Obioban's 2005 IR/IR Coupe

[Obioban]

You're making a conclusion with confirmation bias due to having bought these really expensive dampers (which you tell others not to do), based off a photo.

You'd have to get a picture BEFORE the corner to see if his wheel is closer than yours aka being "packed up". Even then, it could be other factors. No, I don't believe your two cars' front driver corners, and in general, are the exact same.

Jacking down is a made up phrase from Shaikh. Foesn't exist. The phrase is pack up.

Him being deeper into the corner is less spring or heavier corner weight or he's faster . Maybe you have more compression dampening.

Packing up can lead to less control, harsher/harder ride. It's less comfortable as you're further into your travel as the bumps come. But it doesn't mean you dig deeper into a corner. Only speed (before loosing traction) can cause your wheel to compress more in a corner, given fixed spring rate and corner/car weight.

You're not even doing slaloms or something, it's just one corner as far as I can tell.

*Thought of another possiblity - you're talking a smoother line resulting in less compression.

"Jacking down" is not a phrase made up by Shaikh.
Here's Koni defining it: https://www.koni-na.com/en-US/NorthA...-Tuning-Guide/
Here's Eibach defining it: https://eibach.com/us/ft-3-eibach-su...-glossary.html

I plucked those two pictures because it was a nice side by side. But, the reason I noted this was was that, when I downloaded the pictures, my car is notably less rolled over in every picture than the photos from all previous events (on all previous setups) I've done for the last 15 years (despite my setup being softer than everything I've run other than the post flat ride converted Ohlins). It was the first thing that stuck out to me about the entire photo set-- the car was notably less rolled over than any previous event, in every cornering picture. I agree that two pictures in isolation would be meaningless-- I just meant them as an example of an overall trend.

Only speed (before loosing traction) can cause your wheel to compress more in a corner, given fixed spring rate and corner/car weight.

Speed is not the only cause of suspension compression mid corner-- bumps still exist in corners, and compress the suspension. If there's too much rebound, the cornering load does not allow the suspension to return to the static loaded ride height. Next bump repeats the process. This can continue until you're in the bump stops, increasing the effective spring rates. decreasing girp. This is what jacking down is.

Or, as Koni put it in the link above,

Too much rebound control in relation to spring rate will cause a condition known as "jacking down." This is a condition where, after hitting a bump and compressing the spring, the damper does not allow the spring to return to a neutral position before the next bump is encountered. This repeats with each subsequent bump until the car is actually lowered onto the bump stops. Contact with the bump stops causes a drastic increase in roll stiffness. If this condition occurs on the front, the car will understeer; if it occurs on the rear, the car will oversteer.

[Tbonem3]

You're making a conclusion with confirmation bias due to having bought these really expensive dampers (which you tell others not to do), based off a photo.

You'd have to get a picture BEFORE the corner to see if his wheel is closer than yours aka being "packed up". Even then, it could be other factors. No, I don't believe your two cars' front driver corners, and in general, are the exact same.

Jacking down is a made up phrase from Shaikh. Foesn't exist. The phrase is pack up.

Him being deeper into the corner is less spring or heavier corner weight or he's faster . Maybe you have more compression dampening.

Packing up can lead to less control, harsher/harder ride. It's less comfortable as you're further into your travel as the bumps come. But it doesn't mean you dig deeper into a corner. Only speed (before loosing traction) can cause your wheel to compress more in a corner, given fixed spring rate and corner/car weight.

You're not even doing slaloms or something, it's just one corner as far as I can tell.

*Thought of another possiblity - you're talking a smoother line resulting in less compression.

[Obioban]

Then his springs are too light

12 years ago, with 650lb front springs on my car.

[Obioban]

Then his springs are too light

25 lbs off stock Ohlins (and within Ohlins supported range of +-30%).

…. and bang on identical rates to me.

[Tbonem3]

Then his springs are too light

[Obioban]

He can speed his rebound up a little.

He was 2 clicks off full soft. Any less and it never settles down.

[Tbonem3]

He can speed his rebound up a little.

[Obioban]

Shaikh talks a lot about preventing jacking down. Looking through these pictures, I found an interesting comparison, that makes it look like what he's doing in that regard.

The white M3 is on my former Ohlins' setup (I sold it to him). Same spring rates as me, same sway as me, same weight as me. Same corner, same grip level tires. My current setup has more bump and droop travel, so more space available for body roll. I believe the difference we're seeing is his setup has experienced jacking down, while mine has not.

