About a month ago I got AST 5200 2 way adjustable coilover with external canisters and true rear coilover installed on my car. I figured since there is pretty much no information about this coilover on E9x’s I’d do a review. Huge shout out to Andrew@Sonic MS for helping me choose and buy this kit
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The suspension journey on my car has been ZCP suspension -> B&G springs -> Ohlin’s R/T coilover with Swift springs and Vorshlag camber plates -> AST 5200. The AST by far the best suspension setup I’ve had for this car.
Reason for buying the AST? I was not very happy with the Ohlins. While they were really great, I expected a lot out of them since they are so highly reviewed and I feel that’s why I was kind of let down. For normal daily driving they were perfect, comfortable but still reduced a lot of body roll. Most non car people that rode in my car could not tell the difference in comfort from when I had OEM suspension. But I wasn’t happy with them because they are a little too soft for me and at the ride height I liked they didn’t feel great.
After talking about suspensions with Andrew, he recommended the AST’s because he felt they suited what I wanted from the car. After the order was place it took about 6 weeks to get them. They are custom built to customer specifications, I went with the AST recommended specs. The AST’s come with the dampeners, springs, camber plates, and remote canisters. Basically everything is ready to go out the box.
I had a buddy of mine who is great with suspensions help me out with the install. With the two of us, install was smooth and just as easy as any other coilover. Took about 2.5-3 hours total and we were working slowly.
The remote canisters seem to scare a lot of people, but with the AST’s inverted design, the canisters for the front come off the top of the strut, so they are already directly in the engine bay. I mounted mine near the top corners of the hood. Front install was exactly the same as any other coilover plus an extra 20 minutes to route and tie down the canisters.
The rear install is also pretty straightforward. Remove the trunk liner and you see two vents on both side that lead into the wheel wells. Pop the vent out and route the canisters behind the fender liner and into the trunk through the vent holes. Notch a hole in the vent big enough for the canister tube to fit and put the vent back into place. One complaint I have is the line for the rear canisters isn’t very long. I would have liked to have them mounted outside the trunk liner, but wasn’t able to do so. I have the canisters underneath the access panel on the left and next to the battery on the right. It’s super easy to remove the two panels and get to the canisters without having to remove any trunk liner, so it’s not too bad, but I would have liked to show off the canisters
. All of this took less than 30 minutes to do.
The rears are a true coilover, so the spring is moved onto the shock. I talked to a few people if shock tower reinforcement is required. A few guys on the forum have said they’ve ran a true rear setup for years without a problem. AST has also said it is not necessary, so I have not done any reinforcement.
I did the recommended 300 mile break in and left the factory compression and rebound settings for this period. For those first 300 miles my first impressions were that the AST’s are very stiff. If it wasn’t perfectly flat pavement, I felt everything on the road. Hitting bumps or uneven roads was a little on the harsh side. But the car was on rails and body roll was nonexistent haha. I was still able to daily drive during this time without breaking my back which was nice lol.
Once the break in period was done I took the car to Andrew to align, height adjust and dial in the compression/rebound. I was asked what changes I wanted and how I wanted the car to feel and I told him I wanted something more streetable but not too soft. Andrew also said that the nitrogen pressures can be changed so there is a really wide range of how soft or stiff these coilovers can be. He first made some changes on the compression and rebound settings and told me to try it out before messing with the nitrogen. I liked it after those adjustments so we didn’t change the nitrogen pressure. With the correct alignment and dialed in to be a little more daily drivable friendly I am extremely happy with the AST’s.
So far I’ve only done street driving with the AST’s on, but they feel fantastic. The car is very planted and not floaty at all. Ride is firm but not harsh. It’s definitely not soft or as comfortable as the Ohlins, but I daily drive it no problem. The rears with the true rear coilovers make a pretty big difference. The rear end feels a lot tighter and doesn’t slip out as much. It’s hard to explain, but the car feels a little more like a go kart. Very direct, predictable and turn ins are amazing. Andrew was able to dial in the perfect ride height for me with no rub which is still crazy to me considering how low I am. With the Ohlin’s I was slightly higher and would rub occasionally. And now my front lip does not hit the road on dips on the freeway, which was another problem I had with the Ohlin’s. Overall I am very happy with the purchase and would recommend this kit to anyone who wants a great suspension
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