s13 suspention ra28 q's

[ra28sr20]

I have searched but can't find any one who has put s13 shocks and brake assembly in to a ra28 is there a reason i.e. to hard or just won't fit?

I want to know because I am looking at upgrading my brakes and I figured I might as well change to the whole s13 set up because there is a huge range of adjustable coilovers and brakes it would make the car easier to set up

[timbosaurus]

If you thinking of doing that, I wouldve used the 180sx crossmember in the first place. Not need to mod ur xmember to mount ur engine. Has R&P installed. Struts should bolt in OK.

Just gotta mount the xmeber to the 28 chassis. I'm planning on doing that one day, but won't be anytime soon.

Timbo

[The Real Roadrunner]

I figured I might as well change to the whole s13 set up because there is a huge range of adjustable coilovers and brakes it would make the car easier to set up

and then by the time you fix all the alignment problems properly ie bumpsteer and ackerman , you may as well stick with the factory strut/steering arm arrangement and get the brakes fitted to them.

there is a large range of aftermarket dampers available to do it properly and coilovers are only a KONI kit away.

cheers
linden

[Lambolica]

In short the s13 struts do fit in (with minor elongation of the strut top bolts) meaning that you can pretty much run S13 coilovers, and the brake varients there of. However getting a suitable LCA seems to be the snag as well as the pre-mentioned geometry problems.

However concidering that the stock setup is crap, it may be arguable that anything is an improvement. you would be looking at swapping crossmembers or converting to R & P to get a better starting point for setting up the geometry.

Bump steer seems to be the annoying thing to get rid of in RA2* Celicas as they had it almost from factory.

Cheers
Simon

[ra28sr20]

Bump steer seems to be the annoying thing to get rid of in RA2* Celicas as they had it almost from factory.

Tell me about it I cant go round a hair pin without bump steering soooo annoying

I think I might just retro fit the s13 brakes & caliper and upgrade the disks to something from dba

thanx for the help

[timbosaurus]

Hi Linden,

The only real consideration here regarding geometry, is the strup top location.

Because you are using the whole crossmember, rack, control arms, tie rods, ball joints, hubs, strut etc from the same car, as long as the strut top is roughly in the same position the geometry wont be affected.

If it is a minor difference, it can be compensated for by adjustable tops. If it is major, it's not worth the hassle and you should do as you've suggested and modify stock stuff.

It's definately something to look into, as *if* the strut top location is OK, then working with factory s13 geometry will be 100% tha the RA28 stuff.

[ra23celica]

T3 do a coilover kit for RA2x Celica's, as well as RCA's and camber plates. There is a great thread on this forum for building your own coilovers on a Corona/Hilux/Pug strut so you get the bigger brakes you want. And Koni inserts give you adjustable dampers. This would have to be less hassle and cost than adapting S13 gear to fit and work effectively...
And I agree on the bumpsteer comments too, my RA23, on lowered Lovells sport springs and as much negative camber as I can dial in, bump steers something fierce.

[The Real Roadrunner]

Because you are using the whole crossmember, rack, control arms, tie rods, ball joints, hubs, strut etc from the same car, as long as the strut top is roughly in the same position the geometry wont be affected.

It's definately something to look into, as *if* the strut top location is OK, then working with factory s13 geometry will be 100% tha the RA28 stuff.

x member height + fore aft position, strut top location, suspension travel and strut length. trust me it wouldnt be an easy thing to do aand get right the first time.

also the factory S13 front suspension isnt that great from the get go. there are so many things you would have to double check that it would be easier to work with the stock stuff.

if you put an s13 front in an ae71/86 it widens the track by 70mm + adds a fair amount of neg camber up to -3deg per side.

if you put a ae86 front end in an ra23/28 it widens the track by 60mm and gives you about -2.5deg camber.

so if you want to widen your front track by about 130mm overall and run around 7+deg of neg camber and still have major bumpsteer/ackerman issues then by all means give it a go.

just letting you know b4 you start pulling a car apart or collecting s13 bits.

cheers
linden

[psi_guy]

Pics of S13 susp into AE86 and RA23 fitment

I'm 99% sure RA23 front end is that same as RA28. Do a search you'll find out easily enough.

[ra23celica]

RA23 and RA28 front ends are identical. Hence RA2X.....

[Lambolica]

The above link is a good guide, however the legalities in that swap are somewhat questionable. ie having the camber adjustment at the bottom of the strut where the hub assembly bolts on is illegal (in NSW)

When I started looking into it further S14 Uprights looked like a better starting point as they are a little longer. Whilst the thread indicates that the setup is bolt in it ignores hooking up the steering arms and geometry and looks to be more track orientated than road orientated.

That being said. the cost of converting RA2x struts to coilover or using S13/4 coilovers is in roughly the same ball park. Which leaves you with R&D on the S13/4 geometry, or R&D on the factory RA2x geometry. The latter probably being easier to sort out.

Unless you are going R&P which appears to royally screw you either way.

I'm partial to both for various reasons but am leaning to the standard setup and converted coilovers.

Cheers
Simon

[o_man_ra23]

Hmmm... there seems to be a lot in this idea... I might have to look at it further, as there is going to be a royal shakeup of my SA23 front suspension, and such a conversion may in fact be worthwhile. This being said, I am expecting a shitload of R&D anyways, so it may actually be viable for me (and not for many other people). Bumpsteer and Ackerman angles are on my hitlist.

What is the S13 xmember like compared to the RA2x item (width and curve... looking for a rear curve for the 3S front sump)

[timbosaurus]

Hi Linden,

Don't worry, I know your level of experience. So when you are so quick to write off an idea, then I have serious doubts about whether it's actually possible!

But I feel there is no harm in thinking about it, and throwing around some rough figures or jigging up old parts for fun

Looking at the figures of "up to -3deg" and "-2.5", you'd probably realistically be looking at around -5deg camber when you dummy up the s13 xmember and bolt in the strut tops. Another factor is the track change, as you mentioned. Figures indicate a track change of 10.5cm total, which is a bit over 5cm each side. Wheel width and offset plays a big part in that, so maybe flares would be needed.

Camber:
I'm not sure of the adjustment range of T3 camber plates (maybe +/-3deg?) but using them it seems possible to bring the camber under control in some way. I admit this is certainly not optimal for a street car though, and will certainly need smaller diameter coilover springs to fit in.

Caster:
Caster will be a similar story, but with the crossmember's longitudinal position being the influencial factor.


So... *IF* it's possible (it's a big if, i know) to get the package into the car with around -2deg of camber and a few degrees of caster, then I see no reasons at all why the ackerman or bump steer will be any different to an s13 with those numbers (-2caster, +4camber). You are not altering steering at all.

Ride height would be interesting.... maybe sitting 10 inches from the tarmac But that's what threaded coilovers are for.... and RCA's... and short stroke shocks...

EDIT: Also, when you're talking about putting s13 struts into the AE86 and getting -3deg of camber, are you talking about using the '86 xmember and stock LCA brackets? Because that would be completely different to running the s13 xmember. Once again, not trying to be a smartarse, just asking the question.

[The Real Roadrunner]

Hi Linden,

Don't worry, I know your level of experience. So when you are so quick to write off an idea, then I have serious doubts about whether it's actually possible!

So... *IF* it's possible (it's a big if, i know) to get the package into the car with around -2deg of camber and a few degrees of caster, then I see no reasons at all why the ackermanthis is dependant on the wheelbase and rack position fore/aft, its well known on s13/14 track cars that it is up the shit from factory and with the integral steering arm/knuckle arrangement it cant really be fixed (without a shite load of R&D + cost) or bump steer once again crap from factory and the above mentioned factors come into play, it is affected also by the hieght of the rack, main balljoint and the tierod end. will be any different to an s13 with those numbers (-2caster, +4camber). You are not altering steering at all. thats the problem you are altering it unless you have the rack in the exact position fore/aft and height parallel with the BJ as it came from the factory

Ride height would be interesting.... maybe sitting 10 inches from the tarmac But that's what threaded coilovers are forthis once again affects the geometry.... and RCA'sknuckle arrangement= no chance unless you run a rod end setup which due to the disc being in the way gives limited adjustment.... and short stroke shocks...

EDIT: Also, when you're talking about putting s13 struts into the AE86 and getting -3deg of camber, are you talking about using the '86 xmember and stock LCA brackets?ae86 xmember, s13 LCAs and knuckle/coilover arrangement Because that would be completely different to running the s13 xmember. Once again, not trying to be a smartarse, just asking the question.

hope i answered all the Qs.
there's no harm in asking, apart from giving stuff a go how do you think i learnt ?

cheers
linden

[timbosaurus]

its well known on s13/14 track cars that it is up the shit from factory and with the integral steering arm/knuckle arrangement it cant really be fixed (without a shite load of R&D + cost)

Oh, bugger! That was something I didn't know!

I expected an extra 20 years of suspension development to actually produce something decent from the factory.

Oh well, that puts an end to any benefit that this install might have