AST 5200 install tips

MFE

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About 50 track days. No autocross.

Wow. That's a lot. At 100-150 miles a day that's 5000-7500 track miles. It's taken me 10 years of frequent activity to get close to 8000.

The reason I asked is twofold: First, those of us who've been around a while have all seen the guy(s) who throw mod after mod after mod at the car, then 2 cameras, then data acquisition, then 2 more camerals, then some more mods, and then some more, yet...they never really learn to drive out of a problem when SHTF. Every problem they run into, they throw more parts at it, yet they discount or completely ignore the most critical part of all: the nut behind the wheel.

Now, from looking at your videos, you're certainly hustling that car around and making good time, so it looks like you know what you're doing. You're enjoying yourself, and you're flying. That's mostly what it's all about. That said, the second reason I asked is, and don't take this the wrong way, but on that video where you spun out, your steering correction was slow, and almost non-existent. Way too little, way too late. It was save-able, if you had been on top if it and aggressive with the correction and recovery. And watching it, my first thought was...see my first point. My second thought was: Don't count on $2000 worth of shocks to fix the problem.

Just my observations from behind the computer screen, could be completely wrong, but worth a thought.
 

darreng505

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I appreciate all the advice and input guys. I'm certainly not the most knowledgable in this thread. One thing I've done is fully analyze my own performance vs. The cars.
I'm getting closer to driving at the limit but at times certain parts on the car underperform. My suspension definitely needed upgrading as I'm at the point where I'm approaching the cars performance.

I always talk to more experienced people before making decisions as I take the sport seriously as well as fun.
One of the books I love 'ultimate speed secrets' talks about spin situations where you shouldn't add more input. At the time my rears locked and stepped out I was doing 100mph+. Countersteering in that situation (while the car was out of balance) was not the correct maneuver.

I had an instructor with me but later when talking to other racers it was concluded my rear dampers and springs were too weak to keep the rear planted in that situation.

Now, I went back out and got on it good but it just bumped up my todo list for the suspension anyway.

I'm very focused on the nut behind the wheel but I'm driving this car near its abilities and sometimes beyond. Lol

Thanks again for all the candid remarks. Its very helpful.
 

MFE

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At the time my rears locked and stepped out I was doing 100mph+. Countersteering in that situation (while the car was out of balance) was not the correct maneuver.

I beg to differ, you just have to do it fast, and just as importantly, you have to recover (get the wheel back to center) fast so it doesn't snap back the other way.

Skip Barber calls it CPR. Correct, Pause, Recover. And it doesn't matter if you're doing 8 mph on a sheet of ice or 180 mph on the Mulsanne Straight. The difference is the degree and the timing.
 

darreng505

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And that's "what they teach you in the classroom" stuff. It makes a huge difference how fast you are going as to how and more importantly - whether its even possible - to counteract the vector of the car.
If the car is taking a set through a turn and the rear gives a little, sure, CPR. I do it all the time and its necessary to drive at the limit, small momentary gestures when the car - has some traction - with which to turn.

At higher speeds and especially when the car is front loaded and NO TRACTION in the rear, your turning the front wheels will do little good. At that point the car is rotating like a pinwheel and you will just accelerate that spin by trying to control it. Every speed/race book I've read makes this distinction between "correcting" an oversteer and "losing the rear end". Two very different beasts....
 

MFE

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Well, I don't subscribe to the close your eyes and pray school of car control, no matter what's going on with the car. Unless it's airborne or on its roof, you have some control over it. Whether you choose to avail yourself of that control is another matter.
 

BlackBolt9

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Annnnddddd..... finally got to the shop and snapped a few pictures for you.

Boss 302R trunk. Cell isn't there but you can see how we route them, and then bolt them to the cell's box.

MPTrunk_zps5c91630d.jpg


Left side
MPLR_zpsbbd59e91.jpg


Right Side
MPRR_zpsabc80771.jpg


In the car we won the Belle Isle World Challenge race with. This car now has Penske's in it for another series but you get the idea.

Trunk
BlueTrunk_zps67645761.jpg


Left Rear
BlueLR_zpsa90d9942.jpg


Right Rear
BlueRR_zps69d490f2.jpg


Right Front
BlueRF_zps0fe01c3b.jpg


Left front
BlueLF1_zps40da2d0a.jpg


BlueLF2_zps6a70e8fb.jpg


The left front is kind of a pain in the ass where it's at because it's more difficult to get to but the airbox is in the way and we try to keep the resevoirs as far from the engine as possible otherwise you can't even touch them they get so hot. Keeping them away from heat in the engine bay is the biggest hurdle, otherwise it's pretty straight forward and easy to do.
 

darreng505

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Wow! Thanks man. That is great and a big help
I should be getting the shocks this week and will post pics after they get installed. I appreciate it.
 

BlackBolt9

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Wow! Thanks man. That is great and a big help
I should be getting the shocks this week and will post pics after they get installed. I appreciate it.

No problem. Glad that you have found them helpful! Looking forward to seeing the finished pics. I try to help when I can. :beer:
 

BlackBolt9

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We've never done it and honestly, when looking at other cars I've not seen it done before. I can see where it may help reject heat trying to get in, but I'm not sure how much it would hinder the reservoir from dissipating the heat generated in the shock itself. Probably better to defer this question to the pros at AST if you want to try it.

