Lexus IS250 front F-Sport BBK
07-31-2011, 12:01 AM
#1
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Lexus IS250 front F-Sport BBK
I was looking at my options for big brakes. I looked at the specs of the TRD BBK and was very underwhelmed by them. I looked for other alternatives. Since I already had F-Sport wheels, I looked there…after all; F-Sport is a division of TRD. Once I chose the IS250 BBK, I purchased it off of eBay and tried to install them. Since the wheels bolted right on, I was hoping that the brakes will bolt right on…guess what? No such luck… Here is my test fit.
Here is a close up…
Here is a comparison of the OEM disc to the F-Sport disc…
At this point, I did my measurements and set off to design a caliper bracket. This is what I came up with.
Here they are after machining, anodizing and powder coating. My custom ones are the blue ones and the F-Sport kit cam with the black ones. I took the studs out of the black ones and installed them on my caliper bracket.
Another thing that the F-Sport BBK came with were wheel bearing shims. The kit came with shims for the AWD IS250 (top left) and for the 2WD IS250 (top right). None of them fit, so I had to design and machine custom ones for the Gen2 tC (bottom left). All of them stacked up on one another is shown at bottom right.
Here are my two custom caliper brackets facing each other…
Here are the caliper bracket on apposing sides.
Here is the wheel bearing back installed without the sheet metal splash plate and two shims. Since I spaced out the wheel bearings 1-mm, I had to make a shim for the spindle inside (not shown, its just a washer)…had I not done that, the ABS speed sensor would have rubbed on the half-axle and there would have been an increased load on the constant velocity joint. My custom caliper bracket is also installed.
Here is another view from the back. If you look real hard, you can see my custom shim in between the wheel bearing housing (rusted) and the upright (black).
Now for the disc…
The caliper slips right on…note: this caliper was intended for the right side of the IS250, but since these calipers mount forward of the axle, the sides needed to be swapped.
Another angle of the BBK installation…
I got the TRD stainless steel brake lines and installed them…
And this is what they look like from the back side…
Now I need to do the F-Sport rear BBK to get the brake balance somewhere reasonable...
I’ve started a new thread for the rear BBK here https://www.scionlife.com/forums/showthread.php?t=208144
Also...this is for everybody! If you follow the Toyota/Scion instructions of un-staking the axle nut, you will f*&k up the axle…I did and it cost me $500 to learn! You have to completely grind out the staked portion of the nut and then remove it. The metal is so thick there that it smashes the threads when you try to punch it out per instructions. Then removing the nut destroys the threads on the axle spindle!
Here is a close up…
Here is a comparison of the OEM disc to the F-Sport disc…
At this point, I did my measurements and set off to design a caliper bracket. This is what I came up with.
Here they are after machining, anodizing and powder coating. My custom ones are the blue ones and the F-Sport kit cam with the black ones. I took the studs out of the black ones and installed them on my caliper bracket.
Another thing that the F-Sport BBK came with were wheel bearing shims. The kit came with shims for the AWD IS250 (top left) and for the 2WD IS250 (top right). None of them fit, so I had to design and machine custom ones for the Gen2 tC (bottom left). All of them stacked up on one another is shown at bottom right.
Here are my two custom caliper brackets facing each other…
Here are the caliper bracket on apposing sides.
Here is the wheel bearing back installed without the sheet metal splash plate and two shims. Since I spaced out the wheel bearings 1-mm, I had to make a shim for the spindle inside (not shown, its just a washer)…had I not done that, the ABS speed sensor would have rubbed on the half-axle and there would have been an increased load on the constant velocity joint. My custom caliper bracket is also installed.
Here is another view from the back. If you look real hard, you can see my custom shim in between the wheel bearing housing (rusted) and the upright (black).
Now for the disc…
The caliper slips right on…note: this caliper was intended for the right side of the IS250, but since these calipers mount forward of the axle, the sides needed to be swapped.
Another angle of the BBK installation…
I got the TRD stainless steel brake lines and installed them…
And this is what they look like from the back side…
Now I need to do the F-Sport rear BBK to get the brake balance somewhere reasonable...
I’ve started a new thread for the rear BBK here https://www.scionlife.com/forums/showthread.php?t=208144
Also...this is for everybody! If you follow the Toyota/Scion instructions of un-staking the axle nut, you will f*&k up the axle…I did and it cost me $500 to learn! You have to completely grind out the staked portion of the nut and then remove it. The metal is so thick there that it smashes the threads when you try to punch it out per instructions. Then removing the nut destroys the threads on the axle spindle!
