3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Stupid noob question about FD coilovers

Thread Tools
 
Search this Thread
 
Old 05-12-09, 01:24 PM
  #1  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Stupid noob question about FD coilovers

Ok, so last night I started installing coilovers. They are Powered by MAX brand and look like this.



Three nuts on the threaded part and an additional lock nut on the bottom...one for spring perch preload, one to lock the spring perch in place, and one to lock the shock body in place. Now, before last night I had absolutely zero experience with a double wishbone suspension setup. The install was a bigger pain in the *** that I expected...but this isn't even an install question. What I need to know is, is there a way to adjust ride height on the rear shocks without removing the bottom bolt?

What I always did on my old 240SX was unlock the bottom nut that holds the shock body in place, then the second nut (the one that holds the spring preload nut in place), and twist the coilover body so that it screws further into the top, which would pull the suspension arm up. But that does not work on this design, because if you turn the shock body it just lengthens the screw that attaches to the lower mount. Do you really have to remove the lower mount (and therefore also the swaybar endlink and control arm)? No matter what I do, I just keep raising the car instead of lowering it. Again I don't know much about double wishbone suspensions, but it blows my mind why they would have used a design like this and not a ball joint like they did for the front...and why they would have had the sway bar endlink bolt be the bolt for the shock mount...way to be overcomplicated...seems to be a trend on these cars though
Old 05-12-09, 01:45 PM
  #2  
needs more track time

iTrader: (16)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 9,188
Received 509 Likes on 350 Posts
Why not ask the manufacturer how to use their product?

your issue has nothing to do with double wishbone suspension. You are adjusting it incorrectly i.e. using the product incorrectly. You adjust ride height using the collar under the spring. That is why the shock body is threaded...

Hardly a trend with the car. More the user.
Old 05-12-09, 02:21 PM
  #3  
RX7FD3S

iTrader: (3)
 
RX7LINK's Avatar
 
Join Date: Jun 2005
Location: South Bay, North Cali.
Posts: 1,489
Received 7 Likes on 5 Posts
this may help

https://www.rx7club.com/showthread.p...vers+correctly
Old 05-12-09, 02:22 PM
  #4  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
I doubt the manufacturer would be that helpful, they are based out of Japan...there is a US office, but they're hard to get ahold of, and they merely import their products from Japan, I doubt they even have an FD demo car. I posted here because I've seen designs of other FD coilovers and they're the same, except for the adjustable bottom piece. And yes it's user error, I have never seen coilovers like this before, that's why I posted this :p But I'd argue that it has everything to do with the car. All FDs have the same mounting points for the rear shocks, do they not? But yeah, the thing about double wishbone was unrelated, merely was saying how complicated it is compared to other cars I've had experience with. So you say I should adjust ride height using the collar under the spring. What exactly does that mean? Loosen the collar for spring preload? Then what? I was under the impression that the spring needs to be tight against the top of the car, even when it's jacked up. Gah, I sound like an idiot here...this should be self explanatory, but the way I adjusted height before didn't work for these.
Old 05-12-09, 03:16 PM
  #5  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
Not the spring preload. you need the spanner wrench to do it. Its these...

Old 05-12-09, 03:17 PM
  #6  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
On a side note, havent seen these coils before...Any more info on them? Price? Spring rates? Dampening settings?
Old 05-12-09, 03:33 PM
  #7  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Ok, so let me get this straight. Loosen the nuts that you circled. Then twist the threaded part? I don't need to mess with the two nuts under the spring? That's completely the opposite of what I've been reading, haha. I guess there are multiple ways to do it. On the Ground Control coilovers I have on another car, it's impossible to make the top hat seat up next to the upper mount, when the car is up on jacks. Adjusting ride height involves lowering the perch and the springs don't meet with the upper mount until the car is on the ground. Is that ok to do on these kind of coilovers?

