Ground Control faq/video/picture/ideas thread
 

Ground Control Suspension Systems, also know as "GC" has been building a lot of parts for the FT-86 / BRZ / FR-S.

I wanted to start a thread, and hopefully we will be posting answers from the most frequently asked questions, from the phone, from forums and from Facebook.

Actually, we probably can't answer THE most common question "What spring rate should I get?". This would be like asking somebody what color your car should be. We just finalize spring rates after personal communication, like picking out the paint of your car AFTER you see the colors.

I am attaching one of our prototype videos, a work in progress, but pretty cool and 100% FT86 content.



[ame="http://www.youtube.com/watch?v=6Me6EiSG1_k&list=FLNkhTfxMuIUu5EBdg9etUhg& feature=mh_lolz"]FT86 prototype video.wmv - YouTube[/ame]



A few guys will be posting in this thread, but my name is Jay and I am the guy who tests everything.

Not really on topic, but want to trade jobs Jay? :D

Looks like a solid product, it's on my list if I go with coilovers over just springs.

Can't wait to see mine custom painted and blue anno...

1. Does the system allow you to return to stock ride height?
2. How much did you lower the car in the video above? It looks like it doesn't have a lot of travel but it's hard for me to tell.
3. Does your system maintain the same travel as the car is lowered? Or do you lose travel as you lower the car?

Cheers.

I've been waiting for you guys!

I'm still waiting for someone to make a high-end, height adjustable shock body that works with OEM springs.

I think that Ground Control is in the best position to create something to work with the OEM dampers in conjunction with Inserts.

All the autocross guys will shit over this, remain in stock class while getting the ability to corner balance your car, NOM NOM NOM.


in the case of the BRZ/FRS You can perhaps make a sleeve kit for the REAR shocks to work in conjunction with OEM springs, that way at least there will be some adjustment in the rear so you can play around with cross weights, since it's a straight dampers with no strut element (hence no directional limitations) I think it would be relatively easy to just create the right cup.

Thanks! These are PERFECT questions.

What makes a perfect question?

You have asked things, that just seem second nature from being around it all the time, so we would easily overlook how fundamental and basic your questions are.

An important question is one that we would have overlooked.

GC is closed today, but I will call some of the guys and try to answer you tonght or tomorrow. I know the answers, but I want to give you the --exact--answers.

How difficult is it to remove the front spring seat?
Planning to get your kit, had it on a Miata, it was great.

If i order later on can i get it in blue still?

You can't change ride height in stock class.

In stock class the lower perch has to be in the same relative position as a stock strut/shock assembly. It's checked by measuring from the mounting holes on the strut/shock to the upper part of the lower spring perch. So if you made the strut body shorter/longer you'd have to move the perch to compensate.

The only way I've seen guys lower ride height in stock is use degassed shocks (some Konis come that way) which can impact the ride height maybe 1/2".

link? was not aware.

jma, The rear spring seat is just pressed on. A couple lite whacks with a rubber/dead mallet and the lower spring seat falls off. The front spring seat stays attached to the factory strut. Our threaded tube then sits on the perch.

There are basically four kits for this car. Race, street, show and stock conversion.

The street kit is designed to always be able to put the car back up to stock height, as is the coilover conversion for the stock struts.

The race kit, not usually, depends on the spring rates. (because different rates will sag different amounts)

The show kit is designed for people who never want to go back up to stock height.



In the video, that car is about 55mm lower than stock.

In the video, that is the same travel as a STOCK BRZ. I will put the video of stock suspension up soon.



Tricky question. We don't use a generic threaded strut, so the travel is designed for each car.

The answer is No, and the reason is that we are trying to have the suspension bottom out before the tires. Conversely, the kit DOES add travel as you raise the car, which telescopic struts cannot do. This gives the best ride in the most settings.



You must lose travel as you lower the car. If not, two things will happen: the tires will hit (albeit very rare on FT86) or the suspension will be too soft until whatever bit stops moving over a bump, which gives a bad ride.

This would be like jumping off a building, landing on a giant soft pillow, and then the pillow is so soft you hit the pavement.

Yes, in the next batch. Usually once a month or so, or you can have your own batch. Lots of people do that. Green, pink, black, orange, we have done all kinds of colors

I see that there is only an option to make the front suspension double adjustable. Why isn't there an option to make the rear double adjustable as well? Will there ever be an option to have a double adjustable rear?

Technically speaking, if there is room for the wheel up in the arch and an appropriate roll center adjuster is used, is there any reason you can't have as much or more bump travel as stock but at a lower ride height?

I thought that the main issue with too soft a suspension at a lower ride height was twofold, with the first issue being hitting the bumpstops (lack of sufficient travel for the spring rate chosen) and geometry, e.g. once lowered without a roll center adjuster, the "healthy" portion of the camber curve is smaller, and in some cases non existent because the lowering has gone past the limits of the stock suspension geometry.

I saw a race e30 m3 in which they cut and moved all of the suspension mounting points up further into the chassis to lower the car while maintaining stock travel and geometry. Obviously the majority of us aren't going to go cutting out shock towers up and extending them but I don't see any reason why we can't maintain a good amount of bump travel at a lower ride height with a properly setup system.

Now, in reality, the amount of bump travel used by a stiffer suspension is reduced just by the fact that the springs are stiffer and it takes more to compress them to the same extent, but that doesn't mean it isn't good to have good margins still. :)

Nathan

Definitely yes, the double adjust rear are just not ready yet.

Haha!

It's in the Solo2 rulebook for the last decade or so I think... You can find it online just google for 2012 Solo Rulebook.

13.5

3. Adjustable spring perches are allowed, but the spring loadbearing

surface must be in the same location relative to the shock mounting

points as on

i assume you're refering to this? see

Moved from another thread to here:

If i got the coilover conversion now could i add Bilstein's later or would it be better to wait and do it at the same time?