It’s actually more exaggerated than the pics make it look, too, as the AW car is on 17 and I’m on 18s— so at static ride height, my wheels are closer to the fenders

[Obioban]

Been a couple years since I purchased any pics from the track side photographer, so I did. In retrospect, I kind of regret choosing this event for that, as it was the worst event I've been to... ever, but pics seem fine.

[Obioban]

I was also running a flat ride suspension setup but was using KW V2 dampers. I had done a linear spring rate conversion and had Vorshlag plates. When I had a desire to change my suspension I went back and forth a bunch on going with a real FCM shock or getting one of the remote adjustable setups mostly because of your quality of life statement. Ultimately I went with the remotes and more standard springs rates. I have 2 seasons on the adjustable's and am still getting the dialed in. My car is track only but I can say the ride with flat ride was amazing. The car just soaked up everything on track. Multiple passengers commented on ride quality. My car is most certainly faster now with the Moton's but as I have said before my car is way faster than I am anyway...

It is interesting that the primary service sold by FCM is the re valving of the dampers but it would appear that the spring rate change may be the actual secrete sauce. Would you do it again if you had it to do over?

I really only have 1 day on track with them, so I don't think my opinion is fully formed yet.

But, my tentative response is... starting from where I was a year ago, I don't think I've gotten $5000 better than where I was, so probably not. Were I starting over with a car with a stock suspension, probably yes.

[Sergmann]

Not having any knobs to turn is a nice upgrade to quality of life

Overall, I’m happy with them. I think they’re, in net, the best setup I’ve driven, even if they were not quite as mind blowing as I hoped for. Part of that may also be my expectations. FCM is pretty much the only aftermarket vendor I’ve seen pushing flat ride setups. Converting the Ohlins to be flat ride was, bar none, THE BEST performance (and ride quality, and drivability) upgrade I’ve ever done to any car—I’ve since moved every car I own to flat ride. I was hoping for a similar level of mind blowing improvement from the FCM shocks, but mind blowing may be an unrealistic expectation. They’re better than any previous setup I’ve driven/owned on the tarmac, even if I’ve had to alter my driving style/line around them to keep them on the tarmac and off the curbing 😝

I was also running a flat ride suspension setup but was using KW V2 dampers. I had done a linear spring rate conversion and had Vorshlag plates. When I had a desire to change my suspension I went back and forth a bunch on going with a real FCM shock or getting one of the remote adjustable setups mostly because of your quality of life statement. Ultimately I went with the remotes and more standard springs rates. I have 2 seasons on the adjustable's and am still getting the dialed in. My car is track only but I can say the ride with flat ride was amazing. The car just soaked up everything on track. Multiple passengers commented on ride quality. My car is most certainly faster now with the Moton's but as I have said before my car is way faster than I am anyway...

It is interesting that the primary service sold by FCM is the re valving of the dampers but it would appear that the spring rate change may be the actual secrete sauce. Would you do it again if you had it to do over?

[Obioban]

Completely echo everything you said but would build a bit on this. You spent a LOT of effort, custom design, research, custom manufacturing, and tweaking to get the Ohlins to be close to as good as the FCM setup (which was relatively out of the box at this point).

On the street; however, I still prefer your custom Ohlin setup as you do encounter more larger bumps on the street and the Ohlins handle those in a more predictable manner.

When we get to summit point, you should take it out on the back roads not all loaded up with track stuff-- it's actually pretty spectacular on back roads in current form.

[Surge709]

My view may be a bit unfair here—flat ride is a bit of FCM’s secret sauce, and I was already running it. If I had come from any non flat ride setup (that I previously had), these would have completely blown my mind. If I had come from anything other than the Ohlins, I wouldn’t have the complaint about curbing performance being worse, as that’s really the Ohlins specific DFV valve in its element.

Completely echo everything you said but would build a bit on this. You spent a LOT of effort, custom design, research, custom manufacturing, and tweaking to get the Ohlins to be close to as good as the FCM setup (which was relatively out of the box at this point).

On the street; however, I still prefer your custom Ohlin setup as you do encounter more larger bumps on the street and the Ohlins handle those in a more predictable manner.

[Obioban]

Oh, and driving a friends car back to back with mine made me realize it's time to replace my AC condenser. His 20,000 mile AC got more cool more quickly for sure. I might shop that out, since I already have to pay someone to drain/refill the AC...

[Obioban]

Saturday was probably the worst track event I’ve ever been to, but Sunday was pretty good. Consider these impressions from one day of driving on track. Saturday was so obnoxious because of ITS students that it was basically slower than spirited street driving, only everyone around you is intentionally inept… and not giving passes. Horrible. My lap times were ~20 second faster on Sunday than Saturday (on laps that are only ~1:15-1:16 long, so absurdly slower).

