Review: Mann Engineering BRZ lowering springs (25mm)

[PandaBRZ]

Disclosure: I won a set of Mann Engineering lowering springs from the NorCal 86 Drive end of summer raffle. I paid for installation and alignment.

When it comes to modifying my Subaru BRZ, I'm relatively conservative. The car is so good from the factory, I don't want to mess up its handling and balance. When I won a set of lowering springs from Mann Engineering, I was apprehensive about getting them installed. I have a steep driveway and already scraped once coming out of a parking lot at stock height. In the end, curiosity got the best of me and I set up an appointment for them to be installed. For me, it was a test; could I live with a mild 25mm drop?

I had the choice between the 25mm and 35mm drop versions of the springs. I chose to keep the drop conservative and went with the 25mm. To me, a 20-25mm drop looks just right. I set up an appointment to have them installed at Mann Engineering in Santa Clara, California. The staff was friendly and professional, putting me at ease. I got a tour of the shop, which was filled with all kinds of Subarus, and the work spaces were immaculate. They even have a shock dyno tucked away in a room where they service their dampers.



When I went to pick up my car, I was shocked at how low the car looked. "Oh god. What have I done?" I said to myself as I walked up to my car. I had gotten so used to looking at my BRZ at stock height that I was shocked at how much a 25mm drop lowered the car. This feeling of being lowered required me to recalibrate my brain to take most driveways at an angle and to start remembering which parking lots would give me trouble. Having slightly taller 225/45/17 tires lifted the car just a little, which helps getting out of some driveways. Since being lowered, I only scraped my bumper a couple of times, perhaps because I've gotten better at taking inclines at an angle.

As for the ride, I could immediately tell the car was stiffer than stock. Around town, the Mann Engineering springs felt good for the most part. Hitting potholes with the stock suspension was already pretty jarring and the lowering springs exacerbated the issue.

I was excited to take the car on my local canyons to see if the the car maintained its neutral handling. The car felt great in the turns and transitions were faster than stock. Loading up the car in the corner inspired a lot of confidence, even when I was on the stock wheels and tires. If pushed too hard, the car would understeer just a bit, but not much. I could still get the car sideways with enough throttle. The Mann Engineering springs maintained the neutrality of the BRZ's handling, which is what I wanted.



However, the limitations of the stock dampers and lowering springs was quite apparent on bumpy roads. There's a particularly bad bump on one of my favorite backroads that sent me flying out of my seat and unsettled the rear end for a split second. This behavior is because of how the springs are set up.

While the front springs are linear rates, the rear springs are progressive, meaning they get progressively stiffer the more they're compressed. The reason I was sent flying over harder bumps is because the rear spring rates skyrocketed when hitting the bump, overwhelming the rebound of the stock rear dampers. This isn't a knock against the Mann Engineering springs but rather a reality for all lowering springs with progressive rates running on stock struts. It's hard to avoid using progressive rates in the rear as the BRZ and FR-S have very little stroke in the first place. Without the progressive rates, you'll just be riding the bump stops all the time, which would absolutely destroy your spine.

I contacted Michelle at Mann Engineering with my concerns and to learn a little bit more about the development of the springs. Here's what she had to say:

"Springs were decided after the original springs were put on a spring dyno to see what the OE springs do. From there, calculations are made based on what we were trying to achieve with the spring. We know that Subaru OE struts are able to handle a small increase in spring rates and we have a good idea from our experience with Subarus as to know how much the spring rates can be increased based on the springs that are equipped on the car and what we are able to produce from our manufacturer. Finally, we are lucky to have a manufacturer that has a professional test driver who is able to help us confirm our design for handling and ride comfort."

For those who don't know, Mann Engineering is the United States division of Advanced Suspension Technology (AST), a renown suspension manufacturer from the Netherlands. Mann Engineering offers AST coilover systems and support rebuilds and upgrades. They even have their own custom valved versions of the AST 4150 called the Mann Engineering Type-25 coilover, so they definitely know their stuff.

After living with the Mann Engineering lowering springs for over 5 months and 5,000 miles, I feel comfortable enough to review them having given them a fair shake. While I was initially shocked at how different my BRZ felt and handled after the drop, I really like the springs. They provide a good compromise between higher performance, looks, and comfort.

While the stock ride was comfortable enough for my 1,400 mile road trip picking up my car from Colorado, the Mann Engineering springs are significantly stiffer and I wouldn't want to do the same trip in my car now. It's not to say the ride is punishing, but if comfort is high in your priorities, don't lower your car with just springs. Just live with that dreaded wheel gap (which I don't think is that bad) at stock height.



On a sunny day with the windows down and a smooth backroad, the Mann Engineering springs are magical. The car feels extremely planted, especially with the wider wheels and tires I'm running now. The car can be pushed harder and feels extremely stable when loaded up in a corner. There's a hint of understeer when pushed too hard, but the rear can still be easily kicked out with a little extra throttle. The fun nature of the BRZ was kept intact and for that, I am happy.

More info: Mann Engineering Lowering Springs, 25mm Lowering

For more on my BRZ, check out my site. If you want to see the rest of my mods, check out my Wheelwell page in my signature.

Springs: Mann Engineering BRZ 25mm lowering springs [Front: 3.06kg/mm (171lb/in), Rear: 4.18kg/mm (234lb/in)]

Tires: Michelin Pilot Super Sports 225/45/R17

Wheels: OZ Racing Alleggerita 17x8, 48mm offset

Alignment: -1 degrees front, -2.2 rear (stock lower control arms), 0 toe front and rear

[endless_pain]

Wow, that drop looks really good.

[PandaBRZ]

Thanks! I think it looks just right with my wheel and tire set up.

[Hyper4mance2k]

I run Swift Spec R's. At first I ran them on the stock springs, and I was quite impressed. Eventually I switched oner to Bilsteins which completely changed how the car drove. I suggest that as your next mod.
If you like them now, just wait until you replace the shocks. The ride is miles better.

[PandaBRZ]

Yeah that's a good upgrade path. I think I'm just going to get coil overs eventually but the bilsteins are highly regarded when paired with lowering springs.