ST205 Front Brakes

squarepant5

New member
Ohh that looks nice ^^

Here's mine. Lexus IS200 296X32 re-machined PCD discs with 205 calipers. No spacers etc needed (but don't ask me how)

 

athousandleaves

New member
bolting the stock 205 caliper straight to the stock 185 hub is incredibly dangerous.
If you can't take some proper measurements and figure it out yourself then you shouldn't be doing it.
You must use an adapter to go from the hub to the caliper.
 

aus jd 2703

New member
Athousandleaves please explain as the 205 caliper is just bolted to a 205 hub from factory. The dangerous part and why I went wilwood was shaving 2mm of the caliper/hub ears
 

athousandleaves

New member
205 calipers on a 205 hub is 100% safe.
205 calipers on a 185 hub is dangerous.

Put one of each caliper on a flat surface side by side and you'll see why... And that's only one of about 10 reasons why its unsafe.

I finished designing and made a full kit to bolt the 205 calipers onto the 185 safely with an off the shelf rotor a while ago but ran out of money so I couldn't offer them to members here. :shrug: Also with the price of other BBK's coming down I didn't see it to really be worth while for anyone to pursue this modification. You get what you pay for and when it comes to stopping my car, I refuse to go cheap.
 

dkdmonk

New member
Dangerous?
Can you explain, because I didn't see it that way.

PS I had Henry's Engineering make the stainless lines, front and rear.
Cost $60 and I specified length (stock rears and 21 inch for fronts). Fit perfect and turn time was about a week.

I'm lucky my friend has a bridgeport machine we shaved 1mm off both the caliper and the knuckle, turned rotor to 303 (pad sits about 1mm in so I would go 302), did wheel bearings and seals, 40mm bolt goes from knuckle through caliper with washer and lock nut on end (with pads out they can be torqued without any issue), 15mm longer studs, 5mm spacer between rotor/hub, and 10mm spacer between wheel and rotor. 7th gen GTS rims fit with about 5mm clearance.

I know there are other brakes out there these came with our 205 clip so why not use them????
 

athousandleaves

New member
nah, I'm tired of explaining shit to guys that don't have a drop of education.

First you tell me why its safe and if I feel like wasting my time I'll correct you.


Did the superstrut not come with your clip as well? Why aren't you using that too?
 

warracer

New member
athousandleaves":3mmxrfbj said:
nah, I'm tired of explaining shit to guys that don't have a drop of education.

First you tell me why its safe and if I feel like wasting my time I'll correct you.


Did the superstrut not come with your clip as well? Why aren't you using that too?

tumblr_mm77exj49q1spyxjco1_400.gif


But jokes aside, you can't start retro fitting stuff if you don't take every single variable of the conversion in consideration, for instance, caliper-hub offset is very important, you can't mess with that. Also, you can't really fit a smaller diameter disc on a caliper that isn't made for such diameter, you need to use the same diameter. Reason is the caliper will apply uneven compression force to the disc if you go lower in diameter (more toward the edge of the disc). Also, shaving knuckle will weaken the structure of the whole casting, don't do it, it will create contraints concentration points. Also, caster is extremely important, the angle of which the caliper is located versus the chassis, also called ''attack angle''.
 

dkdmonk

New member
Okay, not sure I deserve that :shrug:
You don't know anything about me or my education level.

I feel I completed a great deal of research on this site and others on the 205 front caliper swap on a 185, the only mention I saw of "danger" was one guy that didn't use lock nuts and the caliper bolts came loose and the discussion of the lower ball joint spacing. I feel I addressed both of those areas.

Thanks for your help.
 

athousandleaves

New member
My comments weren't squarely pointed at you but at all the boy racers that pop on here screaming they managed to do it only to have their solution fail, sometimes catastrophically, in traffic which puts peoples lives at risk.


If you based your design on what you've gleamed from reading on this website I would recommend that you throw it all out, and start over by taking your hubs and calipers to a team of racecar engineers. Sorta like what meurz did by taking his car to AP racing for a set of proper brakes.


All that being said, do what you want to your brakes, I'll be waiting in the for sale forums to buy the parts from your crashed cars... :smokes: :rofl:
 

Matty-st185

New member
Guys I have a problem with this very topic

I bought a st185 widebody gt4
It has the st205 brake conversion

Upon driving the car everything is fine
Until:

You use the brake pedal hard after you release
I'm left with a grinding noise ( the type you hear with worn discs and pads)

To resolve the matter quickly I have to stop the car and violently
Turn the steering left and right and resume driving
And the noise goes away ...

Observations I noticed upon inspecting that
The pad does not properly cover the surface area on the disc
Meaning the part of the brake pad closest to the centre of the wheel
Is miss aligned and is hanging about 2mm over the disc surface area
Leaving the pad in contact with the inner part of the disc

When driving the car normally it's fine until hard pressure is applied
Any ideas ? Did someone previously do something wrong ?

The discs are more or less new with slight surface rust
Ant the pads are meaty and newish plenty of meat

Any ideas ... ?

I might have to reverse engineer what was done to check to see if it was
Converted correctly if anyone has the procedures
To fit these correctly could they post it here :)

I have used the search function
And seems to be info on it- some say bolt on some say
Machine shop has to reduce rotor size etc etc
What is the procedure ?

Thanks guys
 

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Matty-st185

New member
They appear to be the st205 disc!
Looking through the forum the disc is very thick
With huge inner vented block patterns


Ball joints ! Good call !
How does it only make an grinding noise under heavy
Braking though ?

See picture as you mentioned
 

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Matty-st185

New member
Another pic other side


So should the be ground down or something ?
Is that safe to do
 

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deecee

New member
Looks like the ball joints are def the issue.

The grinding comes from the inertia of the car coming to a stop eg the weight of the car is transferred to the front of the car putting the suspension under compression and subsequently the a-arm and ball joint will move upwards and the ball joint will come in contact with the disc.

1) most people space the disc out to avoid this issue. Might be more effort than its worth at this stage.
2) you can grind back a bit of the ball joint to reduce or avoid the disc contact. You can't remove too much metal off the ball joint for fear of making it too weak and setting up a scenario for failure. Apparently grinding up to 1mm off is about right.
 

Matty-st185

New member
Great stuff now when someone else has this problem
We will know ...
I will post a my remedy for this issue as soon as I can get to it

As seen in the picture the contact is there but minimal
I'm not sure these discs are damaged as there's a mark but no
Real lip .. I think I might put on drilled and grooved and while at that
Spacing the disc out at this stage would mean if have to some how
Space the caliper to match ? So the the centre of the disc and caliper allign ?
 

deecee

New member
Actually, i dont have this problem myself. There are known issues with this conversion thqt oghers have experienced.
And yes you would have to space the caliper if you space the disc. Hard to do when you are only doing mm. From what i remember the disc had to be spaced 4mm. Are you already using a spacer behind the disc? Note you will need to consider longer wheel studs. Should have 7 full rotations of nuts on the studs.
 

Matty-st185

New member
Ok I will check the rotations on the wheel nuts shortly
And report back ... Any less would mean there is no spacer
As the standard lugs would be in use were banking on ?

Also the pad surface area I'm guessing is correct then ?
 
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