As for what these coils are. I got them from http://www.gtfactory.jp/cms/page.php?9

All the stats are on that page. They come with 8k front / 12k rear springs, but you can request any spring rate. They're $1000 plus shipping. If you're interested, best to call the 800 number rather than email as they don't really reply to emails at all, from what I can see.
Old 05-12-09, 03:41 PM
  #8  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
Yea, you just loosen those nuts with the spanner and then thread the whole threaded tube portion of the shock into the lower shock body, then retorque the nut onto the lower shock body. Very simple, i think your just over thinking it.
Old 05-12-09, 03:43 PM
  #9  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
Oh, and i just realized you said its 8k front and 12k rear...Are you sure its not the other way around? Most coils I had thought had the stiffer springs up front?
Old 05-12-09, 03:51 PM
  #10  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Yeah, I definitely must be overthinking things, haha. And yes that was a typo, it was supposed to be 12k front and 8k rear. I don't really plan on road racing this car, but I do plan on drifting it regularly, so I figured the gap in spring rates would be fine. Thanks for all the help guys, I'll check it out tonight.
Old 05-12-09, 03:55 PM
  #11  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
Right on. I was gonna say thats quite the weird choice in spring rates. Well those look like a nice set of coils, especially for only a grand. Good luck with setting the ride height, you should post some pics when you get it all leveled and back on the ground.

My advice would be to make small changes and record what you do in a book. Ie, 3/4 turns clockwise etc...so you can undo the changes.
Old 05-12-09, 04:40 PM
  #12  
needs more track time

iTrader: (16)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 9,188
Received 509 Likes on 350 Posts
Originally Posted by RX7LINK
It even has pics
Old 05-13-09, 01:41 PM
  #13  
Old Rotary Dog

 
wrankin's Avatar
 
Join Date: Feb 2003
Location: Durham, NC
Posts: 1,461
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by gracer7-rx7
It even has pics
Unfortunately, it also has one of the most inane arguments about spring preload and which nut to adjust, etc that I have ever seen on this board.

Personally, looking at those coilovers, I would leave the sleeve screwed in about as far as possible into the shock body (it looks like it only has about an inch of treads) and leave the bottom nut tight so the sleeve won't spin in/out of the shock body during use. Remember that the weight of the car is being held up by the threads on the sleeve, so I want as much overlap there as possible.

Height adjustment should be done by loosening the upper lock nut (the smaller) and spinning the perch collar up or down to get the ride hight you are looking for. Then lock it back down by tightening the lock nut/collar. Make sure at that setting the shock has enough travel so that it doesn't bottom out under full compression.

After you get you ride height where you want it, the next best step is to take it to an alignment shop to get it corner balanced and aligned, esp to remove some of that negative camber you just added to the rear.

An adjustable spring perch isn't rocket science.
Old 05-13-09, 02:57 PM
  #14  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Question...if I do what you suggest and leave the sleeve screwed into the body as far as I can, would that not put more stress on the bolt stocking out of the bottom, the one that has the lower mounting point on it? Since it would be sticking out further. Or wait...are you suggesting to leave the lower mount screwed into the sleeve as much as possible? And it's not rocket science, no, but there are conflicting opinions on how to adjust ride height. Unless I read your post wrong, what you just said to do (and what I would have done too had I not been told that the top of the spring needs to meet with the body / upper mount like stock) is completely different from what Cgotto6 said to do, which doesn't involve moving the spring perch at all. I believe his procedures are correct for these coilovers, which allow for height adjustment independent of spring perch position. But I followed his suggestion last night and there's only so far that the shock body can be screwed into the sleeve. It looks like stock right now even though it is screwed all the way in. If I want to go lower I think I will have to lower the perch and/or reduce the length of the lower mount.

Ok, so now I DO have an install question. I followed the procedure in the FSM to remove the front coilover assembly, but the lower mounting point is stuck in the control arm. Is there an easy way to get it out? Or am I going to have to drop the control arm and just bash it out?

