jdbaugh1

iTrader: (1)

Is it a bolt on swap with re-drilled rotors or does it require some sort of adapters? Anyone who knows what it takes to put brembos on a 4-lug cobalt your input would be appreciated. I want to keep the 4-lug.

Crav3

iTrader: (1)

I did some research on this before and apparently the brembos bolt on to the spindle and you can use discs off a mini cooper that is 4lug. As for the rear you can convert to discs using cobalt calipers and Saturn rear discs that came 4 lug. Dont knkw exactly what saturn but i have emails where i talked to a company that gave me the info on rear discs

07blackg5

iTrader: (8)

false. the mini brakes are for an lsj swap, and the rotors do not fit well at all. They will work but you will have to redrill them with tighter clearance stud holes, or machine some sort of spacer ring to keep them hubcentric. They are not just a slap on and go mod. The hub hole is huge, and the stud holes are large as well. the rotor can shift around an easy 3/16" in each direction

I just went through this and now have a pair of brand new mini rotors laying in my garage. I ended up buying lsj rotors and having them redrilled. Direct fit. Foximus confirmed before I bought rotors for a second time, but that is what i am running now.

For the brembos, they should be a "direct" fit as well, just need to get rotors redrilled. the only issue might be the infamous hub spacer that has been discontinued.

on the rears, you need a disc rear beam, but other than that everything direct swaps over with redrilled rotors

jdbaugh1

iTrader: (1)

I'm starting to wonder if I should just go with LSJ brakes so I don't have to deal with all the clearance issues of the Brembos. Also for rear beam I guess Powell makes an adapter plate so that I wouldn't have to swap beams. I actually have a pair of LSJ front calipers I think.

What did you do to adjust brake bias so the rears wouldn't have too much bite?

07blackg5

iTrader: (8)

I don't think you will have any issues, but cant say for sure. Lot's of people have done the swaps and I've never heard of any complaints.

is your car abs or no?

My entire car is replumbed with nicopp line, and I have a bias valve installed from a previous brake adventure before the lsj setup. I also have 100tw tires in the front, and 280tw in the rear, so I cant speak from experience with the factory distribution block/prop valve

jdbaugh1

iTrader: (1)

No ABS

07blackg5

iTrader: (8)

I wouldnt worry too much about the bias, especially if you have the same tires on 4 corners and dont have the rear gutted out.

there is a brake thread stickied here somewhere that lists the piston sizes and what not. you can calculate an approximate bias with that info. You might need to estimate some of the information, or look up pad areas on a pad manufacturer site, but you can get a pretty good idea based on the brake hardware and a general weight distribution.

Then you know the bias will be at least what you calculated, if not more front biased if the factory distribution block has a proportioning valve in it. Everyone assumes it does, but I haven't seen anyone cut one open.

Long story short, you will be fine

ECaulk

iTrader: (6)

This, having additional front bias isn't going to screw anything up might just make the back end a little lighter feeling in heavy braking but it's not going to suddenly break free. You'll likely have a similar back end light feeling like the LNFs have (it's interesting the first time you find out that it happens)

jdbaugh1

iTrader: (1)

I'm not worried about too much front bias, I'm worried about locking up the rear wheels too easy because they already lock up easy enough. I was under the assumption that the drum brake Cobalt's put more bias to the rear to give the drums adequate bit. The rear disc brakes don't require as much pressure as the drums and if you don't change anything you end up with too much stopping torque in the rear which will cause them to lock up prematurely. This is absolutely something I do not want as it is already twitchy in autocross and will send my ass end whipping around if I trail brake at all. This is the main reason I haven't done a swap yet. I like the way it handles as is but if I ever go to a track day or something I know my brakes are going to overheat quickly especially the drums.

07blackg5

iTrader: (8)

"front bias" is the same as "rear bias", its just brake bias. you have 100% braking capacity, and the bias is how much braking effort goes to the front, and how much goes to the rear. So saying you aren't worried about the front bias is silly, because it is directly related to the rear bias.

So you want the front bias to be greater, to keep the rears from locking up. What i'm saying is to calculate/estimate the brake bias of the factory lsj setup without the inclusion of a proportioning valve. and if the factory distribution block does in fact reduce pressure to the rear lines, all that will do is bias the braking to the front more, which cant hurt your concern, only improve it

jdbaugh1

iTrader: (1)

Point I was trying to make is I'm worried about the rear brakes having too much stopping power relative to the front. I also don't know where to get information on factory lsj setup unless you are saying it is in the thread you mentioned earlier. I really need the information on my distribution block so I can compare. Is this information available somewhere?

07blackg5

iTrader: (8)

I just ran the rough numbers factoring in brake hardware alone. assuming no proportioning in the distribution block, the bias is roughly 70/30 for the lsj calipers and rotors. if the distribution block does have proportioning effect, it can only lean it more to the front.

Keep in mind there are other factors, like the weight distribution over the front and rear axles. if the ass end is really light, it will lock up easier, and vice versa.

Honestly, worst case scenario if the rears still lock up before the fronts, you can plumb in an adjustable valve. I don't think it will be an issue.

jdbaugh1

iTrader: (1)

See my assumption, and I think it came from something John told me, is that the drum brake Cobalts DO have a proportioning valve to send more to the rear to make up for the difference between drum and disc and if I just threw LSJ brakes on my car I wouldn't have 70/30 bias because of the proportioning valve. But it kind of sounds like you are indicating that the distribution block doesn't favor front or back and all the bias is strictly from the brake setup alone so if I throw LSJ brakes on my car I will have the same brake bias as an LSJ car.

07blackg5

iTrader: (8)

I am not saying it does or doesn't proportion a certain way. I just doubt that it favors the rear, but that doesn't mean its not true.

go to the junkyard and find a distribution block from a drum car and cut it open. That's the only way you will know for sure without testing the new brakes on the car.

You could also just put lsj brakes on the front only and it will shift bias towards the front no matter what

Or replumb the system with an adjustable valve, and ditch the oem.

07blackg5

iTrader: (8)

edited my post

Crav3

iTrader: (1)

My bad, didnt mean to misinform anyone. Just what i was told when i was looking into doing the swap. Good to know mini rotors wont work. Also they used to make the brackets for the rear calipers so you wouldnt have to swap the whole rear assembly.

07blackg5

iTrader: (8)

they fit, just don't stay centered without some sort of additional work. They are also significantly thinner, so the caliper piston will have to be more extended. I'm not sure if that would be an issue at low pad life.

Basically it's not worth using them. Redrill rotors, or 5 lug swap