Got a track related question? I'll try to answer.

[H1C]

Originally Posted by Joesurf79

MCS 2 way non remote coilovers....

.... a few times when on a bumpier track this past weekend, with the car loaded up at apex or just after - I would hit a small bump and hear / feel a stop/clunk from the rear like I am bottoming out?

With spring rates as high as you're running, and with how much thread you have left on the shock body, it doesn't seem likely to me that you're bottoming.

I have MCS 1-ways and also sometimes hear a clunk from the rear in street driving when entering briskly into bumpy or inclined 90 degree turns. On my car it sounds like it's coming from the inside rear on such turns. To me, it sounds like something is moving inside the shock body.

I could have sworn that I read somewhere on here a while back that the clunk in the rear was due to the internal construction of the MCS rear shocks, and that it was normal and harmless. But I can't find the post(s) regarding this issue. Maybe other MCS owners can chime in.

In my case, the clunk isn't frequent or annoying enough (yet) to get me to contact MCS and ask them about it. But I imagine they'd be the best ones to ask. I've emailed them in the past about other stuff and they've always replied promptly.

[lutfy]

Originally Posted by H1C

With spring rates as high as you're running, and with how much thread you have left on the shock body, it doesn't seem likely to me that you're bottoming.

I have MCS 1-ways and also sometimes hear a clunk from the rear in street driving when entering briskly into bumpy or inclined 90 degree turns. On my car it sounds like it's coming from the inside rear on such turns. To me, it sounds like something is moving inside the shock body.

I could have sworn that I read somewhere on here a while back that the clunk in the rear was due to the internal construction of the MCS rear shocks, and that it was normal and harmless. But I can't find the post(s) regarding this issue. Maybe other MCS owners can chime in.

In my case, the clunk isn't frequent or annoying enough (yet) to get me to contact MCS and ask them about it. But I imagine they'd be the best ones to ask. I've emailed them in the past about other stuff and they've always replied promptly.

I have MCS DA with 550/650 with Vorshlag rear mounts. The clunk is metal to metal sound unless you’re running the factory modifiers RSM.

I feel the same clunk at high speed bumps like the shock is bottoming out but the clunk is related to the RSM had the same issue with E36s.

Cheers

Lutfy

[Joesurf79]

Originally Posted by lutfy

I have MCS DA with 550/650 with Vorshlag rear mounts. The clunk is metal to metal sound unless you’re running the factory modifiers RSM.

I feel the same clunk at high speed bumps like the shock is bottoming out but the clunk is related to the RSM had the same issue with E36s.

Cheers

Lutfy

Lutfy - Knowing that you heard a similar noise, and diagnose it to be the rear shock mount - was the occasional clunk something to be concerned about? Did you ever run bumpstops to reduce the impact?


I'm running the Vorshlag rear shock mounts with the bearing perches to eliminate binding.


I heard the clunk a handful of times -coming from the outside rear, when the right side of the car was loaded up in a left hand turn which serves as the transition from downhill to uphill. If I was off line a little, there is a bump approaching / at the apex and if I would hit it - clunk. So basically the totally wrong time to hit the bump - loaded right side, headed uphill, rolling on throttle transferring weight to the rear. This led me to believe that the spring and damper were just overwhelmed as all the load was all going to that right rear corner...


Something is making contact under these conditions, and it sounded harsh a few times.

[H1C]

Originally Posted by Joesurf79

Lutfy - Knowing that you heard a similar noise, and diagnose it to be the rear shock mount - was the occasional clunk something to be concerned about? Did you ever run bumpstops to reduce the impact?


I'm running the Vorshlag rear shock mounts with the bearing perches to eliminate binding.


I heard the clunk a handful of times -coming from the outside rear, when the right side of the car was loaded up in a left hand turn which serves as the transition from downhill to uphill. If I was off line a little, there is a bump approaching / at the apex and if I would hit it - clunk. So basically the totally wrong time to hit the bump - loaded right side, headed uphill, rolling on throttle transferring weight to the rear. This led me to believe that the spring and damper were just overwhelmed as all the load was all going to that right rear corner...


Something is making contact under these conditions, and it sounded harsh a few times.

I have Ground Control RSM's, which have a rubber isolator for the spring, and a rubber spacer/gasket that sits under a big washer for the top nuts. My clunk is more like a "thwok!" -- it doesn't sound like metal to metal -- but I get it under conditions similar to what you describe: brisk turning over bumps or inclines, loaded rear.

At first I thought it might be the rear springs twisting slightly under compression, but that noise is distinct, and also one that I get over speed bumps. I can clearly hear the rubber isolator squeaking then.

Do you think that maybe the no-torque-value 'cinching' instructions from MCS could be a factor:

The 8mm brass hex nut at the top of the damper is the compression / rebound adjuster. PLEASE do not attempt to use this to hold the shaft from turning while installing the first top nut. Install the first top nut onto your mount and snug with a wrench or socket, cinch with a quick jerking motion or hitting with a plastic hammer. This is more than sufficient to secure the shaft to the top mount. Install the second nut and tighten against the first top nut.