Oh and of course I'm going to get an alignment when this is all said and done, or more likely I will align it and corner weigh it using my friend's tools and scales, who road races and knows more about setups than I do. Despite how ignorant this thread might make me sound, I actually do know quite a bit about suspension and how adjusting the ride height affects alignment. Also, if you google "FD Coilover installation" this is thread is one of the first things that comes up. Funny how that works.
Old 05-13-09, 04:16 PM
  #15  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Apparently you can't edit posts after a certain time? Anyway nevermind on the install question. Searched a bit and found that you do have to remove the upper A arm; I was reading the diagram in the FSM wrong. What a pain. Although, it seems like it would be more appropriate to remove the lower arm, as that's the point it's sticking at...
Old 05-13-09, 04:42 PM
  #16  
needs more track time

iTrader: (16)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 9,188
Received 509 Likes on 350 Posts
You have the most disjointed writing/communication style I have ever seen...

Use a long screwdriver to pry the shock bottom out of the front lower control arm. It will come out with little bit of effort.

Once you have the front shock out, take a long hard look at the area where the shock slides into the front lower control arm. You will notice that there is a little sliding insert there. In order to get the shock back in, you will have to compress that back into the control arm. Use a nut and bolt and washers to do that so that you can slide the shock back in w/o much effort.

On the rear shock, you want the bolt as screwed in as possible. The further out it is the more prone it is to breaking.

I have no idea why you think the shock allows for ride height position independent of the spring perch. That just sounds completely wrong.


I'm hoping that you did a search in the Suspension section for other threads on installing shocks and coilovers before you started and that you disconnected the ABS sensor so that you wouldn't stretch and break the wires leading to that sensor. It costs $250 and the used ones are all garbage if you can find one.
Old 05-13-09, 06:28 PM
  #17  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Sorry. I have a hard time explaining things like this over the internet, since I don't know all the technical terms. Likewise I also have a hard time learning things like this from text; I need to be shown. But I posted here anyway hoping that it would at least help a bit. I have a tendency to ramble too Let me try and clarify. I was told that, if the top of the spring does not meet with the upper mount when the car is off the ground, it would negatively impact performance. In other words, if the spring isn't snug against the top mount, you'll have problems. Obviously, lowering the perch (and thus lowering the spring itself) would then be a bad idea. So, I figured there ought to be another way to adjust ride height, especially given Cgrotto6's instructions earlier, which imply that you don't need to mess with the position of the spring perch.

Edit: Further clarification on this. Check out this video.

http://www.youtube.com/watch?v=YHLWtqem_AI

Mine are like the Pro-C model, on the right. The spring perch stays fixed in place when he's adjusting ride height. (About 2:25 in the video.) As Cgrotto6 indicated, he unlocks the bottom-most spanner, then threads the body / sleeve of the shock into the perch. If it were attached, basically I'd just turn the threaded part into the body / sleeve, instead of turning the body / sleeve itself, which is what I did last night. Does that sound right?

I've already tried to pry the shock out. It's not working, but then, both control arms are still in place. I was just hoping that I wouldn't have to remove one to get the shock out. The FSM instructs to remove the upper A arm, but I'm assuming that's because it will be in the way of pulling the coilover assembly out, not because you can't pry the shock out unless the A arm is removed. Guess I better just remove the upper A arm first anyway. And yes I disconnected the brake line and ABS sensor, also per the FSM.
Old 05-13-09, 10:09 PM
  #18  
ERTW

iTrader: (4)
 
rd_turbo's Avatar
 
Join Date: Oct 2004
Location: Mississauga, ON
Posts: 810
Likes: 0
Received 0 Likes on 0 Posts
The problem with aftermarket coilovers is that they come with very short springs and hence reduced travel. The rate is usually much higher than stock, which means that very little compression results in a high preload. Adjusting the spring perch can result in coil binding if the spring is overcompressed by raising the perch or a total loss of preload if the perch is lowered. The length adjuster at the bottom compensates for ride height adjustment which exceeds the available adjustment in the spring.
Old 05-14-09, 12:02 AM
  #19  
needs more track time

iTrader: (16)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 9,188
Received 509 Likes on 350 Posts
Yep. Unbolt the 2 inner upper A arm bolts. you need the space it offers to help pry out the shock bottom.

