Obioban's 2005 IR/IR Coupe

[Obioban]

How did you get a set of Ohlin from perches with 65mm/2.5” ID? Getting away from 60mm would really open up spring options.

I bought them from 3DM, and Ohlins reseller/rebuilder.
(833) 323-1117

[duracellttu]

Ha... more involved question than you might think.

I found a line barely barrel springs that eibach makes, which they call their extreme travel line. That allowed me to use a shorter spring (6" IIRC) up front, while still having sufficient travel, which puts the perch above the tire at my desired ride height, allowing me to run bigger tires without compromising offsets (lets me run an ET35 front, which allows me to not have stupid camber to fit 285s). So, my front left is an eibach extreme travel 6" "barrel" spring. Eibach 0600.2530.0350.

Front left was tricky because the extreme travel line only comes in 50 lb increments.... but then I realized that GC sells and extreme travel spring (made by eibach, though they don't use that branding-- but visibly the same thing and I confirmed that they were with GC) in 6" 375 lb. Ground control GC150.64.66.


Both fronts are either 65mm or 2.5", I forget which (and am pretty sure most spring companies use the same thing here anyway. To fit that on the H&R shock body, I'm using Ohlins spring perches-- same thread pitch, so it's plug and play. Still using the H&R lock ring, because it's free.

Rear left is a TCK 700 lb beehive from my old TCK coilovers. TCK TKE 360 700 R.

Right rear is a GC linear 650 lb spring... I think 6"? With some of their cones on the top side, to protect the chassis from the spring.

Both rears are sitting on the H&R rear ride height adjusters, because they're really nice-- let you adjust the height without taking the spring out, or wheel off, which makes corner balancing way easier.

How did you get a set of Ohlin front perches with 65mm/2.5” ID? Getting away from 60mm would really open up spring options.

[Obioban]

Including the hybrid styles? I'm planning to replace the TC Kline plates currently on my car and NVH is a concern.

Great job and thanks for documenting all of this. I can appreciate the reasoning behind the choices you've made. Looking forward to more reviews of the suspension!

I had the hybrids before. They're closer to street than monoball in NHV. They're a nice product.

Mostly I don't think there's a ton of increased precision to be had from the monoballs/hybrids over street plates (as in, it's not hold chassis geometry like control arm monoballs) and they are a significant NHV contributor. So, the trade off didn't seem worth it to me.

... and the hybrid TMS camber plates have gotten crazy expensive, once you add the perches and shock adapters (and I sold my previous set with the Ohlins).

[Obioban]

Awesome to hear you finally got this installed!! What brand and size springs did you use F and R?

Ha... more involved question than you might think.

I found a line barely barrel springs that eibach makes, which they call their extreme travel line. That allowed me to use a shorter spring (6" IIRC) up front, while still having sufficient travel, which puts the perch above the tire at my desired ride height, allowing me to run bigger tires without compromising offsets (lets me run an ET35 front, which allows me to not have stupid camber to fit 285s). So, my front left is an eibach extreme travel 6" "barrel" spring. Eibach 0600.2530.0350.

Front left was tricky because the extreme travel line only comes in 50 lb increments.... but then I realized that GC sells and extreme travel spring (made by eibach, though they don't use that branding-- but visibly the same thing and I confirmed that they were with GC) in 6" 375 lb. Ground control GC150.64.66.


Both fronts are either 65mm or 2.5", I forget which (and am pretty sure most spring companies use the same thing here anyway. To fit that on the H&R shock body, I'm using Ohlins spring perches-- same thread pitch, so it's plug and play. Still using the H&R lock ring, because it's free.

Rear left is a TCK 700 lb beehive from my old TCK coilovers. TCK TKE 360 700 R.

Right rear is a GC linear 650 lb spring... I think 6"? With some of their cones on the top side, to protect the chassis from the spring.

Both rears are sitting on the H&R rear ride height adjusters, because they're really nice-- let you adjust the height without taking the spring out, or wheel off, which makes corner balancing way easier.

[K-Dawg]

The monoball camber plates are just too much NHV for the amount of precision they add, for me.

Including the hybrid styles? I'm planning to replace the TC Kline plates currently on my car and NVH is a concern.

Great job and thanks for documenting all of this. I can appreciate the reasoning behind the choices you've made. Looking forward to more reviews of the suspension!

[duracellttu]

Awesome to hear you finally got this installed!! What brand and size springs did you use F and R?

[Tbonem3]

Ya I'm concerned (I'm moving from poly tms street plates to vorshlag). Oh well

[Obioban]

Congrats on reaching this point. I'm surprised you're on poly bushed camber plates and rsms though.

The monoball camber plates are just too much NHV for the amount of precision they add, for me.

