AST-5200 2-Way Coilovers

[jeffucd]

Hi Internet,

This well be an ongoing review of my experience with the AST-5200 2-way coilovers. Since it has only been a few weeks with the setup, this will include more of my decision making process and other options I considered. Before I made the jump, I didn't see any of this online, so maybe it'll help the next guy. Be warned that this is a meandering stroll and is not a brass tacks write up. If you're just interested in what I think about the CO's, scroll to the bottom, which I'll keep updated as I put more miles on them.

GENERAL
Prior to my decision to go full CO's, I had a JB4v3 tune, ER catless downpipes, 15/12mm spacers, and Bridgestone RE71r's. I was tracking the car more than any other use (70/30 split between track and street use), and found that I was unevenly wearing down the outside shoulders of the front tires. I met another fellow F80 owner at the track that had great wear on his fronts, and he said it was all thanks to his Ground Control camber plates. So, this all started there.

RESEARCH
I have never liked the front wheel gap of our cars (but not to the point that I wanted to get away from it like a burning building) and since I was now considering CC plates, I figured I'd also search for lowering options and save on the installation. I first started looking at springs only - I liked what people had said on the forums about the Swift R's, have a friend with the Macht Shnells, but hadn't really spent time with any setup for an amount of time to understand their pros and cons. I also didn't know what height I wanted, as I didn't want the wheel gap, but also have a lip in my driveway that might scrape, and didn't want to install springs with a set height only to find out that it didn't work with my situation. Also, I had heard that going with just springs will negatively affect the performance and lifetime of the shocks. This led to me look at the KW HAS, but everything seemed more like a band aid focused on visual improvement, not performance. I first heard of AST as a recommendation from the shop that I had picked to do the work (Sonic Motorsports in San Jose, and specifically with Andrew - can't say enough positive things about their service and my experience with them! I was getting my emails returned at 12AM, text and picture updates without asking for them, and picked up the car on a Saturday afternoon when the shop wasn't open because it worked with my schedule). Anyway, back to the springs - I had read of AST's racing pedigree, affiliation with Moton, and liked the methodology for their springs that gave the car a 1" drop on all corners to prioritize performance. My thought here was that if the shocks were wearing prematurely, at least I could get some performance out of them in the meantime. Since I knew what a level down would be, I checked to get pricing on the next step up, which was a 1-way CO setup. I was particularly interested in seeing what the trade offs were in price, performance, part longevity, and resale value. I don't remember the exact numbers, but the cost difference wasn't insanely more, and from a performance perspective (unfortunately, hadn't had the chance to ride with anyone) I had heard/read that it was a huge plus on all points except for cost. So, that sold me on how I was planning on using the car, so I decided to level up.

COILOVERS
Since I was now going CO, I looked at the options: 1-way vs 2-way vs 3-way. I pretty much ruled out 3-way from the start, as this was by far the most expensive, and I felt that if I had that, I should have an all out race car, which I don't. So, that left 1 and 2 way's. Here comes a load of heresay from what I heard from various sources, as well as my own interpretation of them: KWV3 - the ultimate set it and forget it. It was a 1-way, but for the price point, reliability, resale value, etc. it was the value pick. Downside was that of my 70/30 split of track vs. road time, I'm planning on doing a few distance rallies with drive groups, and imagined not loving the non-adjustability to the setup. I'm also not mechanically inclined and have no tools. It seemed like a compromise, which would have been true for all 1-ways so I decided to pass and level up to the 2-ways. Motons: I heard these were hardcore, no compromises CO's. I saw and heard from a lot of happy people who have them on their personal racecars. Expect metal on metal noise, harsh ride, but top quality and performance in exchange. To me it felt like the same no-compromises approach to that made me decide against the 3-ways. Also, my family will ride in the car from time to time, and I value my marriage and two children, so I decided not to go this way. So, 2-ways it is. JRZ RS2 - this was the one I heard most about. People loved them, but at the same time I heard stories of people disliking them/parts breaking down. Vs others in the segment, this commanded a price premium as well. When I looked into their construction, they seemed skinny in places where others were beefy. I'm no engineer, but I took it into consideration. This was probably my second pick, as I don't necessarily trust/distrust things when there's hype surrounding it, but was willing to try them knowing that it could be a dice roll. A very expensive dice roll, but one with a palatable decent risk/reward factor. AST: I really liked the remote canisters, inverted design, price point, and affiliation with Moton. Plus, it was their springs that I first considered, so that was the leader for me. The AST-5200 kit also came with CC plates, which was a plus, since that's what started this whole thing in the first place. The biggest part for me were the separate gas reservoirs, which meant I could easily adjust them without needing tools or extensive training. Downside was that I wasn't able to find much on the forums about these on the F8X platform, but the company had been around, people liked them on the E9X, and they seemed to be a solid option. The price point was reasonable, and they came highly recommended, so I decided to take the leap sight unseen. I should say that I did check out all the other well known 2-ways, but I'm leaving them out since these were the ones I seriously considered.

