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AST 4150 Series Damper Announced!

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  • AST 4150 Series Damper Announced!

    All New AST 4150 Damper

    Vorshlag is here to pass along the announcement from AST Suspension and AST-USA about the all new AST 4150 Series Damper. The 4150 design builds on the basic architecture and market success of the AST 4100 series monotube single adjustable damper, and brings experience learned in the recent wins in GRAND-AM Continental Tire Sports Car Challenge, including new technology developed specifically for GRAND-AM racing teams. There is also some technology sharing from proven Moton Suspension dampers that have made their way into this strut, which is detailed below.

    You can read about this new 4150 damper in the Official AST-USA Press Release, but I will post all of that and more in this forum post, with pictures, details, and my first hand impressions from driving on these new updates in my own 2011 Mustang test mule for the past couple of months. First, let's start with an exploded view picture of the 4150 strut that points out all of the updates over the outgoing 4100 design (which has been in production from 2006-2011, with several running updates along the way).

    Here it is...

    You can click that picture above for an even larger image. Its a 3D rendering AST made last week but that I marked up today, showing a cut-away view of the production 4150 version. All of these upgrades and new parts have been tested on various race and street cars, including the DDP pistons, low drag seals, and top guide. Let's look at some of the new components and explain what has been changed.

    DDP Technology Piston

    AST's latest digressive piston was developed for GRAND-AM and gives drivers and race engineers the best of both worlds. Drivers love the low speed damping response and body control, while race engineers love the “blow off” (the knee point digression, shown in the dyno plot below), with a tapering off of the rebound forces at high shaft velocities.

    When the rebound adjustment is set to soft, the damper curve looks similar to an OEM street shock profile. When the rebound adjustment is set to firmer settings, the damper curve looks like a race shock. The most critical portion of the dyno plot area is affected the most - the portion at low shaft speeds. So much in racing happens at 0-3 inches per second shaft velocities, and that's where these pistons really step up the damping forces, when adjusted firmer.

    Those two documents above list more details, and you can click them for larger images. The graphed rebound curve shown on the right shows the large amount of adjustment from full soft to full firm, and the super-digressive curve shape that these new DDP pistons can achieve. This “Jekyll and Hyde” personality is exactly what AST 4000 Series customers want: soft street ride and firm race car track performance in ONE shock - all with the turn of a knob.

    Vorshlag's 2011 Mustang GT track testing with DDP pistons and 4150 valving at the bumpiest track in Texas (ECR)

    And let me tell you from first hand experience - it works. Adjusting the knobs on the prototype ASTs in our 2011 Mustang with the DDP pistons makes a night and day difference - with more adjustment potential and valving change than I've ever seen in any shock. We were driving it at one of the bumpiest tracks around last week and were able to get the track set-up dialed in quickly, still soaking up the bumps but with sharp turn-in and controlled braking. When turned down to full soft for the drive home from the track, and it rode like stock. We have taken a number of people for rides in the car on the street at full soft and they think it is the OEM suspension. Those rides alone have pre-sold several sets of 4150s already - these shocks make you a believer.

    Lower Drag Seals & Stronger Top Guide

    High performance seals are a challenge for any damper. They must balance friction and sealing ability while not impacting shock performance and not leaking; All of this makes for a difficult balancing act. While the seal was originally developed for GRAND-AM road racing, AST is taking their knowledge from the track to the street once again.

    These newly redesigned shaft seals have a low-friction polymer inner liner and an outer jacket with the appropriate amount of stiffness and flexibility needed in a street strut. This gives the low seal drag characteristics usually only seen in a race shock, with a street-worthy seal. These new seals reduce hysteresis in the damper plots by decreasing seal drag over 50%.

