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I've had my car for a few years and it came to me with Tein Flex coilovers installed. I've replaced bushings and pillow ***** but I've never been happy with how the car felt. However, I'd never owned an FD prior to this one so I wasn't familiar with how the car SHOULD feel. For reference, my car has about 52k miles on it and is in great shape. Long story short, it took installing adjustable extended travel coil overs on my truck to make me realize how things like pre-load really transform the feel of the vehicle.
So I'm wanting to get some help regarding how I should setup my current Tein Flex coilovers. I believe they are in good shape (probably 30k miles on them?) but they are set too low and or the pre-load is too high. I suspect this for the following reasons...
The ride is simply punishing.
Car doesn't feel confident over anything but completely smooth ground.
Suspension operates in sort of an "on or off" fashion. No travel.
I drive the car a lot but I wouldn't say it's my daily. I have a Toyota Tacoma for that. That being said, I will be planning to track the car a good bit. I'm actually going to the track this weekend and I want it to perform.
Any insights into how to start with a "baseline" setting would be awesome. I fully expect to have to start from the baseline and then fine tune them but I'm just not sure where to start.
Don't have Tein's but i'll throw this out there. Do you know your spring rates and what did you replace your bushings with? And when you tightened up your suspension after replacing the bushings, did you tighten when the suspension was compressed? Reason I ask is that if you tighten with the body jacked and the suspension uncompressed, you could bind the bushings (I managed to bind one side even though I tried to compress the suspension as best I could)
Good questions. I used the PowerFlex bushings. Haven't done the front yet but I intend to get to it in the next few months. I don't think anything is binding since it's felt this way before I did the bushings and because the front is where I think a fair amount of the adjustment needs to be.
Not sure on the spring rates but I can check. Will that be on the springs themselves?
Not sure on the spring rates but I can check. Will that be on the springs themselves?
It should be unless worn off. My guess is they are stiff (10k or over). And if there is NO travel, your suspension is bound. With the car up on jacks, you can check travel (first does it come down when you jack up the car and second, can you compress the suspension with a jack).
Good questions. I used the PowerFlex bushings. Haven't done the front yet
This is part of your problem right here.
The only bushings you can replace in the rear with poly single axis bushings and have the rear suspension work correctly on the FD are the rear upper a-arm inboard bushings and the rear lower shock mount bushing (if done at the same time- not with stock sliding bushings).
If you replace the stock spherical bearing in the toe adjuster links with bushings the rear suspension will bind and rear traction will suffer.
If you replace the stock spherical bearing in the rear lower arm (inboard location) the rear suspension will bind and rear traction will suffer.
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The company should not sell these bushings they are doing the FD RX-7 community a disservice.
Do you have the older Tein Flex or the newer Street Flex version? The Street Flex ride far better. What is your ride height where are your adjustments?
Last edited by IRPerformance; 10-05-16 at 02:52 PM.
And if there is NO travel, your suspension is bound.
I suppose that was a bit of an exaggeration. There is travel but it doesn't seem to be sufficient or progressive enough. For example, I rode in my friend's Porsche Cayman and it's handling is fantastic. However, the suspension seems way softer and easier to cope with over bumps and road imperfections. When the car hits a bump it doesn't totally upset the balance of the car. It's sort of taken in stride. Does that explanation make sense?
Originally Posted by BLUE TII
ItalynStylion
Good questions. I used the PowerFlex bushings. Haven't done the front yet
This is part of your problem right here.
The only bushings you can replace in the rear with poly single axis bushings and have the rear suspension work correctly on the FD are the rear upper a-arm inboard bushings and the rear lower shock mount bushing (if done at the same time- not with stock sliding bushings).
If you replace the stock spherical bearing in the toe adjuster links with bushings the rear suspension will bind and rear traction will suffer.
If you replace the stock spherical bearing in the rear lower arm (inboard location) the rear suspension will bind and rear traction will suffer.
Very interesting. I wasn't aware that certain bushings shouldn't be replaced with poly. This is news to me. Can anyone else confirm this? For the rear lower arm inboard location, the spherical bearing you're referring to, is that the pillow ball mounts? Example pictured below (not mine).
Also, I'm using the Rotary Performance toe arms pictured below (actually my picture) with the sort of "ball end" joints on either end. Is that ok?
This is news to me too. Looking at the '93 Service Highlights, pgs R14-R16, it looks like the lower I-arm has pillow ***** throughout (including the bushing at the subframe). The pillows allow movement in two planes, whereas poly only allows movement in one (up and down). If pillow ***** are replaced with poly, it will limit movement.
That said, I don't think there is much lateral movement to the I-arm where it connects to the sub-frame. I replaced this bushing with poly and it does not seem to bind
I suppose that was a bit of an exaggeration. There is travel but it doesn't seem to be sufficient or progressive enough. For example, I rode in my friend's Porsche Cayman and it's handling is fantastic. However, the suspension seems way softer and easier to cope with over bumps and road imperfections. When the car hits a bump it doesn't totally upset the balance of the car. It's sort of taken in stride. Does that explanation make sense?