Anytime I've seen heat protection for a shock/reservoir, it was in the form of an aluminum or carbon fiber shield mounted between the reservoir and whatever the heat source was (engine, diff, etc.) These shields would often have gold foil on them though.
 

darreng505

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BlackBolt9, do you have any data on what compression and rebound settings (front/rear) work well for the mustangs? I just need a logical starting point to set up the car. I'm coming from single adj dampers...
 

BlackBolt9

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BlackBolt9, do you have any data on what compression and rebound settings (front/rear) work well for the mustangs? I just need a logical starting point to set up the car. I'm coming from single adj dampers...

It all depends on what springs you are running and to a lesser degree, your sway bar and alignment settings.

If they are true Grand Am spec, then you should be safe, just not optimized, anywhere in the adjustment range. When we try a spring change, we usually start with the shocks in the middle of their adjustment range and work from there until we find what the driver likes. Keep in mind, what one driver likes another may hate.

I've seen two pro-drivers in the same car, at the same track, on the same weekend want two significantly different setups, and both were running at the front :??:
 

darreng505

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I'm running 700lb front and 400lb rear.

These shocks are double adjustable so should I set both the compression and rebound in the "middle" setting and move them in lock step for starters? Or is there some best practice for our mustangs that says it needs more or less rebound vs. compression?
 

BlackBolt9

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I'm running 700lb front and 400lb rear.

What does your car weigh? Those spring rates seem a fair amount too high. I'm thinking you need to be more like 550 and 300. Keeping the high spring rates in mind, I would guess you are going to need a stiffer shock valving to keep them under control, but it really depends on the track and your preferences.

These shocks are double adjustable so should I set both the compression and rebound in the "middle" setting and move them in lock step for starters? Or is there some best practice for our mustangs that says it needs more or less rebound vs. compression?

DO NOT move them in lock step, you need to adjust them based on what handling characteristics the car in displaying. Shocks are on a car to control the springs. Obviously you use them to tune the chassis, but how the chassis behaves will be different depending on, springs, sway bars, and car set-up. You can't make a shock setting based off someone else's car and expect it to work the same. I honestly don't have a good place for you to go because I don't think I've EVER seen us run those heavy of spring rates.

First rule of thumb - set up the car as soft as possible, increase spring rate only if there is a problem (such as coil bind, or really poor suspension geometry throughout the range of travel, etc.).

Second - do you have scale pads to corner weight the car and get caster, camber, toe and ride height set correctly? The amount of rake (ride height difference front to rear) can affect braking and corner entry (maybe a little mid-corner) over-steer.

You have a ton of things working together that you need to play with. Trying to come up with a "best practice" isn't really possible once you start playing with a real race car like what you have.

I will say, I think we tend to run our shocks on the softer side, but I think that has more to do with the fact we are running softer spring rates than you are, not because it's a mustang. The track makes the final call on what settings we run. So realistically, I have no way of remembering how we had a car setup somewhere let alone what shock settings we ran without getting ahold of our setup book that we write everything down in. And giving out that much information would probably be frowned on, I hope you can understand why. :beer:
 

darreng505

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I'm on my phone but ill respond in more detail tomorrow.
Car is around 3400 with me in it. I agree the spring rates seem high. Vorshlag suggested 850/500 and capaldi was at 550/350 so I went down the middle to start.
I'm used to a soft suspension but that also contributed to my mishap in the braking zone.

The car is at a race shop and will be corner balanced etc.
I'm sure I will be making adjustments the entire rest of the season.
 

darreng505

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AST sent the wrong front perches so they had to overnight the correct ones for the 2.5" front springs. Arriving today.
My shop was confused at first because the rear springs are 2.25" but the race crew I bought these from bundled 2.5" front springs with the heavy rate I requested. They're the experts!

Sunday I will be out testing and tuning and probably crying that I have to relearn all the handling and change my lines to the new suspension.

I was used to a soft suspension before and my lines were all designed around that. With a more level and stiff suspension with better shocks I probably need crisper turn ins - a good thing.
 

BlackBolt9

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AST sent the wrong front perches so they had to overnight the correct ones for the 2.5" front springs. Arriving today.
My shop was confused at first because the rear springs are 2.25" but the race crew I bought these from bundled 2.5" front springs with the heavy rate I requested. They're the experts!

Sunday I will be out testing and tuning and probably crying that I have to relearn all the handling and change my lines to the new suspension.

I was used to a soft suspension before and my lines were all designed around that. With a more level and stiff suspension with better shocks I probably need crisper turn ins - a good thing.

Don't know if they just aren't in the pictures or if that's what the one large tab on the strut body is, but I don't see front sway bar mounts either... Ours have always been adjustable mounts that are on the same threads as the spring collars...

It's not that uncommon to run different diameter springs front and rear. The two should run different enough spring rates that you wouldn't be able to run rear springs in the front or front springs in the rear anyways.

Don't assume all race teams are experts. I've seen many cars built by "race teams" that I wouldn't have paid for. Lots of shysters in the racing industry looking to make money off people who don't know any better.

Make sure you are making adjustments according to lap times. Stiffer doesn't mean faster. The car may feel quicker because it is twitchy but lap times might not agree.

I still think you are going to be way too stiff. I've never heard of a Boss302S or R running anything near the spring rates you have. If you just want a crisper turn in, you could have just went with a little more toe out in the front end. I'd be the super stiff springs are going to make the car skip around more.

Good luck!
 

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