    One of the benefits of AST and Moton being owned by the same parent company is technology sharing - when there is one design element obviously superior, it can and should make its way into another model across brand lines. There isn't much of this cross-pollination going on between AST and Moton, but one improvement to the 4150 strut design is the addition of the longer and stronger top guide from the Moton Motorsport strut. This Moton top guide is a TANK, and will help minimize shaft deflection under extreme racing loads, and is a welcome addition to the 4150 AST strut. This is another reason why the 4150 will work well on the street and on the race track.

    Discontinuing Steel Shocks

    In 2012, most AST 4150s will come with aluminum shock bodies. Strut bodies will continue to be built from steel, but all shocks will switch to aircraft grade aluminum. Economies of scale have allowed the factory to switch to aluminum without a large increase in cost of manufacture. For some models, this represents a 50% reduction in the weight of the damper (unsprung weight).

    All 4150 aluminum shock bodies will also be fully threaded, unlike the smooth steel bodies on the previous 4100 shock. This allows for a potential to convert almost all 4150 shock models to a "coilover shock", with the appropriate threaded collar, coilover spring and upper spring perch. This is beneficial on cars that normally do not have a coilover shock set-up (there are other issues that must be discussed with your shock dealer, of course), when that is desired for altering the spring motion ratio or reducing suspension mass. There is no longer a need to make an aluminum (5100) and steel (4100) version of every shock, so some former 5100 models for shock-only car set-ups will come under the new 4150 product envelope.

    Structural Improvements

    Several new designs proven in GRAND-AM racing will be added to various products on an “as needed” basis. All strut models will receive a new two piece top guide assembly that separates the dust seal assembly from the oil seal/bearing assembly (see the cut-away picture at top of this post). This two piece design is stronger in compression loading (bottoming out) and side loading (in the turn). Some models will receive weld-on stabilizer brackets which take the guesswork out of setting the stabilizer height and torque setting of the clamping ring.

    Upgradeability to Doubles!

    Finally, the upgrade path of the 5000 series has made it to the 4X50 series shock! Yes, AST 4150s will be upgradeable to 4250 internal double adjustable monotubes. Using a modular build system, customers can send their shocks to AST at a later date and upgrade from a 1 Way shock to a 2 Way internal reservoir or remote reservoir system. Some models may only upgrade to remote reservoirs. An upgrade matrix will be published in early 2012, and I will show the details of the 4250 in this thread as they become available. The upcoming 4250 will replace the 4200 models starting in March, and we will get our hands on them as soon as possible.

    The 4150 dampers have a screw-in bottom assembly that can be removed and the "guts" of the 4250 internal double can go inside most strut and shock models. Any 4150, and especially short bodied struts and shocks that have limited stroke, will also have the option for a remote reservoir assembly to be added there as well, to make them into remote doubles. I think they will be called 4250RR, but that might change. AST-USA did this before on some 4200RR models, as shown above, and it worked great when the additional stroke or added fluid capacity from reservoirs was necessary. The 5200 inverted strut (and the 5200GA) with remote reservoirs is still going to be in the AST line-up, of course.

    Cost & Availability?

    The parts have been tested, the design is finalized and production begins at AST Holland on several 4150 models in early January, so we should see 4150 models coming to our shores by late January. Vorshlag has the following 4150 models already on order with the factory, and we will be stocking these dampers over 4100s at our facility from now on:
    • BMW E36
    • BMW E46
    • BMW E90/92
    • Subaru GD
    • Subaru GR
    • Mustang S197

    Some of these dampers we have on order above have already been pre-sold, so they might not stay in stock here long. We will ramp up our orders with AST-USA as they roll in. Also, the first 4250 models will be coming to us, since we have sets on order. I will post up in this thread with 4250 details as soon as possible, but it will be much of the same as the 4150 but with 4200 style lower piston assemblies. More rugged, more reliable, and still one of the only true internal double adjustable monotubes on the market.

    The 4150 pricing is fairly close to the outgoing 4100 model, and in most cases within $100-150 of the old part numbers. That's not much of a cost increase considering the number and breadth of updates these 4150 dampers have. The upgradeability feature (to 4250 doubles) alone is huge, and will be a big selling point for racers that want to ease their way into double adjustables, with less pain up front.