I had a metal-to-metal clunk in the front over bumps, but it was because I didn't quite cinch the top nuts enough. Once I loosened and re-cinched those, with the suspension loaded on a flat surface, it went away. I tried doing it for the rear, but the rubber gasket under the washer makes it so that it never really cinches to a stop like in the front. I might try tightening the rear top nuts a bit more and see if it makes my thwok! in bumpy turns go away.

Good luck finding a solution to your noise!

[RJasonKlein]

Originally Posted by Joesurf79

Hello Fellow Track junkies!
I have a bunch of track related coilover spring questions.




Background: I was recently blessed with a fantastic bonus that allowed me to pick up my dream damper setup - a set of MCS 2 way non remote coilovers. I had been lusting after for a year, and after multiple phone conversations, I went with the vendor recommendation on spring length. The springs I got are 7" long Hyperco 650# /in and the rates feel great on track. Finally got the damping set where I like it - and these things are great.


Except (!!) a few times when on a bumpier track this past weekend, with the car loaded up at apex or just after - I would hit a small bump and hear / feel a stop/clunk from the rear like I am bottoming out?


One of three things is happening, right?

1) hard parts making contact. I have looked for witness marks or impact marks on all of the arms and have seen no signs of contact on any of them.
2) Damper running out of travel. Not sure how to diagnose if that is the issue
3) Coil-bind is stopping the damper travel. I have removed the springs and looked between coils from all angles and see no evidence on the powder coat that they are making contact with each other.


These are the first set of non-factory dampers I have had, and they did not come with bump stops. Should I source some and see if it goes away? How concerned should I be if I bottom out a handful of times a day? I don't want to damage these things - they are like precision instruments in my mind and I don't want to break / damage / ruin them.


And finally - regarding the spring lengths. To get the ride height that was recommended to me, the front dampers are out of threads on both sides using the 7" springs. The rears have several inches of thread room left. Would a longer spring - say an 8" in an identical rate theoretically have more stroke and possibly achieve less bottoming, or would that only be if the impact was hitting coil bind?


In the front, could I get away with a 6" spring in the same rate and possibly have some more adjustability?


Lots of questions, lots of thanks to anyone with info / data to share

I have MCS singles from Vorshlag Motorsports and the same length springs that you have, but in my case they’re 8K Swifts all around. I’ll be going to a 6” spring this year in the front for that same reason you’ve described. Vorshlag Motorsports recommended the 7” springs because I was only targeting a 1” drop and the MCS dampers were designed for a 2” drop, so the longer springs were a work around - in my opinion, they’re too long.

I have the spherical rear shock mounts and mine have been quiet as a mouse. When I first read your post, my initial thought was that your rear shock mounts were likely the standard mount and the bearing was binding - now, I’m stumped.

After talking directly with Lex Carson at MCS, my understanding is that the MCS dampers have an internal bump stop and should never be used with a traditional external bump stop on the shaft. Good luck sorting out these minor issues, and I’d recommend that you call Vorshlag Motorsports (Terry or Jon) and MCS (Lex has retired, but their support is excellent) and have them help you out.

[lutfy]

Originally Posted by Joesurf79

Lutfy - Knowing that you heard a similar noise, and diagnose it to be the rear shock mount - was the occasional clunk something to be concerned about? Did you ever run bumpstops to reduce the impact?


I'm running the Vorshlag rear shock mounts with the bearing perches to eliminate binding.


I heard the clunk a handful of times -coming from the outside rear, when the right side of the car was loaded up in a left hand turn which serves as the transition from downhill to uphill. If I was off line a little, there is a bump approaching / at the apex and if I would hit it - clunk. So basically the totally wrong time to hit the bump - loaded right side, headed uphill, rolling on throttle transferring weight to the rear. This led me to believe that the spring and damper were just overwhelmed as all the load was all going to that right rear corner...


Something is making contact under these conditions, and it sounded harsh a few times.

Hey mate yeah I have he same setup with the bearing plate (as yours). I let it be as is knowing the clunk will be a standard issue. Go over through the car one more time to ensure everything is solid and tight. Car is at the shop but I believe we ended up with helper spring which helped a fair bit.

Cheers!

[Joesurf79]

Originally Posted by lutfy

Hey mate yeah I have he same setup with the bearing plate (as yours). I let it be as is knowing the clunk will be a standard issue. Go over through the car one more time to ensure everything is solid and tight. Car is at the shop but I believe we ended up with helper spring which helped a fair bit.

Cheers!

Went over everything after disassembly this morning and I found the culprit. It WAS hard parts contact. The bottom of the bearing spring perch and the top of the damper housing were trying to mate lol!

So I was out of travel externally, not internally I assume. There is no play that I can discern in the bearing on the spring perch or the spherical in the strut mount but I'm sure the shock load wasn't good for them...

And measured the distance from the top of the lower spring perch to bottom of the were on the damper housing - just under 4.2" . When I emailed hyperco, they said the usable stroke for these springs, 650# 7" length was like 4.4xx" - so by the numbers and lack of powered coat scuffs, coil bind was not occurring here.

