2011 Mustang GT track log

[neema]

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

summer is the best time. it's surprisingly cool there even while the valley is roasting. There's a speedventures event in september.

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 :/

not too bad. having an oscillating multitool (e.g. Rigid Job Max) makes shaving the foam a piece of cake. I tried doing it with a knife/saw on the rear bumper foam--total waste of time. the hole in the bumper isn't difficult to mount with the little "needle" attachment.

whatever you choose to do, get some sort of tow hook. if you're stuck without it, it can ruin your day.

 

[B2B]

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 :/

If you would rather not cut into the bumper cover, check out the tow hook from Blowfish Racing http://stores.blowfishracing.com/-strse-2/2010-dsh-2013-Mustang-Front-Tow/Detail.bok

Fits and finish is first class and I use the bracket to mount my front license plate when I'm driving on the street.

A few pictures of mine...

 

[neema]

^^^this is the route I'd go if you're a stickler on not cutting the front bumper.



Now for some super high-tech data analysis: here's my run last year compared to this year. Most drastic mods are wheels/tires (305 NT01s vs 285Kumho Ecsta XS) and the LCA relocation brackets. I wasn't pushing it nearly as much in the video on the right, but I seem to have finished the lap sooner. This is about as scientific as my data analysis gets

http://www.youtubemultiplier.com/52...ca-mustang-comparison-before-and-after-lc.php

 

[neema]

Just scanned the for the CEL code and came up with a P0161. Looks like the cat puking out its guts took out the o2 sensor. Good times

 

[sheizasosay]

If you want (can) get rid of the cats and don't want a loud car; the prochamber will shock you at how quiet a catless midpipe can be. It's quieter than a catted x pipe. I had an O/R X, got tired of pissing off neighbors and was worried about cops knowing when I floor it. Added cats to the X. Got a blower. Wanted an O/R pipe due to potential blower/cat issues and went with the prochamber.

 

[neema]

Anyone California people planning on going to NASA norcal event at Sonoma in a couple weeks? I'll be there!

 

[zquez]

If you want (can) get rid of the cats and don't want a loud car; the prochamber will shock you at how quiet a catless midpipe can be. It's quieter than a catted x pipe. I had an O/R X, got tired of pissing off neighbors and was worried about cops knowing when I floor it. Added cats to the X. Got a blower. Wanted an O/R pipe due to potential blower/cat issues and went with the prochamber.

Or you can run an O/R mid-pipe and stock mufflers like I do. Loud at WOT, quiet during cruising and absolutely no drone whatsoever. With SLP axlebacks and off-road pipe it was NASCAR loud. I couldn't even drive the car.

 

[sheizasosay]

The more bar you run, the less net grip you have on that end of the car.

Why is this true if the swaybar keeps you at the best alignment(camber/toe)? I'm asking because I need more rate. I know that I should get it with springs, but I'm back to conventional springs.

 

[NoTicket]

Anyone California people planning on going to NASA norcal event at Sonoma in a couple weeks? I'll be there!

I was actually going to go on 3/16 but had to cancel due to a family reunion. Oh well.

I will be at Laguna Seca with HoD on 2/12 though.

 

[NoTicket]

Why is this true if the swaybar keeps you at the best alignment(camber/toe)? I'm asking because I need more rate. I know that I should get it with springs, but I'm back to conventional springs.

The way that the sway bar works is when your outside wheel pushes up, it will force the connection with the sway bar up as well, putting torsion on the sway bar. This torsion will be counteracted on the other side of the sway bar by the sprint/shock/weight of the interior wheel.

While all this helps keep the car flatter, it also has the side effect of lifting the inside wheel, reducing grip to that wheel.

I think it is too simple to just say you will have less grip. If you had too little sway bar the car would lean too much, and also unload the inside tire.

 

[csamsh]

I know there are more exaggerated pictures out there...but here's my car (on street tires) doing the "inside wheel lift" that NoTicket mentioned- you can see daylight under the driver front tire.



Also: Obligatory "Damn I'm so jealous of y'all that get to run Laguna Seca!!!"