    We are already testing and enjoying the new 4150 and if you have additional questions, feel free to call us at 972-422-7170 or visit us at Vorshlag is an AST dealer, a testing and engineering partner with AST-USA, we were the first AST dealer in the USA, and we continue to be have the best customer service and highest sales of the full catalog of AST models in North America. Vorshlag's new facility is located 100 feet from AST-USA/Moton-USA, which gives us unprecedented access to the new designs, data, and the minds behind this shock brand.

    Last edited by Fair!; 12-30-2011, 11:50 AM.
    Terry Fair -
    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

  • #2
    Re: AST 4150 Series Damper Announced!

    Some of you reading this thread about the AST 4150 product line have been calling us constantly since December asking - when are these new shocks going to be released? The answer is - I really don't know. But we do have some progress to report.

    We were expecting pre-production 4150 models for testing back in January, but they started to arrive in July. January, July... its a "J" month, right? I cannot explain the delay, other than to venture a guess: there were a lot of individual updates from the 4100 model to the 4150 and maybe some of them took a bit longer to develop and perfect than they had originally thought. Again, this is my guess and nothing official from AST Holland. I'm just a dealer on the other side of the world, and not in direct contact with them.

    So to prove that these 4150s are not vaporware, here are some pictures of a few real live test models we have seen here at our shop.

    The two BMW sets above are the first two test sets we have seen in person. We have the E46 4150 set shown above on our daily driven shop car, shown at the bottom of this post. We have heard that there are some 4150 test sets on S197 Mustangs and a Subaru BRZ, but we didn't see or test those directly (but Vorshlag camber plates went on both sets). Below are some close-up detail pictures of some of the externally visible, new features from the AST 4150 test shocks.

    Here's a comparison of a steel body AST 4100 rear shock from a BMW vs the new aluminum body 4150 version:

    We have one test set of 4150 shocks on our BMW E46 330 that we installed 2 weeks ago at Vorshlag, but that's it. This car has been undergoing street testing, and the ride comfort on 550 #/in front and 650 #/in rear springs is exceptional. We tested some of the new valving and DDP pistons on our S197 Mustang for the better part of a year, but that set did not have the many other 4150 updates. We pulled that set off our S197 and are sending them to another tester while we develop our chassis with Moton Club Sports doubles.

    Note to other AST dealers: Vorshlag is an AST and Moton dealer, competing with you for sales of these products. I am asking publicly and nicely for a few of our fellow AST dealers to stop stealing the text written by and the pictures taken by Vorshlag of various AST and Moton shocks. Some of you guys cut-and-paste text from my posts, grab my Facebook pictures, steal our online shopping cart entries, and hot link to our the AST pictures we have shot - not cool. Don't just rehost our pictures and think that's OK, or take the pictures and block out our logo. If you want pictures of AST or Moton products either get them from AST/Moton or buy some shocks and take the pictures yourselves. If you want to announce news about these models, write it yourselves or get the press releases from Moton or AST and go from there. Common sense, but some folks need reminding. Thank you.

    Again - we have seen two test sets and heard of some others, and we have no idea when the production versions of AST 4150 shocks will be available. I will not be guessing dates or predicting timelines further. Vorshlag still has some additional test sets on order, and many sets of production 4150 units are pre-ordered once the test sets are proven. Any potential customer that was waiting on 4150s that had a pre-order with Vorshlag has been contacted and addressed.

    Our E46 330 with AST 4150s is shown at right (next to the new BRZ Vorshlag's Matt). It had AST 4200s right before these went on

    That's all we have for now - just wanted to update this thread with some news. I am not speaking for AST Holland, AST-USA, or anyone else - just passing along what we know at Vorshlag. You now know what we know. We will keep this thread updated with availability and everything else we know. Thank you for your patience.
    Last edited by Fair!; 07-27-2012, 03:01 PM.
    Terry Fair -
    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


    • #3
      Re: AST 4150 Series Damper Announced!