Like anything else in life, it can be a challenge the first time around until you learn how to do it. People learn in different ways. You are correct about that. Most of us don't always realize that.
Old 05-14-09, 02:02 AM
  #20  
Full Member

Thread Starter
iTrader: (1)
 
RMRanger's Avatar
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by rd_turbo
The problem with aftermarket coilovers is that they come with very short springs and hence reduced travel. The rate is usually much higher than stock, which means that very little compression results in a high preload. Adjusting the spring perch can result in coil binding if the spring is overcompressed by raising the perch or a total loss of preload if the perch is lowered. The length adjuster at the bottom compensates for ride height adjustment which exceeds the available adjustment in the spring.
Aren't most aftermarket coilovers designed to compensate for this reduced travel? (i.e. special valving) Thanks though, that's the answer I was looking for concerning that. I don't know what was so complicated about this to me, had a brain fart I suppose. Unfortunately I'm a bit disappointed in the amount of adjustment available in the rear coilovers. I have them maxed out and it's not much lower than the Eibach lowering springs that were previously on there. If I want to go lower, I'll be forced to lower the springs themselves. This seems to be a limitation of the design of the FD though, not the coilover itself. Thanks for all the help guys!

Side note: In the front, I found it very helpful to drop the sway bar as well as remove the upper a arm bolts. I couldn't tell at first, but the main reason it was stuck is because of the sway bar.
Old 05-14-09, 01:52 PM
  #21  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
yea the trick is to undo the upper a arms for the front and rear. No need to remove anything else than that. If you were to remove the lowers you will be ******* up the camber and will need a true alignment after the fact. You will have plenty of room with the upper loose.

As for the guy saying the correct way to adjust coils is with the spring preload he really needs to stop posting false information. This is how you adjust shitty coils, not a set that has a specific design to adjust the ride height while keeping the spring preload constant.

The first link posted by rx7link has the correct way, you just need to skip through all the arguments about how much spring preload to do. Just read that and you will have no problems.
Old 05-14-09, 02:37 PM
  #22  
needs more track time

iTrader: (16)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 9,188
Received 509 Likes on 350 Posts
Originally Posted by Cgotto6
yea the trick is to undo the upper a arms for the front and rear. No need to remove anything else than that.

I never had to remove or unbolt the rear suspension arms. The shock or coilover slides in with plenty of room in the rear w/o removing anything.
Old 05-14-09, 03:07 PM
  #23  
Old Rotary Dog

 
wrankin's Avatar
 
Join Date: Feb 2003
Location: Durham, NC
Posts: 1,461
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by rd_turbo
The problem with aftermarket coilovers is that they come with very short springs and hence reduced travel. The rate is usually much higher than stock, which means that very little compression results in a high preload. Adjusting the spring perch can result in coil binding if the spring is overcompressed by raising the perch or a total loss of preload if the perch is lowered. The length adjuster at the bottom compensates for ride height adjustment which exceeds the available adjustment in the spring.
Think about it.

Ultimately, the ONLY meaningful thing you adjust on for the spring on a coil over is the distance from the lower mounting point of the shock (assuming a shock-down configuration) to the collar that supports the spring. It defines the ride height of that corner (to some extent, see below) and it defines the where the operational range of the shock stroke will be so you can make sure that you don't bottom/top out your shock.

That's it. There is nothing else. Zero. Zip. Nada.

