eage8

iTrader: (9)

Yes. but you'll still need much stiffer springs and roll bars to race the car, this just helps.

camber recovery = the ability of the suspension to recover the camber lost when the body rolls.

Drifting rex

iTrader: (17)

Ahhh ok because as the body rolls even if the suspension travel is completely camber neutral (made that up) it will becaome positive from the body roll?

j9fd3s

iTrader: (3)

the body rolls because its the opposite of the tires force. or maybe its simpler to say it rolls from the centrifugal force.

a "camber neutral" car (i've never heard the term either!) sounds like if you set the camber to zero when the car is at rest, and then rolled the car 3-4 degrees, it would still be at zero camber.

i haven't tried that with the FC, but its close, what you actually want is 0 camber going down the road, and then the suspension to gain camber as you corner, so going straight its 0 and then in a turn its -3 or whatever.

the tire will have maximum grip with some negative camber, how much camber depends on the tire.

Josh18_2k

iTrader: (3)

If you were driving on a glass road, yes, but that's not the real world. High roll centers (IE majority of load transfer goes through susp. members) handle like crap with road disturbances. They also causes jacking, which raises the CG, increasing load transfer. The world is full of compromises!

1-2" above ground in front is typical, a little more in rear.

88rx7racer

eager8, I haven't actually checked the alignment settings on my car yet (newer to FC RX7s and I'm just now tthinking of suspension upgrades, not new to suspension geometry/racing) but the FSM for the S5 cars shows ~4.7 degrees caster. I would assume it would be the same for S4 cars as well.

Are you running the AWR caster/camber plates to get the 7 degrees? Did you have to slightly notch the back of the strut housing to pull it back enough to get that much caster?

I'll have to also look into the RCA balljoint setup from AWR, unfortunately with this car you can't just simply redrill the control arm mounting points a bit higher because of the way the rear control arm mount is setup.

eage8

iTrader: (9)

I'm running ground control camber plates:
Ground Control - Camber/Caster Plate - '86-'91 RX7 (Pair)

I haven't touched my strut towers, this is with my older mazdaspeed plates, but their pretty much the same:


lowering the car will also increase your caster.

88rx7racer

Thanks for the picture, its good to know that 7 degrees caster is somewhat easily attainable for a second gen RX7. For foxbody mustangs you need to move the wheels forward 1.5" plus max the plates to get that much, but then again the front end is very heavy and manual racks were available so it kind makes sense from a boring commuter car standpoint (lack of caster = low steering effort).

nauri9

Check out this new product in development. So far there is AWR's ball joint and now this as products we can buy.

Forums /

nauri9

This is my first time posting an image, hope it works.

Here is the roll center correcting knuckle, I'm estimating 400 dollars for a pair if its close in price to their 240 knuckle mod.

eage8

iTrader: (9)

usually drift knuckles like that lower the ackerman to close to 0 which isn't ideal for anything other than drifting.

nauri9

I've read somewhere that Ackerman mostly is useful at low slip angles and thus low speeds, so an autocross event where the tire slip angle is high Ackerman means less, that's why we run so much toe out.
I still think they are pretty cool, they appear to have around 1.5-2 inches of drop.
If you go to their forum you can see all the products they are developing for the fc, they already have the rear camber links out.
Check it out here. Forums /

Travis R

If you're doing it right, you design your ackermann angles around your expected slip angle.

abeomid

They really need to make a new knuckle instead of cutting and welding the original one. Perhaps that's something they are planning to do. I wouldn't run one with that much cutting and welding on my car. It is a cast part to start with!

eage8

iTrader: (9)

yeah.... now something like this would be really nice

S Chassis billet aluminium knuckles

Turtle13

iTrader: (1)

Serious bump. I want more knowledge!!

eage8

iTrader: (9)

Read my responses and the link I posted

Also, check out my build thread, the last few pages have a lot of roll center talk in them:
https://www.rx7club.com/build-thread...turbo-1031251/

Here is the most recent version of my balljoints that I made adjustable with a large 3/4" bolt after the AWR pin broke:

junito1

Anyone know anything about these? Some Facebook guy which drifts an fc is trying to produce them.

eage8

iTrader: (9)

That's the guy over in this thread:
https://www.rx7club.com/drifting-226...iment-1067736/

you can't use a rod end for a ball joint, it'll crack off right at the threads.