      So a lot has happened with AST products since the previous post here back in 2012. Many years of shock development by multiple sources culminated in the 4150 single adjustable, non-remote reservoir monotube shock design... but only a handful of 4150 models were ever fully developed and imported to the USA. That's a real shame, as this redesigned series worked so well. Let's back up and try to explain.

      When Vorshlag first brought ASTs into the USA as the authorized importer back in 2006, they really only had BMW fitments that were built to be TUV approved, only worked with tender springs, had the rebound and compression circuits tied to the same knob, etc. Some of their kits only worked with OEM top mounts, and came with tapered springs (like some PSS kits). Other early kits wouldn't even fit a car using the stock wheel sizes, much less the 2+ wider wheels the US market tended to use. We worked with Holland to modify their fitments to the way we used suspension in the U.S. market (lowered ride heights, rebound only for singles, track use, select your own springs and mounts, capable of working without tender springs, etc) and then worked with them on quality.

      By 2009, for many reasons, the AST-USA distributorship was spun off as it's own company and the importing was handled by this new entity (most recent name used was HVT). The rest of us here at Vorshlag were happy to no longer have this distributor/importer/warranty center role, and we instead focused on direct customer AST sales and installations, as well as our own line of products and others we resell. Being the importer isn't fun, as you take all the risk, have all the inventory tied up on your books, and have to deal with the overseas shipments as well as the factory - not to mention the warranty work. Occasionally we still helped repair or custom make new strut housings or test fixtures for AST-USA, which was located a few doors down from us for the past 3 years. We also still spent time helping to promote, sell, repair and improve the AST line-up.

      As almost everyone probably knows, the first generation 4100 kits had some issues in both fit and longevity. We worked with AST-Holland and then AST-USA to help bring these competition-level dampers at club level prices to many thousands of enthusiasts, and if it was sold correctly and installed properly there were usually very good results. The market for single adjustable, non-remote monotube coilovers was born with the first 4100 design. We continued to work with these two groups to help them build a better series of dampers - one that was more reliable and easier to install - which culminated in the AST 4150 single adjustable design. The design for the 4150 was first talked about at the Holland factory in May of 2009, but it took almost three years for these to finally come to production. Eventually almost all of the nagging 4100 problems were resolved: The adjustable swaybar bracket became fixed, a stronger top guide was installed, a more secure top cap was fitted, and better seals and pistons were integrated, among other updates.

      After 4150 models were slowly introduced in early 2012, the only issues we continued to have with AST were delivery times. Promised delivery dates were pushed back many months as changes continued to added. Also, some dealers were selling some damper kits that were not appropriate to what the customer really needed, but it's hard to control that. We ended up only seeing about 5 or 6 car models that were converted to the 4150 updates, and of those we only sold 4 types of these models that we felt were made to the proper lengths. Of the kits we sold - BMW E36, BMW E46, S2000 and Mustang S197 - we had very few issues and many happy customers. Of course there was a price increase with the 4150 roll out, and that angered some buyers, but these were still the lowest cost monotube adjustable coilovers made, when compared to other high quality brands.

      It wasn't all smooth sailing for the dealers or the importer. After struggling with exceptionally long AST delivery times for nearly two years we came to the final realization in 2013 that we could not reliably supply our customers with AST coilover kits or parts any longer. We don't know exactly where the breakdown was, but some of our last few orders from 2013 took 4-6+ months to come in, which is simply unacceptable. As the domestic supply for a given part number dried up we pulled that product entry, to the point where we had zero AST products on our website, including now. We also pulled the handful of Moton entries off of our website many months earlier, as there seemed to be no calls or inquiries on this brand after it was taken over by AST.