You could check binding by loosening the suspension bolts and see if there is any change in travel. My guess it's more your coilovers vice bushings, but they are certainly contributing factors. Poly is stiffer than stock and will transmit more road vibrations.
As Ihor mentioned, ride height can affect travel as well
One more thought is the condition of the shocks. How many miles on them?
You could check binding by loosening the suspension bolts and see if there is any change in travel. My guess it's more your coilovers vice bushings, but they are certainly contributing factors. Poly is stiffer than stock and will transmit more road vibrations.
As Ihor mentioned, ride height can affect travel as well
One more thought is the condition of the shocks. How many miles on them?
When I get home (out of town on business right now) I plan to remove the coil completely and check the movement/articulation of the suspension without the shock loading it up. That way I can easily see if there's any binding. I don't suspect there is but I'll certainly check.
I think the shocks have about 30k miles on them. The whole car only has 52k on it.
Here's what I suspect is REALLY going on. I think the pre-load on the spring is quite high and the right height is somewhat low. I'm thinking if I can reduce the pre-load and "raise" the setting on the coil it may actually sit at nearly the same height but have a more progressive load/unload characteristic.
Is my logic sound on that?
Originally Posted by IRperformance
Do you have the older Tein Flex or the newer Street Flex version? The Street Flex ride far better. What is your ride height where are your adjustments?
I don't know the answer to that (since I didn't purchase them originally) so I'll have to check when I get home. I'll also check the adjustments and settings and post pictures.
The toe links are where poly really binds up the FD ad you have spherical bearings so you are fine.
The rear lower arm inboard at the subframe should be spherical bearing (like stock rubber bushed one), but won't bind as badly as the toe links (gentler arc into the 2nd axis from the long longitudinal link attached).
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Yeah, sounds like you just need to take any preload out of the coilovers and get it raised back up to ~25- 25.5" at the fender arches.
Also, set your damping soft and work up to where it isn't "bouncy" or bottoming any more. Too harsh damping will worsen traction over rough pavement.
Too soft damping can hurt traction too, but probably only that soft on blown coilovers.
What is your wheel/tire combo?
I have had some tires/fitment that just sucked over rough pavement too. Like too stiff a sidewall on a too low grip if a tire.
What is your wheel/tire combo?
I have had some tires/fitment that just sucked over rough pavement too. Like too stiff a sidewall on a too low grip if a tire.
Old school Antera 17" wheels with Continental Extreme Contact DW tires. Fronts I think are 235 and rears are 275.
Spring rates should be 10/8 if they weren't changed by the previous owner. I have recently installed a set of Tein flex on my fd and I have to say it completely transformed my car. Everything else suspension wise on the car is stock. It acts like the cayman you mentioned, bumps don't seem to phase it too much. MUCH BETTER than the Apexi N1s I had with 12/12kg.
Spring rates should be 10/8 if they weren't changed by the previous owner. I have recently installed a set of Tein flex on my fd and I have to say it completely transformed my car. Everything else suspension wise on the car is stock. It acts like the cayman you mentioned, bumps don't seem to phase it too much. MUCH BETTER than the Apexi N1s I had with 12/12kg.
What is your ride height set at and where is your preload? Stock settings or no? Do you think you could take a picture of your settings for front/rear? If not that's ok, I understand it may be tough to get.
You have separately adjustable pre-load and ride height, right? If so, set preload to the bare minimum to hold the spring, like 1-2mm. Any preload is unnecessarily reducing bump travel.
Luckly the rear shock is pretty easy to disconnect to play around with things. My car has freshish pillow *****, tow links, trailing arms, and Ohlins with 9k springs in the back. May be a good reference in North Dallas area.
What track are you headed to? I'm going to Cresson weekend 15th.
Luckly the rear shock is pretty easy to disconnect to play around with things. My car has freshish pillow *****, tow links, trailing arms, and Ohlins with 9k springs in the back. May be a good reference in North Dallas area.
What track are you headed to? I'm going to Cresson weekend 15th.
Would love to get a quick ride in your car if you're willing to meet up. Happy to give you some seat time in mine too. Mine has fresh pillow ***** and toe links too. So that will help narrow things down to the coilovers themselves.
pre-load centers the bump/droop measurements. it depends on spring rates and total travel of the shock.
spring rates determine how well the ride is along with damping.
That said,
8/6 KG spring rates front/rear I like a lot. pre-load is I think .25" or .5" front and .75" rear for mine.
pre-load will give you a little better traction over bumpy sections, softer rates have more mechanical grip at loss of some handling. sways will gain it back but still lose overall grip.
I like 7-9KG front and 5-7kg rear spring rates for the street. you can go higher on autox type stuff as a premium is needed on handling over grip. high speed bumpy roads like soft rate springs.
