Roll Center Adjusters

[jb_22]

I've also bought the RCA adjusters from T3.. Listed as an AE86 item although they bolt straight up to a TA22 strut/balljoint - emailed Gabe and he gave me all the info I needed and was very helpful. I think they were $US110. Mine are the negative camber variety that push the base of the strut outwards 25mm or so - giving ~1.5 deg of neg camber

In terms of improving the roll characteristics they are great - made as much of a difference as a whiteline anti-roll bar. One problem though is the negative camber RCAs increase the postive scrub radius (a result of moving the strut and hence tyre centreline further outboard without moving the LCA balljoint), which tends to cause the car to wander a bit over poor road surfaces. I figure this could be fixed by using Sigma GH LCAs and the standard T3 RCAs.. gah acronymns!.. but have yet to experiment. Another note is the NCRCAs are illegal as far as Aust. laws are concerned as they increase the track 50mm - this doesn't apply to the standard type RCAs as they do not change the track.

Somedays I think I do too much thinking about suspension geometry, haha... I blame you Polyphony for making Gran Turismo! I also found a suspension geometry app (susprog or something or other) - might be able to dig around my PC if anyone is interested.

My $0.02. Cheers, JB

[Gold28]

Yeah, in theory the RCA's will have a similar effect to a bigger front sway bar. When you put the RCA's in, it effectively moves the roll center up closer to the vertical center of gravity of the car which is generally somewhere around the gear knob height, maybe a little lower. Anyhoo, this basically shortens the moment arm between the center of gravity and the instantaneous roll center, reducing the roll authority.

So whereas the roll bar changes the spring stiffness to increase roll stiffness, the RCA's change the geometry to increase stiffness.

This is one effect and the implications of changing geometry can often be negative but RCA's generally should be seen as a way to lower the car without mucking up the geometry, in the same way that dropped spindles work for a double wishbone setup.

[TheToyman75]

Thanks guys.

I have ordered the T3 ones from Techno Toy tuning $80US plus $25US shipping.

[YLD-16L]

FYI

KE20/25 owners you need to order the early Datsun T3 RCA units. They fit perfectly but will need dowels installed (Datsun uses a centre spigot instead).

The TE27 ones won't fit as they are the same bolt spacing as AE86.

[Rip It]

Call Dave at AJPS (All Japanese Panels and Spares) He has a wide range to suit Toyotas and if he doesn't have them he might be able to get them made for you, will be more than happy to help you out.

[Tonyger]

My apologies for bring up an old thread, but I can't seem to work out the different sizing of the rcas and which would work.

The T3 is 35mm, AJPS have both 40 and 50mm. How does one pick which one to use?

Thanks

Tony

[ddeane]

Tony the RCA is designed to retain the suspension geometry resulting from lowering the car. Therefore if you have lowered the car 35mm you would use a 35mm RCA.

Craig

My apologies for bring up an old thread, but I can't seem to work out the different sizing of the rcas and which would work.

The T3 is 35mm, AJPS have both 40 and 50mm. How does one pick which one to use?

Thanks

Tony

[Tonyger]

Tony the RCA is designed to retain the suspension geometry resulting from lowering the car. Therefore if you have lowered the car 35mm you would use a 35mm RCA.

Craig

Hi Craig,

Thanks for the reply.

Is that measured from the wheel arch to the hub or lowest point of the car or is there another point to measure from?

Thanks

Tony

[Gold28]

Front wheel arch will do. Compare the height with a standard car and pick one close to that measurement.