[Tbonem3]

Congrats on reaching this point. I'm surprised you're on poly bushed camber plates and rsms though.

[Obioban]

I did a bunch of mods over the winter. The most significant (for me, anyway) was the Fat Cats suspension.

Because of moving, it's been hard to make actual progress on getting the car 100% (was driving for a while with no sway bars connected, etc). But, as of last week I'm installed, bump/droop ratios optimized, corner balanced, aligned, corner balanced again, and preload dialed out. I've put ~100 (street only so far) miles on the car, and and comfortable giving very early impressions.

My complete setup is as follows:
Fat Cat Motorsports Stage 3 Coilovers (every option they offer)
Springs: 375 FL, 350 FR, 700 RL, 650 RR (equal frequencies left/right, 1.97hz front, 2.10hz rear, 75% front roll couple with sway in middle of adjustment range)
Ground control street camber plates
Ground control street RSMs
Ground control Front sway/bushings/brackets/end links
CSL Rear sway/bushings/brackets, with home made adjustable end link
Sealed monoball RTABs
TMS Sealed monoball FCABs
Bimmerworld sealed monoball rear adjustable camber arms
CSL Kingpins

I'm running at 60% bump, 40% droop up front, with a .5" rake (seem to be optimal for high speed oversteer/understeer), which puts me at ~14" front, 13.5" rear. In terms of alignment, I'm at -1.5 up front (this will be pyrometer based set more negative on track) and -2.0 rear (this will be left alone on track). I'm super psyched to have a setup that lets me run high enough to have a reasonable street camber, with the CSL kingpins-- should be a pretty killer camber curve and let me get away with meaningfully less static camber on track! Rear geometry should also be pretty good, with the CMP bushings raising the subframe and minimal drop. My geometry is also pretty rigidly held, as the only bushings in the entire setup are rear upper control arm inside bushing-- everything else is a sealed monoball (shock mounts and drivetrain mounts are still bushed/stock, so NHV is pretty minimal).

Onward to initial street impressions of the FCM setup:
The only word I can think of to describe the car is unflappable. Nothing seems to phase it. If you've ever driven a car with too much tire (the level of grip is more than the suspension can deal with), this feels like what the opposite would be. The closest analogy that fits is a stock FRS/BRZ/86, on the default prius tires-- only with PS4S levels of grip.

It is remarkably different than any setup I've driven before. And I've been all over the map-- Motons and JRZs on the e36 track car, TCKs and Ohlins on this car, Stock springs with Koni yellows on the M5, Dinan springs with Koni yellows on the M3 wagon. I can't say it definitively till I've been on track (after which I'll make a dedicated thread about the setup), but so far this setup feels faster and easier (to drive) than any of the above. Plus, I'm excited to have a setup that just valved for my specific corner weights and spring rates, so I don't have to mess with adjusting shock valving before/during/after track events. It's just correct for the car.

I'm pretty excited for this setup-- don't think I'll be changing again. I look forward to seeing what it's like on track!

[Obioban]

Street review of wavetrac: indistinguishable from stock.

No track time on it yet.

[Obioban]

I have a binder that is at least 150 to 250 pages with all receipts and a detailed job description of every job I have (and the one shop I occasionally use) completed. Even has a table of contents and an excel spreadsheet so I can see exactly what I've spent. 0 out of 10, don't recommend knowing those numbers lol.

I have very intentionally never slightly thought about that.

[oceansize]

I have attempted to bring my mod list up to date. There's probably some things I'm missing, but... it's closer than it was.

I have a binder that is at least 150 to 250 pages with all receipts and a detailed job description of every job I have (and the one shop I occasionally use) completed. Even has a table of contents and an excel spreadsheet so I can see exactly what I've spent. 0 out of 10, don't recommend knowing those numbers lol.

[Obioban]

I have attempted to bring my mod list up to date. There's probably some things I'm missing, but... it's closer than it was.

Engine:
OEM ( Die Wethje) CSL Airbox
Schrick 280/272 cams
TMS pullies
Dr VANOS cryo treated exhaust hub
Beisan systems lifetime VANOS sealing plate o-rings
Beisan systems lifetime VANOS solenoid
Beisan oil pump disk
Beisan VANOS rattle repair kit
Beisan VANOS seals
Beisan timing chain tensioner guide
TurboToy (modified ARP) cam bolts
updated BMW high pressure vanos oil line
lifetime CPV o-ring

Exhaust:
SuperSprint V1 stepped headers (swaintech coated)
SuperSprint HJS catted V1 Section 1
SuperSprint resonated twin tube section 2
SuperSprint Street muffler