 

[SoundGuyDave]

Quote:
Originally Posted by sheizasosay
Why is this true if the swaybar keeps you at the best alignment(camber/toe)? I'm asking because I need more rate. I know that I should get it with springs, but I'm back to conventional springs.

The way that the sway bar works is when your outside wheel pushes up, it will force the connection with the sway bar up as well, putting torsion on the sway bar. This torsion will be counteracted on the other side of the sway bar by the sprint/shock/weight of the interior wheel.

While all this helps keep the car flatter, it also has the side effect of lifting the inside wheel, reducing grip to that wheel.

I think it is too simple to just say you will have less grip. If you had too little sway bar the car would lean too much, and also unload the inside tire.

No Ticket has the physics of it right. My comment was specific to the context of the discussion from which it was lifted, which was discussing using a FRONT swaybar to tune out an oversteer tendency... In that very specific scenario, I still stand by what I said, oversimplified or not... Also, having "too little swaybar" may not be an issue, if you have sufficient spring rate to provide the needed wheel rate. So there. Yes, that would probably get you FAR too stiff of a ride to be able to handle track irregularities, but "in theory" with enough spring rate you won't "need" a swaybar.

 

[neema]

I ended up switching back to my stock rear swaybar and I like the feel better. KW Clubsports have 350lb rear springs, which is higher than most spring rates offered and used on a street/hybrid setup. The ST sway bar that was on the car was a hollow 27mm bar, which is also on the higher end of the spectrum.

I can't leave anything alone, so I'm switching to true rear coilovers to try using less spring rate while maintaining wheel rate. One track near me (Buttonwillow) has some not so smooth sections, so I'm hoping a slightly softer spring helps over bumps. I'll then adjust steady state grip with adjustable roll center via a watts link. I hope my logic is correct.

I'm still worried about oil starvation. I wish oil pans were easy to install.

I was actually going to go on 3/16 but had to cancel due to a family reunion. Oh well.

I will be at Laguna Seca with HoD on 2/12 though.

HoD events are nicely organized. This is my first time with NASA. I hope they uphold a good standard of safety/organization. Their prices are significantly cheaper than HoDs.

 

[NoTicket]

No Ticket has the physics of it right. My comment was specific to the context of the discussion from which it was lifted, which was discussing using a FRONT swaybar to tune out an oversteer tendency... In that very specific scenario, I still stand by what I said, oversimplified or not... Also, having "too little swaybar" may not be an issue, if you have sufficient spring rate to provide the needed wheel rate. So there. Yes, that would probably get you FAR too stiff of a ride to be able to handle track irregularities, but "in theory" with enough spring rate you won't "need" a swaybar.

You were absolutely correct in what you were saying. What I should have said was it is too simple to THINK about it in terms of more bar = less grip when thinking about how/why sway bars affect traction and handling characteristics. It's not as if my explanation was complete either.

 

[SoundGuyDave]

LOL!! I was just busting your chops, man! Let's face it, in a linear thread, statements tend to hang together a lot better than they do in a thread where the topic jumps around...

In the end, chassis tuning is an exact science, at least from the physics standpoint. Now, as soon as you add driver input... oh, boy...

 

[sheizasosay]

Neema, as far as the tail wag you reported on corner exit a few things come to mind-

Your rear spring rate is high, but you also have a rake. Smaller sway bar was a good move. You think maybe lowering the rear might help shift weight to the rear? Corner weighting the car is ideal, but if you can't do that....lowering the rear will help. Good time to ask what your LCA angle is.

Also, you mentioned decreasing compression in the rear. Instead of telling you to go one way or the other with your damper adjustments you should take a look at Sachs tuning guide for dampers. It's good.

 

[Norm Peterson]

Why is this true if the swaybar keeps you at the best alignment(camber/toe)? I'm asking because I need more rate. I know that I should get it with springs, but I'm back to conventional springs.

You have to keep two somewhat contradictory concepts in mind.

One is as you note, grip as a function of camber. Making the front stiffer in roll tends to help this aspect of tire grip, or at least may allow you to set cambers that are not quite as far negative.

The other is that total grip at one end of the car is sensitive to how much load is being transferred across that end, and where this effect is concerned making the front end stiffer in roll tends to hurt grip. Somewhere there is a sweet spot, which also depends on how much roll stiffness you've got (or will put) at the other end.