      Luckily, back in 2012 we saw these signs early and moved to find other quality monotube dampers solutions for our customers. We worked with Motion Control Suspension (MCS - run by the former Moton principles) to supply lower cost single and double adjustable dampers without remotes in addition to their established double and triple remote dampers, and have helped them develop a few new models that they didn't offer before.

      We also set-up a dealership with Bilstein/Bilstein Motorsports, and have been adding their products to our website as well, and building bespoke dampers for select car models using all Bilstein parts. Sales with these two brands have been more sizable than we anticipated and have eclipsed even the best months we ever had with AST products. The biggest benefits with these two monotube shock offerings was the added reliability and a more stable and speedy supply. We have not yet had a single damper returned in 2 years for any sort of failure from either brand, and every custom built MCS damper set has arrived in 1-4 weeks time (MCS always quotes 2-6 weeks, to be safe).

      There were many other brands that we could sell but none of them had the quality or the value that the Bilstein and MCS options offered, nor the car model range. We have wholesale access to many brands of twin tube shocks, but we won't sell those - they are just a fundamentally old design with too many drawbacks. We were also approached by many groups trying to resell Chinese made monotubes, but we won't touch those - the quality and reliability problems those suffer from are legendary.

      We have recently found out that AST-Holland has been working to establish a new distributor in the USA. The HVT and AST groups have officially parted ways, and that's all I know of that. It seems that as HVT moved into new directions with their own shock offerings using a variety of parts from a number of sources worldwide, AST Holland has also gone in another direction here in the 'States. Very recently a company fairly new to AST and the distributor-dealer model has come onboard as the new AST importer and is beginning to build a new AST dealer network, and we wish them good luck. They are now in the earliest stages of a long process deciding what to import and how to spec new parts, setting up a new website and phone number, and establishing new dealer requirements.

      After speaking to them directly about changes in how ASTs will be configured and sold we expect price increases in all AST shock series. As of yet we do not see any remedy to ASTs extended delivery times, though. We are hopeful that they will soon have limitless inventories and can further develop the many gaps in the 4150 line-up (and then maybe tackle the long missing 4250 double adjustable internal?), but for now we will take a "wait and see" attitude. We will make decisions regarding this shock brand after they have established their new policies, prices, warranties/rebuild centers, and have available AST inventory in the USA.

      If you are contemplating purchasing AST coilovers the only advice we can give is - be patient and do your homework. You should confirm availability before placing any order. Just because they are on a website, does not mean the shocks you want are really available or will be in stock any time soon. We could easily add the AST product entries back to the Vorshlag site and let people order them, but it might be another multi-month wait before we could actually get product, and we won't string people along like that. When there is product here in the USA then we will offer the AST kits, one by one - if the pricing and other configuration aspects aren't drastically changed.

      Over the next few weeks we expect to hear from the new AST distributor and we will update this thread with any pricing or the "ordering changes" that have been rumored. Instead of speculating further, we are going to leave it at that for now.

      For now, we have our solutions in place. Already covering the existing car models made in the 4150 design, and dozens more, MCS has monotube coilover solutions today with the TT1 single adjustable non-remote. And they didn't wait years to develop the "internal double" but instead came out with the TT2 double adjustables almost immediately after making the singles (see picture above). That is a very popular model with our customers that do competition events, as having separate compression and rebound adjustment is very helpful for car setup. For additional stroke and adjustments they have the RR2 and RR3 remote doubles and triples for many car models as well (see below). So for now, if we have a customer who needs a monotube adjustable coilover, we start with MCS and go from there. For lower cost options we will look at the Bilstein line-up, and we expect to have more options coming soon from this brand.

      As for the many low cost Asian import offerings that are always popping up to fill this void, we can only offer this advice: The bitterness of poor quality remains long after the sweetness of low price is forgotten

      Thank you for your patience,
      Last edited by Fair!; 02-19-2014, 04:28 PM.
      Terry Fair -
      2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
      EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev