AST 5200 Grand Am series

[dawgdog]

This is my third suspension modification. I started out with H&R springs. I liked the new look but not the ride or performance. After riding in a fellow forum member's car with the Ground Control kit that retains EDC, I decided to go that direction. That was a real improvement and I was happy. But I knew that could not be the ideal setup even though it works very well. I found I did not use EDC anyway and always had it on the most aggressive setting which seemed to handle the 440lb front and 600lb rear springs best.

So I decided to try something new and found that there were not a lot of choices if one wanted an out of the box fully integrated kit. So I ended up with a setup that was not out of the box.

I bought the suspension from Bruce at BRRacing. The springs are Swift and the rate is roughly 500 lbs front 800 lbs rear. There have been a few hiccups along the way but in the end everything worked out. They had to machine the lower rear shock mount; the upper rear shock mount came from Turner. The Vorshlag camber plates had to be modified to fit the Grand Am shocks. I ended up using the rear spring mount adjuster from my Ground Control kit as I didn't have the stock one with me at the time. Installation was done by my friend Noah at Cohesive Garage in West Seattle. He did a great job but it wasn't easy and it struck me this was car surgery! It was a bit tricky running the hoses for the remote dampers as they needed to go under the fender liners. The other AST 5 series I have seen have the hoses in front come off the top of the Vorshlag camber plates so the installation of the canisters in the engine bay is easy. But the Grand Am spec ones come off below the camber plate.

So now that they are on and I have done one track day so what do I think? I really love this setup. As a preliminary track setup I have it set 9 clicks from the softest setting on both compression and rebound. This is more comfortable than either the H&R or the Ground Control setup. You feel the bumps but the dampers take the harshness out of it. And the car sets perfectly in the turns and there is just a feeling of being in complete control. My installer Noah is an instructor for Alfa and has a history on track with my car and he was very favorably impressed. I do not time at the track but I am in the A run group and at the PCA event a Pacific Raceways Saturday was very competitive with a GT3 driven by an instructor. A friend who does time was behind me and gave me his lap time which I'm pretty sure is about 2 seconds faster than I drove last time out. I had to take a fair amount of air out of my tires as my tire temps went up significantly from last time out 10 days ago.

I'm not an expert and this is just my personal impression. JAJ was at the track
Saturday and he knows the technical side. All I know is this feels better and I think I am significantly faster through the turns. One of the reasons I wanted this suspension is I have a friend with a modded 330 with AST 4100s and he is super fast and that car is so composed.

Not interested in discussing prices - contact vendors.

[aus]

I thought Harold had AST kits that are ready for install?
How's the Grand Am kit different from the other 5 series dampers?

Nice write-up and pics.

[JAJ]

As dawgdog said, I was there to see this setup on its first time out, and from watching the car through a couple of fast corners with some major bumps, it looks very composed. These high-end double adjustable setups have that strange ability to control the body motion so that with the right settings, the ride gets smoother and the grip gets higher all at the same time.

Great write up - well done!

[E90///M3`]

these look seexy...

[STALKER]

Congrats on the set up. Looking forward to getting more feedback.

What alignment settings and ride height did you go with? Are they 9" springs?

Do they make the AST 5100s for our application?

[HP Autosport]

I hope the rear shock towers were reinforced...How well the stock rear shock towers take the racing type eye to eye damper with bearing ends is unknown.

Originally Posted by aus

I thought Harold had AST kits that are ready for install?
How's the Grand Am kit different from the other 5 series dampers?

Nice write-up and pics.

This isn't one of my typical kits or any typical kit you would get from another AST dealer. This is a Grand Am kits you see on the Grand Am M3's.

Originally Posted by STALKER

Congrats on the set up. Looking forward to getting more feedback.

What alignment settings and ride height did you go with? Are they 9" springs?

Do they make the AST 5100s for our application?

Without Swift helpers in the rear, you must be a Swift 9" spring.

Yes, AST 5100 is available.

[montreal red]

just curious, what did you use to get rid of the EDC codes that would come up since you dont have edc shocks anymore ? did someone coded them out for you?

[HP Autosport]

Originally Posted by montreal red

just curious, what did you use to get rid of the EDC codes that would come up since you dont have edc shocks anymore ? did someone coded them out for you?

KW or MS EDC emulators will do it.

[RickyBobby]

Very nice! I've been officially "one upped". I've had my AST's for almost a year now and am still super happy with them. Mine are not quite as impressive as those Grand-Am series though. You made the right choice with Bruce and crew at BRracing.
Did you get the digressive valving package?

[STALKER]

Originally Posted by RickyBobby

Very nice! I've been officially "one upped". I've had my AST's for almost a year now and am still super happy with them. Mine are not quite as impressive as those Grand-Am series though. You made the right choice with Bruce and crew at BRracing.
Did you get the digressive valving package?

What is the digressive valving package??

[JAJ]

Originally Posted by RickyBobby

Did you get the digressive valving package?