It is irrelevant how you obtain this setting. Screwing the sleeve in/out at the shock body effectively does the same thing as raising/lowering the spring perch. It changes that distance. I was pointing out that for that specific coil over design where the bottom of the sleeve is threaded into the body (as opposed to sitting on a perch or fixed in place by other means) you probably want to make sure that you have a sufficient amount of thread engagement between the sleeve and the shock body.

All the talk about pre-loading is confusing and unnecessary. The simple fact is that if you "preload" a spring by raising that spring perch (regardless of how you do it) all you are doing is raising that corner which causes more load to be taken up by the springs on that diagonal (front and opposite rear) and correspondingly you are *decreasing* the spring load on the other diagonal (both front and rear). If you then go the other side and preload *that* spring (ie say you were setting up the two fronts), you increase the load on that diagonal and you *decrease* the spring load on the one you were just at!

Effectively all you have done is raise the ride height of the car.

The "proper" balance on the car is determined by its corner weights and is obtained by adjusting the perches so that the weight on each tire (which is directly proportional to the spring load) is such that the two diagonal weights are equal (ie. LF+RR = RF+LR). And guess what? The optimal corner weight numbers are determined almost completely by the wheel base and track and location of the center of gravity of the car, not the spring heights nor their *stiffness*.

If the spring is binding, then there is no way you can "adjust it out" without screwing up your corner weighting. Any decrease in the load on one spring causes a corresponding increase in the load on the springs on the other diagonal. Because the ideal/optimum corner weights are independent of spring height or stiffness you cannot prevent a spring from binding by raising or lowering the collar. If your spring is binding you must either a) get a longer spring, b) get a stiffer spring, or c) get a spring with a different design (like a barrel spring) that doesn't bind as easily for the same length and stiffness.

If the shocks are reaching the limits of their travel, then you have your ride height set wrong and you will need to increase or decrease it to prevent that situation. Note you are not changing the load on the springs (since you need to adjust both side equally to maintain corner weighting), you are just chaging the range of motion that the shock operates at. If you can't do this successfully, then your shocks and springs are mismatched and you need to change one or the other.


If anyone sees something wrong with what I have said, let me know.

-b
Old 05-14-09, 03:53 PM
  #24  
Talk to me....

iTrader: (2)
 
Uncle Hungry's Avatar
 
Join Date: Sep 2007
Location: 600' up
Posts: 1,057
Received 51 Likes on 35 Posts
If I just read your post correctly Wranklin, which I may not have, I believe you are wrong. Changing the ride night by adjusting the lower "shock body" does not reduce the shock travel where lowering via the spring perch does, plain and simple. Unless I just misunderstood your post.
Old 05-14-09, 04:14 PM
  #25  
Rotary Freak

iTrader: (8)
 
Cgotto6's Avatar
 
Join Date: Nov 2003
Location: Bothell, Washington
Posts: 1,893
Received 2 Likes on 2 Posts
Exactly. I believe wanklin is wrong in part of his thinking. He is spot on in the concepts of corner weighting and the effects of raising and lowering each wheel and its effects on the other wheels. The problem I have is how you are suggesting to achieve the change in ride height. There is a reason that manufactures offer a nicer/more expensive/more feature sets of coilovers, and one of the biggest differences between an entry set of coils and a step or two up is being able to adjust ride height seperate of spring preload. And yes there are many benefits of being able to adjust these seperate.

Why do you keep telling him to adjust the ride height of the car by using the spring preload lock nuts when the manufacture has provided him with a seperate means of adjusting the overall length of the coilover without effecting the preload or the range of movement of the shock?

Edit: I just went looking around Tein's website and found some pretty useful info. The way I interpret what it says is that there are actually two ways to adjust the height of the car, and both ways are considered proper. It looks as if Wanklin and I are both correct. Have a read here: http://www.tein.com/products/features.html#RideHeight


Quick Reply: Stupid noob question about FD coilovers



All times are GMT -5. The time now is 02:54 PM.