BC Racing Coilovers into MA61

[82MKII]

I've had my MA61 for the last 10 years or so, and apart from dropping a 2J into it, some new rims and Whiteline sway bars haven't done much else to it.
With the advent of the TECCWA club in WA, we now have some great driving events to participate in, so it was finally time to replace the 31 year old suspension.

Here's the list I ended up changing:
1. BC Racing Coilover conversion (kit designed for MX73) front & rear (I got this kit from Just Jap). I liked the fact these kits are genuinely height adjustable (ie you don't have to play with preload to lower the car) and they also had reasonable reviews. Front springs 62mm diam, 180mm free length, 10kg/mm. Rear 117 mm diameter at one end, 119 mm diameter at other end (ground flat), 200mm free length, 8kg/mm.
2. Techno Toy Tuning castor rods, steering arms and outer tie rod ends
3. New lower control arm bushes & ball joints
4. New slotted DBA standard rotors (had these sitting around in a box for the last couple of years)
5. Put in recond power steering rack (a fresh one that came out of my parts car a few years ago).

The first thing I had to do was to get the old struts out, chop the spindles off and get them welded to the coil over. The pic below illustrates this quite well.


Contrary to what some people think you don't need a spring compressor to get the struts out. Just do the following:
1. Crack (don't completely undo) the big nut on the top of the strut
2. Jack up the front of the car & support on stands. Remove the wheels, disconnect the calliper, undo the sway bar links
3. Support one of the front hubs with a jack, so that you can slowly lower the wheel.
4. Undo the big nut that you cracked in step 1
5. Slowly lower the front hub down with the jack, and the front spring eventually just falls out!

Once the strut is out you have to undo the huge nut at the top of it (gland nut) to disassemble. This is where you need a mate with the biggest shifter in the world. Alternatively you can clamp it in a vice but it was pretty hard work.


Once the struts were out, I had them welded, and the whole kit of bits from BC Racing looked like this:


I also purchased some TTT steering arms. These things are massively thick, and are also shorter than stock (in fact have 2 holes so you can go uber short), so should quicken up the steering and make for more fun during autokhanas.



I pulled the lower control arms out and had new superpro bushes and new ball joints installed.


Once this was all done it was time to re-install. I started with the new ps rack, which was possible but really quite annoying when doing it from under the car only supported with chassis stands. Eventually after a lot of hours lying on my back realising how inflexible I was I finally got it all in.

When re-assembling the hubs I installed new bearings, seals and the new slotted rotors. The TTT stuff went in fine except for some minor filing out of the holes that connect to the lower control arm.
Castor rods, LCA and steering arms in:

Now with the strut bolted up:

Check out the size of that steering arm:

All bolted up with calliper on:


The rear installation was a much simpler affair, given you are just replacing the existing shock with a new (adjustable length) one, and the existing spring with a new much stiffer & shorter one and an adjustable height spring perch. My only comment is that BC were a bit light-on in the hardware they supplied (1 nyloc nut and a washer to secure the top end of the strut to the body). I had to rat some bits off my parts car to get enough bits to properly mount it to the body.

[82MKII]

Height before:

Height after:


Notes on height setting:
Front guards were initially 645mm above ground, now 625mm. Height adjustment remaining - can go about 15mm lower, and about 60mm higher. Note also the front springs drooped about 15mm over the first day after they were installed.
Rear guards were initially 655mm above ground, now 630mm. Height adjustment remaining - can go about 40mm lower, and 0mm higher. This is really the only disappointing thing about this kit, the rear is only just high enough. Note also the rear springs drooped about 10mm over the first day after they were installed.

I took it off for a wheel alignment and set the front as follows:
Castor: 5 degrees, Camber: -2 degrees, Total toe out: 3mm
Note: the camber adjustment is pretty much maxed-out to get -2 degrees. Looking at the camber plates, they could probably be milled out to get maybe -3, but I'll see how it all goes with -2 for starters.

On the road it is simply night vs day. It now feels so firm and planted - kind of like an 86, but with 3x the power and the glorious note of the 2J and the steel-wheeled twins.
The TECCWA September autokhana is coming up tomorrow - so should be a good test.

[patrickleslie]

Nice write up and impressive shopping list! I figure if the MX73 kit fits Supra struts then it will also fit for those of us who are running Celica struts?

[CELICASUPRA7M]

nice work, the the 10/8 spring rates will be mega stiff compared to stock.
You probably want to rotate the caster rod mount 90 deg I recon.