Norm

 

[sheizasosay]

No Ticket has the physics of it right. My comment was specific to the context of the discussion from which it was lifted, which was discussing using a FRONT swaybar to tune out an oversteer tendency... In that very specific scenario, I still stand by what I said, oversimplified or not... Also, having "too little swaybar" may not be an issue, if you have sufficient spring rate to provide the needed wheel rate. So there. Yes, that would probably get you FAR too stiff of a ride to be able to handle track irregularities, but "in theory" with enough spring rate you won't "need" a swaybar.

Ok, I took you out of context. I also assumed that you thought like what a massive suspension community says. Don't worry Dave, I got you placed well above the general retardation of the internetz, but I think it was a "fair" error on my part to take you out of context considering it's as common as it is. It at least allows me to raise my point.

What I am about to post took me about 4 seconds. That's with a mediocre 40 GWAM typing, the internetz to decipher what I wanted, post the perfect link and click on it. Felt real good.
http://www.autocross101.com/Sway_Bars_101.html which basically has "THE LAWS OF THE SWAYBAR(tm)" j/k, but really, it says that a stiffer front bar:

1. Decreases front chassis roll.
2. Decreases front grip or traction, while increasing rear grip or traction.
3. Faster steering response.
4. Decreases off-power steering at corner entry.

So even though I took you out of context, I would call it common. I just don't understand why all these "LAWS OF THE SWAYBAR(tm)" are not worded to my liking. Don't they know I will make a fuss? According to that, you add a stiffer swaybar then you are losing grip at the area you put the swaybar(front/rear). I believe that to be incorrect. And the reason why is because the swaybar may correct your alignment and that may give you more grip than you originally had. So I don't like the wording. I also don't have any proof. Yay!

You have to keep two somewhat contradictory concepts in mind.

One is as you note, grip as a function of camber. Making the front stiffer in roll tends to help this aspect of tire grip, or at least may allow you to set cambers that are not quite as far negative.

The other is that total grip at one end of the car is sensitive to how much load is being transferred across that end, and where this effect is concerned making the front end stiffer in roll tends to hurt grip. Somewhere there is a sweet spot, which also depends on how much roll stiffness you've got (or will put) at the other end.




Norm

Oh I believe in the sweet spot Norm. That's my point really. I think my case will probably make the most sense for folks running soft springs/big bars. Only problem is, I have no proof and can't really back it up. It's not something I'm calling a fact. It's something I'm challenging, but will not be able to follow through with a test. So I guess it really becomes a "food for thought" unless somebody else has something better than my hunch.

 

[NoTicket]

If you add bar at both ends of the car and the roll stiffness relationship remains in tact (which will require adding different amounts at each end), you should be able to increase overall grip up to some limit.

Are you going with the Hotchkiss bars? Those are some big ass bars.

 

[neema]

Neema, as far as the tail wag you reported on corner exit a few things come to mind-

Your rear spring rate is high, but you also have a rake. Smaller sway bar was a good move. You think maybe lowering the rear might help shift weight to the rear? Corner weighting the car is ideal, but if you can't do that....lowering the rear will help. Good time to ask what your LCA angle is.

Also, you mentioned decreasing compression in the rear. Instead of telling you to go one way or the other with your damper adjustments you should take a look at Sachs tuning guide for dampers. It's good.

The tail wag was sorted out. I wish I changed parts out at a slower rate because it could be attributed to two things: LCA relocating brackets and/or 305 rear tires. In general, the car was much more composed and easier to drive fast without letting it all hang out. I'm hoping the stock rear sway bar will give me the "room" to get on the power/rotate the car with the throttle a little earlier.

Also, I would lower the rear more, but it physically can't go lower with these springs. One height adjusters is bottomed out in the back and the other side had to be a little higher in height to get close to the 50/50 cross weight when corner balancing.

Here's a video showing the old 27mm sway bar on the car. If the car stepped out or behaved erratically, I'd point my finger at driver error more than anything else. Otherwise, it drove okay. Traffic clears around 4 minutes in.