I like wide wheels with grippy tires on the front and rear.
I'm running their Street Flex with 8k/6k Swift spring, I set the bump/droop to about 65/35 and it is very comfortable on the street. I agree with lOOkatme about the softer spring, the original 10k/8k spring was a little stiff on bumpy road.
As far as pre-load it depends on spring rate and total shock travel, 8k rear didn't need much pre-load, but 6k rear definitely need pre-load or I'll be sitting at 80/20 bump/droop and the car will ride like crap lol.
up until a few years ago i had both a Longacre Digital Spring Rater and a shock dyno.
added to 22 years of SCCA Natl racing in competitive GT3. for the Nat'l Championship.
suspension design and setup is my strong suit.
preload is just raising the spring rate.
linear springs are.... linear.
that means if a spring has a rating of 8 KG per MM/449 pounds per inch
at one inch compression it will have a rate of 449.
at two inches of compression:
898 pounds/16 KG/MM
at three inches of compression:
1347 pounds/24 KG
as you add preload you are simply compressing the spring and raising the rate.
the FD has a road racing chassis dynamic.
one of the key features is camber gain in bump. this means that the dynamic change in camber compensates for chassis roll in a corner.
the roll process communicates w the driver allowing him to drive very close to the limit without putting it in the armco.
most other "sportscars" lose grip w roll due to an inferior camber curve.
as to coil overs needing rebuilding at 30,000 miles. might be. i logged
over 50,000 on my Tein RSRs and they remained perfect on my shock dyno.
i have dynoed over 30 OE shocks ranging from units w 3000 miles to over 100,000 miles and without exception they all dyno'd exactly the same. no degradation as long as they did not have a hydraulic leak.
while coil overs differ a bit as to shock settings i like about 6 from full soft front and 3 from full soft rear for most Tein systems for aggressive street.
i still maintain that a $200+ set of Eibach Pro Kit shocks w the stock shocks is totally awesome for many apps. rate is up 33% at 350/255. the springs set the car at a really nice ride height.
camber needs to be reset with any change in ride height.
up until a few years ago i had both a Longacre Digital Spring Rater and a shock dyno.
added to 22 years of SCCA Natl racing in competitive GT3. for the Nat'l Championship.
suspension design and setup is my strong suit.
preload is just raising the spring rate.
linear springs are.... linear.
that means if a spring has a rating of 8 KG per MM/449 pounds per inch
at one inch compression it will have a rate of 449.
at two inches of compression:
898 pounds/16 KG/MM
at three inches of compression:
1347 pounds/24 KG
as you add preload you are simply compressing the spring and raising the rate.
the FD has a road racing chassis dynamic.
one of the key features is camber gain in bump. this means that the dynamic change in camber compensates for chassis roll in a corner.
the roll process communicates w the driver allowing him to drive very close to the limit without putting it in the armco.
most other "sportscars" lose grip w roll due to an inferior camber curve.
as to coil overs needing rebuilding at 30,000 miles. might be. i logged
over 50,000 on my Tein RSRs and they remained perfect on my shock dyno.
i have dynoed over 30 OE shocks ranging from units w 3000 miles to over 100,000 miles and without exception they all dyno'd exactly the same. no degradation as long as they did not have a hydraulic leak.
while coil overs differ a bit as to shock settings i like about 6 from full soft front and 3 from full soft rear for most Tein systems for aggressive street.
i still maintain that a $200+ set of Eibach Pro Kit shocks w the stock shocks is totally awesome for many apps. rate is up 33% at 350/255. the springs set the car at a really nice ride height.
camber needs to be reset with any change in ride height.
set tire at 30 front 27 rear cold.
Howard
pre-loading the spring does not raise the spring rate. All it does is change your bump and droop.
If you add .75" of pre-load and put the car down on the ground, the spring compresses .75" less than it would with no pre-load. But the spring still compresses the same with pre-load vrs. no pre-load.
so if you have 600lbs on one corner, spring rate of 300lbs/in, no pre-load the spring compresses 2 inches, with 1" preload the spring compresses 1" with 600lbs, but overall both springs are still compressed 2". One just sits 1" higher than the other changing your droop/bump ratio.
i just recently sold my twin flex z, they were too smooth and comfy lol for my liking haha lol... i think your preload is set up wrong it makes a big difference.
with that being said if the pre owner had the preload set wrong and ride height that low.. 30k mile the shocks is probably in for a rebuild.
i just finished installed a set of custom stance coilover revalved for the rx7, ordered them from autornd from rishie, took me about 1 week to get. they have helper spring in the back revolved for longer stroke in the rear and you can pick whatever spring rate you want.
I'm waiting for the rest of the car to be put back together so i can give it a test drive.
The only company that makes bushings correct IMO is superpro. they angle the bushings so they do not contact suspension pieces. you get free movement of the suspension in the directions that should have free movement.
10-05-16, 11:13 AM