[rdorman]

how stiff are the springs? too stiff for daily street use?

im looking very closely at a BC kit for mine, but im not sure if 10/8 will be too stiff.
ive also got celica struts which give about -2deg camber anyway, so should give me a bit more adjustment, if youre saying you get -2 max i should be able to go from what, 0 to -4? that would be rediculous though

[patrickleslie]

i should be able to go from what, 0 to -4? that would be rediculous though

With camber tops maxed out each way I would guess you could get between +1 to -4 camber with the Celica struts, assuming they DO fit the mx73 kit

[rdorman]

just reading on a celica forum they use the same mx73 kits, and were discussing the opposite, ie using ma61 struts but didnt because of the +2deg camber haha.

82mkII, do you have any photos of how the rears are mounted? does the adjustable perch just sit where the old spring and rubber base sat? or do you keep the rubber there?

[82MKII]

The OD of my struts was 51mm, so the MX73 kit should work with anything with that OD.
I would have liked to rotate the caster rod mount as well, but with it up that way I can still get to my strut bar mounting bolts.

The 10/8 is stiff (coming from 31 year old suspension) but I am used to it now. If my car was a daily driver, driven over rough roads I'd get sick of it, but my daily has 2 wheels and 1 gear so no problem there.

I gave it a good workout at the autokhana today, and it now has so much more front-end grip, almost to the point where the rear is a little too happy to step out. By the end of the session I was starting to get the hang of turning the car using the brakes on corner entry. It would start to step out, but being a lot stiffer now was easier and more predictable to hold around the corner. The other thing it will now do (and I'm starting to get the hang of it), is predictable lift-off oversteer - which can be handy going through slaloms.
The dampers were set to soft during most of the session. I firmed them up at one point but thought it was a little worse.
I managed to improve my time on the 'top gear' track (one we do at the end of all the TECCWA autokhanas) by 1.4 seconds over the car prior to the upgrade, so it seems to have done good things.

Theres another event coming up at Barbagallo in a fortnight so I'll see how it goes there.

[rdorman]

cheers for that! ive got the opportunity to get the same kit, but im not sure if the 10/8 would be too stiff for adelaides roads...

any photos of the rear end?

[82MKII]

Sorry, no photos of the rear end. But the new spring sits on top of the rear swing arm (same way as the stock spring), then the adjustable perch sits on top of the new spring (the top end of the spring is ground flat for the perch to sit on).
I might be able to get a photo later in the week if you need one.

[rdorman]

no worries, ill let you know. how much did you pay for the kit, and if so, to get it welded to the struts?
do you know if you can get softer springs for these?

[1G-GTE]

ive done this on my ma61 with ra60 struts and steering arms and id say its at least 4 degrees when its maxed out it may even be more I will have to measure it one day.
I used S13 camber tops which sit slightly diagonal,
this isn't the best photo to show the camber. also i got more lock by cutting out the arm stoppers im going to wedl new ones in soon.



this was from cutting the stops off I also got more about a third of what shown in the photo just from ra60 arms. I wouldn't recommend do struts and arms for more lock but the camber and faster steering are heaps betterer.



This is roughly 6 degrees

btw rdorman I paid $740 for stuts with 8kg springs and S13 camber tops and $150 for tig welding make sure if you do ra60 steering arms and struts you get a quote for the reaming of the hole as I got majorly ripped in the bum $140 I almost died needless to say that engineering place will never get my business again

[rdorman]

jesus christ, 140 for reaming, thats a good arse reaming!

ive already got celica struts, that was swapped over by the previous owner. im under the impression that he swapped the steering arms too, so that should all be dandy.
will be calling a workshop tomorrow to discuss prices, then calling someone thats selling a set of 10/8kg BC's. hopefully its not too stiff for street / daily and fun, if it is ill just have to change springs..

[82MKII]

The kit was $1199 delivered from Just Jap. They originally said I could get different rates but changed their mind when they checked.
Given the setup of the fronts, they should be easy to change, but the rears are quite 'special' (see info in original post for spring details).
Cost me $110 for local suspension shop to cut the struts and weld them.

[patrickleslie]

make sure if you do ra60 steering arms and struts you get a quote for the reaming of the hole as I got majorly ripped in the bum $140 I almost died needless to say that engineering place will never get my business again

Yeah...or get the Supra balljoints lathed down to suit Celica arms! $20
Balljoints are a consumable part, cheaper in the short term, and a mistake is irrelevant in the long run. If they screw up your Celica ps arms, well...