotor (it visually came out, but took a few extra passes on the lathe), but that may be the vibration that's coming through. I may have to completely start over with new rotors and pads to get back to smooth braking. So much for using carbotechs for their rotor-friendliness

Pics!:

Body roll seems under control

Brake dive

In case anyone is wondering how 305/35/18s on 10.5" wheels tuck into fenders under compression:

And a heavy traffic session with a nice off-track visit at the end. Woops: http://youtu.be/IGAZ0nGHNLM



Also, magnaflow cats suck. Their off-road cats (doesn't this mean race/track use?) X-pipe blew it's guts out on the 3rd or 4th session (and still blows chunks every now and then). The car lost a ton of power on track at the end of the day and now throws a CEL. I thought I was in limp mode or something. Time to throw the stock h-pipe back on and see if the car feels normal again.

 

[TheViking]

God that looks like such a fun track! Did they offer a special discount for late model Mustangs? I've never seen so many on the track at once. Nice job with the off track recovery, looks like it could have gotten a lot worse.

Was reading through your earlier posts, I had the exact same question regarding the adapter with the Cooltech kit but never heard back from Kendall. Let me know if yours starts leaking

 

[dontlifttoshift]

Covering your rear license plate like a sir!!

 

[neema]

God that looks like such a fun track! Did they offer a special discount for late model Mustangs? I've never seen so many on the track at once. Nice job with the off track recovery, looks like it could have gotten a lot worse.

Was reading through your earlier posts, I had the exact same question regarding the adapter with the Cooltech kit but never heard back from Kendall. Let me know if yours starts leaking

It was just a regular HPDE open to any joe-blow, but There was a mustang group photo and discount offered through another forum (bossmustangsonline), hence the large mustang turnout.

The few times I've checked, the oil filter adapter/relocator have been okay. I marked the bolt and the adapter to see if they start moving relative to each other and also between the block itself. Turns out the whole adapter rotated slightly (maybe a degree) but the bolt never changed its position, so it's still snug so far.

That corner where I went off is notorious for 180° spins that end ugly on the infield wall. If you're going off there, make sure it's off to the right!



This weekend I need to hook up the SCT and find out what the CEL really is. Hopefully it's just cat failure. We'll see how good mangaflow's warranty is.

 

[sheizasosay]

That's a really badass ride Neema!

 

[Rpm427sc]

Also, magnaflow cats suck. Their off-road cats (doesn't this mean race/track use?) X-pipe blew it's guts out on the 3rd or 4th session (and still blows chunks every now and then). The car lost a ton of power on track at the end of the day and now throws a CEL. I thought I was in limp mode or something. Time to throw the stock h-pipe back on and see if the car feels normal again.

I will never run a catted X/H-pipe again for this reason. The factory cats shattered and clogged which caused my #8 connecting rod to snap under boost. Bears, Rattle snakes and Cat converters: 3 things I don't fuck with.

 

[barbaro]

Very nice track set up. I really love the attention you payed to cooling. I have always wanted to run Laguna Seca and I intend to do it one day soon. I have the feeling you will be getting a lot faster. Good luck to you

 

[Budwise]

How tough was the tow hook install? I'm doing 3-4 track events per year and have yet to get the guts up to cut a hole in my car :/

 

[2013MustangGT]

How tough was the tow hook install? I'm doing 3-4 track events per year and have yet to get the guts up to cut a hole in my car :/

The cooltech tow hook bolts onto your bumper. The Ford tow hook needs to be welded on or bolted on a the Ford racing bumper. I have the Ford bumper beam with tow hook. I suggest going with the Cooltech tow hook. It cost less and does a great job.