Some fun from the weekend...

[Gray Ghost GT]

Nicely done - great video! Shaving 2.5 seconds is huge, but I know you can shave off another full second. Keep at it! Mike

 

[Captain_Stangin']

Damn that's a bumpy track! Nice driving.

 

[SoundGuyDave]

Dave

It sounds like you are having way too much fun.

How do you find the ground clearance on the street with the Dunlops, as per Tire Rack, they are 25.6 " diameter which reduces your ground clearance almost 3/4 inch from the stock 27" dia?

It is also interesting to note that, again per Tire Rack, the Hoosier's weigh 24 lb versus 32 for the Dunlop's - a significant difference in unsprung and rotational mass.

To be honest, I have only slight ground-clearance issues, and only then on tall obstacles, like speed bumps. For me, the low point on the car is the leading edge of the resonators, which I have right after the midpipe to axle-pipe joint... Ocassionally, I'll "ping" those off something, but it's a vanishingly rare occurrence. Since both the street and race rubber I run are the same size, it doesn't change the ride height, CG, or anything else. Yes, the Dunlops are heavier, and yes, I can feel the difference under accel and braking, but that said, if I get out on track with the Dunlops, either I'm just out having fun hooning around, or it's wet. If it's wet, then the extra rotational mass really doesn't become a factor, since I can't brake or accelerate that hard anyway. When they're fresh, the wet grip is awesome! Not so much when they're cycled-out and half melted, though! I think Philostang will comment on that at a later time... For a "fun" tire, that will last a season easily for the average track-guy, or most of a season for a track-whore like me, the price to performance ratio is excellent. I'm sure that the Hoosier Wets would be a better tire, but I can only fit FOUR tires on my trailer, so...

Dave can chime in on the street ride quality from his lowering springs...I'm looking forward to this.

Okay, here we go... First, just to set the record straight, I don't technically have lowering springs, they're linear-rate, and they're coil-overs, so I can set my ride height to anything that I want it to be. That said, like John (Philostang), I've got my rockers down to around 4". Too much lower, and the bumpstops get a workout, the roll centers drop underground, and the car handles like crap. Where I've got them seems to be the best compromise. Now, all that said, I'm running pretty low rates for coilovers, but they're a lot higher than just about ANY of the "normal" mustang spring rates. 350lb/in up front, and 300lb/in in back. That, by itself will stiffen up the car appreciably, and not in a good way on the streets around Chicago. For those of you that don't know, the official definition of "road" around here is "a series of potholes of varied size and depth, with minute amounts of connecting blacktop." Fer chrissake, the State Animal is the sawhorse!

All that said, however, ride quality is a function of the entire suspension as a system. That includes the springs, tire sidewall stiffness, damper curves, and bushing compliance. I have stiff springs, short, stiff tire sidewalls, very aggressive compression curves on the dampers, and rod-ends in place of most of the bushings. To describe the street ride as "brutal" would be charitable! My ride is SOOOOO hard! (How hard is it?) It's so hard that my Dentist offered to pay me to keep it that stiff, since all my fillings keep getting knocked out! That's an exaggeration, but honestly, it's not what I would call "daily-driver friendly" at all. To be fair, though, when Sam helped me put this whole thing together, I told him, point blank, that the car is a track toy that just happens to get driven to the track rather than trailered. There is no real compromise there at all. I wanted it to lean towards track performance, and that's exactly what I got. Just like an 8-second drag car, with the little skinnies up front and no front bar is in danger of falling over just turning into the driveway, compromises had to be made in the name of performance, and they were.

If I had to do it all over again, I think I'd wind up in exactly the same place I am now, but probably without the intermediate steps.

 

[Sam Strano]

All that said, however, ride quality is a function of the entire suspension as a system. That includes the springs, tire sidewall stiffness, damper curves, and bushing compliance. I have stiff springs, short, stiff tire sidewalls, very aggressive compression curves on the dampers, and rod-ends in place of most of the bushings. To describe the street ride as "brutal" would be charitable! My ride is SOOOOO hard! (How hard is it?) It's so hard that my Dentist offered to pay me to keep it that stiff, since all my fillings keep getting knocked out! That's an exaggeration, but honestly, it's not what I would call "daily-driver friendly" at all. To be fair, though, when Sam helped me put this whole thing together, I told him, point blank, that the car is a track toy that just happens to get driven to the track rather than trailered. There is no real compromise there at all. I wanted it to lean towards track performance, and that's exactly what I got. Just like an 8-second drag car, with the little skinnies up front and no front bar is in danger of falling over just turning into the driveway, compromises had to be made in the name of performance, and they were.

If I had to do it all over again, I think I'd wind up in exactly the same place I am now, but probably without the intermediate steps.

Two points to expand on here:

1. Imagine what happens with say, 700 front springs like some folks want to run.

2. This is why I don't recommend springs nearly that stiff for compromise cars, and use so many Steeda Sports, and springs similar to them). There are kits out there using 400 pound front springs, one uses a 630.... That's way, way too much IMHO.

 

[Sleeper_08]

Dave

Thanks for the detailed response.

I just measured my car and with the 27" KDWs on it the distance from the ground to the horizontal surface of the rocker is about 4 7/8 inches left and right and front and rear. Is this where you are measuring to?

If I get smaller diameter tires my "rub point" is probably going to be the Steeda LCA relocation brackets. The brackets are already so low that guided car washes are a no no. My exhaust is stock.

 

[Philostang]

Sleep,

I have the same relocation brackets (man do you get whacked for them in NASA TT points - not recommended). Dave's not running them (wise man). I've not had any trouble with their ground clearance, since most things in that vicinity are just going to get run over by the tire anyway. If it's big enough to not get crushed (speed bump, etc.), the tire will lift and take the bracket with it.

Where you described the measurement is where I took mine.

Best,
-j

 

[Sleeper_08]

Sleep,

I have the same relocation brackets (man do you get whacked for them in NASA TT points - not recommended). Dave's not running them (wise man). I've not had any trouble with their ground clearance, since most things in that vicinity are just going to get run over by the tire anyway. If it's big enough to not get crushed (speed bump, etc.), the tire will lift and take the bracket with it.

Where you described the measurement is where I took mine.

Best,
-j

Thanks for the response.

The only place the LCA Relocation Brackets have rubbed was when I tried drive it through a car wash.

 

[BBQBats]

Just saw the video, awesome run Dave!