"Might as well" makes some changes
I realized I haven't really posted a full detail post on what has happened post-spin!
This is a longer post on changes to the car after my little spin at Laguna Seca. My original plan before my Laguna Seca off-road experience was to run the PS4S tires till the end of life. Also before the event, I ordered a set of Volk wheels that will arrive sometime in Spring 2021. The spin left me working on what the next steps were for me. I developed a checklist of items I wanted to address while it was "down."
# Goals List
- Assess the damage and order new parts
- Explore the idea of a set of dedicated track wheels.
- Increase wheel clearance with shorter coil-over springs
- increase spring rates with a higher priority for track use vs street.
- Redial the suspension
- Enjoy the car!
# Evaluation
During the Laguna Seca T1 spin, I hit two pit exit cones @ 117mph and spun into the gravel trap at T2. The damage report was as listed: GTS lip cracked, cracked bumper center grille, scuffed front bumper, under tray damage and face pitted and barrel scored BBS GT4 wheels from rocks between ST60 calipers. I was fortunate enough that this was all that was damaged. Luckily everything was pretty much easily replaceable except the BBS GT4 and GTS Lip. The GTS lip was just a pain in the ass for driveways, speed bumps etc and I decided to forego replacing the lip. As for the BBS..
# Wheels replacement time?
The GT4 faces all have pits from the gravel flying at it and the front barrels received scores from pebbles lodged between the barrel and the ST60 calipers. I asked myself, are these still structurally fine? Are they repairable? Should they be used on the track? Would they be okay on the street? With these questions in my head, I had to alter my original plan I had for these wheels. The original plan was to use the BBS GT4 for the street and my incoming wheels as my track set. Since the incoming wheels are taking at least 6 months to arrive, this incident made me realize 6 month wait rims probably isn't an ideal set of track wheels. This led to the decision to find a set of readily available rims that also were easily replaceable. With a track set to purchase, a set incoming from Japan, and the BBS GT4, thats 3 sets of wheels for a car that barely can use 1 set of wheels! Something had to go. Back and forth in my head, I ended up deciding to list the BBS since the I wouldn't just sell the wheels I've been waiting already a few months for and I didn't need two sets of street wheels.
My game plan became this: sell the BBS GT4s, use incoming wheels for street duty, and find a decent forged wheel for track use. I debated between Apex, BW, and Titan7s and ended up favoring Titan7 for track use. I ordered a squared set of 18x10.5 ET25 TR10 from Vividracing on a Tuesday afternoon and I receive them the next day! That is what I call availability! EC7R was a contender but it was so close to the GT4s that I wanted to try something new visually. I also bought a set of 5mm spacers to match the 18x10.5et20 on the other set of wheels.
# Titan7 TR10
I picked the TR10 because the radial TR10 looks more at home on a sedan. The TS5 seems more appropriate on the E92 and I didn't think it flowed as well for an E90. I opted for 10.5" rim so my options for tire sizes could be 275 through 295 tires. For now I wanted to keep the 275/35/18 and focus on a 200 treadwear tire. When I ordered tires, RT660 was not available just yet, so I went with Hankook RS4s. This should be a fun set of tires to run! With a 18x10.5 wheel up front, the inner wheel clearance needed some help from a shorter main spring. I also wanted to raise my spring rates so this was the perfect opportunity to switch over.
# Springs
Without a question, the 400lbs/in || 700lbs/in springs were on the softer side of things. The original build of the MCS 2WNR was to emulate Ohlins R&T Spring rates of 342/685 for the sake of being more street use than track use. After a few HPDEs now, I got the feel of the car and felt I could raise the rates a bit, sacrifice a bit of road comfort for better track use.
With all that said, the parts were starting to pile up!
VT Motorworks handled mounting the tires onto the R10s so I could do the rest of the work.
# Installation.
I ended up removing the front bumper too to readjust. Talk about a relaxing Sunday right?!
I set the wheels to 18x10.5 et20 (net)
Initial ride height adjustment
The shorter springs and stiffer spring rate altered my ride height dramatically so I had to reset it back to where I wanted it.
I ended up with F/R -25mm/-20mm from stock, or F/R -15mm/-10mm from ZCP springs. This gave the front a little less fender gap while not veering too off from the factory geometry too much. It is very similar to what I originally did years ago.
The final measurements fender to bottom center rim edge.
Front : 585mm ~ 23"
Rear: 572mm ~ 22.5"
# Alignment and Tie Rods
I went to VT Motorworks last Saturday for new tie rods and alignment after finalizing the height.
wyatth and
inviktus59 were also there doing a wheel swap so it was cool to see 3 slicktop E90s there. SuperSprint, Eisenmann Sport, and MPE were also all there for roll call.
My alignment was set with minimal toe-in front and rear and -3.0 front camber, -2.0 rear camber. We will fiddle more with this if we need to in the future but I think its a good place to start.
Thanks for reading the long post!
Car is now ready for last track day of the year next month!
On a final note, Venoxy Gauges and Apple CarPlay truly makes the interior feel a little bit more modern. It reaffirms my choice to keep a CIC screen.
Happy Thanksgiving everyone!