So my plan is to put in the helper springs/collars which won't increase usable spring stroke or damper travel, but they WILL separate the bottom of the spring perch and top of damper by another .893" at this ride heigth. Other than that all i can think to do is add ride heigth.

I'll call MCS and vorshalg on Monday and pick their brains if i get a chance at work. A HUGE THANKS to everyone for their info and discussion here! Joe V

[H1C]

Originally Posted by Joesurf79

Went over everything after disassembly this morning and I found the culprit. It WAS hard parts contact. The bottom of the bearing spring perch and the top of the damper housing were trying to mate lol!

So I was out of travel externally, not internally I assume. There is no play that I can discern in the bearing on the spring perch or the spherical in the strut mount but I'm sure the shock load wasn't good for them...

And measured the distance from the top of the lower spring perch to bottom of the were on the damper housing - just under 4.2" . When I emailed hyperco, they said the usable stroke for these springs, 650# 7" length was like 4.4xx" - so by the numbers and lack of powered coat scuffs, coil bind was not occurring here.

So my plan is to put in the helper springs/collars which won't increase usable spring stroke or damper travel, but they WILL separate the bottom of the spring perch and top of damper by another .893" at this ride heigth. Other than that all i can think to do is add ride heigth.

I'll call MCS and vorshalg on Monday and pick their brains if i get a chance at work. A HUGE THANKS to everyone for their info and discussion here! Joe V

Yikes! -- glad you got it figured out. I dunno if the radial bearing adds to the stack height, and whether going with Vorshlag's non-radial bearing option would save you some space there, and reduce the chance of external bottoming.

But if you could reduce stack height by going that route, there are thin spring isolators available like these:

https://eibach.com/us/i-1414-spring-isolator.html

Maybe not as good as radial bearings at preventing binding, but probably better than nothing. Good luck getting everything sorted!

[JSube]

@CSGmike & anyone else-
I've been pretty happy with the performance and even wear of my G-Loc R16 front pads. They have 4 days on track from my '15 STI and 9 days in the '17 PP BRZ. All 4 fronts measure 5/16s each.
The rears are Carbotech at 4/16s, older than the fronts and recommended for the STI, possibly XP-12s. They have a few more STI days on them than the G-Locs.

Question is, I have a 3 day HPDE 2 weekends from now at Mid-Ohio with lots of track time, just 2 groups of advanced drivers running back and forth all day long. I imagine I will wear out before my pads do! But...I'm wondering if the smart thing would be to bring my next set of pads with me, and if so, just stay with G-Locs? Other track pads preferred over G-Locs for HPDEs by anyone else...Mike?

Thanks, all!

[Joesurf79]

Originally Posted by JSube

@CSGmike & anyone else-
I've been pretty happy with the performance and even wear of my G-Loc R16 front pads. They have 4 days on track from my '15 STI and 9 days in the '17 PP BRZ. All 4 fronts measure 5/16s each.
The rears are Carbotech at 4/16s, older than the fronts and recommended for the STI, possibly XP-12s. They have a few more STI days on them than the G-Locs.

Question is, I have a 3 day HPDE 2 weekends from now at Mid-Ohio with lots of track time, just 2 groups of advanced drivers running back and forth all day long. I imagine I will wear out before my pads do! But...I'm wondering if the smart thing would be to bring my next set of pads with me, and if so, just stay with G-Locs? Other track pads preferred over G-Locs for HPDEs by anyone else...Mike?

Thanks, all!

Pads are light and easy to swap in the paddock. Never hurts to bring the next set. Worst case, you hauled a couple pounds extra to the track

[CSG Mike]

Originally Posted by JSube

@CSGmike & anyone else-
I've been pretty happy with the performance and even wear of my G-Loc R16 front pads. They have 4 days on track from my '15 STI and 9 days in the '17 PP BRZ. All 4 fronts measure 5/16s each.
The rears are Carbotech at 4/16s, older than the fronts and recommended for the STI, possibly XP-12s. They have a few more STI days on them than the G-Locs.

Question is, I have a 3 day HPDE 2 weekends from now at Mid-Ohio with lots of track time, just 2 groups of advanced drivers running back and forth all day long. I imagine I will wear out before my pads do! But...I'm wondering if the smart thing would be to bring my next set of pads with me, and if so, just stay with G-Locs? Other track pads preferred over G-Locs for HPDEs by anyone else...Mike?

Thanks, all!

Lets chat more. PM me your number.

Pads are not a one size fits all,a nd you have enough experience that it's time to try using different pads to figure out your personal preferences.

[pinoy_dorifto]

Originally Posted by CSG Mike

Gonna try to turn this into a giant Q&A.

Post your question, and I'll answer to the best of my ability (or try to find you the answer and cite sources).

YGPM WITH SOME QUESTIONS '

[EffaressNOOB]

First time tracking this Wednesday and it's supposed to rain..... YAY or NAY??? RRR is offering a BOGO here in Savannah, GA, USA if anybody wants that information. $150 for 2 drivers!

[jvincent]

Tracking in the rain is awesome.

You can't go as fast so in some way's it's less "dangerous" and it really gives you feedback on if you're driving the right line and smooth on your inputs.

So, YAY.