INSTALL
The work was done at Sonic Motorsports in late July. Along with the CO's, they also swapped out the JB4 for Stage 2 BM3, added charge pipes, coded the EDC error out, and installed the CO's. We decided to go with a "1 finger gap" in the front wheel well, and to drop the rears at the same rate to prioritize performance. I was concerned that the rear would look too tucked with the drop, but figured that was secondary at this point. I'd imagine this was just over 1 inch, as the car began as a 3ish finger gap. The parts were shipped straight to Sonic, so I only saw them in pictures. To me, they looked like a clean and durable design. The remote canisters were installed (2) under the hood and (2) in the trunk. I liked that Sonic put them where they did in the trunk, since it wouldn't get hit as I loaded the trunk. The 1 finger gap was dead on, and I thought the car looked great. I was also relieved that the rear looked just fine too. I left the shop with all settings dialed in to 6 out of 11. This would give it a sporty feel while the parts settled, and I would return after 200-300 miles for an alignment and addressing anything that came up. After that, Sonic would give me a little settings cheat sheet and rundown of how to adjust the car for street or track.

FIRST IMPRESSIONS
Honestly, the first thing I noticed about the car was the tune. I know that isn't the point of this thread, but moving from JB4 to BM3 was a night and day difference. Power delivery is smoother, where you want it, plentiful, controllable, and actually makes the car sound better. Plus, BURBLES! OK, back to the CO's. I had read people's impressions on what a CO feels like vs. standard suspension when driving - it's not floaty, it's firm but not jarring, etc. While I can't really explain it much better, I did notice that the car felt more planted, turn in was sharper, and the suspension behaved predictably. It is definitely not harsh, but that's just the sporty setting for now. I've only put around 150 miles on the setup, but so far it feels great. Very different from stock and I'm hoping to notice a big positive difference once I get it on the track. I'll be back for the alignment at the end of August and will post more then.

THINKING ABOUT IT?
I'm in the Bay Area and am happy to meet up if anyone else is considering any of the mods on the car and would like to experience it in person first. You can see me at some BMWCCA events or with raddrives.com for their 1 day or 3 day drives, but also have a 3 month old at home so time is somewhat limited.

[Speed District]

Thanks for the insight!! Great choice on mods too man. We have events up at Laguna Seca sometimes if you are interested

[Justin.AutoTalent]

The AST were a solid choice! Can't wait to hear your feedback once you get some track times. I'm glad to hear you were well taken care of and that you're enjoying all the mods

[x.shell]

Thank you for the write up. The AST 5200 might be in my future one day. Also, lovely collection you got there.


* Added this thread to the Master List.

[jeffucd]

Originally Posted by exo-shell

Thank you for the write up. The AST 5200 might be in my future one day. Also, lovely collection you got there.


* Added this thread to the Master List.

Much appreciated re: write up. Wish the cars were all mine- I just rent a space at a local garage.

[///Machiavelli]

Not concerned at all about going true coil over in the rear and the subsequent increased load on the shock tower?

[mcvaughan]

Originally Posted by ///Machiavelli

Not concerned at all about going true coil over in the rear and the subsequent increased load on the shock tower?

You bring up an interesting point. What would be the reason to deviate from the original design intention of separating the coil and strut? It's not like it's going to give you more interior space for more tire; in fact it should be less.

[tom @ eas]

Good choice on the ASTs, solid performer on the track and still civil enough for street use.