Because Bilstein has not released anything in regards to your car I can't say if our current coilover kit would work with them. If your firm on using Bilsteins with the GC coilover kit I would wait for right now.

I'm not set on bilsteins but would prefer to not use the Koni inserts. I want to keep a factory style upper mount, no camber plates or I would just get your whole kit.

You can use koni inserts with stock tophats IIRC.

Yeah I just don't want inserts I'd prefer a full replacement.

Thanks for moving this, any answers??

Joe, we also offer a "Street System" for your car that reuses your factory strut/shock mounts. This will include front GC Black strut housings w/Koni (single adjustable only) inserts, GC coilover hardware, Eibach springs, and Koni single adjustable rear shocks. This system is $1349.

I'll be posting some pics in the next couple of days.

Any questions about this call,email, or PM me

Adam

Thanks Adam that sounds really good for me, can't do anything right now but can't wait to see the pics.

I will quote from the very first post in this thread, and then explain.


I understand that it may appear that the words "touring. aggressive" etc. would mean a specific spring rate and length. Those words are simply descriptions of what type of suspension you get, including dampers and bumpstops.

Ground Control does not have any kits in a box. So if you order a suspension, we don't just go to the fax machine and drop ship a box to your house.

In fact, if you specify "aggressive" for example, we still don't have a box to send to you. These words are, let's say, categories of what type of suspension we would build for you.

So, one might think that asking about "touring, aggressive, race" springs, we would only have to develop 6 combinations of spring rates and dampers to answer that question. That would only be only scratching the surface...... Ground Control has a huge inventory of springs, and they are combined to be the best result for each customer, rather than the easiest result for Ground Control to have in a box.

The obvious variations would be based on your address, and any other comments or wishes you may have about your car.

Its basically the most custom kit I could find, so I bought it! I am starting out with their recommended rates. I have a plan to try a stiffer equal rate setup at the track but suspect its gonna be firm for off track use.

The coils are like $60 each, so its pretty cheap to get a stiffer set, and if you have them valve you with dual adjustables, you should have plenty of adjustment so long as your 2nd set of coils are just marginally stiffer. if I need anything revalved shock wise, they are right there and ready to work with me. Wasnt able to find that from any other vendor-abilty to custom order and spec coils and valving.

The costs just seal the deal like icing on a cake, the customer service is stellar and each order is a custom order. Tough to beat, so long as you dont mind waiting for them to build your order- takes a few weeks.

I own Bilsteins and I own Konis in my garage already. I cant see any good reason to hold out to see what they come up with. I think what the GC setup comes matched with will be plenty good, and likely come in at a lesser cost from my experience with Bilsteins. They look a little prettier, the bilstiens, but that have had their share of finish corrosion issues, so going by the cover of that book is not a way to choose. Internally, I do think youre dealing with six of half dozen there, both top notch construction. The uber stout welds on the GC sold me. The RSM is beefy. The bar is alum, and way cool, and those camber plates are thick like a prime rib steak. Thats bad assed.

Gem, the only reason it took a few weeks for your system is at the time you placed your order we where waiting for a new batch of aluminum to show up which included your blue parts. We now have everything in stock and are shipping complete systems within 7 working days and camberplates within 2 working days.

Adam

i need money.
coilover kit sounds awesome.

They have some even cooler stuff for us street only guys coming too, I am pretty sure I've found my suspension also.

I ordered this strut tower bar and camber plates from my local shop yesterday.
Looking forward to it

Gregg

what color did you get-curious?

got it in Pewter. I needed about 1 more degree of camber for my track setup.

Street GC questions
 

This is an excellent question.

What I believe the original poster is asking, is "How hard is the car to steer without a bearing".

Well, to explain: Every Ground Control camber/caster plate HAS a steering bearing, but this is not necessarily true of all camber plates.

The confusion arises from that fact that the GC RACE camber/caster plates have TWO bearings, and the Street have a bushing and a steering bearing.

So, when we say the street camber/caster plates don't have a bearing, we really mean that we made a whole separate strut mount with a bushing, but the steering bearing is still there. (That's why this is such a good question)

And now to finally answer the question:
The steering is exactly the same as the race and the same as stock FT86. There is a bit of ride flex, intentionally, to allow for noise isolation from brakes, wheel bearings swaybar links etc.

I have attached a video of the testing, to show the minimal, yet necessary flex, for NVH reduction. (Ground Control does not believe in making "One size fits all camber plates")

http://www.youtube.com/watch?v=Tlo6dIyhPUQ&feature=youtu.be

http://youtu.be/Tlo6dIyhPUQ

Continued
 

From this thread:

http://www.ft86club.com/forums/showp...8&postcount=20

GC has been fortunate to be able to do extensive testing, because we had Koni build special strut inserts in Holland, and they are already here. We did not have to wait for anything to arrive in February or March.

Attached below are 4 different FT86 struts, including Koni race and Koni SPGC custom valving. Any one these four pairs of damping could be chosen by you (or for you).

(four pairs, each plot is a max and min of each damper, so 8 graphs total.)

Also attached is a picture of one of the custom valved GC strut inserts. As you can see, it is not a regular off the shelf Koni strut.

Differences between Street and Track / School / Race suspensions.
 

The street suspension uses, compared to track:

Longer stroke front strut with street damping.

Street camber/caster plate (still top mount)

Softer rear shocks, top adjustable Koni, using the billet mounts.

Of courses four different springs.

And the least obvious of all, less camber built into the GC housings, so that a low street car can be adjusted to zero camber if desired.

The "race" suspension is completely custom made, and any or all these above , including strut length, can be changed (or not, whatever makes the car faster)

Any other questions, please post here.