*While I hadn’t purchased these shocks directly from Amain, the following review is true user experience.
I purchased these as an alternative to the plastic CVA shocks I previously installed on my TT-02. Although mine are the 55mm model, the shock bodies ARE the same and parts ARE interchangeable between the 50mm and 55mm QUTUS dampers. The shock bodies themselves are of the larger bore type so you have more oil to provide smoother dampening.
The first thing about these shocks and why I bought them was for their “quick tuning” system for which the product is named after. By installing either of the adjustable two-piece damper pistons, you can change the handling of the car to suit different track conditions on the fly and all without the need to remove those pesky “Jesus Clips” that go flying off into the distance.
Speaking of the pistons, you have a choice of either adjustable or fixed pistons. The adjustable pistons come in both four-way and six-way adjustable, depending on one’s own preference to tuning. While the fixed pistons come in two-, three-, and four-hole designs with 1.2mm holes, the adjustable pistons are 1mm. More on this later.
Within the kit includes a set of 5.5mm pillow ball ends, both in stud and nut form. This is important to note because these are larger than any other shock set sold by Yeah Racing and are exclusive to the QUTUS line.
Now, while I love these dampers, there were some things about them I must point out about them.
First of all, while I mentioned that parts are interchangeable, they’re only interchangeable within the QUTUS line. The upper ends, lower ends, springs, pistons and shafts are all specific to the QUTUS line. Some parts DO interchange as you can switch the 50mm M-Chassis dampers to either a 52mm or 55mm by just switching the shafts. (52mm shaft is included with the 50mm QUTUS set ONLY and not sold separately)
Next, the spring diameter must be mentioned. With some QUTUS sets, you have the choice of either two or three different springs for different track settings (“Slider” models have only two spring sets; “Challenger” models have three sets). Not a big deal but what if you needed to replace the springs after the season? Well, unfortunately this is an area where the QUTUS exclusivity comes into play as the springs are NOT interchangeable with any other Shock Gear set. However, I have taken the liberty of measuring the spring inner diameter (I.D.) at approximately 14mm whereas the normal Shock Gear set are at 13mm. The heights too are VERY short compared to say an actual TRF spring. It may have to do with the fact that a 55mm QUTUS has the same springs as the 50mm but be warned that you may have to put quite A LOT of preload onto the springs in order to get the shocks to not bottom out while racing. I currently have mine set to 4mm of preload and have more than enough dampening before I completely bottom out and this is with 104cst TLR oil and the soft (red) QUTUS springs.
One more thing I must mention is the piston hole size. The standard adjustable piston hole size can only accommodate shock oil between 100-300cst. This is important as disregarding the specifications can lead to the damper not working as intended. However, if you like using heavier oil, you can drill the pistons out to as much as 1.2mm but are limited to a new range of 300-500cst. It’s up to you what you choose but I went with the standard setup and bought more oil since the provided amount seems too little for even a future top off. *EDIT: I’ve switched to using TLR 15wt (104cst) oil as this was the lowest oil I could get affordably and works decent.
Finally, one of the last things that I must mention though on a positive side is how the provided 2mm “Jesus Clips” are actually very painlessly easy to install. Compared to the Tamiya cir-clips, these will go on VERY easy with or without a Tamiya E-ring tool. Even getting the piston wrong, I was able to switch it out with ease as a result of the different cir-clips!
Overall, I’m very pleased with these and how much they will provide my car with plentiful tuning options for different situations. But most of all why I love them? That bling factor that was drastically needed for the rear of my TT-02 which can be seen because I have no rear bumper on my NSX-GT body.
If you were on the fence about these, just get them; you won’t be disappointed.
*UPDATE 5/23/22: I’ve since built up the shocks using TLR 15wt oil and noticed how much longer the process of bleeding the air out of these shocks takes. Literally, you fill these shocks up, wait 20 minutes (or more) to have to come back to cycle the shock(s), top them off and hope it’s okay to seal it up just to find out the rebound is slow or you can feel the air trapped inside. I believe it has something to do with the two-piece adjustable piston design which can trap air between them. Even spinning the piston while cycling the shaft up and down doesn’t help much. My personal recommendation when you get to the bleeding process is to either borrow or buy a vacuum shock bleeder. That way, you can expel ALL the air trapped inside, making the shocks much more consistent in compression and rebound.
Also, I recommend buying at least 2oz worth of shock oil because what Yeah Racing will give you with these is simply not enough. I went through quite a bit of oil to get the shocks to feel exactly the way I needed to but thankfully I have enough for a few rebuilds. Be warned though: consider getting more oil if you plan on buying these because you’ll likely need it!
Aloha.