[x.shell]

Originally Posted by ///Machiavelli

Not concerned at all about going true coil over in the rear and the subsequent increased load on the shock tower?

Originally Posted by mcvaughan

You bring up an interesting point. What would be the reason to deviate from the original design intention of separating the coil and strut? It's not like it's going to give you more interior space for more tire; in fact it should be less.

The best reason for going to a true coilover strut assembly on the rear is ease of adjustment on ride height and corner balancing.

In terms of space, there really is no down side as a wide tire will hit the fender lining and fuel lines before hitting the rear shock. There was already room to spare for the strut assembly with the OEM layout.

As far as the structural integrity of the shock tower goes, all I can say is that several dedicated track cars has been running the true coilover set up for the rears without any issues.

[jeffucd]

Originally Posted by ///Machiavelli

Not concerned at all about going true coil over in the rear and the subsequent increased load on the shock tower?

I wasn't aware of this issue until you mentioned it here. I spoke to Sonic today and they said that the issue isn't a problem on the F8X platform, but on the E9X and E46 it was an absolute must to address if going full CO.

They also said that they have been running true coilovers on their cars for 40K miles so far and have not had any issues.

That being said, do you understand the opposite to be true?

[Sean@PSI]

Great choice with the ASTs! - These have great feedback on every kit we have sold.

[Drew@Sonic MS]

Originally Posted by ///Machiavelli

Not concerned at all about going true coil over in the rear and the subsequent increased load on the shock tower?

Originally Posted by mcvaughan

You bring up an interesting point. What would be the reason to deviate from the original design intention of separating the coil and strut? It's not like it's going to give you more interior space for more tire; in fact it should be less.

Not an issue whatsoever on F8x, plus being able to run lower spring rates as the spring sits right on the shock is another bonus.

Glad you're enjoying them Jeff!

[x.shell]

Originally Posted by Drew@Sonic MS

Not an issue whatsoever on F8x, plus being able to run lower spring rates as the spring sits right on the shock is another bonus.

Glad you're enjoying them Jeff!

In regards to the new spring location, do you know the equivalent spring rate that is compared to 700lbs of the OEM location?

[Drew@Sonic MS]

Originally Posted by exo-shell

In regards to the new spring location, do you know the equivalent spring rate that is compared to 700lbs of the OEM location?

I don't believe I've ever been in non-true ASTs, my only comparison would be to KW V3 and 2-way CS. Really not an accurate comparison since AST is charged with high pressure nitrogen and the adjustment range is huge. On the CS I was running 12kg/15kg if not higher and Moton's I was happiest at 8kg/10kg. Without really testing it, I'd guess if I converted the Moton's to OEM location I'd probably run 12kg?

[Dumpspec]

Did you have to drill a big ole hole to run the canister in the trunk?

[Drew@Sonic MS]

Originally Posted by dumpm3

Did you have to drill a big ole hole to run the canister in the trunk?

It depends on the kit and the car - some come with a grommet that you can pull out and run the canister through. Some kits also have QR in the rear too.

[Dumpspec]

Originally Posted by Drew@Sonic MS

It depends on the kit and the car - some come with a grommet that you can pull out and run the canister through. Some kits also have QR in the rear too.

ahh ok. i just picked up a set of AST 5200 for my m4 and trying to figure out how to run the canister to the trunk haha. i really don't want to drill a big hole but seems like that s the only option. i wish AST came with the quick connects like JRZ so we don't have to drill a big hole.

[Drew@Sonic MS]

Originally Posted by dumpm3

ahh ok. i just picked up a set of AST 5200 for my m4 and trying to figure out how to run the canister to the trunk haha. i really don't want to drill a big hole but seems like that s the only option. i wish AST came with the quick connects like JRZ so we don't have to drill a big hole.

You can option it to have QC for the rear. Some cars have the grommet so no need to spend more to have QC but obviously if there's no grommet the QC is worth it. Drill a hole and then get an OEM grommet would be my suggestion.