Last edited by 2tCornot2tC; 10-02-2011 at 12:44 PM. Reason: Added link to rear BBK thread
07-31-2011, 01:42 AM
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Like I said in my first post, the brake balance is so front biased now that I don’t think that stopping distance has gone down any. I have such massive tires on the car (255/35 ZR19) that I could not get the ABS to kick on with the OEM brakes. Now the fronts are so powerful that I can activate the ABS at will. The pedal force is much lighter…
07-31-2011, 11:58 AM
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I’m a lot more than just that…
In college, I majored in Machine Design and minored in Computer Science…
In California I passed all the exams for a Professional Engineering License in Mechanical Engineering…and got it, but I never renewed it (paid them their annual fee), so I don’t have it any more.
By trait, I’m an Aircraft Structures Engineer…that is how I pay for these habits/addictions.
And in another thread, I’ve admitted to having designed racing cars, including an F-1 car.
Oh yeah, I used to race super bikes at Willow Springs Race Track back in the late ‘80s.
But, I’m a gear-head. In England I’d be called a petrol-head.
In college, I majored in Machine Design and minored in Computer Science…
In California I passed all the exams for a Professional Engineering License in Mechanical Engineering…and got it, but I never renewed it (paid them their annual fee), so I don’t have it any more.
By trait, I’m an Aircraft Structures Engineer…that is how I pay for these habits/addictions.
And in another thread, I’ve admitted to having designed racing cars, including an F-1 car.
Oh yeah, I used to race super bikes at Willow Springs Race Track back in the late ‘80s.
But, I’m a gear-head. In England I’d be called a petrol-head.
07-31-2011, 02:12 PM
#12
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These are NOT Lexus parts, these are TRD/F-Sport parts designed for a Lexus…so, no…I think this is a funner car. It’s all about having fun…
I’d be _____ing insane if I didn’t…I want world class stopping power so I need to increase the rear stopping power to get the brake balance right. I’m half way there…it’s not a question of if I could make it fit (you can see that I can, I hope), it’s a question of when I will have the time to do the next mod.
08-01-2011, 03:14 AM
#18
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Location: Nashua, NH
Posts: 2,102
I’m a lot more than just that…
In college, I majored in Machine Design and minored in Computer Science…
In California I passed all the exams for a Professional Engineering License in Mechanical Engineering…and got it, but I never renewed it (paid them their annual fee), so I don’t have it any more.
By trait, I’m an Aircraft Structures Engineer…that is how I pay for these habits/addictions.
And in another thread, I’ve admitted to having designed racing cars, including an F-1 car.
Oh yeah, I used to race super bikes at Willow Springs Race Track back in the late ‘80s.
But, I’m a gear-head. In England I’d be called a petrol-head.
In college, I majored in Machine Design and minored in Computer Science…
In California I passed all the exams for a Professional Engineering License in Mechanical Engineering…and got it, but I never renewed it (paid them their annual fee), so I don’t have it any more.
By trait, I’m an Aircraft Structures Engineer…that is how I pay for these habits/addictions.
And in another thread, I’ve admitted to having designed racing cars, including an F-1 car.
Oh yeah, I used to race super bikes at Willow Springs Race Track back in the late ‘80s.
But, I’m a gear-head. In England I’d be called a petrol-head.
yeah....I am just an electrical engeering who's currently getting an MBA
what part number are the stainless brake lines and will they fit the stock calipers? if not then do you know of any that would fit?
$4500 is pretty expensive but most people on this forum spend much more over time....
plus it's all about the marginal utility aka the enjoyment he gets out of something
08-01-2011, 03:29 AM
#19
That is an impressive project. I personally wouldn't go the same route, but then, different strokes.
Do you think you will also be spending the 4k for the rear brakes as well? How is the stability of the car with only the front brakes done, say stopping hard from 55-60mph, would there be any risk of the back end slipping out?
Do you think you will also be spending the 4k for the rear brakes as well? How is the stability of the car with only the front brakes done, say stopping hard from 55-60mph, would there be any risk of the back end slipping out?
08-01-2011, 03:59 AM
#20
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Posts: 1,075
http://www.trdsparks.com/displayparts.php?Mdl_dtl=748&Part_cat=11&parts_id=4020
Last edited by 2tCornot2tC; 08-01-2011 at 04:41 AM.