Project #YAE92 M3: Part 6 – Roll, Stop, and Stick
Like aerodynamics, the suspension on a car is highly specific to the cars setup and modifications. Our E92 M3 is so different than a stock E92 M3 that many off-the-shelf aftermarket parts just won’t work for our application. It’s simple, off the shelf parts are built for stock or mildly modified cars. Ours is far from stock. For instance, our car weighs in at 2,795lbs roughly 900lbs lighter than stock. Stock M3’s come with a staggered street tire setup, we run a wider stickier full slick in a squared size on all four corners. We have aftermarket aerodynamic aides like a front splitter and a rear wing, stock M3s do not. All of these things have an impact on a suspension setup. Our car is very custom and we need a very custom suspension to do the job.
This is why we went with BC Racing Custom Coilovers. They offer a truly customizable plug and play coilover. We are running their new ZR Series triple adjustable coilovers, which is their top of the line system. We chose everything from shock body length and spring rates to the length of the stainless steel braided lines for our external reservoir and BC Racing Custom Coilovers did the rest. They assembled the coilovers with our custom spring rates, valve the shocks to match, and then shock dyno all of them to make sure we are getting consistent and matching performance on all four corners. When they arrived all we had to do was bolt them up, set our ride height, and corner balance! I personally have been using BC Racing coilovers on my own street and track cars for years and have a lot of confidence in their quality and capability and they’ve done nothing but continue to impress. We ran their double-adjustable ER Series coilovers at last year’s 25 Hours of Thunderhill and they felt exactly the same at hour 25 as they did at hour 1 of the race. There was no sign of fatigue or shock fade at any time and all the adjustments stayed put the entire race. Once we cleaned off the dirt they looked brand new! We have roughly 21 hours of track time on our new BC Racing ZR Series triple adjustables so far this season and the story is no different. The good news is they’ll offer all the same services to you as well. We didn’t get any special treatment a normal customer wouldn’t get when ordering a custom set of coilovers for their own car.
Read More About Project #YAE92 M3 Here!
BC Racing ZR Series Triple Adjustable Coilovers offer three separate adjustments; rebound adjustment, and separate high speed and low speed compression adjustment, and ride height adjustment separate from spring preload. They are one of the only manufacturers truly offering an affordable custom coilover. If your race car is running off-the-shelf coilovers, you’re doing it wrong.
The external reservoirs of our coilovers are where we adjust high and low speed compression. The custom length stainless steel braided lines allowed us to mount ours in easy to reach areas for quick adjustability. Our front reservoirs are mounted in the engine bay while our rears are mounted on the bulkhead in the trunk.During the off-season we made the switch over to a stiffer aftermarket anti-sway bar setup, but in testing for this season we quickly figured out that it was a bad move. Being that our car weighs 900lbs less than stock, off-the-shelf parts are not specifically made for highly customized cars so the aftermarket sway bars we installed ended up being way too stiff for our setup, despite running on full slicks. So we made the move back down to the stock sway bars and the car handles much better. The only downside is that we don’t have any adjustability. Later on we may even try a set of softer sway bars off of a stock 335i to see if we can get even better use and life out of our tires.
One of the most important aspects of a suspension system is the suspension arms. This is where we found the biggest gap in aftermarket parts available for the E92 M3. Aside from aftermarket rear toe arms, it was near impossible to find any adjustable replacement arms for this platform. That’s why we teamed up with SPL Parts and began R&D for a complete suspension arm kit. We started working with SPL and prototype arms in 2014 and tested and tweaked them for over a year. Finally in 2015 we are proud to announce that SPL Parts has a complete line of E92 M3 adjustable arms. Their products are top notch as you can see in the photos and they are highly regarded in the Nissan and Porsche communities as the best in the business.
In this photo you see the front suspension arms from SPL. From the bottom of the image we start with the front lower control arms, moving up the image we see the front tension/trailing arm and front tie rod end crossing paths. All from SPL Parts, and all amazing. Coupled with our BC Racing coilovers and BC Racing adjustable front sway bar end links we can now adjust the following on the front end of the car: Camber, caster, toe, ride height, roll center, bump steer, kingpin inclination, and scrub. All while eliminating the soft stock suspension bushings and all completely bolt-on.