[jeffucd]

Update after 1 track day and a long distance road trip:

PERFORMANCE
I ran the car at Sonoma back in July with the settings on 6 out 11 front and rear. This is the setup that the shop recommended. Prior to the changes, I ran a best time of 1:58 a handful of times, but with the changes, I was able to run 3 laps back to back to back in the 1:56's. Turn in felt much sharper, through the corners it felt level and compliant, and I was able to roll onto the throttle earlier. Also, when the car did break traction, it still acted predictably. I had a brown moment going over 100mph into turn 10 where I went into power oversteer, but was able to gather the car up, brake, then make the right instead of going into the concrete wall. It could have been much worse, and the suspension definitely had a positive impact.

COMFORT
The shop recommended I try 5 for street driving and 6 for track and I've largely only left it there. I was initially planning on dialing it for comfort when the family was in the car, and to dial it up when on the track, but the ride is great in the firmer setting and I haven't felt the need to do it at all. Even on a 1,000 mile road trip I took in October, on roads from the SF Bay Area, up to the Sierras, South on 395, and through to Vegas, I never once felt the urge to change the settings. The sounds are probably the most noticeable change in day-to-day comfort. When driving normally, the increased road noise is very apparent. I didn't have a co-pilot with me on the drive, but at times it got loud enough where you'd have to raise your voice quite a bit to carry a conversation (we were on radios). Also, there are also sounds that come from the suspension that sound very different from the stock setup. Not metal on metal or worrisome, but low, dull tones that are noticeably different than the stock setup.

VISUALS
The "1 finger drop" seems to have pretty much stayed at the level when the work was first done, and really looks great. The car was aligned after a few hundred miles, but I didn't notice any noticeable changes in height. I've been asked a few times whether or not it bottoms out because it's such a tight visual fit, but functionally I have never had a problem, and it has never bottomed out or scraped the body. In all, I'm very happy with how it looks. I'm running 15mm spacers front and 12mm rear.

LIVEABILITY
By taking an angle over bumps and out of driveways I have yet to scrape the nose. Maybe it's time for a splitter? The most significant change I've had to make (which really isn't that big a deal at all) is to be careful when driving in/out of sloped driveways - the wheels will lift and the limited slip will kick in and peel out/stall/lurch if I drive it normally (I have a manual). I've gone over some pretty high bumps and the car hasn't high centered either. It has been a while since I've driven a lowered car and am surprised that it doesn't hit more often. Now it makes me feel like I should have lowered it sooner!

HINDSIGHT
The setup rocks, I'm really happy with it. I think it fits the car very sell since the M3 is an all around performer, and I've found that the AST's are much the same on both road and track. That being said, I haven't had much need to change the settings on the car, but paid quite a premium for it over the 5100's. While I like to think that the 5200's include features and performance that can't be obtained by the lower model, it makes me wonder if I could have just done with 1-way adjustable CO's/non-adjustable + bought a nice watch instead. But, I don't regret it, as it's just what I wanted.

[NicL]

Thanks for you detailed review on the set. I have been looking for a coilover set and doing some research recently. I am now kind of struggled to pick among KW CS2, TCKR D/A, AST 5200 and Moton 2-Way Sport. I have got some questions to ask and I wish you can give some help.

1. If I am not wrong, the way how you can use the remote canisters to adjust the set (both AST and Moton) is more convenient than most of other brands, I can't actually tell on most of pictures how you can adjust them (I guess most of them requires to take rims off???).

2. Since AST acquired Moton years ago, and now Moton is like a premium line of AST, I can't really tell the difference between AST 5200 and Moton 2-Way Sport in terms of the ways of adjustment. With around $1500 price difference, I am not sure if Moton has that much quality advanced.

3. What is the double digressive piston different from a standard one, I saw a option on the order page.

Thank you so much!!!

[Drew@Sonic MS]

Originally Posted by NicL

Thanks for you detailed review on the set. I have been looking for a coilover set and doing some research recently. I am now kind of struggled to pick among KW CS2, TCKR D/A, AST 5200 and Moton 2-Way Sport. I have got some questions to ask and I wish you can give some help.

1. If I am not wrong, the way how you can use the remote canisters to adjust the set (both AST and Moton) is more convenient than most of other brands, I can't actually tell on most of pictures how you can adjust them (I guess most of them requires to take rims off???).