Engine Management:
CSL Engine Management
MCCHIP-DKR Dyno tune
OE CSL IAT
OE CSL Map rail/sensor
Aux/clutched fan replaced with ecu controlled (using Z4M values) spal fan
SMG shift lights turned on
post cat 02s turned down but left on (ready)
secondary air pump sensor disabled
cold start sequence disabled
non sport throttle mapping
sport button disabled for future alternate use
sport mode memory enabled
EGT tweaked for HJS Cats' allowable max temps
Top speed limiter removed
Dyno limiter removed
CSL warmup light values

Suspension:
Fat Cat Motorsports Stage 3 Coilovers
Springs: 375 FL, 350 FR, 700 RL, 650 RR (equal frequencies left/right, 1.97hz front, 2.10hz rear, 75% front roll couple with sway in middle of adjustment range)
Corner balanced and preload dialed out, with equal ride heights left/right with me in the drivers seat
Ground control street camber plates
Ground control street RSMs
Ground control Front sway/bushings/brackets/end links
CSL Rear sway/bushings/brackets, with home made adjustable end link
Sealed monoball RTABs
Bimmerworld sealed monoball rear adjustable camber arms
CSL Kingpins

Steering
ZHP/yellow tag steering rack
25% assist reduction by shimming pressure regulator
CHF-11 conversion
Alcantara steering wheel

Brakes:
817.3 DSC unit (CSL)
Porsche 996 calipers
CSL/ZCP/Z4M rotors (FCP)
stainless lines
OE Porsche Street pads (FCP)
track pads (FCP)
Castrol SRF (FCP)
Hard Motorsport Brake Ducts
Hard motorsport backing plates

Body:
Evolve CF roof
Vorsteiner CSL trunk
Fucy CSL diffuser
Gunmetal grills/gills
Depo smoked front corner lights
35% tint (3M)
vinyl M stripes on trunk badge (stock colors, less prone to fading)
modern BMW wheel center caps
shark fin removed
OEM driver’s side keyhole cover (to deter thieves)

Wheels:
18" RAC RG-63s in gunmetal (street)
17" Apex ARC-8s (track)
TMS 75mm studs

Lights:
TFX projectors
55w bulbs/ballasts/ignitors in 4300k
85w halogen highs, programmed to come on with the xenon highs
Outer brake light ring enabled for normal braking
Brake lights programmed to strobe under hard stops
e9X LED license plate lights

Interior:
Cobra Nogaros in Imola Red leather, with factory heating pads install and adjustable lumbar
Brey Krause Mounts on factory e46 manual sliders
Brey Krause Rear deck harness mounts
Alcantara wrapped header liner
Alcantara wrapped pillars
Alcantara wrapped rear deck
Alcantara wrapped steering wheel
imola leather wrapped center console
imola leather wrapped arm rest
imola leather wrapped ebrake book
Z8 ebrake handle
M3 oval interior mirror retrofit

Stereo:
100% of factory stereo, mounting brackets, and wiring harness deleted
Avin Avant 4 with speakers plugged in directly to unit
Wireless CarPlay module

Chassis:
Vincebar, epoxy/rivet under floor version
TMS subframe reinforcement kit with extra reinforcements
BMW structural foam in subframe cavity
updated BMW diff mount bolts
CMP subframe raising solid mounts
front strut tower inserts to remove slots
Slonik chassis reenforcement plate

Misc:
Wavetrac differential
Brail GU1R lithium ion battery (6 lbs), mounted in the engine bay to eliminate 6 lb battery cable
Entire factory stereo (inc wiring harness, mounts, etc) removed
Light weight (2 speaker) stereo powered by head unit installed
Avin 9" touch screen head unit install (wireless CarPlay 99% of the time)
CSL Cabin air filter housing
Auto Solutions SSK
RE Transmission mounts
Hella Horns
CDV delete
VAG grocery bag hooks
CSL Aux coolant pump
Washer tank swapped for e39 high intensity washer tank
e39 washer stalk for extra button to toggle M Track Mode while preserving on quick DSC off and steering wheel controls

Coding (non comprehensive highlights):
CSL oil level display (in cluster) enabled
M track mode enabled
Strobing shift lights

[S14]

Haven't needed replacement pads yet, so will cross that bridge when I come to it.

I started out with 4 cylinders, but it was way more difficult that way. With 2 cylinders, I know what the level is when scale. With 4, whenever I would change one all 4 would change, and I'd have to figure out what the new equal amount should be. Plus more tubes to trip over and fluid to fill. It was just a mess.

With the new system, I just leave one on the highest, and then compare, one at a time, each scale to that. Quick, minimal fuss, easy to determine if level, less stuff to store.

... when we move, I'm going to use them to level my new 4 post lift and then probably get rid of them. Once I know the lift is level, they are no longer useful.

gotcha, that makes sense. sometimes simple is best.