Michelin PSC2s/track connect:
Amazing. Tires feel like other R comps I’ve driven, don’t get greasy over a 25 minute session on a 95 degree day, have plenty of grip, and are as civil as a PS4S on the street. Unless these wear out absurdly quickly, I’ll be running them for a long time—the per corner PSI changes at the end of each session really idiot proof optimizing tire pressures, and per corner temperature monitoring actually had me tweaking my driving style to keep them from overheating (specifically the left rear in the bowl).

Wavetrac:
Mostly unnoticeable. In good ways and bad—silent, didn’t do anything that threw me off or unexpected, but also didn’t blow me away in any way. It feels instant, predicable, and doesn’t open up when I use curbs (more on that to come). It doesn’t do anything funky under braking, etc. I guess the only “bad” is that I just don’t feel… impressed? I don’t know. Perhaps I was expecting too much of a change. It just feels good, and didn’t do anything that caused me to think about it, good or bad.

Fat Cats Suspension:
Compared to every previous non flat ride setup I’ve had (TCK D/As, Motons/JRZs, and stock Ohlins), these are better. Compared to the flat ride converted and bump/droop corrected Ohlins, it’s more of a mixed bag. The Ohlins are just better at taking curbs. As in, it is almost as if the curbs don’t exist. I had to pretty significantly change my line, as I formally used a TON of curbing, and with the FCM setup that was throwing the car (whereas the Ohlins would just absorb it). I’m a bit disappointed there, as I expected FCM’s KBO to be similar to, but better than, Ohlins’ DFV valve. That was not how it felt in practice, on curbs. I set both setups to 60% bump, 40% droop, and the FCM’s have more total travel, so I don’t think it was a bottoming out issue.

That said, other than the curbing, the FCMs were pretty great. On small to medium bumps the car is remarkably unphased—almost as if they don’t exist. It feels very neutral, exactly as the spread sheet predicted—I can make it oversteer or unsteer at my discretion. Most importantly (to me), other than altering my line to use less curbing, nothing about what it did made me think about what the suspension was doing. It was consistent, predictable, fast, and felt exactly dialed in. Damping felt exactly on point. Jacking down was nonexistent—never did it feel like I was bottoming out the bump stops through a corner. Not having any knobs to turn is a nice upgrade to quality of life—like having the tire pressure adjustments told to me, it’s really nice to just have things set correctly and not think about it.

My view may be a bit unfair here—flat ride is a bit of FCM’s secret sauce, and I was already running it. If I had come from any non flat ride setup (that I previously had), these would have completely blown my mind. If I had come from anything other than the Ohlins, I wouldn’t have the complaint about curbing performance being worse, as that’s really the Ohlins specific DFV valve in its element.

Overall, I’m happy with them. I think they’re, in net, the best setup I’ve driven, even if they were not quite as mind blowing as I hoped for. Part of that may also be my expectations. FCM is pretty much the only aftermarket vendor I’ve seen pushing flat ride setups. Converting the Ohlins to be flat ride was, bar none, THE BEST performance (and ride quality, and drivability) upgrade I’ve ever done to any car—I’ve since moved every car I own to flat ride. I was hoping for a similar level of mind blowing improvement from the FCM shocks, but mind blowing may be an unrealistic expectation. They’re better than any previous setup I’ve driven/owned on the tarmac, even if I’ve had to alter my driving style/line around them to keep them on the tarmac and off the curbing 😝

Oh, and for those that care, I believe the car is faster with the FCMs, as well. Hard to say, as different days, conditions, and me being rusty (first event of the year because we moved), but in 95 degrees ambient, me out of practice, and 240 treadwear tires (PSC2s) now vs 100 last year (NT01s) (if that matters at all), my times were similar. On a cooler day, with me back in the groove more, I’m sure the car would now be 1-2 seconds faster a lap.

Vincebar:
No notable change from the drivers seat.

CMP subframe bushings:
Things did feel more directly related in the rear. Hard to know how much of that is subframe bushing related vs suspension related.

Avin
For whatever reason, it won't pair with Michelin telemetry unit, so I had to run my iPhone on the dash to run the track connect app. Annoying.


I feel like all of the above sounds kind of ambivalent, but that's not actually how I feel-- the car feels great. I love having less to tweak-- basically I'm just setting camber by the pyrometer and tire pressures by what the app tells me to do. Just driving, and not worrying about the setup, is pretty wonderful.