2. Since AST acquired Moton years ago, and now Moton is like a premium line of AST, I can't really tell the difference between AST 5200 and Moton 2-Way Sport in terms of the ways of adjustment. With around $1500 price difference, I am not sure if Moton has that much quality advanced.

3. What is the double digressive piston different from a standard one, I saw a option on the order page.

Thank you so much!!!

KW CS 2-Way isn't really comparable to the other suspensions in my opinion, not bad by any means though.

1. AST/Moton only bump is on the canister - the dampening is on the shock. Moton in the engine bay, AST is on the bottom (inverted shocks).

2. Most of it has to do with the internals of the shock so not something you can "see".

3. It's a type of damper valving - double-digressive just means that the valving is is digressive on compression as well as rebound. Just means that compression and rebound force changes non-linearly.

If this car is being driven on the streets, I'd suggest the AST 5300 over the Moton 2-Way.

[x.shell]

Originally Posted by jeffucd

Update after 1 track day and a long distance road trip:

PERFORMANCE
I ran the car at Sonoma back in July with the settings on 6 out 11 front and rear. This is the setup that the shop recommended. Prior to the changes, I ran a best time of 1:58 a handful of times, but with the changes, I was able to run 3 laps back to back to back in the 1:56's. Turn in felt much sharper, through the corners it felt level and compliant, and I was able to roll onto the throttle earlier than usual. Also, when the car did break traction, it still acted predictably. I had a brown moment going over 100mph into turn 10 where I went into power oversteer, but was able to gather the car up, brake, then make the right before instead of going into the concrete wall. It could have been much worse, and the suspension definitely had a positive impact.

COMFORT
The shop recommended I try 5 for street driving and 6 for track and I've largely only left it there. I was initially planning on dialing it for comfort when the family was in the car, and to dial it up when on the track, but the ride is great in the firmer setting and I haven't felt the need to do it at all. Even on a 1,000 mile road trip I took in October, on roads from the SF Bay Area, up to the Sierras, South on 395, and through to Vegas, I never once felt the urge to change the settings. The sounds are probably the most noticeable change in day-to-day comfort. When driving normally, the increased road noise is very apparent. I didn't have a co-pilot with me on the drive, but at times it got loud enough where you'd have to raise your voice quite a bit to carry a conversation (we were on radios). Also, there are also sounds that come from the suspension that sound very different from the stock setup. Not metal on metal, or questionable, but more just low, dull tones that are different from the stock setup.

VISUALS
The "1 finger drop" seems to have pretty much stayed at the level when the work was first done, and really looks great. The car was aligned after a few hundred miles, but I didn't notice any noticeable changes in height. I've been asked a few times whether or not it bottoms out because it's such a tight visual fit, but functionally I have never had a problem, and it has never bottomed out or scraped the body. In all, I'm very happy with how it looks. I'm running 15mm spacers front and 12mm rear.

LIVEABILITY
By taking an angle over bumps and out of driveways I have yet to scrape the nose. The most significant change I've had to make (which really isn't that big a deal at all) is to be careful when driving in/out of sloped driveways - the wheels will lift and the limited slip will kick in and peel out/stall/lurch if I drive it like normal. I've gone over some pretty high bumps and the car hasn't high centered either. It has been a while since I've driven a lowered car and am surprised that it doesn't hit more often. Now it makes me feel like I should have lowered it sooner!

HINDSIGHT
The setup rocks, I'm really happy with it. I think it fits the car very sell since the M3 is an all around performer, and I've found that the AST's are much the same - road and track. That being said, I haven't had much need to change the settings on the car, but paid quite a premium for it over the 5100's. While I like to think that the 5200's include features and performance that can't be obtained by the lower models, it makes me wonder if I could have just done with 1-way adjustable CO's + bought a nice watch instead. But, I don't regret it, as it's just what I wanted.

Great write up. I'm glad you're liking the coilovers. A good suspension makes for a happy driver; that's what I say.

Quick question. Did you leave the spacers on when you took it to the track?

Also, part of the overall noise in the cabin can be attributed to the RE71R. They're really loud; especially after it's been worn down even a little bit. When I mounted my spare wheels with Continental ECS on it, the noise reduction compared to the RE71R was the first thing I noticed.