Unless you're running a high downforce Prototype car, digressive valving would be normal for this kind of setup. Otherwise it will ride like a buckboard.

For STALKER's benefit, the digressive damping curve has less damping as the speed of shock motion increases. "Progressive" would mean damper rate increases at higher speeds, and is the opposite of "digressive". High speed damping is set to absorb bumps in the track, and should be softer than low speed damping, which is set to control body motion when the driver is braking or turning.

[JAJ]

Originally Posted by HP Autowerks

I hope the rear shock towers were reinforced...

The dampers are still just dampers - they don't have springs on them, so there's no need to reinforce the rear shock towers.

It's the subframe mounts that are taking more abuse with the higher rate springs - if there could be problems, that's where it will be.

[brracing]

For all to note....the new AST Grand-Am sets are slightly upgraded versions of the AST 5xxx series. Most in the series are running the 5200, so these sets are more readily available, along w the parts. Turner has also been running these sets on some of their BMW Grand-Am cars, so there is more info available on the setups and implementations....although, most are all done on "pure" racecars, not track combo cars. The kits can be made to work, and offer some other advantages....by being a pure "eye to eye" setup, they are easier to pull and replace, so if a spring rate change is needed or desired, you can now do that without the hassle of undoing the upper camber plate and remote resv....you simply pull the eye bolts, and presto....you have your shock out, and even on the front strut, you can undo the front strut body and take off the springs. The rears in this case are true "coil-overs".
Unlike a street setup, we changed the length of the springs in the front, and also added another sweet little trick to ensure no spring bind during normal turning or parking lot travel.
Great write - up Carl....have fun, you have a GREAT car to play with.

Bruce
BRracing

[rzm3]

Very nice set up! The fronts are also inverted I can see.

Is the trick needle thrust bearings?

[HP Autosport]

Originally Posted by JAJ

The dampers are still just dampers - they don't have springs on them, so there's no need to reinforce the rear shock towers.

It's the subframe mounts that are taking more abuse with the higher rate springs - if there could be problems, that's where it will be.

I can see it's not a coilover rear and am fully aware of AST line of products.

Time will tell.

Dampers are just dampers and many E36/E46 shock towers fail in the past without going to a coilover type setup.

[dawgdog]

Originally Posted by STALKER

Congrats on the set up. Looking forward to getting more feedback.

What alignment settings and ride height did you go with? Are they 9" springs?

Do they make the AST 5100s for our application?

Stalker, I kept the ride height the same which is approx 25.5" from the fender to the ground front and rear. The front springs are 6" with 3" helper springs and a radial bearing on top.

Not sure that AST makes the 5100 in the Grand Am series but the 5100 would be a very nice setup indeed. Probably all I needed.

I'll message you my alignment setting when I get them out of my glovebox.

[STALKER]

Originally Posted by dawgdog

Stalker, I kept the ride height the same which is approx 25.5" from the fender to the ground front and rear. The front springs are 6" with 3" helper springs and a radial bearing on top.

Not sure that AST makes the 5100 in the Grand Am series but the 5100 would be a very nice setup indeed. Probably all I needed.

I'll message you my alignment setting when I get them out of my glovebox.

Thanks for the info.

[HP Autosport]

Originally Posted by dawgdog

Not sure that AST makes the 5100 in the Grand Am series but the 5100 would be a very nice setup indeed. Probably all I needed.

.

Yes, it would be a rebound adjustable only without the external reservoirs.

[RickyBobby]

Originally Posted by JAJ

Unless you're running a high downforce Prototype car, digressive valving would be normal for this kind of setup. Otherwise it will ride like a buckboard.

For STALKER's benefit, the digressive damping curve has less damping as the speed of shock motion increases. "Progressive" would mean damper rate increases at higher speeds, and is the opposite of "digressive". High speed damping is set to absorb bumps in the track, and should be softer than low speed damping, which is set to control body motion when the driver is braking or turning.

I was referring to a new digressive valve that ast had on their Facebook page a few months back. I know nothing about it other than it was being tested at the time, so I was just curious if the OP got that particular upgrade.

[JAJ]

Originally Posted by RickyBobby

I was referring to a new digressive valve that ast had on their Facebook page a few months back. I know nothing about it other than it was being tested at the time, so I was just curious if the OP got that particular upgrade.

I had a look at their Facebook page and found a graph comparing two different digressive pistons, a new one with a really sharp blowoff knee and an older one with a softer knee. Is that the diagram you're talking about?

[STALKER]

Are the shock noisy for daily use? Any more feedback?

[dawgdog]

Originally Posted by STALKER

Are the shock noisy for daily use? Any more feedback?

No, they are not. And the ride is incredible. I dialed down the compression by two clicks and upped the rebound by one. So I am 3 clicks from full compression and 2 from full rebound. I drove today on a route where I was jarred by the H& R and the Ground Control and it was so composed. Can't wait to try this setting on the track Friday.

This is my best mod yet, by far. Like having a new car.