Custom Brake Sizing

ATMironov

Well-Known Member
So I am doing the research for a custom brake set up and am trying to size the master cylinders.
I've contact Tilton for some guidance and they need some information.
I think I've tracked down all the right info, but if anyone knows for certain if these answers are right or wrong, please let me know.

I am planning on using the LNF SS Front Calipers.
Front Calipers:
4 Piston, 1.5" Diameter each piston
12.25" Diameter Rotor

I order the parking brake kit with the goblin, so I believe I'll be getting Pontiac Solstice rear calipers and rotors"
Those appear to be a Single 1.570" Piston with a 10.93" Rotor

Does 1950lbs seem about right for a complete Extended Frame Track Goblin with 300lb driver and a full tank a gas?
Does a 40% Front 60% Rear weight distribution seem about right as well?

Wheelbase for the extended Frame - 97.5"

Thanks!
Andrew
 
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Ross

Goblin Guru
With a 200 lb driver, the weight is 600 on the front wheels and 1100 on the rear.
Since the passengers sit halfway between the wheels, that would make it 650 and 1150 for a weight distribution of 36% front, 64% rear.
Full gas tank would be 63 more pounds.
19782


That is a lot of front braking power. The stock Cobalt brakes are made for a car twice the weight of a Goblin, and are a bit too powerful for a Goblin, so I have added a vacuum regulator to reduce my power assist on the brake pedal.
 
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Rauq

Goblin Guru
Check out Tinkles' thread on fitting 2-piece rotors to go with the LNF Brembos. Because the front is fabricated, I believe factory rotors won't drop right on.
 

Goblin Graber

Well-Known Member
Someone with an LNF will have to verify this but my car uses 10” rotors on the back and 11” ones on the front.

You do get Solstice calipers with the parking brake but I don’t think you get Solstice rotors. I think they still use the same 10” base model front rotors in the back.
 

pisco

Well-Known Member
So I am doing the research for a custom brake set up and am trying to size the master cylinders.
I've contact Tilton for some guidance and they need some information.
I think I've tracked down all the right info, but if anyone knows for certain if these answers are right or wrong, please let me know.

I am planning on using the LNF SS Front Calipers.
Front Calipers:
4 Piston, 1.5" Diameter each piston
12.25" Diameter Rotor

I order the parking brake kit with the goblin, so I believe I'll be getting Pontiac Solstice rear calipers and rotors"
Those appear to be a Single 1.570" Piston with a 10.93" Rotor

Does 1950lbs seem about right for a complete Extended Frame Track Goblin with 300lb driver and a full tank a gas?
Does a 40% Front 60% Rear weight distribution seem about right as well?

Wheelbase for the extended Frame - 97.5"

Thanks!
Andrew
I can measure and report back when I get home. I still have all my brake components on the shelf
 

ATMironov

Well-Known Member
Check out Tinkles' thread on fitting 2-piece rotors to go with the LNF Brembos. Because the front is fabricated, I believe factory rotors won't drop right on.
I checked with him on the caliper, and assumed the rotor would fit. You know what they say about assuming.
Thanks for pointing that out.
 

ATMironov

Well-Known Member
With a 200 lb driver, the weight is 600 on the front wheels and 1100 on the rear.
Since the passengers sit halfway between the wheels, that would make it 650 and 1150 for a weight distribution of 36% front, 64% rear.
Full gas tank would be 63 more pounds.
View attachment 19782

That is a lot of front braking power. The stock Cobalt brakes are made for a car twice the weight of a Goblin, and are a bit too powerful for a Goblin, so I have added a vacuum regulator to reduce my power assist on the brake pedal.
Thanks for that!
And I agree, putting a stock pedal assembly with the brembos isn’t a great idea.
the system I’m building will be full manual brakes designed for the actual specs of the car.
 

Rttoys

Goblin Guru
The stock goblin setup has more than enough stopping power even for the track. Like Ross said, regulating the vacuum and/or brake proportioning will be key to utilizing the power it already has.
 

ATMironov

Well-Known Member
The stock goblin setup has more than enough stopping power even for the track. Like Ross said, regulating the vacuum and/or brake proportioning will be key to utilizing the power it already has.
I totally agree that the kit brakes are sufficient to stop the car but I am after more than just getting the car stopped.
This will be a dedicated track car, so being able to tune the system and keep it cool are driving my decisions.
The larger rotors and calipers will dissipate heat much better allowing me a larger range of usable brake pads and fluids. Independent front and rear master cylinders with an adjustable bias will allow fine tuning of the system and on the fly adjustments for changing track conditions.

So when the track is damp and the car is twitchy under braking, I don't have to park it. I'll jus make the adjustments and keep driving.

Cheers
 

Rauq

Goblin Guru
If I recall correctly, Tinkles said his setup was in the interest of cosmetics as much as anything else, so more power to you. I do like the appearance of the Brembo calipers so if you can develop a system that stops at least as well (and no doubt it will) I'm sure there will always be an interest in replicating and perhaps even improving.
 

Lonny

Administrator
Staff member
I think the Brembos will look cool and a lot of folks want to do it.

You will need to run a large front wheel. Some wheels are made differently inside so some wheels clear better than others even if they are the same diameter.

As far as temperature, the tough part is getting small enough brakes to allow them to operate in their proper heat range. For brakes to work properly they need to get hot enough to transfer some added compounds from the pads to the rotors.
If you can't get the brakes hot enough it can cause braking problems because the materials from the pads do not transfer evenly onto the rotors.

 
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