Hi Guys,

Is it possible to use Koni 8611 Double Adjustable Strut Insert in the 93-95 RX-7?
In combination with Ground Control Kit perhaps.


Perhaps this shows better what I meant to do: http://www.msprotege.com/forum/showt...hp?t=123651640

Thanks

 

Considering that the FD does not use a McPherson strut type front suspension, why would you want to?

-bill

 

Well, make a coil over for it.

The strut/shock insert is just an insert, the method done in second link is to cut the shock, remove internals, secure the insert, and put on the GC kit.

Thus we end up with a coil over right?

Maybe I misunderstood what you mean.

 

8611 Koni DA Insert


With stock housing:


Add this GC Kit:


And finally looks like this; a Coilover Kit with easily change insert and varierty of spring rate:

 

so......where does the other control arm bolt to?

 

The only problem would b for the rears. Koni 8611 is adj on top and at the bottom , one for rebound, and one for compression. So the bottom of the rears is a mounting piont

 

FDs do not use struts. They do not have "strut housings" or "inserts".

 

My point exactly (in the second post) - and the pictures shown appear to be an FC. Also looking at the pics, I think I would want more support for that GC collar than just that little tab on the side of the housing.

So what is the point of all this??!!

 

once again.....

 

People do fabricate housings for these 8611, especially since they might not fit every car that uses inserts. Check out these ones someone fabricated
http://www.nissanperformancemag.com/...project_racer/

 

the point everyone's trying to make is.....

FD's don't have struts anywhere in their suspension!

 

Ive installed coilovers on some people's car's. I'm a little confused now. What is your definition of a strut? What do you mean?

 

strut and shocks are the same they are dampeners

the 8611 is called strut insert, because most of car with mcpherson suspension has strut with replaceable inserts.

But, if you engineer this right, the strut insert is basically a shock which you can put in any housing. In this case, I want to put it in FD shock housing.

This is thinking out of the box. In this case the box is the word "strut".

 

the bottom adjustment is for compression. and top is for rebound.
I think the rear actually will be accessible top and bottom, but front would be difficult since FD uses bushing at the bottom and its closed end model.
The rear can be open but there is the arm in the way.

So most likely its double adjustable with having to remove the unit to adjust the compression....

Any thoughts how we can make this for FD? Sounds like a cheaper and better coilover solution:
- cheaper $300/corner replacement. Broke a corner, you only need to buy the insert, not need to have the whole unit replaced.
- good, fast, local/domestic support for revalving/rebuilding - Koni USA, truechoice, ground control, ankeny, and many more.
- good experience with the shock, people uses them for road race, autocross, rally, and those who rebuild above knows what to revalve them to for the purpose.

 

Amen. Just because your suspension is labeled "multi-link" it does not mean you dont have a strut. In my book, a "strut" is a damper that goes together with a spring. A damper by itself is a "shock".

I really dont know why you guys are saying it doesnt use struts. You almost made me think it uses "leaf springs", but even those still use shocks or some sort of damper.

Inserts are common for many cars. Koni offers very high quality dampers for many cars. And almost all of them are inserts.

ANyways, Sorry , i forgot which side had the closed bottom, its been a while since my last install . So if you used a 8611, you would have to take out the insert to adjust the bottom setting. I forgot if the bottom adjsutment is for compression or rebound. Or you could find a way to adjust it without taking out the strut.

I think Koni has a 8610 shock that is a lot cheaper and has jsut one adjustment at the top. Those are nice, but not as nice

 

http://www.ground-control-store.com/...hp/II=42/CA=23
http://www.racingbeat.com/resultset....rtNumber=14365

Get Koni to revalve the shocks to the springs that you'll order from Ground Control, add the compression adjuster and dyno match at both 3 in/sec and 10 in/sec.

Or you can just call Koni and ask them to build a custom shock with the valving to your specs, with both the compression and rebuilt adjusters, with fitment exactly matching the FD shock size specifications.

It's about the same process for my FC, but since I bought the street strut inserts earlier, I'm sending them in to get revalved and having the second adjuster added on. Makes me think I should've just bought the Koni Reds instead of the Yellows, would've been cheaper that way.

On the flip side, you could always go with Bilstein's as well, they offer custom shock service from the factory.

There's a reason why there are two words, struts and shocks. If they were the same, we wouldn't call them two different things. Even though a lot of people use the two interchangeably, they're not the same thing. If you were to call Koni and ask them for strut inserts for your double wishbone suspension, they'd be a little confused at first.

Wikipedia is your friend. =P

 

THE definition of a strut, to be specific a MacPherson Strut (named after the Ford engineer who invented it) in the front and Chapman Strut (named after Colin Chapman, yes the Lotus guy) is a damper that also serves to locate the suspension.

The front of pre-'92 RX-7s, all other earlier RX-cars, and five bazillion other designs use MacPherson struts.

FDs, Miatas, RX-8s, and a bunch of other cars do not, they have upper and lower control arms and the shock only serves to do damping and hold the spring.

Chapman struts aren't a concern for us, but to be complete, they are found in *most* front wheel drives with independent suspension, as well as MR2s, Datsun Z-cars (not ZX), Imprezas...

Take the strut out and the wheel flops around with nothing to hold it in alignment. It's a locating member.

 

okay...so strut insert is a shock correct?

Anyway, so can we have a housing for this shock to give us double adjustable coilover suspension setup?

 

What about length? The FD shocks are pretty short, are they not?

I understand what you are saying, but you need to bear in mind, struts generally work at a motion ratio to close to 1:1 with wheel travel that you may as well call it 1:1 fot general purposes. FDs do not have a 1:1 linkage ratio, they pick up the shocks on the control arm, so they lose leverage. This means that a damper in an FD will move less for a given wheel travel, so the springs need to be stiffer for a given wheel rate, and thus the shock also needs to be stiffer for a given wheel rate. What works great on a lightweight strut-equipped car would probably suck on a heavier car with a control-arm suspension, or at a bare minimum not have the same damping.

 

Why not just have Koni make double adjustable coil over shocks with the correct valving?
As peejay says, the strut cartridge and a plan old coil-over shock are going to have different valving for a bunch of different reasons. Even the angle the damper is to the suspension movement is taken into account for springs and damping.

I'm sure you could make some kind of housing, get Koni to make REALLY short insert and put it on your car but why when you can just buy a coilover shock?

And lets all remember one thing: Dampening is getting something wet, damping is what a shock does.

 

Im curious how much R and D companies like TEIN, and other coilover companies put into making their coilovers? How does this compare with koni 8611 or a 8610?

 

peejay,

I don't quite understand what you mean by the ratio.
FD suspension travel is very little that I know, maybe 2 inch max between loaded to unloaded. Uhm..this is on a coilover system already.

 

The "ratio" is the amount of shock travel compared to the amount of wheel travel.

In a McPherson Strut type suspension, you get almost a full inch of damper compression for every inch of wheel travel. So you have close to a 1:1 ratio.

The geometry of unequal length arms where the damper mounting points tend to be further inboard results in less damper and spring compression for a given amount of wheel travel. So you may (for example) only get 1/2" of compression for every inch of wheel travel (a 1:2 ratio). You would thus need twice the spring stiffness and twice the damping force to get the same suspension response.

Strut inserts meant for a 1:1 ratio probably do not have sufficient damping capacity for use in this application.

This is basic suspension stuff. If you don't understand it, then you really shouldn't be trying to engineer your own solution.

-bill

 

FD is about 0.7:1

Did everyone miss my post a few posts ago on how to do it for the FD? It's not that hard, if you have the money. It's completely written up already!

I even listed which parts to buy. It may not be an 8611 but it's functionally identical to one. (Independent compression and rebound adjusters + custom valving to match custom coil-over springs from Eibach Race Springs/Ground Control)

I don't trust Japanese brands for one reason alone: hearsay. It's a horrible reason to dis-trust them, but I'm not fond of non-independent adjusters that adjust both compression and rebound at the same time, i.e. lockstep.

For further reading (even though the subject matter is autox, it can also apply to road racing), please read http://farnorthracing.com/autocross_secrets6.html

It's a page on which shocks the author thinks is good, and which shocks, in his word, are "crap."

Here are the cost estimates for the FC setup, I think the FD setup may be quite similar.

Koni Struts: $680
Revalve plus add compression adjuster: $1600
Ground Control Coilover Kit w/ Eibach Race Springs (these are linear, unlike the Eibach pro-kit, which I believe are progressive and crap for hard track driving): $409
Ground Control Camber/Caster Plate: $299

Total: ~$3K

I think high-end Japanese coil-overs cost $4k?

If you have even more money, you can look to see if Ohlins, Penske, Moton, or JRZ have fitment with their independent triple or quadruple adjustable shocks. (independent high and low speed compression and rebound adjustment). But I think this is like $10k or $10k a corner? Something ridiculous.

 

koni probably sells the "8611" insert with the bushings/brackets to fit the fd.

http://www.3rdgenrx7.com/images/koni.jpg